/* Jim - A small embeddable Tcl interpreter
 * Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
 * Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
 *
 * $Id: jim.c,v 1.163 2005/09/19 15:47:15 antirez Exp $
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * A copy of the license is also included in the source distribution
 * of Jim, as a TXT file name called LICENSE.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <pkgconf/athttpd.h>

#define __JIM_CORE__
#define JIM_OPTIMIZATION /* comment to avoid optimizations and reduce size */

#ifndef JIM_ANSIC
#define JIM_DYNLIB      /* Dynamic library support for UNIX and WIN32 */
#endif /* JIM_ANSIC */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>
#include <limits.h>
#include <assert.h>
#include <errno.h>
#include <time.h>

/* Include the platform dependent libraries for
 * dynamic loading of libraries. */
#ifdef JIM_DYNLIB
#if defined(_WIN32) || defined(WIN32)
#ifndef WIN32
#define WIN32 1
#endif
#define STRICT
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#if _MSC_VER >= 1000
#pragma warning(disable:4146)
#endif /* _MSC_VER */
#else
#include <dlfcn.h>
#endif /* WIN32 */
#endif /* JIM_DYNLIB */

#include <cyg/athttpd/jim.h>

#ifdef HAVE_BACKTRACE
#include <execinfo.h>
#endif

/* -----------------------------------------------------------------------------
 * Global variables
 * ---------------------------------------------------------------------------*/

/* A shared empty string for the objects string representation.
 * Jim_InvalidateStringRep knows about it and don't try to free. */
static char *JimEmptyStringRep = (char*) "";

/* -----------------------------------------------------------------------------
 * Required prototypes of not exported functions
 * ---------------------------------------------------------------------------*/
static void JimChangeCallFrameId(Jim_Interp *interp, Jim_CallFrame *cf);
static void JimFreeCallFrame(Jim_Interp *interp, Jim_CallFrame *cf, int flags);
static void JimRegisterCoreApi(Jim_Interp *interp);

static Jim_HashTableType JimVariablesHashTableType;

/* -----------------------------------------------------------------------------
 * Utility functions
 * ---------------------------------------------------------------------------*/

/*
 * Convert a string to a jim_wide INTEGER.
 * This function originates from BSD.
 *
 * Ignores `locale' stuff.  Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
#ifdef HAVE_LONG_LONG
#define JimIsAscii(c) (((c) & ~0x7f) == 0)
static jim_wide JimStrtoll(const char *nptr, char **endptr, register int base)
{
    register const char *s;
    register unsigned jim_wide acc;
    register unsigned char c;
    register unsigned jim_wide qbase, cutoff;
    register int neg, any, cutlim;

    /*
     * Skip white space and pick up leading +/- sign if any.
     * If base is 0, allow 0x for hex and 0 for octal, else
     * assume decimal; if base is already 16, allow 0x.
     */
    s = nptr;
    do {
        c = *s++;
    } while (isspace(c));
    if (c == '-') {
        neg = 1;
        c = *s++;
    } else {
        neg = 0;
        if (c == '+')
            c = *s++;
    }
    if ((base == 0 || base == 16) &&
        c == '0' && (*s == 'x' || *s == 'X')) {
        c = s[1];
        s += 2;
        base = 16;
    }
    if (base == 0)
        base = c == '0' ? 8 : 10;

    /*
     * Compute the cutoff value between legal numbers and illegal
     * numbers.  That is the largest legal value, divided by the
     * base.  An input number that is greater than this value, if
     * followed by a legal input character, is too big.  One that
     * is equal to this value may be valid or not; the limit
     * between valid and invalid numbers is then based on the last
     * digit.  For instance, if the range for quads is
     * [-9223372036854775808..9223372036854775807] and the input base
     * is 10, cutoff will be set to 922337203685477580 and cutlim to
     * either 7 (neg==0) or 8 (neg==1), meaning that if we have
     * accumulated a value > 922337203685477580, or equal but the
     * next digit is > 7 (or 8), the number is too big, and we will
     * return a range error.
     *
     * Set any if any `digits' consumed; make it negative to indicate
     * overflow.
     */
    qbase = (unsigned)base;
    cutoff = neg ? (unsigned jim_wide)-(LLONG_MIN + LLONG_MAX) + LLONG_MAX
        : LLONG_MAX;
    cutlim = (int)(cutoff % qbase);
    cutoff /= qbase;
    for (acc = 0, any = 0;; c = *s++) {
        if (!JimIsAscii(c))
            break;
        if (isdigit(c))
            c -= '0';
        else if (isalpha(c))
            c -= isupper(c) ? 'A' - 10 : 'a' - 10;
        else
            break;
        if (c >= base)
            break;
        if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
            any = -1;
        else {
            any = 1;
            acc *= qbase;
            acc += c;
        }
    }
    if (any < 0) {
        acc = neg ? LLONG_MIN : LLONG_MAX;
        errno = ERANGE;
    } else if (neg)
        acc = -acc;
    if (endptr != 0)
        *endptr = (char *)(any ? s - 1 : nptr);
    return (acc);
}
#endif

/* Glob-style pattern matching. */
static int JimStringMatch(const char *pattern, int patternLen,
        const char *string, int stringLen, int nocase)
{
    while(patternLen) {
        switch(pattern[0]) {
        case '*':
            while (pattern[1] == '*') {
                pattern++;
                patternLen--;
            }
            if (patternLen == 1)
                return 1; /* match */
            while(stringLen) {
                if (JimStringMatch(pattern+1, patternLen-1,
                            string, stringLen, nocase))
                    return 1; /* match */
                string++;
                stringLen--;
            }
            return 0; /* no match */
            break;
        case '?':
            if (stringLen == 0)
                return 0; /* no match */
            string++;
            stringLen--;
            break;
        case '[':
        {
            int not, match;

            pattern++;
            patternLen--;
            not = pattern[0] == '^';
            if (not) {
                pattern++;
                patternLen--;
            }
            match = 0;
            while(1) {
                if (pattern[0] == '\\') {
                    pattern++;
                    patternLen--;
                    if (pattern[0] == string[0])
                        match = 1;
                } else if (pattern[0] == ']') {
                    break;
                } else if (patternLen == 0) {
                    pattern--;
                    patternLen++;
                    break;
                } else if (pattern[1] == '-' && patternLen >= 3) {
                    int start = pattern[0];
                    int end = pattern[2];
                    int c = string[0];
                    if (start > end) {
                        int t = start;
                        start = end;
                        end = t;
                    }
                    if (nocase) {
                        start = tolower(start);
                        end = tolower(end);
                        c = tolower(c);
                    }
                    pattern += 2;
                    patternLen -= 2;
                    if (c >= start && c <= end)
                        match = 1;
                } else {
                    if (!nocase) {
                        if (pattern[0] == string[0])
                            match = 1;
                    } else {
                        if (tolower((int)pattern[0]) == tolower((int)string[0]))
                            match = 1;
                    }
                }
                pattern++;
                patternLen--;
            }
            if (not)
                match = !match;
            if (!match)
                return 0; /* no match */
            string++;
            stringLen--;
            break;
        }
        case '\\':
            if (patternLen >= 2) {
                pattern++;
                patternLen--;
            }
            /* fall through */
        default:
            if (!nocase) {
                if (pattern[0] != string[0])
                    return 0; /* no match */
            } else {
                if (tolower((int)pattern[0]) != tolower((int)string[0]))
                    return 0; /* no match */
            }
            string++;
            stringLen--;
            break;
        }
        pattern++;
        patternLen--;
        if (stringLen == 0) {
            while(*pattern == '*') {
                pattern++;
                patternLen--;
            }
            break;
        }
    }
    if (patternLen == 0 && stringLen == 0)
        return 1;
    return 0;
}

int JimStringCompare(const char *s1, int l1, const char *s2, int l2,
        int nocase)
{
    unsigned char *u1 = (unsigned char*) s1, *u2 = (unsigned char*) s2;

    if (nocase == 0) {
        while(l1 && l2) {
            if (*u1 != *u2)
                return (int)*u1-*u2;
            u1++; u2++; l1--; l2--;
        }
        if (!l1 && !l2) return 0;
        return l1-l2;
    } else {
        while(l1 && l2) {
            if (tolower((int)*u1) != tolower((int)*u2))
                return tolower((int)*u1)-tolower((int)*u2);
            u1++; u2++; l1--; l2--;
        }
        if (!l1 && !l2) return 0;
        return l1-l2;
    }
}

/* Search 's1' inside 's2', starting to search from char 'index' of 's2'.
 * The index of the first occurrence of s1 in s2 is returned. 
 * If s1 is not found inside s2, -1 is returned. */
int JimStringFirst(const char *s1, int l1, const char *s2, int l2, int index)
{
    int i;

    if (!l1 || !l2 || l1 > l2) return -1;
    if (index < 0) index = 0;
    s2 += index;
    for (i = index; i <= l2-l1; i++) {
        if (memcmp(s2, s1, l1) == 0)
            return i;
        s2++;
    }
    return -1;
}

int Jim_WideToString(char *buf, jim_wide wideValue)
{
    const char *fmt = "%" JIM_WIDE_MODIFIER;
    return sprintf(buf, fmt, wideValue);
}

int Jim_StringToWide(const char *str, jim_wide *widePtr, int base)
{
    char *endptr;

#ifdef HAVE_LONG_LONG
    *widePtr = JimStrtoll(str, &endptr, base);
#else
    *widePtr = strtol(str, &endptr, base);
#endif
    if (str[0] == '\0')
        return JIM_ERR;
    if (endptr[0] != '\0') {
        while(*endptr) {
            if (!isspace((int)*endptr))
                return JIM_ERR;
            endptr++;
        }
    }
    return JIM_OK;
}

int Jim_StringToIndex(const char *str, int *intPtr)
{
    char *endptr;

    *intPtr = strtol(str, &endptr, 10);
    if (str[0] == '\0')
        return JIM_ERR;
    if (endptr[0] != '\0') {
        while(*endptr) {
            if (!isspace((int)*endptr))
                return JIM_ERR;
            endptr++;
        }
    }
    return JIM_OK;
}

/* The string representation of references has two features in order
 * to make the GC faster. The first is that every reference starts
 * with a non common character '~', in order to make the string matching
 * fater. The second is that the reference string rep his 32 characters
 * in length, this allows to avoid to check every object with a string
 * repr < 32, and usually there are many of this objects. */

#define JIM_REFERENCE_SPACE (35+JIM_REFERENCE_TAGLEN)

static int JimFormatReference(char *buf, Jim_Reference *refPtr, jim_wide id)
{
    const char *fmt = "<reference.<%s>.%020" JIM_WIDE_MODIFIER ">";
    sprintf(buf, fmt, refPtr->tag, id);
    return JIM_REFERENCE_SPACE;
}

int Jim_DoubleToString(char *buf, double doubleValue)
{
    char *s;
    int len;

    len = sprintf(buf, "%.17g", doubleValue);
    s = buf;
    while(*s) {
        if (*s == '.') return len;
        s++;
    }
    /* Add a final ".0" if it's a number. But not
     * for NaN or InF */
    if (isdigit((int)buf[0])
        || ((buf[0] == '-' || buf[0] == '+')
            && isdigit((int)buf[1]))) {
        s[0] = '.';
        s[1] = '0';
        s[2] = '\0';
        return len+2;
    }
    return len;
}

int Jim_StringToDouble(const char *str, double *doublePtr)
{
    char *endptr;

    *doublePtr = strtod(str, &endptr);
    if (str[0] == '\0' || endptr[0] != '\0')
        return JIM_ERR;
    return JIM_OK;
}

static jim_wide JimPowWide(jim_wide b, jim_wide e)
{
    jim_wide i, res = 1;
    if ((b==0 && e!=0) || (e<0)) return 0;
    for(i=0; i<e; i++) {res *= b;}
    return res;
}

/* -----------------------------------------------------------------------------
 * Special functions
 * ---------------------------------------------------------------------------*/
void Jim_Panic(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    fprintf(stderr, "\nJIM INTERPRETER PANIC: ");
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n\n");
    va_end(ap);
#ifdef HAVE_BACKTRACE
    {
        void *array[40];
        int size, i;
        char **strings;

        size = backtrace(array, 40);
        strings = backtrace_symbols(array, size);
        for (i = 0; i < size; i++)
            printf("[backtrace] %s\n", strings[i]);
        printf("[backtrace] Include the above lines and the output\n");
        printf("[backtrace] of 'nm <executable>' in the bug report.\n");
    }
#endif
    abort();
}

/* -----------------------------------------------------------------------------
 * Memory allocation
 * ---------------------------------------------------------------------------*/

/* Macro used for memory debugging.
 * In order for they to work you have to rename Jim_Alloc into _Jim_Alloc
 * and similary for Jim_Realloc and Jim_Free */
#if 0
#define Jim_Alloc(s) (printf("%s %d: Jim_Alloc(%d)\n",__FILE__,__LINE__,s),_Jim_Alloc(s))
#define Jim_Free(p) (printf("%s %d: Jim_Free(%p)\n",__FILE__,__LINE__,p),_Jim_Free(p))
#define Jim_Realloc(p,s) (printf("%s %d: Jim_Realloc(%p,%d)\n",__FILE__,__LINE__,p,s),_Jim_Realloc(p,s))
#endif

void *Jim_Alloc(int size)
{
    void *p = malloc(size);
    if (p == NULL)
        Jim_Panic("Out of memory");
    return p;
}

void Jim_Free(void *ptr) {
    free(ptr);
}

void *Jim_Realloc(void *ptr, int size)
{
    void *p = realloc(ptr, size);
    if (p == NULL)
        Jim_Panic("Out of memory");
    return p;
}

char *Jim_StrDup(const char *s)
{
    int l = strlen(s);
    char *copy = Jim_Alloc(l+1);

    memcpy(copy, s, l+1);
    return copy;
}

char *Jim_StrDupLen(const char *s, int l)
{
    char *copy = Jim_Alloc(l+1);
    
    memcpy(copy, s, l+1);
    copy[l] = 0;    /* Just to be sure, original could be substring */
    return copy;
}

/* -----------------------------------------------------------------------------
 * Time related functions
 * ---------------------------------------------------------------------------*/
/* Returns microseconds of CPU used since start. */
static jim_wide JimClock(void)
{
#if (defined WIN32) && !(defined JIM_ANSIC)
    LARGE_INTEGER t, f;
    QueryPerformanceFrequency(&f);
    QueryPerformanceCounter(&t);
    return (long)((t.QuadPart * 1000000) / f.QuadPart);
#else /* !WIN32 */
    clock_t clocks = clock();

    return (long)(clocks*(1000000/CLOCKS_PER_SEC));
#endif /* WIN32 */
}

/* -----------------------------------------------------------------------------
 * Hash Tables
 * ---------------------------------------------------------------------------*/

/* -------------------------- private prototypes ---------------------------- */
static int JimExpandHashTableIfNeeded(Jim_HashTable *ht);
static unsigned int JimHashTableNextPower(unsigned int size);
static int JimInsertHashEntry(Jim_HashTable *ht, const void *key);

/* -------------------------- hash functions -------------------------------- */

/* Thomas Wang's 32 bit Mix Function */
unsigned int Jim_IntHashFunction(unsigned int key)
{
    key += ~(key << 15);
    key ^=  (key >> 10);
    key +=  (key << 3);
    key ^=  (key >> 6);
    key += ~(key << 11);
    key ^=  (key >> 16);
    return key;
}

/* Identity hash function for integer keys */
unsigned int Jim_IdentityHashFunction(unsigned int key)
{
    return key;
}

/* Generic hash function (we are using to multiply by 9 and add the byte
 * as Tcl) */
unsigned int Jim_GenHashFunction(const unsigned char *buf, int len)
{
    unsigned int h = 0;
    while(len--)
        h += (h<<3)+*buf++;
    return h;
}

/* ----------------------------- API implementation ------------------------- */
/* reset an hashtable already initialized with ht_init().
 * NOTE: This function should only called by ht_destroy(). */
static void JimResetHashTable(Jim_HashTable *ht)
{
    ht->table = NULL;
    ht->size = 0;
    ht->sizemask = 0;
    ht->used = 0;
    ht->collisions = 0;
}

/* Initialize the hash table */
int Jim_InitHashTable(Jim_HashTable *ht, Jim_HashTableType *type,
        void *privDataPtr)
{
    JimResetHashTable(ht);
    ht->type = type;
    ht->privdata = privDataPtr;
    return JIM_OK;
}

/* Resize the table to the minimal size that contains all the elements,
 * but with the invariant of a USER/BUCKETS ration near to <= 1 */
int Jim_ResizeHashTable(Jim_HashTable *ht)
{
    int minimal = ht->used;

    if (minimal < JIM_HT_INITIAL_SIZE)
        minimal = JIM_HT_INITIAL_SIZE;
    return Jim_ExpandHashTable(ht, minimal);
}

/* Expand or create the hashtable */
int Jim_ExpandHashTable(Jim_HashTable *ht, unsigned int size)
{
    Jim_HashTable n; /* the new hashtable */
    unsigned int realsize = JimHashTableNextPower(size), i;

    /* the size is invalid if it is smaller than the number of
     * elements already inside the hashtable */
    if (ht->used >= size)
        return JIM_ERR;

    Jim_InitHashTable(&n, ht->type, ht->privdata);
    n.size = realsize;
    n.sizemask = realsize-1;
    n.table = Jim_Alloc(realsize*sizeof(Jim_HashEntry*));

    /* Initialize all the pointers to NULL */
    memset(n.table, 0, realsize*sizeof(Jim_HashEntry*));

    /* Copy all the elements from the old to the new table:
     * note that if the old hash table is empty ht->size is zero,
     * so Jim_ExpandHashTable just creates an hash table. */
    n.used = ht->used;
    for (i = 0; i < ht->size && ht->used > 0; i++) {
        Jim_HashEntry *he, *nextHe;

        if (ht->table[i] == NULL) continue;
        
        /* For each hash entry on this slot... */
        he = ht->table[i];
        while(he) {
            unsigned int h;

            nextHe = he->next;
            /* Get the new element index */
            h = Jim_HashKey(ht, he->key) & n.sizemask;
            he->next = n.table[h];
            n.table[h] = he;
            ht->used--;
            /* Pass to the next element */
            he = nextHe;
        }
    }
    assert(ht->used == 0);
    Jim_Free(ht->table);

    /* Remap the new hashtable in the old */
    *ht = n;
    return JIM_OK;
}

/* Add an element to the target hash table */
int Jim_AddHashEntry(Jim_HashTable *ht, const void *key, void *val)
{
    int index;
    Jim_HashEntry *entry;

    /* Get the index of the new element, or -1 if
     * the element already exists. */
    if ((index = JimInsertHashEntry(ht, key)) == -1)
        return JIM_ERR;

    /* Allocates the memory and stores key */
    entry = Jim_Alloc(sizeof(*entry));
    entry->next = ht->table[index];
    ht->table[index] = entry;

    /* Set the hash entry fields. */
    Jim_SetHashKey(ht, entry, key);
    Jim_SetHashVal(ht, entry, val);
    ht->used++;
    return JIM_OK;
}

/* Add an element, discarding the old if the key already exists */
int Jim_ReplaceHashEntry(Jim_HashTable *ht, const void *key, void *val)
{
    Jim_HashEntry *entry;

    /* Try to add the element. If the key
     * does not exists Jim_AddHashEntry will suceed. */
    if (Jim_AddHashEntry(ht, key, val) == JIM_OK)
        return JIM_OK;
    /* It already exists, get the entry */
    entry = Jim_FindHashEntry(ht, key);
    /* Free the old value and set the new one */
    Jim_FreeEntryVal(ht, entry);
    Jim_SetHashVal(ht, entry, val);
    return JIM_OK;
}

/* Search and remove an element */
int Jim_DeleteHashEntry(Jim_HashTable *ht, const void *key)
{
    unsigned int h;
    Jim_HashEntry *he, *prevHe;

    if (ht->size == 0)
        return JIM_ERR;
    h = Jim_HashKey(ht, key) & ht->sizemask;
    he = ht->table[h];

    prevHe = NULL;
    while(he) {
        if (Jim_CompareHashKeys(ht, key, he->key)) {
            /* Unlink the element from the list */
            if (prevHe)
                prevHe->next = he->next;
            else
                ht->table[h] = he->next;
            Jim_FreeEntryKey(ht, he);
            Jim_FreeEntryVal(ht, he);
            Jim_Free(he);
            ht->used--;
            return JIM_OK;
        }
        prevHe = he;
        he = he->next;
    }
    return JIM_ERR; /* not found */
}

/* Destroy an entire hash table */
int Jim_FreeHashTable(Jim_HashTable *ht)
{
    unsigned int i;

    /* Free all the elements */
    for (i = 0; i < ht->size && ht->used > 0; i++) {
        Jim_HashEntry *he, *nextHe;

        if ((he = ht->table[i]) == NULL) continue;
        while(he) {
            nextHe = he->next;
            Jim_FreeEntryKey(ht, he);
            Jim_FreeEntryVal(ht, he);
            Jim_Free(he);
            ht->used--;
            he = nextHe;
        }
    }
    /* Free the table and the allocated cache structure */
    Jim_Free(ht->table);
    /* Re-initialize the table */
    JimResetHashTable(ht);
    return JIM_OK; /* never fails */
}

Jim_HashEntry *Jim_FindHashEntry(Jim_HashTable *ht, const void *key)
{
    Jim_HashEntry *he;
    unsigned int h;

    if (ht->size == 0) return NULL;
    h = Jim_HashKey(ht, key) & ht->sizemask;
    he = ht->table[h];
    while(he) {
        if (Jim_CompareHashKeys(ht, key, he->key))
            return he;
        he = he->next;
    }
    return NULL;
}

Jim_HashTableIterator *Jim_GetHashTableIterator(Jim_HashTable *ht)
{
    Jim_HashTableIterator *iter = Jim_Alloc(sizeof(*iter));

    iter->ht = ht;
    iter->index = -1;
    iter->entry = NULL;
    iter->nextEntry = NULL;
    return iter;
}

Jim_HashEntry *Jim_NextHashEntry(Jim_HashTableIterator *iter)
{
    while (1) {
        if (iter->entry == NULL) {
            iter->index++;
            if (iter->index >=
                    (signed)iter->ht->size) break;
            iter->entry = iter->ht->table[iter->index];
        } else {
            iter->entry = iter->nextEntry;
        }
        if (iter->entry) {
            /* We need to save the 'next' here, the iterator user
             * may delete the entry we are returning. */
            iter->nextEntry = iter->entry->next;
            return iter->entry;
        }
    }
    return NULL;
}

/* ------------------------- private functions ------------------------------ */

/* Expand the hash table if needed */
static int JimExpandHashTableIfNeeded(Jim_HashTable *ht)
{
    /* If the hash table is empty expand it to the intial size,
     * if the table is "full" dobule its size. */
    if (ht->size == 0)
        return Jim_ExpandHashTable(ht, JIM_HT_INITIAL_SIZE);
    if (ht->size == ht->used)
        return Jim_ExpandHashTable(ht, ht->size*2);
    return JIM_OK;
}

/* Our hash table capability is a power of two */
static unsigned int JimHashTableNextPower(unsigned int size)
{
    unsigned int i = JIM_HT_INITIAL_SIZE;

    if (size >= 2147483648U)
        return 2147483648U;
    while(1) {
        if (i >= size)
            return i;
        i *= 2;
    }
}

/* Returns the index of a free slot that can be populated with
 * an hash entry for the given 'key'.
 * If the key already exists, -1 is returned. */
static int JimInsertHashEntry(Jim_HashTable *ht, const void *key)
{
    unsigned int h;
    Jim_HashEntry *he;

    /* Expand the hashtable if needed */
    if (JimExpandHashTableIfNeeded(ht) == JIM_ERR)
        return -1;
    /* Compute the key hash value */
    h = Jim_HashKey(ht, key) & ht->sizemask;
    /* Search if this slot does not already contain the given key */
    he = ht->table[h];
    while(he) {
        if (Jim_CompareHashKeys(ht, key, he->key))
            return -1;
        he = he->next;
    }
    return h;
}

/* ----------------------- StringCopy Hash Table Type ------------------------*/

static unsigned int JimStringCopyHTHashFunction(const void *key)
{
    return Jim_GenHashFunction(key, strlen(key));
}

static const void *JimStringCopyHTKeyDup(void *privdata, const void *key)
{
    int len = strlen(key);
    char *copy = Jim_Alloc(len+1);
    JIM_NOTUSED(privdata);

    memcpy(copy, key, len);
    copy[len] = '\0';
    return copy;
}

static void *JimStringKeyValCopyHTValDup(void *privdata, const void *val)
{
    int len = strlen(val);
    char *copy = Jim_Alloc(len+1);
    JIM_NOTUSED(privdata);

    memcpy(copy, val, len);
    copy[len] = '\0';
    return copy;
}

static int JimStringCopyHTKeyCompare(void *privdata, const void *key1,
        const void *key2)
{
    JIM_NOTUSED(privdata);

    return strcmp(key1, key2) == 0;
}

static void JimStringCopyHTKeyDestructor(void *privdata, const void *key)
{
    JIM_NOTUSED(privdata);

    Jim_Free((void*)key); /* ATTENTION: const cast */
}

static void JimStringKeyValCopyHTValDestructor(void *privdata, void *val)
{
    JIM_NOTUSED(privdata);

    Jim_Free((void*)val); /* ATTENTION: const cast */
}

static Jim_HashTableType JimStringCopyHashTableType = {
    JimStringCopyHTHashFunction,        /* hash function */
    JimStringCopyHTKeyDup,              /* key dup */
    NULL,                               /* val dup */
    JimStringCopyHTKeyCompare,          /* key compare */
    JimStringCopyHTKeyDestructor,       /* key destructor */
    NULL                                /* val destructor */
};

/* This is like StringCopy but does not auto-duplicate the key.
 * It's used for intepreter's shared strings. */
static Jim_HashTableType JimSharedStringsHashTableType = {
    JimStringCopyHTHashFunction,        /* hash function */
    NULL,                               /* key dup */
    NULL,                               /* val dup */
    JimStringCopyHTKeyCompare,          /* key compare */
    JimStringCopyHTKeyDestructor,       /* key destructor */
    NULL                                /* val destructor */
};

/* This is like StringCopy but also automatically handle dynamic
 * allocated C strings as values. */
static Jim_HashTableType JimStringKeyValCopyHashTableType = {
    JimStringCopyHTHashFunction,        /* hash function */
    JimStringCopyHTKeyDup,              /* key dup */
    JimStringKeyValCopyHTValDup,        /* val dup */
    JimStringCopyHTKeyCompare,          /* key compare */
    JimStringCopyHTKeyDestructor,       /* key destructor */
    JimStringKeyValCopyHTValDestructor, /* val destructor */
};

typedef struct AssocDataValue {
    Jim_InterpDeleteProc *delProc;
    void *data;
} AssocDataValue;

static void JimAssocDataHashTableValueDestructor(void *privdata, void *data)
{
    AssocDataValue *assocPtr = (AssocDataValue *)data;
    if (assocPtr->delProc != NULL)
        assocPtr->delProc((Jim_Interp *)privdata, assocPtr->data);
    Jim_Free(data);
}

static Jim_HashTableType JimAssocDataHashTableType = {
    JimStringCopyHTHashFunction,         /* hash function */
    JimStringCopyHTKeyDup,               /* key dup */
    NULL,                                /* val dup */
    JimStringCopyHTKeyCompare,           /* key compare */
    JimStringCopyHTKeyDestructor,        /* key destructor */
    JimAssocDataHashTableValueDestructor /* val destructor */
};

/* -----------------------------------------------------------------------------
 * Stack - This is a simple generic stack implementation. It is used for
 * example in the 'expr' expression compiler.
 * ---------------------------------------------------------------------------*/
void Jim_InitStack(Jim_Stack *stack)
{
    stack->len = 0;
    stack->maxlen = 0;
    stack->vector = NULL;
}

void Jim_FreeStack(Jim_Stack *stack)
{
    Jim_Free(stack->vector);
}

int Jim_StackLen(Jim_Stack *stack)
{
    return stack->len;
}

void Jim_StackPush(Jim_Stack *stack, void *element) {
    int neededLen = stack->len+1;
    if (neededLen > stack->maxlen) {
        stack->maxlen = neededLen*2;
        stack->vector = Jim_Realloc(stack->vector, sizeof(void*)*stack->maxlen);
    }
    stack->vector[stack->len] = element;
    stack->len++;
}

void *Jim_StackPop(Jim_Stack *stack)
{
    if (stack->len == 0) return NULL;
    stack->len--;
    return stack->vector[stack->len];
}

void *Jim_StackPeek(Jim_Stack *stack)
{
    if (stack->len == 0) return NULL;
    return stack->vector[stack->len-1];
}

void Jim_FreeStackElements(Jim_Stack *stack, void (*freeFunc)(void *ptr))
{
    int i;

    for (i = 0; i < stack->len; i++)
        freeFunc(stack->vector[i]);
}

/* -----------------------------------------------------------------------------
 * Parser
 * ---------------------------------------------------------------------------*/

/* Token types */
#define JIM_TT_NONE -1        /* No token returned */
#define JIM_TT_STR 0        /* simple string */
#define JIM_TT_ESC 1        /* string that needs escape chars conversion */
#define JIM_TT_VAR 2        /* var substitution */
#define JIM_TT_DICTSUGAR 3    /* Syntax sugar for [dict get], $foo(bar) */
#define JIM_TT_CMD 4        /* command substitution */
#define JIM_TT_SEP 5        /* word separator */
#define JIM_TT_EOL 6        /* line separator */

/* Additional token types needed for expressions */
#define JIM_TT_SUBEXPR_START 7
#define JIM_TT_SUBEXPR_END 8
#define JIM_TT_EXPR_NUMBER 9
#define JIM_TT_EXPR_OPERATOR 10

/* Parser states */
#define JIM_PS_DEF 0        /* Default state */
#define JIM_PS_QUOTE 1        /* Inside "" */

/* Parser context structure. The same context is used both to parse
 * Tcl scripts and lists. */
struct JimParserCtx {
    const char *prg;     /* Program text */
    const char *p;       /* Pointer to the point of the program we are parsing */
    int len;             /* Left length of 'prg' */
    int linenr;          /* Current line number */
    const char *tstart;
    const char *tend;    /* Returned token is at tstart-tend in 'prg'. */
    int tline;           /* Line number of the returned token */
    int tt;              /* Token type */
    int eof;             /* Non zero if EOF condition is true. */
    int state;           /* Parser state */
    int comment;         /* Non zero if the next chars may be a comment. */
};

#define JimParserEof(c) ((c)->eof)
#define JimParserTstart(c) ((c)->tstart)
#define JimParserTend(c) ((c)->tend)
#define JimParserTtype(c) ((c)->tt)
#define JimParserTline(c) ((c)->tline)

static int JimParseScript(struct JimParserCtx *pc);
static int JimParseSep(struct JimParserCtx *pc);
static int JimParseEol(struct JimParserCtx *pc);
static int JimParseCmd(struct JimParserCtx *pc);
static int JimParseVar(struct JimParserCtx *pc);
static int JimParseBrace(struct JimParserCtx *pc);
static int JimParseStr(struct JimParserCtx *pc);
static int JimParseComment(struct JimParserCtx *pc);
static char *JimParserGetToken(struct JimParserCtx *pc,
        int *lenPtr, int *typePtr, int *linePtr);

/* Initialize a parser context.
 * 'prg' is a pointer to the program text, linenr is the line
 * number of the first line contained in the program. */
void JimParserInit(struct JimParserCtx *pc, const char *prg, 
        int len, int linenr)
{
    pc->prg = prg;
    pc->p = prg;
    pc->len = len;
    pc->tstart = NULL;
    pc->tend = NULL;
    pc->tline = 0;
    pc->tt = JIM_TT_NONE;
    pc->eof = 0;
    pc->state = JIM_PS_DEF;
    pc->linenr = linenr;
    pc->comment = 1;
}

int JimParseScript(struct JimParserCtx *pc)
{
    while(1) { /* the while is used to reiterate with continue if needed */
        if (!pc->len) {
            pc->tstart = pc->p;
            pc->tend = pc->p-1;
            pc->tline = pc->linenr;
            pc->tt = JIM_TT_EOL;
            pc->eof = 1;
            return JIM_OK;
        }
        switch(*(pc->p)) {
        case '\\':
            if (*(pc->p+1) == '\n')
                return JimParseSep(pc);
            else {
                pc->comment = 0;
                return JimParseStr(pc);
            }
            break;
        case ' ':
        case '\t':
        case '\r':
            if (pc->state == JIM_PS_DEF)
                return JimParseSep(pc);
            else {
                pc->comment = 0;
                return JimParseStr(pc);
            }
            break;
        case '\n':
        case ';':
            pc->comment = 1;
            if (pc->state == JIM_PS_DEF)
                return JimParseEol(pc);
            else
                return JimParseStr(pc);
            break;
        case '[':
            pc->comment = 0;
            return JimParseCmd(pc);
            break;
        case '$':
            pc->comment = 0;
            if (JimParseVar(pc) == JIM_ERR) {
                pc->tstart = pc->tend = pc->p++; pc->len--;
                pc->tline = pc->linenr;
                pc->tt = JIM_TT_STR;
                return JIM_OK;
            } else
                return JIM_OK;
            break;
        case '#':
            if (pc->comment) {
                JimParseComment(pc);
                continue;
            } else {
                return JimParseStr(pc);
            }
        default:
            pc->comment = 0;
            return JimParseStr(pc);
            break;
        }
        return JIM_OK;
    }
}

int JimParseSep(struct JimParserCtx *pc)
{
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (*pc->p == ' ' || *pc->p == '\t' || *pc->p == '\r' ||
           (*pc->p == '\\' && *(pc->p+1) == '\n')) {
        if (*pc->p == '\\') {
            pc->p++; pc->len--;
            pc->linenr++;
        }
        pc->p++; pc->len--;
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_SEP;
    return JIM_OK;
}

int JimParseEol(struct JimParserCtx *pc)
{
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (*pc->p == ' ' || *pc->p == '\n' ||
           *pc->p == '\t' || *pc->p == '\r' || *pc->p == ';') {
        if (*pc->p == '\n')
            pc->linenr++;
        pc->p++; pc->len--;
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_EOL;
    return JIM_OK;
}

/* Todo. Don't stop if ']' appears inside {} or quoted.
 * Also should handle the case of puts [string length "]"] */
int JimParseCmd(struct JimParserCtx *pc)
{
    int level = 1;
    int blevel = 0;

    pc->tstart = ++pc->p; pc->len--;
    pc->tline = pc->linenr;
    while (1) {
        if (pc->len == 0) {
            break;
        } else if (*pc->p == '[' && blevel == 0) {
            level++;
        } else if (*pc->p == ']' && blevel == 0) {
            level--;
            if (!level) break;
        } else if (*pc->p == '\\') {
            pc->p++; pc->len--;
        } else if (*pc->p == '{') {
            blevel++;
        } else if (*pc->p == '}') {
            if (blevel != 0)
                blevel--;
        } else if (*pc->p == '\n')
            pc->linenr++;
        pc->p++; pc->len--;
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_CMD;
    if (*pc->p == ']') {
        pc->p++; pc->len--;
    }
    return JIM_OK;
}

int JimParseVar(struct JimParserCtx *pc)
{
    int brace = 0, stop = 0, ttype = JIM_TT_VAR;

    pc->tstart = ++pc->p; pc->len--; /* skip the $ */
    pc->tline = pc->linenr;
    if (*pc->p == '{') {
        pc->tstart = ++pc->p; pc->len--;
        brace = 1;
    }
    if (brace) {
        while (!stop) {
            if (*pc->p == '}' || pc->len == 0) {
                stop = 1;
                if (pc->len == 0)
                    continue;
            }
            else if (*pc->p == '\n')
                pc->linenr++;
            pc->p++; pc->len--;
        }
        if (pc->len == 0)
            pc->tend = pc->p-1;
        else
            pc->tend = pc->p-2;
    } else {
        while (!stop) {
            if (!((*pc->p >= 'a' && *pc->p <= 'z') ||
                (*pc->p >= 'A' && *pc->p <= 'Z') ||
                (*pc->p >= '0' && *pc->p <= '9') || *pc->p == '_'))
                stop = 1;
            else {
                pc->p++; pc->len--;
            }
        }
        /* Parse [dict get] syntax sugar. */
        if (*pc->p == '(') {
            while (*pc->p != ')' && pc->len) {
                pc->p++; pc->len--;
                if (*pc->p == '\\' && pc->len >= 2) {
                    pc->p += 2; pc->len -= 2;
                }
            }
            if (*pc->p != '\0') {
                pc->p++; pc->len--;
            }
            ttype = JIM_TT_DICTSUGAR;
        }
        pc->tend = pc->p-1;
    }
    /* Check if we parsed just the '$' character.
     * That's not a variable so an error is returned
     * to tell the state machine to consider this '$' just
     * a string. */
    if (pc->tstart == pc->p) {
        pc->p--; pc->len++;
        return JIM_ERR;
    }
    pc->tt = ttype;
    return JIM_OK;
}

int JimParseBrace(struct JimParserCtx *pc)
{
    int level = 1;

    pc->tstart = ++pc->p; pc->len--;
    pc->tline = pc->linenr;
    while (1) {
        if (*pc->p == '\\' && pc->len >= 2) {
            pc->p++; pc->len--;
            if (*pc->p == '\n')
                pc->linenr++;
        } else if (*pc->p == '{') {
            level++;
        } else if (pc->len == 0 || *pc->p == '}') {
            level--;
            if (pc->len == 0 || level == 0) {
                pc->tend = pc->p-1;
                if (pc->len != 0) {
                    pc->p++; pc->len--;
                }
                pc->tt = JIM_TT_STR;
                return JIM_OK;
            }
        } else if (*pc->p == '\n') {
            pc->linenr++;
        }
        pc->p++; pc->len--;
    }
    return JIM_OK; /* unreached */
}

int JimParseStr(struct JimParserCtx *pc)
{
    int newword = (pc->tt == JIM_TT_SEP || pc->tt == JIM_TT_EOL ||
            pc->tt == JIM_TT_NONE || pc->tt == JIM_TT_STR);
    if (newword && *pc->p == '{') {
        return JimParseBrace(pc);
    } else if (newword && *pc->p == '"') {
        pc->state = JIM_PS_QUOTE;
        pc->p++; pc->len--;
    }
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (1) {
        if (pc->len == 0) {
            pc->tend = pc->p-1;
            pc->tt = JIM_TT_ESC;
            return JIM_OK;
        }
        switch(*pc->p) {
        case '\\':
            if (pc->state == JIM_PS_DEF &&
                *(pc->p+1) == '\n') {
                pc->tend = pc->p-1;
                pc->tt = JIM_TT_ESC;
                return JIM_OK;
            }
            if (pc->len >= 2) {
                pc->p++; pc->len--;
            }
            break;
        case '$':
        case '[':
            pc->tend = pc->p-1;
            pc->tt = JIM_TT_ESC;
            return JIM_OK;
        case ' ':
        case '\t':
        case '\n':
        case '\r':
        case ';':
            if (pc->state == JIM_PS_DEF) {
                pc->tend = pc->p-1;
                pc->tt = JIM_TT_ESC;
                return JIM_OK;
            } else if (*pc->p == '\n') {
                pc->linenr++;
            }
            break;
        case '"':
            if (pc->state == JIM_PS_QUOTE) {
                pc->tend = pc->p-1;
                pc->tt = JIM_TT_ESC;
                pc->p++; pc->len--;
                pc->state = JIM_PS_DEF;
                return JIM_OK;
            }
            break;
        }
        pc->p++; pc->len--;
    }
    return JIM_OK; /* unreached */
}

int JimParseComment(struct JimParserCtx *pc)
{
    while (*pc->p) {
        if (*pc->p == '\n') {
            pc->linenr++;
            if (*(pc->p-1) != '\\') {
                pc->p++; pc->len--;
                return JIM_OK;
            }
        }
        pc->p++; pc->len--;
    }
    return JIM_OK;
}

/* xdigitval and odigitval are helper functions for JimParserGetToken() */
static int xdigitval(int c)
{
    if (c >= '0' && c <= '7') return c-'0';
    if (c >= 'a' && c <= 'f') return c-'a'+10;
    if (c >= 'A' && c <= 'F') return c-'A'+10;
    return -1;
}

static int odigitval(int c)
{
    if (c >= '0' && c <= '7') return c-'0';
    return -1;
}

/* Perform Tcl escape substitution of 's', storing the result
 * string into 'dest'. The escaped string is guaranteed to
 * be the same length or shorted than the source string.
 * Slen is the length of the string at 's', if it's -1 the string
 * length will be calculated by the function.
 *
 * The function returns the length of the resulting string. */
static int JimEscape(char *dest, const char *s, int slen)
{
    char *p = dest;
    int i, len;
    
    if (slen == -1)
        slen = strlen(s);

    for (i = 0; i < slen; i++) {
        switch(s[i]) {
        case '\\':
            switch(s[i+1]) {
            case 'a': *p++ = 0x7; i++; break;
            case 'b': *p++ = 0x8; i++; break;
            case 'f': *p++ = 0xc; i++; break;
            case 'n': *p++ = 0xa; i++; break;
            case 'r': *p++ = 0xd; i++; break;
            case 't': *p++ = 0x9; i++; break;
            case 'v': *p++ = 0xb; i++; break;
            case '\0': *p++ = '\\'; i++; break;
            case '\n': *p++ = ' '; i++; break;
            default:
                  if (s[i+1] == 'x') {
                    int val = 0;
                    int c = xdigitval(s[i+2]);
                    if (c == -1) {
                        *p++ = 'x';
                        i++;
                        break;
                    }
                    val = c;
                    c = xdigitval(s[i+3]);
                    if (c == -1) {
                        *p++ = val;
                        i += 2;
                        break;
                    }
                    val = (val*16)+c;
                    *p++ = val;
                    i += 3;
                    break;
                  } else if (s[i+1] >= '0' && s[i+1] <= '7')
                  {
                    int val = 0;
                    int c = odigitval(s[i+1]);
                    val = c;
                    c = odigitval(s[i+2]);
                    if (c == -1) {
                        *p++ = val;
                        i ++;
                        break;
                    }
                    val = (val*8)+c;
                    c = odigitval(s[i+3]);
                    if (c == -1) {
                        *p++ = val;
                        i += 2;
                        break;
                    }
                    val = (val*8)+c;
                    *p++ = val;
                    i += 3;
                  } else {
                    *p++ = s[i+1];
                    i++;
                  }
                  break;
            }
            break;
        default:
            *p++ = s[i];
            break;
        }
    }
    len = p-dest;
    *p++ = '\0';
    return len;
}

/* Returns a dynamically allocated copy of the current token in the
 * parser context. The function perform conversion of escapes if
 * the token is of type JIM_TT_ESC.
 *
 * Note that after the conversion, tokens that are grouped with
 * braces in the source code, are always recognizable from the
 * identical string obtained in a different way from the type.
 *
 * For exmple the string:
 *
 * {expand}$a
 * 
 * will return as first token "expand", of type JIM_TT_STR
 *
 * While the string:
 *
 * expand$a
 *
 * will return as first token "expand", of type JIM_TT_ESC
 */
char *JimParserGetToken(struct JimParserCtx *pc,
        int *lenPtr, int *typePtr, int *linePtr)
{
    const char *start, *end;
    char *token;
    int len;

    start = JimParserTstart(pc);
    end = JimParserTend(pc);
    if (start > end) {
        if (lenPtr) *lenPtr = 0;
        if (typePtr) *typePtr = JimParserTtype(pc);
        if (linePtr) *linePtr = JimParserTline(pc);
        token = Jim_Alloc(1);
        token[0] = '\0';
        return token;
    }
    len = (end-start)+1;
    token = Jim_Alloc(len+1);
    if (JimParserTtype(pc) != JIM_TT_ESC) {
        /* No escape conversion needed? Just copy it. */
        memcpy(token, start, len);
        token[len] = '\0';
    } else {
        /* Else convert the escape chars. */
        len = JimEscape(token, start, len);
    }
    if (lenPtr) *lenPtr = len;
    if (typePtr) *typePtr = JimParserTtype(pc);
    if (linePtr) *linePtr = JimParserTline(pc);
    return token;
}

/* The following functin is not really part of the parsing engine of Jim,
 * but it somewhat related. Given an string and its length, it tries
 * to guess if the script is complete or there are instead " " or { }
 * open and not completed. This is useful for interactive shells
 * implementation and for [info complete].
 *
 * If 'stateCharPtr' != NULL, the function stores ' ' on complete script,
 * '{' on scripts incomplete missing one or more '}' to be balanced.
 * '"' on scripts incomplete missing a '"' char.
 *
 * If the script is complete, 1 is returned, otherwise 0. */
int Jim_ScriptIsComplete(const char *s, int len, char *stateCharPtr)
{
    int level = 0;
    int state = ' ';

    while(len) {
        switch (*s) {
            case '\\':
                if (len > 1)
                    s++;
                break;
            case '"':
                if (state == ' ') {
                    state = '"';
                } else if (state == '"') {
                    state = ' ';
                }
                break;
            case '{':
                if (state == '{') {
                    level++;
                } else if (state == ' ') {
                    state = '{';
                    level++;
                }
                break;
            case '}':
                if (state == '{') {
                    level--;
                    if (level == 0)
                        state = ' ';
                }
                break;
        }
        s++;
        len--;
    }
    if (stateCharPtr)
        *stateCharPtr = state;
    return state == ' ';
}

/* -----------------------------------------------------------------------------
 * Tcl Lists parsing
 * ---------------------------------------------------------------------------*/
static int JimParseListSep(struct JimParserCtx *pc);
static int JimParseListStr(struct JimParserCtx *pc);

int JimParseList(struct JimParserCtx *pc)
{
    if (pc->len == 0) {
        pc->tstart = pc->tend = pc->p;
        pc->tline = pc->linenr;
        pc->tt = JIM_TT_EOL;
        pc->eof = 1;
        return JIM_OK;
    }
    switch(*pc->p) {
    case ' ':
    case '\n':
    case '\t':
    case '\r':
        if (pc->state == JIM_PS_DEF)
            return JimParseListSep(pc);
        else
            return JimParseListStr(pc);
        break;
    default:
        return JimParseListStr(pc);
        break;
    }
    return JIM_OK;
}

int JimParseListSep(struct JimParserCtx *pc)
{
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (*pc->p == ' ' || *pc->p == '\t' || *pc->p == '\r' || *pc->p == '\n')
    {
        pc->p++; pc->len--;
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_SEP;
    return JIM_OK;
}

int JimParseListStr(struct JimParserCtx *pc)
{
    int newword = (pc->tt == JIM_TT_SEP || pc->tt == JIM_TT_EOL ||
            pc->tt == JIM_TT_NONE);
    if (newword && *pc->p == '{') {
        return JimParseBrace(pc);
    } else if (newword && *pc->p == '"') {
        pc->state = JIM_PS_QUOTE;
        pc->p++; pc->len--;
    }
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (1) {
        if (pc->len == 0) {
            pc->tend = pc->p-1;
            pc->tt = JIM_TT_ESC;
            return JIM_OK;
        }
        switch(*pc->p) {
        case '\\':
            pc->p++; pc->len--;
            break;
        case ' ':
        case '\t':
        case '\n':
        case '\r':
            if (pc->state == JIM_PS_DEF) {
                pc->tend = pc->p-1;
                pc->tt = JIM_TT_ESC;
                return JIM_OK;
            } else if (*pc->p == '\n') {
                pc->linenr++;
            }
            break;
        case '"':
            if (pc->state == JIM_PS_QUOTE) {
                pc->tend = pc->p-1;
                pc->tt = JIM_TT_ESC;
                pc->p++; pc->len--;
                pc->state = JIM_PS_DEF;
                return JIM_OK;
            }
            break;
        }
        pc->p++; pc->len--;
    }
    return JIM_OK; /* unreached */
}

/* -----------------------------------------------------------------------------
 * Jim_Obj related functions
 * ---------------------------------------------------------------------------*/

/* Return a new initialized object. */
Jim_Obj *Jim_NewObj(Jim_Interp *interp)
{
    Jim_Obj *objPtr;

    /* -- Check if there are objects in the free list -- */
    if (interp->freeList != NULL) {
        /* -- Unlink the object from the free list -- */
        objPtr = interp->freeList;
        interp->freeList = objPtr->nextObjPtr;
    } else {
        /* -- No ready to use objects: allocate a new one -- */
        objPtr = Jim_Alloc(sizeof(*objPtr));
    }

    /* Object is returned with refCount of 0. Every
     * kind of GC implemented should take care to don't try
     * to scan objects with refCount == 0. */
    objPtr->refCount = 0;
    /* All the other fields are left not initialized to save time.
     * The caller will probably want set they to the right
     * value anyway. */

    /* -- Put the object into the live list -- */
    objPtr->prevObjPtr = NULL;
    objPtr->nextObjPtr = interp->liveList;
    if (interp->liveList)
        interp->liveList->prevObjPtr = objPtr;
    interp->liveList = objPtr;

    return objPtr;
}

/* Free an object. Actually objects are never freed, but
 * just moved to the free objects list, where they will be
 * reused by Jim_NewObj(). */
void Jim_FreeObj(Jim_Interp *interp, Jim_Obj *objPtr)
{
    /* Check if the object was already freed, panic. */
    if (objPtr->refCount != 0)  {
        Jim_Panic("!!!Object %p freed with bad refcount %d", objPtr,
                objPtr->refCount);
    }
    /* Free the internal representation */
    Jim_FreeIntRep(interp, objPtr);
    /* Free the string representation */
    if (objPtr->bytes != NULL) {
        if (objPtr->bytes != JimEmptyStringRep)
            Jim_Free(objPtr->bytes);
    }
    /* Unlink the object from the live objects list */
    if (objPtr->prevObjPtr)
        objPtr->prevObjPtr->nextObjPtr = objPtr->nextObjPtr;
    if (objPtr->nextObjPtr)
        objPtr->nextObjPtr->prevObjPtr = objPtr->prevObjPtr;
    if (interp->liveList == objPtr)
        interp->liveList = objPtr->nextObjPtr;
    /* Link the object into the free objects list */
    objPtr->prevObjPtr = NULL;
    objPtr->nextObjPtr = interp->freeList;
    if (interp->freeList)
        interp->freeList->prevObjPtr = objPtr;
    interp->freeList = objPtr;
    objPtr->refCount = -1;
}

/* Invalidate the string representation of an object. */
void Jim_InvalidateStringRep(Jim_Obj *objPtr)
{
    if (objPtr->bytes != NULL) {
        if (objPtr->bytes != JimEmptyStringRep)
            Jim_Free(objPtr->bytes);
    }
    objPtr->bytes = NULL;
}

#define Jim_SetStringRep(o, b, l) \
    do { (o)->bytes = b; (o)->length = l; } while (0)

/* Set the initial string representation for an object.
 * Does not try to free an old one. */
void Jim_InitStringRep(Jim_Obj *objPtr, const char *bytes, int length)
{
    if (length == 0) {
        objPtr->bytes = JimEmptyStringRep;
        objPtr->length = 0;
    } else {
        objPtr->bytes = Jim_Alloc(length+1);
        objPtr->length = length;
        memcpy(objPtr->bytes, bytes, length);
        objPtr->bytes[length] = '\0';
    }
}

/* Duplicate an object. The returned object has refcount = 0. */
Jim_Obj *Jim_DuplicateObj(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_Obj *dupPtr;

    dupPtr = Jim_NewObj(interp);
    if (objPtr->bytes == NULL) {
        /* Object does not have a valid string representation. */
        dupPtr->bytes = NULL;
    } else {
        Jim_InitStringRep(dupPtr, objPtr->bytes, objPtr->length);
    }
    if (objPtr->typePtr != NULL) {
        if (objPtr->typePtr->dupIntRepProc == NULL) {
            dupPtr->internalRep = objPtr->internalRep;
        } else {
            objPtr->typePtr->dupIntRepProc(interp, objPtr, dupPtr);
        }
        dupPtr->typePtr = objPtr->typePtr;
    } else {
        dupPtr->typePtr = NULL;
    }
    return dupPtr;
}

/* Return the string representation for objPtr. If the object
 * string representation is invalid, calls the method to create
 * a new one starting from the internal representation of the object. */
const char *Jim_GetString(Jim_Obj *objPtr, int *lenPtr)
{
    if (objPtr->bytes == NULL) {
        /* Invalid string repr. Generate it. */
        if (objPtr->typePtr->updateStringProc == NULL) {
            Jim_Panic("UpdataStringProc called against '%s' type.",
                objPtr->typePtr->name);
        }
        objPtr->typePtr->updateStringProc(objPtr);
    }
    if (lenPtr)
        *lenPtr = objPtr->length;
    return objPtr->bytes;
}

/* Just returns the length of the object's string rep */
int Jim_Length(Jim_Obj *objPtr)
{
    int len;

    Jim_GetString(objPtr, &len);
    return len;
}

/* -----------------------------------------------------------------------------
 * String Object
 * ---------------------------------------------------------------------------*/
static void DupStringInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static int SetStringFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType stringObjType = {
    "string",
    NULL,
    DupStringInternalRep,
    NULL,
    JIM_TYPE_REFERENCES,
};

void DupStringInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    JIM_NOTUSED(interp);

    /* This is a bit subtle: the only caller of this function
     * should be Jim_DuplicateObj(), that will copy the
     * string representaion. After the copy, the duplicated
     * object will not have more room in teh buffer than
     * srcPtr->length bytes. So we just set it to length. */
    dupPtr->internalRep.strValue.maxLength = srcPtr->length;
}

int SetStringFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    /* Get a fresh string representation. */
//    (void*) Jim_GetString(objPtr, NULL);
    Jim_GetString(objPtr, NULL);
    /* Free any other internal representation. */
    Jim_FreeIntRep(interp, objPtr);
    /* Set it as string, i.e. just set the maxLength field. */
    objPtr->typePtr = &stringObjType;
    objPtr->internalRep.strValue.maxLength = objPtr->length;
    return JIM_OK;
}

Jim_Obj *Jim_NewStringObj(Jim_Interp *interp, const char *s, int len)
{
    Jim_Obj *objPtr = Jim_NewObj(interp);

    if (len == -1)
        len = strlen(s);
    /* Alloc/Set the string rep. */
    if (len == 0) {
        objPtr->bytes = JimEmptyStringRep;
        objPtr->length = 0;
    } else {
        objPtr->bytes = Jim_Alloc(len+1);
        objPtr->length = len;
        memcpy(objPtr->bytes, s, len);
        objPtr->bytes[len] = '\0';
    }

    /* No typePtr field for the vanilla string object. */
    objPtr->typePtr = NULL;
    return objPtr;
}

/* This version does not try to duplicate the 's' pointer, but
 * use it directly. */
Jim_Obj *Jim_NewStringObjNoAlloc(Jim_Interp *interp, char *s, int len)
{
    Jim_Obj *objPtr = Jim_NewObj(interp);

    if (len == -1)
        len = strlen(s);
    Jim_SetStringRep(objPtr, s, len);
    objPtr->typePtr = NULL;
    return objPtr;
}

/* Low-level string append. Use it only against objects
 * of type "string". */
void StringAppendString(Jim_Obj *objPtr, const char *str, int len)
{
    int needlen;

    if (len == -1)
        len = strlen(str);
    needlen = objPtr->length + len;
    if (objPtr->internalRep.strValue.maxLength < needlen ||
        objPtr->internalRep.strValue.maxLength == 0) {
        if (objPtr->bytes == JimEmptyStringRep) {
            objPtr->bytes = Jim_Alloc((needlen*2)+1);
        } else {
            objPtr->bytes = Jim_Realloc(objPtr->bytes, (needlen*2)+1);
        }
        objPtr->internalRep.strValue.maxLength = needlen*2;
    }
    memcpy(objPtr->bytes + objPtr->length, str, len);
    objPtr->bytes[objPtr->length+len] = '\0';
    objPtr->length += len;
}

/* Low-level wrapper to append an object. */
void StringAppendObj(Jim_Obj *objPtr, Jim_Obj *appendObjPtr)
{
    int len;
    const char *str;

    str = Jim_GetString(appendObjPtr, &len);
    StringAppendString(objPtr, str, len);
}

/* Higher level API to append strings to objects. */
void Jim_AppendString(Jim_Interp *interp, Jim_Obj *objPtr, const char *str,
        int len)
{
    if (Jim_IsShared(objPtr))
        Jim_Panic("Jim_AppendString called with shared object");
    if (objPtr->typePtr != &stringObjType)
        SetStringFromAny(interp, objPtr);
    StringAppendString(objPtr, str, len);
}

void Jim_AppendObj(Jim_Interp *interp, Jim_Obj *objPtr,
        Jim_Obj *appendObjPtr)
{
    int len;
    const char *str;

    str = Jim_GetString(appendObjPtr, &len);
    Jim_AppendString(interp, objPtr, str, len);
}

void Jim_AppendStrings(Jim_Interp *interp, Jim_Obj *objPtr, ...)
{
    va_list ap;

    if (objPtr->typePtr != &stringObjType)
        SetStringFromAny(interp, objPtr);
    va_start(ap, objPtr);
    while (1) {
        char *s = va_arg(ap, char*);

        if (s == NULL) break;
        Jim_AppendString(interp, objPtr, s, -1);
    }
    va_end(ap);
}

int Jim_StringEqObj(Jim_Obj *aObjPtr, Jim_Obj *bObjPtr, int nocase)
{
    const char *aStr, *bStr;
    int aLen, bLen, i;

    if (aObjPtr == bObjPtr) return 1;
    aStr = Jim_GetString(aObjPtr, &aLen);
    bStr = Jim_GetString(bObjPtr, &bLen);
    if (aLen != bLen) return 0;
    if (nocase == 0)
        return memcmp(aStr, bStr, aLen) == 0;
    for (i = 0; i < aLen; i++) {
        if (tolower((int)aStr[i]) != tolower((int)bStr[i]))
            return 0;
    }
    return 1;
}

int Jim_StringMatchObj(Jim_Obj *patternObjPtr, Jim_Obj *objPtr,
        int nocase)
{
    const char *pattern, *string;
    int patternLen, stringLen;

    pattern = Jim_GetString(patternObjPtr, &patternLen);
    string = Jim_GetString(objPtr, &stringLen);
    return JimStringMatch(pattern, patternLen, string, stringLen, nocase);
}

int Jim_StringCompareObj(Jim_Obj *firstObjPtr,
        Jim_Obj *secondObjPtr, int nocase)
{
    const char *s1, *s2;
    int l1, l2;

    s1 = Jim_GetString(firstObjPtr, &l1);
    s2 = Jim_GetString(secondObjPtr, &l2);
    return JimStringCompare(s1, l1, s2, l2, nocase);
}

/* Convert a range, as returned by Jim_GetRange(), into
 * an absolute index into an object of the specified length.
 * This function may return negative values, or values
 * bigger or equal to the length of the list if the index
 * is out of range. */
static int JimRelToAbsIndex(int len, int index)
{
    if (index < 0)
        return len + index;
    return index;
}

/* Convert a pair of index as normalize by JimRelToAbsIndex(),
 * into a range stored in *firstPtr, *lastPtr, *rangeLenPtr, suitable
 * for implementation of commands like [string range] and [lrange].
 *
 * The resulting range is guaranteed to address valid elements of
 * the structure. */
static void JimRelToAbsRange(int len, int first, int last,
        int *firstPtr, int *lastPtr, int *rangeLenPtr)
{
    int rangeLen;

    if (first > last) {
        rangeLen = 0;
    } else {
        rangeLen = last-first+1;
        if (rangeLen) {
            if (first < 0) {
                rangeLen += first;
                first = 0;
            }
            if (last >= len) {
                rangeLen -= (last-(len-1));
                last = len-1;
            }
        }
    }
    if (rangeLen < 0) rangeLen = 0;

    *firstPtr = first;
    *lastPtr = last;
    *rangeLenPtr = rangeLen;
}

Jim_Obj *Jim_StringRangeObj(Jim_Interp *interp,
        Jim_Obj *strObjPtr, Jim_Obj *firstObjPtr, Jim_Obj *lastObjPtr)
{
    int first, last;
    const char *str;
    int len, rangeLen;

    if (Jim_GetIndex(interp, firstObjPtr, &first) != JIM_OK ||
        Jim_GetIndex(interp, lastObjPtr, &last) != JIM_OK)
        return NULL;
    str = Jim_GetString(strObjPtr, &len);
    first = JimRelToAbsIndex(len, first);
    last = JimRelToAbsIndex(len, last);
    JimRelToAbsRange(len, first, last, &first, &last, &rangeLen);
    return Jim_NewStringObj(interp, str+first, rangeLen);
}

static Jim_Obj *JimStringToLower(Jim_Interp *interp, Jim_Obj *strObjPtr)
{
    char *buf = Jim_Alloc(strObjPtr->length+1);
    int i;

    memcpy(buf, strObjPtr->bytes, strObjPtr->length+1);
    for (i = 0; i < strObjPtr->length; i++)
        buf[i] = tolower(buf[i]);
    return Jim_NewStringObjNoAlloc(interp, buf, strObjPtr->length);
}

static Jim_Obj *JimStringToUpper(Jim_Interp *interp, Jim_Obj *strObjPtr)
{
    char *buf = Jim_Alloc(strObjPtr->length+1);
    int i;

    memcpy(buf, strObjPtr->bytes, strObjPtr->length+1);
    for (i = 0; i < strObjPtr->length; i++)
        buf[i] = toupper(buf[i]);
    return Jim_NewStringObjNoAlloc(interp, buf, strObjPtr->length);
}

/* This is the core of the [format] command.
 * TODO: Export it, make it real... for now only %s and %%
 * specifiers supported. */
Jim_Obj *Jim_FormatString(Jim_Interp *interp, Jim_Obj *fmtObjPtr,
        int objc, Jim_Obj *const *objv)
{
    const char *fmt;
    int fmtLen;
    Jim_Obj *resObjPtr;

    fmt = Jim_GetString(fmtObjPtr, &fmtLen);
    resObjPtr = Jim_NewStringObj(interp, "", 0);
    while (fmtLen) {
        const char *p = fmt;
        char spec[2], c;
        jim_wide wideValue;

        while (*fmt != '%' && fmtLen) {
            fmt++; fmtLen--;
        }
        Jim_AppendString(interp, resObjPtr, p, fmt-p);
        if (fmtLen == 0)
            break;
        fmt++; fmtLen--; /* skip '%' */
        if (*fmt != '%') {
            if (objc == 0) {
                Jim_FreeNewObj(interp, resObjPtr);
                Jim_SetResultString(interp,
                        "not enough arguments for all format specifiers", -1);
                return NULL;
            } else {
                objc--;
            }
        }
        switch(*fmt) {
        case 's':
            Jim_AppendObj(interp, resObjPtr, objv[0]);
            objv++;
            break;
        case 'c':
            if (Jim_GetWide(interp, objv[0], &wideValue) == JIM_ERR) {
                Jim_FreeNewObj(interp, resObjPtr);
                return NULL;
            }
            c = (char) wideValue;
            Jim_AppendString(interp, resObjPtr, &c, 1);
            break;
        case '%':
            Jim_AppendString(interp, resObjPtr, "%" , 1);
            break;
        default:
            spec[0] = *fmt; spec[1] = '\0';
            Jim_FreeNewObj(interp, resObjPtr);
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "bad field specifier \"",  spec, "\"", NULL);
            return NULL;
        }
        fmt++;
        fmtLen--;
    }
    return resObjPtr;
}

/* -----------------------------------------------------------------------------
 * Compared String Object
 * ---------------------------------------------------------------------------*/

/* This is strange object that allows to compare a C literal string
 * with a Jim object in very short time if the same comparison is done
 * multiple times. For example every time the [if] command is executed,
 * Jim has to check if a given argument is "else". This comparions if
 * the code has no errors are true most of the times, so we can cache
 * inside the object the pointer of the string of the last matching
 * comparison. Because most C compilers perform literal sharing,
 * so that: char *x = "foo", char *y = "foo", will lead to x == y,
 * this works pretty well even if comparisons are at different places
 * inside the C code. */

static Jim_ObjType comparedStringObjType = {
    "compared-string",
    NULL,
    NULL,
    NULL,
    JIM_TYPE_REFERENCES,
};

/* The only way this object is exposed to the API is via the following
 * function. Returns true if the string and the object string repr.
 * are the same, otherwise zero is returned.
 *
 * Note: this isn't binary safe, but it hardly needs to be.*/
int Jim_CompareStringImmediate(Jim_Interp *interp, Jim_Obj *objPtr,
        const char *str)
{
    if (objPtr->typePtr == &comparedStringObjType &&
        objPtr->internalRep.ptr == str)
        return 1;
    else {
        const char *objStr = Jim_GetString(objPtr, NULL);
        if (strcmp(str, objStr) != 0) return 0;
        if (objPtr->typePtr != &comparedStringObjType) {
            Jim_FreeIntRep(interp, objPtr);
            objPtr->typePtr = &comparedStringObjType;
        }
        objPtr->internalRep.ptr = (char*)str; /*ATTENTION: const cast */
        return 1;
    }
}

int qsortCompareStringPointers(const void *a, const void *b)
{
    char * const *sa = (char * const *)a;
    char * const *sb = (char * const *)b;
    return strcmp(*sa, *sb);
}

int Jim_GetEnum(Jim_Interp *interp, Jim_Obj *objPtr,
        const char **tablePtr, int *indexPtr, const char *name, int flags)
{
    const char **entryPtr = NULL;
    char **tablePtrSorted;
    int i, count = 0;

    *indexPtr = -1;
    for (entryPtr = tablePtr, i = 0; *entryPtr != NULL; entryPtr++, i++) {
        if (Jim_CompareStringImmediate(interp, objPtr, *entryPtr)) {
            *indexPtr = i;
            return JIM_OK;
        }
        count++; /* If nothing matches, this will reach the len of tablePtr */
    }
    if (flags & JIM_ERRMSG) {
        if (name == NULL)
            name = "option";
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "bad ", name, " \"", Jim_GetString(objPtr, NULL), "\": must be one of ",
            NULL);
        tablePtrSorted = Jim_Alloc(sizeof(char*)*count);
        memcpy(tablePtrSorted, tablePtr, sizeof(char*)*count);
        qsort(tablePtrSorted, count, sizeof(char*), qsortCompareStringPointers);
        for (i = 0; i < count; i++) {
            if (i+1 == count && count > 1)
                Jim_AppendString(interp, Jim_GetResult(interp), "or ", -1);
            Jim_AppendString(interp, Jim_GetResult(interp),
                    tablePtrSorted[i], -1);
            if (i+1 != count)
                Jim_AppendString(interp, Jim_GetResult(interp), ", ", -1);
        }
        Jim_Free(tablePtrSorted);
    }
    return JIM_ERR;
}

/* -----------------------------------------------------------------------------
 * Source Object
 *
 * This object is just a string from the language point of view, but
 * in the internal representation it contains the filename and line number
 * where this given token was read. This information is used by
 * Jim_EvalObj() if the object passed happens to be of type "source".
 *
 * This allows to propagate the information about line numbers and file
 * names and give error messages with absolute line numbers.
 *
 * Note that this object uses shared strings for filenames, and the
 * pointer to the filename together with the line number is taken into
 * the space for the "inline" internal represenation of the Jim_Object,
 * so there is almost memory zero-overhead.
 *
 * Also the object will be converted to something else if the given
 * token it represents in the source file is not something to be
 * evaluated (not a script), and will be specialized in some other way,
 * so the time overhead is alzo null.
 * ---------------------------------------------------------------------------*/

static void FreeSourceInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupSourceInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);

static Jim_ObjType sourceObjType = {
    "source",
    FreeSourceInternalRep,
    DupSourceInternalRep,
    NULL,
    JIM_TYPE_REFERENCES,
};

void FreeSourceInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_ReleaseSharedString(interp,
            objPtr->internalRep.sourceValue.fileName);
}

void DupSourceInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    dupPtr->internalRep.sourceValue.fileName =
        Jim_GetSharedString(interp,
                srcPtr->internalRep.sourceValue.fileName);
    dupPtr->internalRep.sourceValue.lineNumber =
        dupPtr->internalRep.sourceValue.lineNumber;
    dupPtr->typePtr = &sourceObjType;
}

static void JimSetSourceInfo(Jim_Interp *interp, Jim_Obj *objPtr,
        const char *fileName, int lineNumber)
{
    if (Jim_IsShared(objPtr))
        Jim_Panic("JimSetSourceInfo called with shared object");
    if (objPtr->typePtr != NULL)
        Jim_Panic("JimSetSourceInfo called with typePtr != NULL");
    objPtr->internalRep.sourceValue.fileName =
        Jim_GetSharedString(interp, fileName);
    objPtr->internalRep.sourceValue.lineNumber = lineNumber;
    objPtr->typePtr = &sourceObjType;
}

/* -----------------------------------------------------------------------------
 * Script Object
 * ---------------------------------------------------------------------------*/

#define JIM_CMDSTRUCT_EXPAND -1

static void FreeScriptInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupScriptInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static int SetScriptFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType scriptObjType = {
    "script",
    FreeScriptInternalRep,
    DupScriptInternalRep,
    NULL,
    JIM_TYPE_REFERENCES,
};

/* The ScriptToken structure represents every token into a scriptObj.
 * Every token contains an associated Jim_Obj that can be specialized
 * by commands operating on it. */
typedef struct ScriptToken {
    int type;
    Jim_Obj *objPtr;
    int linenr;
} ScriptToken;

/* This is the script object internal representation. An array of
 * ScriptToken structures, with an associated command structure array.
 * The command structure is a pre-computed representation of the
 * command length and arguments structure as a simple liner array
 * of integers.
 * 
 * For example the script:
 *
 * puts hello
 * set $i $x$y [foo]BAR
 *
 * will produce a ScriptObj with the following Tokens:
 *
 * ESC puts
 * SEP
 * ESC hello
 * EOL
 * ESC set
 * EOL
 * VAR i
 * SEP
 * VAR x
 * VAR y
 * SEP
 * CMD foo
 * ESC BAR
 * EOL
 *
 * This is a description of the tokens, separators, and of lines.
 * The command structure instead represents the number of arguments
 * of every command, followed by the tokens of which every argument
 * is composed. So for the example script, the cmdstruct array will
 * contain:
 *
 * 2 1 1 4 1 1 2 2
 *
 * Because "puts hello" has two args (2), composed of single tokens (1 1)
 * While "set $i $x$y [foo]BAR" has four (4) args, the first two
 * composed of single tokens (1 1) and the last two of double tokens
 * (2 2).
 *
 * The precomputation of the command structure makes Jim_Eval() faster,
 * and simpler because there aren't dynamic lengths / allocations.
 *
 * -- {expand} handling --
 *
 * Expand is handled in a special way. When a command
 * contains at least an argument with the {expand} prefix,
 * the command structure presents a -1 before the integer
 * describing the number of arguments. This is used in order
 * to send the command exection to a different path in case
 * of {expand} and guarantee a fast path for the more common
 * case. Also, the integers describing the number of tokens
 * are expressed with negative sign, to allow for fast check
 * of what's an {expand}-prefixed argument and what not.
 *
 * For example the command:
 *
 * list {expand}{1 2}
 *
 * Will produce the following cmdstruct array:
 *
 * -1 2 1 -2
 *
 * -- the substFlags field of the structure --
 *
 * The scriptObj structure is used to represent both "script" objects
 * and "subst" objects. In the second case, the cmdStruct related
 * fields are not used at all, but there is an additional field used
 * that is 'substFlags': this represents the flags used to turn
 * the string into the intenral representation used to perform the
 * substitution. If this flags are not what the application requires
 * the scriptObj is created again. For example the script:
 *
 * subst -nocommands $string
 * subst -novariables $string
 *
 * Will recreate the internal representation of the $string object
 * two times.
 */
typedef struct ScriptObj {
    int len; /* Length as number of tokens. */
    int commands; /* number of top-level commands in script. */
    ScriptToken *token; /* Tokens array. */
    int *cmdStruct; /* commands structure */
    int csLen; /* length of the cmdStruct array. */
    int substFlags; /* flags used for the compilation of "subst" objects */
    int inUse; /* Used to share a ScriptObj. Currently
              only used by Jim_EvalObj() as protection against
              shimmering of the currently evaluated object. */
    char *fileName;
} ScriptObj;

void FreeScriptInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    int i;
    struct ScriptObj *script = (void*) objPtr->internalRep.ptr;

    script->inUse--;
    if (script->inUse != 0) return;
    for (i = 0; i < script->len; i++) {
        if (script->token[i].objPtr != NULL)
            Jim_DecrRefCount(interp, script->token[i].objPtr);
    }
    Jim_Free(script->token);
    Jim_Free(script->cmdStruct);
    Jim_Free(script->fileName);
    Jim_Free(script);
}

void DupScriptInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    JIM_NOTUSED(interp);
    JIM_NOTUSED(srcPtr);

    /* Just returns an simple string. */
    dupPtr->typePtr = NULL;
}

/* Add a new token to the internal repr of a script object */
static void ScriptObjAddToken(Jim_Interp *interp, struct ScriptObj *script,
        char *strtoken, int len, int type, char *filename, int linenr)
{
    int prevtype;
    struct ScriptToken *token;

    prevtype = (script->len == 0) ? JIM_TT_EOL : \
        script->token[script->len-1].type;
    /* Skip tokens without meaning, like words separators
     * following a word separator or an end of command and
     * so on. */
    if (prevtype == JIM_TT_EOL) {
        if (type == JIM_TT_EOL || type == JIM_TT_SEP) {
            Jim_Free(strtoken);
            return;
        }
    } else if (prevtype == JIM_TT_SEP) {
        if (type == JIM_TT_SEP) {
            Jim_Free(strtoken);
            return;
        } else if (type == JIM_TT_EOL) {
            /* If an EOL is following by a SEP, drop the previous
             * separator. */
            script->len--;
            Jim_DecrRefCount(interp, script->token[script->len].objPtr);
        }
    } else if (prevtype != JIM_TT_EOL && prevtype != JIM_TT_SEP &&
            type == JIM_TT_ESC && len == 0)
    {
        /* Don't add empty tokens used in interpolation */
        Jim_Free(strtoken);
        return;
    }
    /* Make space for a new istruction */
    script->len++;
    script->token = Jim_Realloc(script->token,
            sizeof(ScriptToken)*script->len);
    /* Initialize the new token */
    token = script->token+(script->len-1);
    token->type = type;
    /* Every object is intially as a string, but the
     * internal type may be specialized during execution of the
     * script. */
    token->objPtr = Jim_NewStringObjNoAlloc(interp, strtoken, len);
    /* To add source info to SEP and EOL tokens is useless because
     * they will never by called as arguments of Jim_EvalObj(). */
    if (filename && type != JIM_TT_SEP && type != JIM_TT_EOL)
        JimSetSourceInfo(interp, token->objPtr, filename, linenr);
    Jim_IncrRefCount(token->objPtr);
    token->linenr = linenr;
}

/* Add an integer into the command structure field of the script object. */
static void ScriptObjAddInt(struct ScriptObj *script, int val)
{
    script->csLen++;
    script->cmdStruct = Jim_Realloc(script->cmdStruct,
                    sizeof(int)*script->csLen);
    script->cmdStruct[script->csLen-1] = val;
}

/* Search a Jim_Obj contained in 'script' with the same stinrg repr.
 * of objPtr. Search nested script objects recursively. */
static Jim_Obj *ScriptSearchLiteral(Jim_Interp *interp, ScriptObj *script,
        ScriptObj *scriptBarrier, Jim_Obj *objPtr)
{
    int i;

    for (i = 0; i < script->len; i++) {
        if (script->token[i].objPtr != objPtr &&
            Jim_StringEqObj(script->token[i].objPtr, objPtr, 0)) {
            return script->token[i].objPtr;
        }
        /* Enter recursively on scripts only if the object
         * is not the same as the one we are searching for
         * shared occurrences. */
        if (script->token[i].objPtr->typePtr == &scriptObjType &&
            script->token[i].objPtr != objPtr) {
            Jim_Obj *foundObjPtr;

            ScriptObj *subScript =
                script->token[i].objPtr->internalRep.ptr;
            /* Don't recursively enter the script we are trying
             * to make shared to avoid circular references. */
            if (subScript == scriptBarrier) continue;
            if (subScript != script) {
                foundObjPtr =
                    ScriptSearchLiteral(interp, subScript,
                            scriptBarrier, objPtr);
                if (foundObjPtr != NULL)
                    return foundObjPtr;
            }
        }
    }
    return NULL;
}

/* Share literals of a script recursively sharing sub-scripts literals. */
static void ScriptShareLiterals(Jim_Interp *interp, ScriptObj *script,
        ScriptObj *topLevelScript)
{
    int i, j;

    return;
    /* Try to share with toplevel object. */
    if (topLevelScript != NULL) {
        for (i = 0; i < script->len; i++) {
            Jim_Obj *foundObjPtr;
            char *str = script->token[i].objPtr->bytes;

            if (script->token[i].objPtr->refCount != 1) continue;
            if (script->token[i].objPtr->typePtr == &scriptObjType) continue;
            if (strchr(str, ' ') || strchr(str, '\n')) continue;
            foundObjPtr = ScriptSearchLiteral(interp,
                    topLevelScript,
                    script, /* barrier */
                    script->token[i].objPtr);
            if (foundObjPtr != NULL) {
                Jim_IncrRefCount(foundObjPtr);
                Jim_DecrRefCount(interp,
                        script->token[i].objPtr);
                script->token[i].objPtr = foundObjPtr;
            }
        }
    }
    /* Try to share locally */
    for (i = 0; i < script->len; i++) {
        char *str = script->token[i].objPtr->bytes;

        if (script->token[i].objPtr->refCount != 1) continue;
        if (strchr(str, ' ') || strchr(str, '\n')) continue;
        for (j = 0; j < script->len; j++) {
            if (script->token[i].objPtr !=
                    script->token[j].objPtr &&
                Jim_StringEqObj(script->token[i].objPtr,
                            script->token[j].objPtr, 0))
            {
                Jim_IncrRefCount(script->token[j].objPtr);
                Jim_DecrRefCount(interp,
                        script->token[i].objPtr);
                script->token[i].objPtr =
                    script->token[j].objPtr;
            }
        }
    }
}

/* This method takes the string representation of an object
 * as a Tcl script, and generates the pre-parsed internal representation
 * of the script. */
int SetScriptFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr)
{
    int scriptTextLen;
    const char *scriptText = Jim_GetString(objPtr, &scriptTextLen);
    struct JimParserCtx parser;
    struct ScriptObj *script = Jim_Alloc(sizeof(*script));
    ScriptToken *token;
    int args, tokens, start, end, i;
    int initialLineNumber;
    int propagateSourceInfo = 0;

    script->len = 0;
    script->csLen = 0;
    script->commands = 0;
    script->token = NULL;
    script->cmdStruct = NULL;
    script->inUse = 1;
    /* Try to get information about filename / line number */
    if (objPtr->typePtr == &sourceObjType) {
        script->fileName =
            Jim_StrDup(objPtr->internalRep.sourceValue.fileName);
        initialLineNumber = objPtr->internalRep.sourceValue.lineNumber;
        propagateSourceInfo = 1;
    } else {
        script->fileName = Jim_StrDup("?");
        initialLineNumber = 1;
    }

    JimParserInit(&parser, scriptText, scriptTextLen, initialLineNumber);
    while(!JimParserEof(&parser)) {
        char *token;
        int len, type, linenr;

        JimParseScript(&parser);
        token = JimParserGetToken(&parser, &len, &type, &linenr);
        ScriptObjAddToken(interp, script, token, len, type,
                propagateSourceInfo ? script->fileName : NULL,
                linenr);
    }
    token = script->token;

    /* Compute the command structure array
     * (see the ScriptObj struct definition for more info) */
    start = 0; /* Current command start token index */
    end = -1; /* Current command end token index */
    while (1) {
        int expand = 0; /* expand flag. set to 1 on {expand} form. */
        int interpolation = 0; /* set to 1 if there is at least one
                      argument of the command obtained via
                      interpolation of more tokens. */
        /* Search for the end of command, while
         * count the number of args. */
        start = ++end;
        if (start >= script->len) break;
        args = 1; /* Number of args in current command */
        while (token[end].type != JIM_TT_EOL) {
            if (end == 0 || token[end-1].type == JIM_TT_SEP ||
                    token[end-1].type == JIM_TT_EOL)
            {
                if (token[end].type == JIM_TT_STR &&
                    token[end+1].type != JIM_TT_SEP &&
                    token[end+1].type != JIM_TT_EOL &&
                    !strcmp(token[end].objPtr->bytes, "expand"))
                    expand++;
            }
            if (token[end].type == JIM_TT_SEP)
                args++;
            end++;
        }
        interpolation = !((end-start+1) == args*2);
        /* Add the 'number of arguments' info into cmdstruct.
         * Negative value if there is list expansion involved. */
        if (expand)
            ScriptObjAddInt(script, -1);
        ScriptObjAddInt(script, args);
        /* Now add info about the number of tokens. */
        tokens = 0; /* Number of tokens in current argument. */
        expand = 0;
        for (i = start; i <= end; i++) {
            if (token[i].type == JIM_TT_SEP ||
                token[i].type == JIM_TT_EOL)
            {
                if (tokens == 1 && expand)
                    expand = 0;
                ScriptObjAddInt(script,
                        expand ? -tokens : tokens);

                expand = 0;
                tokens = 0;
                continue;
            } else if (tokens == 0 && token[i].type == JIM_TT_STR &&
                   !strcmp(token[i].objPtr->bytes, "expand"))
            {
                expand++;
            }
            tokens++;
        }
    }
    /* Perform literal sharing, but only for objects that appear
     * to be scripts written as literals inside the source code,
     * and not computed at runtime. Literal sharing is a costly
     * operation that should be done only against objects that
     * are likely to require compilation only the first time, and
     * then are executed multiple times. */
    if (propagateSourceInfo && interp->framePtr->procBodyObjPtr) {
        Jim_Obj *bodyObjPtr = interp->framePtr->procBodyObjPtr;
        if (bodyObjPtr->typePtr == &scriptObjType) {
            ScriptObj *bodyScript =
                bodyObjPtr->internalRep.ptr;
            ScriptShareLiterals(interp, script, bodyScript);
        }
    } else if (propagateSourceInfo) {
        ScriptShareLiterals(interp, script, NULL);
    }
    /* Free the old internal rep and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    Jim_SetIntRepPtr(objPtr, script);
    objPtr->typePtr = &scriptObjType;
    return JIM_OK;
}

ScriptObj *Jim_GetScript(Jim_Interp *interp, Jim_Obj *objPtr)
{
    if (objPtr->typePtr != &scriptObjType) {
        SetScriptFromAny(interp, objPtr);
    }
    return (ScriptObj*) Jim_GetIntRepPtr(objPtr);
}

/* -----------------------------------------------------------------------------
 * Commands
 * ---------------------------------------------------------------------------*/

/* Commands HashTable Type.
 *
 * Keys are dynamic allocated strings, Values are Jim_Cmd structures. */
static void Jim_CommandsHT_ValDestructor(void *interp, void *val)
{
    Jim_Cmd *cmdPtr = (void*) val;

    if (cmdPtr->cmdProc == NULL) {
        Jim_DecrRefCount(interp, cmdPtr->argListObjPtr);
        Jim_DecrRefCount(interp, cmdPtr->bodyObjPtr);
        if (cmdPtr->staticVars) {
            Jim_FreeHashTable(cmdPtr->staticVars);
            Jim_Free(cmdPtr->staticVars);
        }
    } else if (cmdPtr->delProc != NULL) {
            /* If it was a C coded command, call the delProc if any */
            cmdPtr->delProc(interp, cmdPtr->privData);
    }
    Jim_Free(val);
}

static Jim_HashTableType JimCommandsHashTableType = {
    JimStringCopyHTHashFunction,        /* hash function */
    JimStringCopyHTKeyDup,        /* key dup */
    NULL,                    /* val dup */
    JimStringCopyHTKeyCompare,        /* key compare */
    JimStringCopyHTKeyDestructor,        /* key destructor */
    Jim_CommandsHT_ValDestructor        /* val destructor */
};

/* ------------------------- Commands related functions --------------------- */

int Jim_CreateCommand(Jim_Interp *interp, const char *cmdName,
        Jim_CmdProc cmdProc, void *privData, Jim_DelCmdProc delProc)
{
    Jim_HashEntry *he;
    Jim_Cmd *cmdPtr;

    he = Jim_FindHashEntry(&interp->commands, cmdName);
    if (he == NULL) { /* New command to create */
        cmdPtr = Jim_Alloc(sizeof(*cmdPtr));
        cmdPtr->cmdProc = cmdProc;
        cmdPtr->privData = privData;
        cmdPtr->delProc = delProc;
        Jim_AddHashEntry(&interp->commands, cmdName, cmdPtr);
    } else {
        Jim_InterpIncrProcEpoch(interp);
        /* Free the arglist/body objects if it was a Tcl procedure */
        cmdPtr = he->val;
        if (cmdPtr->cmdProc == NULL) {
            Jim_DecrRefCount(interp, cmdPtr->argListObjPtr);
            Jim_DecrRefCount(interp, cmdPtr->bodyObjPtr);
            if (cmdPtr->staticVars) {
                Jim_FreeHashTable(cmdPtr->staticVars);
                Jim_Free(cmdPtr->staticVars);
            }
            cmdPtr->staticVars = NULL;
        } else if (cmdPtr->delProc != NULL) {
            /* If it was a C coded command, call the delProc if any */
            cmdPtr->delProc(interp, cmdPtr->privData);
        }
        cmdPtr->cmdProc = cmdProc;
        cmdPtr->privData = privData;
    }
    /* There is no need to increment the 'proc epoch' because
     * creation of a new procedure can never affect existing
     * cached commands. We don't do negative caching. */
    return JIM_OK;
}

int Jim_CreateProcedure(Jim_Interp *interp, const char *cmdName,
        Jim_Obj *argListObjPtr, Jim_Obj *staticsListObjPtr, Jim_Obj *bodyObjPtr,
        int arityMin, int arityMax)
{
    Jim_Cmd *cmdPtr;

    cmdPtr = Jim_Alloc(sizeof(*cmdPtr));
    cmdPtr->cmdProc = NULL; /* Not a C coded command */
    cmdPtr->argListObjPtr = argListObjPtr;
    cmdPtr->bodyObjPtr = bodyObjPtr;
    Jim_IncrRefCount(argListObjPtr);
    Jim_IncrRefCount(bodyObjPtr);
    cmdPtr->arityMin = arityMin;
    cmdPtr->arityMax = arityMax;
    cmdPtr->staticVars = NULL;
   
    /* Create the statics hash table. */
    if (staticsListObjPtr) {
        int len, i;

        Jim_ListLength(interp, staticsListObjPtr, &len);
        if (len != 0) {
            cmdPtr->staticVars = Jim_Alloc(sizeof(Jim_HashTable));
            Jim_InitHashTable(cmdPtr->staticVars, &JimVariablesHashTableType,
                    interp);
            for (i = 0; i < len; i++) {
                Jim_Obj *objPtr, *initObjPtr, *nameObjPtr;
                Jim_Var *varPtr;
                int subLen;

                Jim_ListIndex(interp, staticsListObjPtr, i, &objPtr, JIM_NONE);
                /* Check if it's composed of two elements. */
                Jim_ListLength(interp, objPtr, &subLen);
                if (subLen == 1 || subLen == 2) {
                    /* Try to get the variable value from the current
                     * environment. */
                    Jim_ListIndex(interp, objPtr, 0, &nameObjPtr, JIM_NONE);
                    if (subLen == 1) {
                        initObjPtr = Jim_GetVariable(interp, nameObjPtr,
                                JIM_NONE);
                        if (initObjPtr == NULL) {
                            Jim_SetResult(interp,
                                    Jim_NewEmptyStringObj(interp));
                            Jim_AppendStrings(interp, Jim_GetResult(interp),
                                "variable for initialization of static \"",
                                Jim_GetString(nameObjPtr, NULL),
                                "\" not found in the local context",
                                NULL);
                            goto err;
                        }
                    } else {
                        Jim_ListIndex(interp, objPtr, 1, &initObjPtr, JIM_NONE);
                    }
                    varPtr = Jim_Alloc(sizeof(*varPtr));
                    varPtr->objPtr = initObjPtr;
                    Jim_IncrRefCount(initObjPtr);
                    varPtr->linkFramePtr = NULL;
                    if (Jim_AddHashEntry(cmdPtr->staticVars,
                            Jim_GetString(nameObjPtr, NULL),
                            varPtr) != JIM_OK)
                    {
                        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
                        Jim_AppendStrings(interp, Jim_GetResult(interp),
                            "static variable name \"",
                            Jim_GetString(objPtr, NULL), "\"",
                            " duplicated in statics list", NULL);
                        Jim_DecrRefCount(interp, initObjPtr);
                        Jim_Free(varPtr);
                        goto err;
                    }
                } else {
                    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
                    Jim_AppendStrings(interp, Jim_GetResult(interp),
                        "too many fields in static specifier \"",
                        objPtr, "\"", NULL);
                    goto err;
                }
            }
        }
    }

    /* Add the new command */
    Jim_DeleteHashEntry(&interp->commands, cmdName); /* it may already exist */
    Jim_AddHashEntry(&interp->commands, cmdName, cmdPtr);
    /* There is no need to increment the 'proc epoch' because
     * creation of a new procedure can never affect existing
     * cached commands. We don't do negative caching. */
    return JIM_OK;

err:
    Jim_FreeHashTable(cmdPtr->staticVars);
    Jim_Free(cmdPtr->staticVars);
    Jim_DecrRefCount(interp, argListObjPtr);
    Jim_DecrRefCount(interp, bodyObjPtr);
    Jim_Free(cmdPtr);
    return JIM_ERR;
}

int Jim_DeleteCommand(Jim_Interp *interp, const char *cmdName)
{
    if (Jim_DeleteHashEntry(&interp->commands, cmdName) == JIM_ERR)
        return JIM_ERR;
    Jim_InterpIncrProcEpoch(interp);
    return JIM_OK;
}

int Jim_RenameCommand(Jim_Interp *interp, const char *oldName, 
        const char *newName)
{
    Jim_Cmd *cmdPtr;
    Jim_HashEntry *he;
    Jim_Cmd *copyCmdPtr;

    if (newName[0] == '\0') /* Delete! */
        return Jim_DeleteCommand(interp, oldName);
    /* Rename */
    he = Jim_FindHashEntry(&interp->commands, oldName);
    if (he == NULL)
        return JIM_ERR; /* Invalid command name */
    cmdPtr = he->val;
    copyCmdPtr = Jim_Alloc(sizeof(Jim_Cmd));
    *copyCmdPtr = *cmdPtr;
    /* In order to avoid that a procedure will get arglist/body/statics
     * freed by the hash table methods, fake a C-coded command
     * setting cmdPtr->cmdProc as not NULL */
    cmdPtr->cmdProc = (void*)1;
    /* Also make sure delProc is NULL. */
    cmdPtr->delProc = NULL;
    /* Destroy the old command, and make sure the new is freed
     * as well. */
    Jim_DeleteHashEntry(&interp->commands, oldName);
    Jim_DeleteHashEntry(&interp->commands, newName);
    /* Now the new command. We are sure it can't fail because
     * the target name was already freed. */
    Jim_AddHashEntry(&interp->commands, newName, copyCmdPtr);
    /* Increment the epoch */
    Jim_InterpIncrProcEpoch(interp);
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * Command object
 * ---------------------------------------------------------------------------*/

static int SetCommandFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType commandObjType = {
    "command",
    NULL,
    NULL,
    NULL,
    JIM_TYPE_REFERENCES,
};

int SetCommandFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_HashEntry *he;
    const char *cmdName;

    /* Get the string representation */
    cmdName = Jim_GetString(objPtr, NULL);
    /* Lookup this name into the commands hash table */
    he = Jim_FindHashEntry(&interp->commands, cmdName);
    if (he == NULL)
        return JIM_ERR;

    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &commandObjType;
    objPtr->internalRep.cmdValue.procEpoch = interp->procEpoch;
    objPtr->internalRep.cmdValue.cmdPtr = (void*)he->val;
    return JIM_OK;
}

/* This function returns the command structure for the command name
 * stored in objPtr. It tries to specialize the objPtr to contain
 * a cached info instead to perform the lookup into the hash table
 * every time. The information cached may not be uptodate, in such
 * a case the lookup is performed and the cache updated. */
Jim_Cmd *Jim_GetCommand(Jim_Interp *interp, Jim_Obj *objPtr, int flags)
{
    if ((objPtr->typePtr != &commandObjType ||
        objPtr->internalRep.cmdValue.procEpoch != interp->procEpoch) &&
        SetCommandFromAny(interp, objPtr) == JIM_ERR) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "invalid command name \"", objPtr->bytes, "\"",
                NULL);
        }
        return NULL;
    }
    return objPtr->internalRep.cmdValue.cmdPtr;
}

/* -----------------------------------------------------------------------------
 * Variables
 * ---------------------------------------------------------------------------*/

/* Variables HashTable Type.
 *
 * Keys are dynamic allocated strings, Values are Jim_Var structures. */
static void JimVariablesHTValDestructor(void *interp, void *val)
{
    Jim_Var *varPtr = (void*) val;

    Jim_DecrRefCount(interp, varPtr->objPtr);
    Jim_Free(val);
}

static Jim_HashTableType JimVariablesHashTableType = {
    JimStringCopyHTHashFunction,        /* hash function */
    JimStringCopyHTKeyDup,              /* key dup */
    NULL,                               /* val dup */
    JimStringCopyHTKeyCompare,        /* key compare */
    JimStringCopyHTKeyDestructor,     /* key destructor */
    JimVariablesHTValDestructor       /* val destructor */
};

/* -----------------------------------------------------------------------------
 * Variable object
 * ---------------------------------------------------------------------------*/

#define JIM_DICT_SUGAR 100 /* Only returned by SetVariableFromAny() */

static int SetVariableFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType variableObjType = {
    "variable",
    NULL,
    NULL,
    NULL,
    JIM_TYPE_REFERENCES,
};

/* Return true if the string "str" looks like syntax sugar for [dict]. I.e.
 * is in the form "varname(key)". */
static int Jim_NameIsDictSugar(const char *str, int len)
{
    if (len == -1)
        len = strlen(str);
    if (len && str[len-1] == ')' && strchr(str, '(') != NULL)
        return 1;
    return 0;
}

/* This method should be called only by the variable API.
 * It returns JIM_OK on success (variable already exists),
 * JIM_ERR if it does not exists, JIM_DICT_GLUE if it's not
 * a variable name, but syntax glue for [dict] i.e. the last
 * character is ')' */
int SetVariableFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr)
{
    Jim_HashEntry *he;
    const char *varName;
    int len;

    /* Check if the object is already an uptodate variable */
    if (objPtr->typePtr == &variableObjType &&
        objPtr->internalRep.varValue.callFrameId == interp->framePtr->id)
        return JIM_OK; /* nothing to do */
    /* Get the string representation */
    varName = Jim_GetString(objPtr, &len);
    /* Make sure it's not syntax glue to get/set dict. */
    if (Jim_NameIsDictSugar(varName, len))
            return JIM_DICT_SUGAR;
    /* Lookup this name into the variables hash table */
    he = Jim_FindHashEntry(&interp->framePtr->vars, varName);
    if (he == NULL) {
        /* Try with static vars. */
        if (interp->framePtr->staticVars == NULL)
            return JIM_ERR;
        if (!(he = Jim_FindHashEntry(interp->framePtr->staticVars, varName)))
            return JIM_ERR;
    }
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &variableObjType;
    objPtr->internalRep.varValue.callFrameId = interp->framePtr->id;
    objPtr->internalRep.varValue.varPtr = (void*)he->val;
    return JIM_OK;
}

/* -------------------- Variables related functions ------------------------- */
static int JimDictSugarSet(Jim_Interp *interp, Jim_Obj *ObjPtr,
        Jim_Obj *valObjPtr);
static Jim_Obj *JimDictSugarGet(Jim_Interp *interp, Jim_Obj *ObjPtr);

/* For now that's dummy. Variables lookup should be optimized
 * in many ways, with caching of lookups, and possibly with
 * a table of pre-allocated vars in every CallFrame for local vars.
 * All the caching should also have an 'epoch' mechanism similar
 * to the one used by Tcl for procedures lookup caching. */

int Jim_SetVariable(Jim_Interp *interp, Jim_Obj *nameObjPtr, Jim_Obj *valObjPtr)
{
    const char *name;
    Jim_Var *var;
    int err;

    if ((err = SetVariableFromAny(interp, nameObjPtr)) != JIM_OK) {
        /* Check for [dict] syntax sugar. */
        if (err == JIM_DICT_SUGAR)
            return JimDictSugarSet(interp, nameObjPtr, valObjPtr);
        /* New variable to create */
        name = Jim_GetString(nameObjPtr, NULL);

        var = Jim_Alloc(sizeof(*var));
        var->objPtr = valObjPtr;
        Jim_IncrRefCount(valObjPtr);
        var->linkFramePtr = NULL;
        /* Insert the new variable */
        Jim_AddHashEntry(&interp->framePtr->vars, name, var);
        /* Make the object int rep a variable */
        Jim_FreeIntRep(interp, nameObjPtr);
        nameObjPtr->typePtr = &variableObjType;
        nameObjPtr->internalRep.varValue.callFrameId =
            interp->framePtr->id;
        nameObjPtr->internalRep.varValue.varPtr = var;
    } else {
        var = nameObjPtr->internalRep.varValue.varPtr;
        if (var->linkFramePtr == NULL) {
            Jim_IncrRefCount(valObjPtr);
            Jim_DecrRefCount(interp, var->objPtr);
            var->objPtr = valObjPtr;
        } else { /* Else handle the link */
            Jim_CallFrame *savedCallFrame;

            savedCallFrame = interp->framePtr;
            interp->framePtr = var->linkFramePtr;
            err = Jim_SetVariable(interp, var->objPtr, valObjPtr);
            interp->framePtr = savedCallFrame;
            if (err != JIM_OK)
                return err;
        }
    }
    return JIM_OK;
}

int Jim_SetVariableStr(Jim_Interp *interp, const char *name, Jim_Obj *objPtr)
{
    Jim_Obj *nameObjPtr;
    int result;

    nameObjPtr = Jim_NewStringObj(interp, name, -1);
    Jim_IncrRefCount(nameObjPtr);
    result = Jim_SetVariable(interp, nameObjPtr, objPtr);
    Jim_DecrRefCount(interp, nameObjPtr);
    return result;
}

int Jim_SetGlobalVariableStr(Jim_Interp *interp, const char *name, Jim_Obj *objPtr)
{
    Jim_CallFrame *savedFramePtr;
    int result;

    savedFramePtr = interp->framePtr;
    interp->framePtr = interp->topFramePtr;
    result = Jim_SetVariableStr(interp, name, objPtr);
    interp->framePtr = savedFramePtr;
    return result;
}

int Jim_SetVariableStrWithStr(Jim_Interp *interp, const char *name, const char *val)
{
    Jim_Obj *nameObjPtr, *valObjPtr;
    int result;

    nameObjPtr = Jim_NewStringObj(interp, name, -1);
    valObjPtr = Jim_NewStringObj(interp, val, -1);
    Jim_IncrRefCount(nameObjPtr);
    Jim_IncrRefCount(valObjPtr);
    result = Jim_SetVariable(interp, nameObjPtr, valObjPtr);
    Jim_DecrRefCount(interp, nameObjPtr);
    Jim_DecrRefCount(interp, valObjPtr);
    return result;
}

int Jim_SetVariableLink(Jim_Interp *interp, Jim_Obj *nameObjPtr,
        Jim_Obj *targetNameObjPtr, Jim_CallFrame *targetCallFrame)
{
    const char *varName;
    int len;

    /* Check for cycles. */
    if (interp->framePtr == targetCallFrame) {
        Jim_Obj *objPtr = targetNameObjPtr;
        Jim_Var *varPtr;
        /* Cycles are only possible with 'uplevel 0' */
        while(1) {
            if (Jim_StringEqObj(objPtr, nameObjPtr, 0)) {
                Jim_SetResultString(interp,
                    "can't upvar from variable to itself", -1);
                return JIM_ERR;
            }
            if (SetVariableFromAny(interp, objPtr) != JIM_OK)
                break;
            varPtr = objPtr->internalRep.varValue.varPtr;
            if (varPtr->linkFramePtr != targetCallFrame) break;
            objPtr = varPtr->objPtr;
        }
    }
    varName = Jim_GetString(nameObjPtr, &len);
    if (Jim_NameIsDictSugar(varName, len)) {
        Jim_SetResultString(interp,
            "Dict key syntax invalid as link source", -1);
        return JIM_ERR;
    }
    /* Perform the binding */
    Jim_SetVariable(interp, nameObjPtr, targetNameObjPtr);
    /* We are now sure 'nameObjPtr' type is variableObjType */
    nameObjPtr->internalRep.varValue.varPtr->linkFramePtr = targetCallFrame;
    return JIM_OK;
}

/* Return the Jim_Obj pointer associated with a variable name,
 * or NULL if the variable was not found in the current context.
 * The same optimization discussed in the comment to the
 * 'SetVariable' function should apply here. */
Jim_Obj *Jim_GetVariable(Jim_Interp *interp, Jim_Obj *nameObjPtr, int flags)
{
    int err;

    /* All the rest is handled here */
    if ((err = SetVariableFromAny(interp, nameObjPtr)) != JIM_OK) {
        /* Check for [dict] syntax sugar. */
        if (err == JIM_DICT_SUGAR)
            return JimDictSugarGet(interp, nameObjPtr);
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "can't read \"", nameObjPtr->bytes,
                "\": no such variable", NULL);
        }
        return NULL;
    } else {
        Jim_Var *varPtr;
        Jim_Obj *objPtr;
        Jim_CallFrame *savedCallFrame;

        varPtr = nameObjPtr->internalRep.varValue.varPtr;
        if (varPtr->linkFramePtr == NULL)
            return varPtr->objPtr;
        /* The variable is a link? Resolve it. */
        savedCallFrame = interp->framePtr;
        interp->framePtr = varPtr->linkFramePtr;
        objPtr = Jim_GetVariable(interp, varPtr->objPtr, JIM_NONE);
        if (objPtr == NULL && flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "can't read \"", nameObjPtr->bytes,
                "\": no such variable", NULL);
        }
        interp->framePtr = savedCallFrame;
        return objPtr;
    }
}

Jim_Obj *Jim_GetGlobalVariable(Jim_Interp *interp, Jim_Obj *nameObjPtr,
        int flags)
{
    Jim_CallFrame *savedFramePtr;
    Jim_Obj *objPtr;

    savedFramePtr = interp->framePtr;
    interp->framePtr = interp->topFramePtr;
    objPtr = Jim_GetVariable(interp, nameObjPtr, flags);
    interp->framePtr = savedFramePtr;

    return objPtr;
}

Jim_Obj *Jim_GetVariableStr(Jim_Interp *interp, const char *name, int flags)
{
    Jim_Obj *nameObjPtr, *varObjPtr;

    nameObjPtr = Jim_NewStringObj(interp, name, -1);
    Jim_IncrRefCount(nameObjPtr);
    varObjPtr = Jim_GetVariable(interp, nameObjPtr, flags);
    Jim_DecrRefCount(interp, nameObjPtr);
    return varObjPtr;
}

Jim_Obj *Jim_GetGlobalVariableStr(Jim_Interp *interp, const char *name,
        int flags)
{
    Jim_CallFrame *savedFramePtr;
    Jim_Obj *objPtr;

    savedFramePtr = interp->framePtr;
    interp->framePtr = interp->topFramePtr;
    objPtr = Jim_GetVariableStr(interp, name, flags);
    interp->framePtr = savedFramePtr;

    return objPtr;
}

/* Unset a variable.
 * Note: On success unset invalidates all the variable objects created
 * in the current call frame incrementing. */
int Jim_UnsetVariable(Jim_Interp *interp, Jim_Obj *nameObjPtr, int flags)
{
    const char *name;
    Jim_Var *varPtr;
    int err;
    
    if ((err = SetVariableFromAny(interp, nameObjPtr)) != JIM_OK) {
        /* Check for [dict] syntax sugar. */
        if (err == JIM_DICT_SUGAR)
            return JimDictSugarSet(interp, nameObjPtr, NULL);
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "can't unset \"", nameObjPtr->bytes,
            "\": no such variable", NULL);
        return JIM_ERR; /* var not found */
    }
    varPtr = nameObjPtr->internalRep.varValue.varPtr;
    /* If it's a link call UnsetVariable recursively */
    if (varPtr->linkFramePtr) {
        int retval;

        Jim_CallFrame *savedCallFrame;

        savedCallFrame = interp->framePtr;
        interp->framePtr = varPtr->linkFramePtr;
        retval = Jim_UnsetVariable(interp, varPtr->objPtr, JIM_NONE);
        interp->framePtr = savedCallFrame;
        if (retval != JIM_OK && flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "can't unset \"", nameObjPtr->bytes,
                "\": no such variable", NULL);
        }
        return retval;
    } else {
        name = Jim_GetString(nameObjPtr, NULL);
        if (Jim_DeleteHashEntry(&interp->framePtr->vars, name)
                != JIM_OK) return JIM_ERR;
        /* Change the callframe id, invalidating var lookup caching */
        JimChangeCallFrameId(interp, interp->framePtr);
        return JIM_OK;
    }
}

/* ----------  Dict syntax sugar (similar to array Tcl syntax) -------------- */

/* Given a variable name for [dict] operation syntax sugar,
 * this function returns two objects, the first with the name
 * of the variable to set, and the second with the rispective key.
 * For example "foo(bar)" will return objects with string repr. of
 * "foo" and "bar".
 *
 * The returned objects have refcount = 1. The function can't fail. */
static void JimDictSugarParseVarKey(Jim_Interp *interp, Jim_Obj *objPtr,
        Jim_Obj **varPtrPtr, Jim_Obj **keyPtrPtr)
{
    const char *str, *p;
    char *t;
    int len, keyLen, nameLen;
    Jim_Obj *varObjPtr, *keyObjPtr;

    str = Jim_GetString(objPtr, &len);
    p = strchr(str, '(');
    p++;
    keyLen = len-((p-str)+1);
    nameLen = (p-str)-1;
    /* Create the objects with the variable name and key. */
    t = Jim_Alloc(nameLen+1);
    memcpy(t, str, nameLen);
    t[nameLen] = '\0';
    varObjPtr = Jim_NewStringObjNoAlloc(interp, t, nameLen);

    t = Jim_Alloc(keyLen+1);
    memcpy(t, p, keyLen);
    t[keyLen] = '\0';
    keyObjPtr = Jim_NewStringObjNoAlloc(interp, t, keyLen);

    Jim_IncrRefCount(varObjPtr);
    Jim_IncrRefCount(keyObjPtr);
    *varPtrPtr = varObjPtr;
    *keyPtrPtr = keyObjPtr;
}

/* Helper of Jim_SetVariable() to deal with dict-syntax variable names.
 * Also used by Jim_UnsetVariable() with valObjPtr = NULL. */
static int JimDictSugarSet(Jim_Interp *interp, Jim_Obj *objPtr,
        Jim_Obj *valObjPtr)
{
    Jim_Obj *varObjPtr, *keyObjPtr;
    int err = JIM_OK;

    JimDictSugarParseVarKey(interp, objPtr, &varObjPtr, &keyObjPtr);
    err = Jim_SetDictKeysVector(interp, varObjPtr, &keyObjPtr, 1,
            valObjPtr);
    Jim_DecrRefCount(interp, varObjPtr);
    Jim_DecrRefCount(interp, keyObjPtr);
    return err;
}

/* Helper of Jim_GetVariable() to deal with dict-syntax variable names */
static Jim_Obj *JimDictSugarGet(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_Obj *varObjPtr, *keyObjPtr, *dictObjPtr, *resObjPtr;

    JimDictSugarParseVarKey(interp, objPtr, &varObjPtr, &keyObjPtr);
    dictObjPtr = Jim_GetVariable(interp, varObjPtr, JIM_ERRMSG);
    if (!dictObjPtr) {
        resObjPtr = NULL;
        goto err;
    }
    if (Jim_DictKey(interp, dictObjPtr, keyObjPtr, &resObjPtr, JIM_ERRMSG)
            != JIM_OK) {
        resObjPtr = NULL;
    }
err:
    Jim_DecrRefCount(interp, varObjPtr);
    Jim_DecrRefCount(interp, keyObjPtr);
    return resObjPtr;
}

/* --------- $var(INDEX) substitution, using a specialized object ----------- */

static void FreeDictSubstInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupDictSubstInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr,
        Jim_Obj *dupPtr);

static Jim_ObjType dictSubstObjType = {
    "dict-substitution",
    FreeDictSubstInternalRep,
    DupDictSubstInternalRep,
    NULL,
    JIM_TYPE_NONE,
};

void FreeDictSubstInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_DecrRefCount(interp, objPtr->internalRep.dictSubstValue.varNameObjPtr);
    Jim_DecrRefCount(interp, objPtr->internalRep.dictSubstValue.indexObjPtr);
}

void DupDictSubstInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr,
        Jim_Obj *dupPtr)
{
    JIM_NOTUSED(interp);

    dupPtr->internalRep.dictSubstValue.varNameObjPtr =
        srcPtr->internalRep.dictSubstValue.varNameObjPtr;
    dupPtr->internalRep.dictSubstValue.indexObjPtr =
        srcPtr->internalRep.dictSubstValue.indexObjPtr;
    dupPtr->typePtr = &dictSubstObjType;
}

/* This function is used to expand [dict get] sugar in the form
 * of $var(INDEX). The function is mainly used by Jim_EvalObj()
 * to deal with tokens of type JIM_TT_DICTSUGAR. objPtr points to an
 * object that is *guaranteed* to be in the form VARNAME(INDEX).
 * The 'index' part is [subst]ituted, and is used to lookup a key inside
 * the [dict]ionary contained in variable VARNAME. */
Jim_Obj *Jim_ExpandDictSugar(Jim_Interp *interp, Jim_Obj *objPtr)
{
    Jim_Obj *varObjPtr, *keyObjPtr, *dictObjPtr, *resObjPtr;
    Jim_Obj *substKeyObjPtr = NULL;

    if (objPtr->typePtr != &dictSubstObjType) {
        JimDictSugarParseVarKey(interp, objPtr, &varObjPtr, &keyObjPtr);
        Jim_FreeIntRep(interp, objPtr);
        objPtr->typePtr = &dictSubstObjType;
        objPtr->internalRep.dictSubstValue.varNameObjPtr = varObjPtr;
        objPtr->internalRep.dictSubstValue.indexObjPtr = keyObjPtr;
    }
    if (Jim_SubstObj(interp, objPtr->internalRep.dictSubstValue.indexObjPtr,
                &substKeyObjPtr, JIM_NONE)
            != JIM_OK) {
        substKeyObjPtr = NULL;
        goto err;
    }
    Jim_IncrRefCount(substKeyObjPtr);
    dictObjPtr = Jim_GetVariable(interp,
            objPtr->internalRep.dictSubstValue.varNameObjPtr, JIM_ERRMSG);
    if (!dictObjPtr) {
        resObjPtr = NULL;
        goto err;
    }
    if (Jim_DictKey(interp, dictObjPtr, substKeyObjPtr, &resObjPtr, JIM_ERRMSG)
            != JIM_OK) {
        resObjPtr = NULL;
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "Variable '", Jim_GetString(varObjPtr, NULL),
                "' does not contain a valid dictionary", NULL);
        goto err;
    }
err:
    if (substKeyObjPtr) Jim_DecrRefCount(interp, substKeyObjPtr);
    return resObjPtr;
}

/* -----------------------------------------------------------------------------
 * CallFrame
 * ---------------------------------------------------------------------------*/

static Jim_CallFrame *JimCreateCallFrame(Jim_Interp *interp)
{
    Jim_CallFrame *cf;
    if (interp->freeFramesList) {
        cf = interp->freeFramesList;
        interp->freeFramesList = cf->nextFramePtr;
    } else {
        cf = Jim_Alloc(sizeof(*cf));
        cf->vars.table = NULL;
    }

    cf->id = interp->callFrameEpoch++;
    cf->parentCallFrame = NULL;
    cf->argv = NULL;
    cf->argc = 0;
    cf->procArgsObjPtr = NULL;
    cf->procBodyObjPtr = NULL;
    cf->nextFramePtr = NULL;
    cf->staticVars = NULL;
    if (cf->vars.table == NULL)
        Jim_InitHashTable(&cf->vars, &JimVariablesHashTableType, interp);
    return cf;
}

/* Used to invalidate every caching related to callframe stability. */
static void JimChangeCallFrameId(Jim_Interp *interp, Jim_CallFrame *cf)
{
    cf->id = interp->callFrameEpoch++;
}

#define JIM_FCF_NONE 0 /* no flags */
#define JIM_FCF_NOHT 1 /* don't free the hash table */
static void JimFreeCallFrame(Jim_Interp *interp, Jim_CallFrame *cf,
        int flags)
{
    if (cf->procArgsObjPtr) Jim_DecrRefCount(interp, cf->procArgsObjPtr);
    if (cf->procBodyObjPtr) Jim_DecrRefCount(interp, cf->procBodyObjPtr);
    if (!(flags & JIM_FCF_NOHT))
        Jim_FreeHashTable(&cf->vars);
    else {
        int i;
        Jim_HashEntry **table = cf->vars.table, *he;

        for (i = 0; i < JIM_HT_INITIAL_SIZE; i++) {
            he = table[i];
            while (he != NULL) {
                Jim_HashEntry *nextEntry = he->next;
                Jim_Var *varPtr = (void*) he->val;

                Jim_DecrRefCount(interp, varPtr->objPtr);
                Jim_Free(he->val);
                Jim_Free((void*)he->key); /* ATTENTION: const cast */
                Jim_Free(he);
                table[i] = NULL;
                he = nextEntry;
            }
        }
        cf->vars.used = 0;
    }
    cf->nextFramePtr = interp->freeFramesList;
    interp->freeFramesList = cf;
}

/* -----------------------------------------------------------------------------
 * References
 * ---------------------------------------------------------------------------*/

/* References HashTable Type.
 *
 * Keys are jim_wide integers, dynamically allocated for now but in the
 * future it's worth to cache this 8 bytes objects. Values are poitners
 * to Jim_References. */
static void JimReferencesHTValDestructor(void *interp, void *val)
{
    Jim_Reference *refPtr = (void*) val;

    Jim_DecrRefCount(interp, refPtr->objPtr);
    if (refPtr->finalizerCmdNamePtr != NULL) {
        Jim_DecrRefCount(interp, refPtr->finalizerCmdNamePtr);
    }
    Jim_Free(val);
}

unsigned int JimReferencesHTHashFunction(const void *key)
{
    /* Only the least significant bits are used. */
    const jim_wide *widePtr = key;
    unsigned int intValue = (unsigned int) *widePtr;
    return Jim_IntHashFunction(intValue);
}

unsigned int JimReferencesHTDoubleHashFunction(const void *key)
{
    /* Only the least significant bits are used. */
    const jim_wide *widePtr = key;
    unsigned int intValue = (unsigned int) *widePtr;
    return intValue; /* identity function. */
}

const void *JimReferencesHTKeyDup(void *privdata, const void *key)
{
    void *copy = Jim_Alloc(sizeof(jim_wide));
    JIM_NOTUSED(privdata);

    memcpy(copy, key, sizeof(jim_wide));
    return copy;
}

int JimReferencesHTKeyCompare(void *privdata, const void *key1, 
        const void *key2)
{
    JIM_NOTUSED(privdata);

    return memcmp(key1, key2, sizeof(jim_wide)) == 0;
}

void JimReferencesHTKeyDestructor(void *privdata, const void *key)
{
    JIM_NOTUSED(privdata);

    Jim_Free((void*)key);
}

static Jim_HashTableType JimReferencesHashTableType = {
    JimReferencesHTHashFunction,    /* hash function */
    JimReferencesHTKeyDup,          /* key dup */
    NULL,                           /* val dup */
    JimReferencesHTKeyCompare,      /* key compare */
    JimReferencesHTKeyDestructor,   /* key destructor */
    JimReferencesHTValDestructor    /* val destructor */
};

/* -----------------------------------------------------------------------------
 * Reference object type and References API
 * ---------------------------------------------------------------------------*/

static void UpdateStringOfReference(struct Jim_Obj *objPtr);

static Jim_ObjType referenceObjType = {
    "reference",
    NULL,
    NULL,
    UpdateStringOfReference,
    JIM_TYPE_REFERENCES,
};

void UpdateStringOfReference(struct Jim_Obj *objPtr)
{
    int len;
    char buf[JIM_REFERENCE_SPACE+1];
    Jim_Reference *refPtr;

    refPtr = objPtr->internalRep.refValue.refPtr;
    len = JimFormatReference(buf, refPtr, objPtr->internalRep.refValue.id);
    objPtr->bytes = Jim_Alloc(len+1);
    memcpy(objPtr->bytes, buf, len+1);
    objPtr->length = len;
}

/* returns true if 'c' is a valid reference tag character.
 * i.e. inside the range [_a-zA-Z0-9] */
static int isrefchar(int c)
{
    if (c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
        (c >= '0' && c <= '9')) return 1;
    return 0;
}

int SetReferenceFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    jim_wide wideValue;
    int i, len;
    const char *str, *start, *end;
    char refId[21];
    Jim_Reference *refPtr;
    Jim_HashEntry *he;

    /* Get the string representation */
    str = Jim_GetString(objPtr, &len);
    /* Check if it looks like a reference */
    if (len < JIM_REFERENCE_SPACE) goto badformat;
    /* Trim spaces */
    start = str;
    end = str+len-1;
    while (*start == ' ') start++;
    while (*end == ' ' && end > start) end--;
    if (end-start+1 != JIM_REFERENCE_SPACE) goto badformat;
    /* <reference.<1234567>.%020> */
    if (memcmp(start, "<reference.<", 12) != 0) goto badformat;
    if (start[12+JIM_REFERENCE_TAGLEN] != '>' || end[0] != '>') goto badformat;
    /* The tag can't contain chars other than a-zA-Z0-9 + '_'. */
    for (i = 0; i < JIM_REFERENCE_TAGLEN; i++) {
        if (!isrefchar(start[12+i])) goto badformat;
    }
    /* Extract info from the refernece. */
    memcpy(refId, start+14+JIM_REFERENCE_TAGLEN, 20);
    refId[20] = '\0';
    /* Try to convert the ID into a jim_wide */
    if (Jim_StringToWide(refId, &wideValue, 10) != JIM_OK) goto badformat;
    /* Check if the reference really exists! */
    he = Jim_FindHashEntry(&interp->references, &wideValue);
    if (he == NULL) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "Invalid reference ID \"", str, "\"", NULL);
        return JIM_ERR;
    }
    refPtr = he->val;
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &referenceObjType;
    objPtr->internalRep.refValue.id = wideValue;
    objPtr->internalRep.refValue.refPtr = refPtr;
    return JIM_OK;

badformat:
    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
    Jim_AppendStrings(interp, Jim_GetResult(interp),
            "expected reference but got \"", str, "\"", NULL);
    return JIM_ERR;
}

/* Returns a new reference pointing to objPtr, having cmdNamePtr
 * as finalizer command (or NULL if there is no finalizer).
 * The returned reference object has refcount = 0. */
Jim_Obj *Jim_NewReference(Jim_Interp *interp, Jim_Obj *objPtr, Jim_Obj *tagPtr,
        Jim_Obj *cmdNamePtr)
{
    struct Jim_Reference *refPtr;
    jim_wide wideValue = interp->referenceNextId;
    Jim_Obj *refObjPtr;
    const char *tag;
    int tagLen, i;

    /* Perform the Garbage Collection if needed. */
    Jim_CollectIfNeeded(interp);

    refPtr = Jim_Alloc(sizeof(*refPtr));
    refPtr->objPtr = objPtr;
    Jim_IncrRefCount(objPtr);
    refPtr->finalizerCmdNamePtr = cmdNamePtr;
    if (cmdNamePtr)
        Jim_IncrRefCount(cmdNamePtr);
    Jim_AddHashEntry(&interp->references, &wideValue, refPtr);
    refObjPtr = Jim_NewObj(interp);
    refObjPtr->typePtr = &referenceObjType;
    refObjPtr->bytes = NULL;
    refObjPtr->internalRep.refValue.id = interp->referenceNextId;
    refObjPtr->internalRep.refValue.refPtr = refPtr;
    interp->referenceNextId++;
    /* Set the tag. Trimmered at JIM_REFERENCE_TAGLEN. Everything
     * that does not pass the 'isrefchar' test is replaced with '_' */
    tag = Jim_GetString(tagPtr, &tagLen);
    if (tagLen > JIM_REFERENCE_TAGLEN)
        tagLen = JIM_REFERENCE_TAGLEN;
    for (i = 0; i < JIM_REFERENCE_TAGLEN; i++) {
        if (i < tagLen)
            refPtr->tag[i] = tag[i];
        else
            refPtr->tag[i] = '_';
    }
    refPtr->tag[JIM_REFERENCE_TAGLEN] = '\0';
    return refObjPtr;
}

Jim_Reference *Jim_GetReference(Jim_Interp *interp, Jim_Obj *objPtr)
{
    if (objPtr->typePtr != &referenceObjType &&
        SetReferenceFromAny(interp, objPtr) == JIM_ERR)
        return NULL;
    return objPtr->internalRep.refValue.refPtr;
}

int Jim_SetFinalizer(Jim_Interp *interp, Jim_Obj *objPtr, Jim_Obj *cmdNamePtr)
{
    Jim_Reference *refPtr;

    if ((refPtr = Jim_GetReference(interp, objPtr)) == NULL)
        return JIM_ERR;
    Jim_IncrRefCount(cmdNamePtr);
    if (refPtr->finalizerCmdNamePtr)
        Jim_DecrRefCount(interp, refPtr->finalizerCmdNamePtr);
    refPtr->finalizerCmdNamePtr = cmdNamePtr;
    return JIM_OK;
}

int Jim_GetFinalizer(Jim_Interp *interp, Jim_Obj *objPtr, Jim_Obj **cmdNamePtrPtr)
{
    Jim_Reference *refPtr;

    if ((refPtr = Jim_GetReference(interp, objPtr)) == NULL)
        return JIM_ERR;
    *cmdNamePtrPtr = refPtr->finalizerCmdNamePtr;
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * References Garbage Collection
 * ---------------------------------------------------------------------------*/

/* This the hash table type for the "MARK" phase of the GC */
static Jim_HashTableType JimRefMarkHashTableType = {
    JimReferencesHTHashFunction,    /* hash function */
    JimReferencesHTKeyDup,          /* key dup */
    NULL,                           /* val dup */
    JimReferencesHTKeyCompare,      /* key compare */
    JimReferencesHTKeyDestructor,   /* key destructor */
    NULL                            /* val destructor */
};

/* #define JIM_DEBUG_GC 1 */

/* Performs the garbage collection. */
int Jim_Collect(Jim_Interp *interp)
{
    Jim_HashTable marks;
    Jim_HashTableIterator *htiter;
    Jim_HashEntry *he;
    Jim_Obj *objPtr;
    int collected = 0;

    /* Avoid recursive calls */
    if (interp->lastCollectId == -1) {
        /* Jim_Collect() already running. Return just now. */
        return 0;
    }
    interp->lastCollectId = -1;

    /* Mark all the references found into the 'mark' hash table.
     * The references are searched in every live object that
     * is of a type that can contain references. */
    Jim_InitHashTable(&marks, &JimRefMarkHashTableType, NULL);
    objPtr = interp->liveList;
    while(objPtr) {
        if (objPtr->typePtr == NULL ||
            objPtr->typePtr->flags & JIM_TYPE_REFERENCES) {
            const char *str, *p;
            int len;

            /* If the object is of type reference, to get the
             * Id is simple... */
            if (objPtr->typePtr == &referenceObjType) {
                Jim_AddHashEntry(&marks,
                    &objPtr->internalRep.refValue.id, NULL);
#ifdef JIM_DEBUG_GC
                printf("MARK (reference): %d refcount: %d\n", 
                    (int) objPtr->internalRep.refValue.id,
                    objPtr->refCount);
#endif
                objPtr = objPtr->nextObjPtr;
                continue;
            }
            /* Get the string repr of the object we want
             * to scan for references. */
            p = str = Jim_GetString(objPtr, &len);
            /* Skip objects too little to contain references. */
            if (len < JIM_REFERENCE_SPACE) {
                objPtr = objPtr->nextObjPtr;
                continue;
            }
            /* Extract references from the object string repr. */
            while(1) {
                int i;
                jim_wide id;
                char buf[21];

                if ((p = strstr(p, "<reference.<")) == NULL)
                    break;
                /* Check if it's a valid reference. */
                if (len-(p-str) < JIM_REFERENCE_SPACE) break;
                if (p[41] != '>' || p[19] != '>' || p[20] != '.') break;
                for (i = 21; i <= 40; i++)
                    if (!isdigit((int)p[i]))
                        break;
                /* Get the ID */
                memcpy(buf, p+21, 20);
                buf[20] = '\0';
                Jim_StringToWide(buf, &id, 10);

                /* Ok, a reference for the given ID
                 * was found. Mark it. */
                Jim_AddHashEntry(&marks, &id, NULL);
#ifdef JIM_DEBUG_GC
                printf("MARK: %d\n", (int)id);
#endif
                p += JIM_REFERENCE_SPACE;
            }
        }
        objPtr = objPtr->nextObjPtr;
    }

    /* Run the references hash table to destroy every reference that
     * is not referenced outside (not present in the mark HT). */
    htiter = Jim_GetHashTableIterator(&interp->references);
    while ((he = Jim_NextHashEntry(htiter)) != NULL) {
        const jim_wide *refId;
        Jim_Reference *refPtr;

        refId = he->key;
        /* Check if in the mark phase we encountered
         * this reference. */
        if (Jim_FindHashEntry(&marks, refId) == NULL) {
#ifdef JIM_DEBUG_GC
            printf("COLLECTING %d\n", (int)*refId);
#endif
            collected++;
            /* Drop the reference, but call the
             * finalizer first if registered. */
            refPtr = he->val;
            if (refPtr->finalizerCmdNamePtr) {
                char *refstr = Jim_Alloc(JIM_REFERENCE_SPACE+1);
                Jim_Obj *objv[3], *oldResult;

                JimFormatReference(refstr, refPtr, *refId);

                objv[0] = refPtr->finalizerCmdNamePtr;
                objv[1] = Jim_NewStringObjNoAlloc(interp,
                        refstr, 32);
                objv[2] = refPtr->objPtr;
                Jim_IncrRefCount(objv[0]);
                Jim_IncrRefCount(objv[1]);
                Jim_IncrRefCount(objv[2]);

                /* Drop the reference itself */
                Jim_DeleteHashEntry(&interp->references, refId);

                /* Call the finalizer. Errors ignored. */
                oldResult = interp->result;
                Jim_IncrRefCount(oldResult);
                Jim_EvalObjVector(interp, 3, objv);
                Jim_SetResult(interp, oldResult);
                Jim_DecrRefCount(interp, oldResult);

                Jim_DecrRefCount(interp, objv[0]);
                Jim_DecrRefCount(interp, objv[1]);
                Jim_DecrRefCount(interp, objv[2]);
            } else {
                Jim_DeleteHashEntry(&interp->references, refId);
            }
        }
    }
    Jim_FreeHashTableIterator(htiter);
    Jim_FreeHashTable(&marks);
    interp->lastCollectId = interp->referenceNextId;
    interp->lastCollectTime = time(NULL);
    return collected;
}

#define JIM_COLLECT_ID_PERIOD 5000
#define JIM_COLLECT_TIME_PERIOD 300

void Jim_CollectIfNeeded(Jim_Interp *interp)
{
    jim_wide elapsedId;
    int elapsedTime;
    
    elapsedId = interp->referenceNextId - interp->lastCollectId;
    elapsedTime = time(NULL) - interp->lastCollectTime;


    if (elapsedId > JIM_COLLECT_ID_PERIOD ||
        elapsedTime > JIM_COLLECT_TIME_PERIOD) {
        Jim_Collect(interp);
    }
}

/* -----------------------------------------------------------------------------
 * Interpreter related functions
 * ---------------------------------------------------------------------------*/

Jim_Interp *Jim_CreateInterp(void)
{
    Jim_Interp *i = Jim_Alloc(sizeof(*i));
    Jim_Obj *pathPtr;

    i->errorLine = 0;
    i->errorFileName = Jim_StrDup("");
    i->numLevels = 0;
    i->maxNestingDepth = JIM_MAX_NESTING_DEPTH;
    i->returnCode = JIM_OK;
    i->procEpoch = 0;
    i->callFrameEpoch = 0;
    i->liveList = i->freeList = NULL;
    i->scriptFileName = Jim_StrDup("");
    i->referenceNextId = 0;
    i->lastCollectId = 0;
    i->lastCollectTime = time(NULL);
    i->freeFramesList = NULL;
    i->prngState = NULL;
    i->evalRetcodeLevel = -1;

    /* Note that we can create objects only after the
     * interpreter liveList and freeList pointers are
     * initialized to NULL. */
    Jim_InitHashTable(&i->commands, &JimCommandsHashTableType, i);
    Jim_InitHashTable(&i->references, &JimReferencesHashTableType, i);
    Jim_InitHashTable(&i->sharedStrings, &JimSharedStringsHashTableType,
            NULL);
    Jim_InitHashTable(&i->stub, &JimStringCopyHashTableType, NULL);
    Jim_InitHashTable(&i->assocData, &JimAssocDataHashTableType, i);
    Jim_InitHashTable(&i->packages, &JimStringKeyValCopyHashTableType, NULL);
    i->framePtr = i->topFramePtr = JimCreateCallFrame(i);
    i->emptyObj = Jim_NewEmptyStringObj(i);
    i->result = i->emptyObj;
    i->stackTrace = Jim_NewListObj(i, NULL, 0);
    i->unknown = Jim_NewStringObj(i, "unknown", -1);
    Jim_IncrRefCount(i->emptyObj);
    Jim_IncrRefCount(i->result);
    Jim_IncrRefCount(i->stackTrace);
    Jim_IncrRefCount(i->unknown);

    /* Initialize key variables every interpreter should contain */
    pathPtr = Jim_NewStringObj(i, "./", -1);
    Jim_SetVariableStr(i, "jim_libpath", pathPtr);
    Jim_SetVariableStrWithStr(i, "jim_interactive", "0");

    /* Export the core API to extensions */
    JimRegisterCoreApi(i);
    return i;
}

/* This is the only function Jim exports directly without
 * to use the STUB system. It is only used by embedders
 * in order to get an interpreter with the Jim API pointers
 * registered. */
Jim_Interp *ExportedJimCreateInterp(void)
{
    return Jim_CreateInterp();
}

void Jim_FreeInterp(Jim_Interp *i)
{
    Jim_CallFrame *cf = i->framePtr, *prevcf, *nextcf;
    Jim_Obj *objPtr, *nextObjPtr;

    Jim_DecrRefCount(i, i->emptyObj);
    Jim_DecrRefCount(i, i->result);
    Jim_DecrRefCount(i, i->stackTrace);
    Jim_DecrRefCount(i, i->unknown);
    Jim_Free((void*)i->errorFileName);
    Jim_Free((void*)i->scriptFileName);
    Jim_FreeHashTable(&i->commands);
    Jim_FreeHashTable(&i->references);
    Jim_FreeHashTable(&i->stub);
    Jim_FreeHashTable(&i->assocData);
    Jim_FreeHashTable(&i->packages);
    Jim_Free(i->prngState);
    /* Free the call frames list */
    while(cf) {
        prevcf = cf->parentCallFrame;
        JimFreeCallFrame(i, cf, JIM_FCF_NONE);
        cf = prevcf;
    }
    /* Check that the live object list is empty, otherwise
     * there is a memory leak. */
    if (i->liveList != NULL) {
        Jim_Obj *objPtr = i->liveList;
    
        printf("\n-------------------------------------\n");
        printf("Objects still in the free list:\n");
        while(objPtr) {
            const char *type = objPtr->typePtr ?
                objPtr->typePtr->name : "";
            printf("%p \"%-10s\": '%.20s' (refCount: %d)\n",
                    objPtr, type,
                    objPtr->bytes ? objPtr->bytes
                    : "(null)", objPtr->refCount);
            if (objPtr->typePtr == &sourceObjType) {
                printf("FILE %s LINE %d\n",
                objPtr->internalRep.sourceValue.fileName,
                objPtr->internalRep.sourceValue.lineNumber);
            }
            objPtr = objPtr->nextObjPtr;
        }
        printf("-------------------------------------\n\n");
        Jim_Panic("Live list non empty freeing the interpreter! Leak?");
    }
    /* Free all the freed objects. */
    objPtr = i->freeList;
    while (objPtr) {
        nextObjPtr = objPtr->nextObjPtr;
        Jim_Free(objPtr);
        objPtr = nextObjPtr;
    }
    /* Free cached CallFrame structures */
    cf = i->freeFramesList;
    while(cf) {
        nextcf = cf->nextFramePtr;
        if (cf->vars.table != NULL)
            Jim_Free(cf->vars.table);
        Jim_Free(cf);
        cf = nextcf;
    }
    /* Free the sharedString hash table. Make sure to free it
     * after every other Jim_Object was freed. */
    Jim_FreeHashTable(&i->sharedStrings);
    /* Free the interpreter structure. */
    Jim_Free(i);
}

/* Store the call frame relative to the level represented by
 * levelObjPtr into *framePtrPtr. If levelObjPtr == NULL, the
 * level is assumed to be '1'.
 *
 * If a newLevelptr int pointer is specified, the function stores
 * the absolute level integer value of the new target callframe into
 * *newLevelPtr. (this is used to adjust interp->numLevels
 * in the implementation of [uplevel], so that [info level] will
 * return a correct information).
 *
 * This function accepts the 'level' argument in the form
 * of the commands [uplevel] and [upvar].
 *
 * For a function accepting a relative integer as level suitable
 * for implementation of [info level ?level?] check the
 * GetCallFrameByInteger() function. */
int Jim_GetCallFrameByLevel(Jim_Interp *interp, Jim_Obj *levelObjPtr,
        Jim_CallFrame **framePtrPtr, int *newLevelPtr)
{
    long level;
    const char *str;
    Jim_CallFrame *framePtr;

    if (newLevelPtr) *newLevelPtr = interp->numLevels;
    if (levelObjPtr) {
        str = Jim_GetString(levelObjPtr, NULL);
        if (str[0] == '#') {
            char *endptr;
            /* speedup for the toplevel (level #0) */
            if (str[1] == '0' && str[2] == '\0') {
                if (newLevelPtr) *newLevelPtr = 0;
                *framePtrPtr = interp->topFramePtr;
                return JIM_OK;
            }

            level = strtol(str+1, &endptr, 0);
            if (str[1] == '\0' || endptr[0] != '\0' || level < 0)
                goto badlevel;
            /* An 'absolute' level is converted into the
             * 'number of levels to go back' format. */
            level = interp->numLevels - level;
            if (level < 0) goto badlevel;
        } else {
            if (Jim_GetLong(interp, levelObjPtr, &level) != JIM_OK || level < 0)
                goto badlevel;
        }
    } else {
        str = "1"; /* Needed to format the error message. */
        level = 1;
    }
    /* Lookup */
    framePtr = interp->framePtr;
    if (newLevelPtr) *newLevelPtr = (*newLevelPtr)-level;
    while (level--) {
        framePtr = framePtr->parentCallFrame;
        if (framePtr == NULL) goto badlevel;
    }
    *framePtrPtr = framePtr;
    return JIM_OK;
badlevel:
    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
    Jim_AppendStrings(interp, Jim_GetResult(interp),
            "bad level \"", str, "\"", NULL);
    return JIM_ERR;
}

/* Similar to Jim_GetCallFrameByLevel() but the level is specified
 * as a relative integer like in the [info level ?level?] command. */
static int JimGetCallFrameByInteger(Jim_Interp *interp, Jim_Obj *levelObjPtr,
        Jim_CallFrame **framePtrPtr)
{
    jim_wide level;
    jim_wide relLevel; /* level relative to the current one. */
    Jim_CallFrame *framePtr;

    if (Jim_GetWide(interp, levelObjPtr, &level) != JIM_OK)
        goto badlevel;
    if (level > 0) {
        /* An 'absolute' level is converted into the
         * 'number of levels to go back' format. */
        relLevel = interp->numLevels - level;
    } else {
        relLevel = -level;
    }
    /* Lookup */
    framePtr = interp->framePtr;
    while (relLevel--) {
        framePtr = framePtr->parentCallFrame;
        if (framePtr == NULL) goto badlevel;
    }
    *framePtrPtr = framePtr;
    return JIM_OK;
badlevel:
    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
    Jim_AppendStrings(interp, Jim_GetResult(interp),
            "bad level \"", Jim_GetString(levelObjPtr, NULL), "\"", NULL);
    return JIM_ERR;
}

static void JimSetErrorFileName(Jim_Interp *interp, char *filename)
{
    Jim_Free((void*)interp->errorFileName);
    interp->errorFileName = Jim_StrDup(filename);
}

static void JimSetErrorLineNumber(Jim_Interp *interp, int linenr)
{
    interp->errorLine = linenr;
}

static void JimResetStackTrace(Jim_Interp *interp)
{
    Jim_DecrRefCount(interp, interp->stackTrace);
    interp->stackTrace = Jim_NewListObj(interp, NULL, 0);
    Jim_IncrRefCount(interp->stackTrace);
}

static void JimAppendStackTrace(Jim_Interp *interp, const char *procname,
        const char *filename, int linenr)
{
    if (Jim_IsShared(interp->stackTrace)) {
        interp->stackTrace =
            Jim_DuplicateObj(interp, interp->stackTrace);
        Jim_IncrRefCount(interp->stackTrace);
    }
    Jim_ListAppendElement(interp, interp->stackTrace,
            Jim_NewStringObj(interp, procname, -1));
    Jim_ListAppendElement(interp, interp->stackTrace,
            Jim_NewStringObj(interp, filename, -1));
    Jim_ListAppendElement(interp, interp->stackTrace,
            Jim_NewIntObj(interp, linenr));
}

int Jim_SetAssocData(Jim_Interp *interp, const char *key, Jim_InterpDeleteProc *delProc, void *data)
{
    AssocDataValue *assocEntryPtr = (AssocDataValue *)Jim_Alloc(sizeof(AssocDataValue));
    assocEntryPtr->delProc = delProc;
    assocEntryPtr->data = data;
    return Jim_AddHashEntry(&interp->assocData, key, assocEntryPtr);
}

void *Jim_GetAssocData(Jim_Interp *interp, const char *key)
{
    Jim_HashEntry *entryPtr = Jim_FindHashEntry(&interp->assocData, key);
    if (entryPtr != NULL) {
        AssocDataValue *assocEntryPtr = (AssocDataValue *)entryPtr->val;
        return assocEntryPtr->data;
    }
    return NULL;
}

int Jim_DeleteAssocData(Jim_Interp *interp, const char *key)
{
    return Jim_DeleteHashEntry(&interp->assocData, key);
}

/* -----------------------------------------------------------------------------
 * Shared strings.
 * Every interpreter has an hash table where to put shared dynamically
 * allocate strings that are likely to be used a lot of times.
 * For example, in the 'source' object type, there is a pointer to
 * the filename associated with that object. Every script has a lot
 * of this objects with the identical file name, so it is wise to share
 * this info.
 *
 * The API is trivial: Jim_GetSharedString(interp, "foobar")
 * returns the pointer to the shared string. Every time a reference
 * to the string is no longer used, the user should call
 * Jim_ReleaseSharedString(interp, stringPointer). Once no one is using
 * a given string, it is removed from the hash table.
 * ---------------------------------------------------------------------------*/
const char *Jim_GetSharedString(Jim_Interp *interp, const char *str)
{
    Jim_HashEntry *he = Jim_FindHashEntry(&interp->sharedStrings, str);

    if (he == NULL) {
        char *strCopy = Jim_StrDup(str);

        Jim_AddHashEntry(&interp->sharedStrings, strCopy, (void*)1);
        return strCopy;
    } else {
        long refCount = (long) he->val;

        refCount++;
        he->val = (void*) refCount;
        return he->key;
    }
}

void Jim_ReleaseSharedString(Jim_Interp *interp, const char *str)
{
    long refCount;
    Jim_HashEntry *he = Jim_FindHashEntry(&interp->sharedStrings, str);

    if (he == NULL)
        Jim_Panic("Jim_ReleaseSharedString called with "
              "unknown shared string '%s'", str);
    refCount = (long) he->val;
    refCount--;
    if (refCount == 0) {
        Jim_DeleteHashEntry(&interp->sharedStrings, str);
    } else {
        he->val = (void*) refCount;
    }
}

/* -----------------------------------------------------------------------------
 * Integer object
 * ---------------------------------------------------------------------------*/
#define JIM_INTEGER_SPACE 24

static void UpdateStringOfInt(struct Jim_Obj *objPtr);
static int SetIntFromAny(Jim_Interp *interp, Jim_Obj *objPtr, int flags);

static Jim_ObjType intObjType = {
    "int",
    NULL,
    NULL,
    UpdateStringOfInt,
    JIM_TYPE_NONE,
};

void UpdateStringOfInt(struct Jim_Obj *objPtr)
{
    int len;
    char buf[JIM_INTEGER_SPACE+1];

    len = Jim_WideToString(buf, objPtr->internalRep.wideValue);
    objPtr->bytes = Jim_Alloc(len+1);
    memcpy(objPtr->bytes, buf, len+1);
    objPtr->length = len;
}

int SetIntFromAny(Jim_Interp *interp, Jim_Obj *objPtr, int flags)
{
    jim_wide wideValue;
    const char *str;

    /* Get the string representation */
    str = Jim_GetString(objPtr, NULL);
    /* Try to convert into a jim_wide */
    if (Jim_StringToWide(str, &wideValue, 0) != JIM_OK) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "expected integer but got \"", str, "\"", NULL);
        }
        return JIM_ERR;
    }
    if ((wideValue == JIM_WIDE_MIN || wideValue == JIM_WIDE_MAX) &&
        errno == ERANGE) {
        Jim_SetResultString(interp,
            "Integer value too big to be represented", -1);
        return JIM_ERR;
    }
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &intObjType;
    objPtr->internalRep.wideValue = wideValue;
    return JIM_OK;
}

int Jim_GetWide(Jim_Interp *interp, Jim_Obj *objPtr, jim_wide *widePtr)
{
    if (objPtr->typePtr != &intObjType &&
        SetIntFromAny(interp, objPtr, JIM_ERRMSG) == JIM_ERR)
        return JIM_ERR;
    *widePtr = objPtr->internalRep.wideValue;
    return JIM_OK;
}

/* Get a wide but does not set an error if the format is bad. */
static int JimGetWideNoErr(Jim_Interp *interp, Jim_Obj *objPtr,
        jim_wide *widePtr)
{
    if (objPtr->typePtr != &intObjType &&
        SetIntFromAny(interp, objPtr, JIM_NONE) == JIM_ERR)
        return JIM_ERR;
    *widePtr = objPtr->internalRep.wideValue;
    return JIM_OK;
}

int Jim_GetLong(Jim_Interp *interp, Jim_Obj *objPtr, long *longPtr)
{
    jim_wide wideValue;
    int retval;

    retval = Jim_GetWide(interp, objPtr, &wideValue);
    if (retval == JIM_OK) {
        *longPtr = (long) wideValue;
        return JIM_OK;
    }
    return JIM_ERR;
}

void Jim_SetWide(Jim_Interp *interp, Jim_Obj *objPtr, jim_wide wideValue)
{
    if (Jim_IsShared(objPtr))
        Jim_Panic("Jim_SetWide called with shared object");
    if (objPtr->typePtr != &intObjType) {
        Jim_FreeIntRep(interp, objPtr);
        objPtr->typePtr = &intObjType;
    }
    Jim_InvalidateStringRep(objPtr);
    objPtr->internalRep.wideValue = wideValue;
}

Jim_Obj *Jim_NewIntObj(Jim_Interp *interp, jim_wide wideValue)
{
    Jim_Obj *objPtr;

    objPtr = Jim_NewObj(interp);
    objPtr->typePtr = &intObjType;
    objPtr->bytes = NULL;
    objPtr->internalRep.wideValue = wideValue;
    return objPtr;
}

/* -----------------------------------------------------------------------------
 * Double object
 * ---------------------------------------------------------------------------*/
#define JIM_DOUBLE_SPACE 30

static void UpdateStringOfDouble(struct Jim_Obj *objPtr);
static int SetDoubleFromAny(Jim_Interp *interp, Jim_Obj *objPtr);

static Jim_ObjType doubleObjType = {
    "double",
    NULL,
    NULL,
    UpdateStringOfDouble,
    JIM_TYPE_NONE,
};

void UpdateStringOfDouble(struct Jim_Obj *objPtr)
{
    int len;
    char buf[JIM_DOUBLE_SPACE+1];

    len = Jim_DoubleToString(buf, objPtr->internalRep.doubleValue);
    objPtr->bytes = Jim_Alloc(len+1);
    memcpy(objPtr->bytes, buf, len+1);
    objPtr->length = len;
}

int SetDoubleFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    double doubleValue;
    const char *str;

    /* Get the string representation */
    str = Jim_GetString(objPtr, NULL);
    /* Try to convert into a double */
    if (Jim_StringToDouble(str, &doubleValue) != JIM_OK) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "expected number but got '", str, "'", NULL);
        return JIM_ERR;
    }
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &doubleObjType;
    objPtr->internalRep.doubleValue = doubleValue;
    return JIM_OK;
}

int Jim_GetDouble(Jim_Interp *interp, Jim_Obj *objPtr, double *doublePtr)
{
    if (objPtr->typePtr != &doubleObjType &&
        SetDoubleFromAny(interp, objPtr) == JIM_ERR)
        return JIM_ERR;
    *doublePtr = objPtr->internalRep.doubleValue;
    return JIM_OK;
}

void Jim_SetDouble(Jim_Interp *interp, Jim_Obj *objPtr, double doubleValue)
{
    if (Jim_IsShared(objPtr))
        Jim_Panic("Jim_SetDouble called with shared object");
    if (objPtr->typePtr != &doubleObjType) {
        Jim_FreeIntRep(interp, objPtr);
        objPtr->typePtr = &doubleObjType;
    }
    Jim_InvalidateStringRep(objPtr);
    objPtr->internalRep.doubleValue = doubleValue;
}

Jim_Obj *Jim_NewDoubleObj(Jim_Interp *interp, double doubleValue)
{
    Jim_Obj *objPtr;

    objPtr = Jim_NewObj(interp);
    objPtr->typePtr = &doubleObjType;
    objPtr->bytes = NULL;
    objPtr->internalRep.doubleValue = doubleValue;
    return objPtr;
}

/* -----------------------------------------------------------------------------
 * List object
 * ---------------------------------------------------------------------------*/
static void ListAppendElement(Jim_Obj *listPtr, Jim_Obj *objPtr);
static void FreeListInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupListInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static void UpdateStringOfList(struct Jim_Obj *objPtr);
static int SetListFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

/* Note that while the elements of the list may contain references,
 * the list object itself can't. This basically means that the
 * list object string representation as a whole can't contain references
 * that are not presents in the single elements. */
static Jim_ObjType listObjType = {
    "list",
    FreeListInternalRep,
    DupListInternalRep,
    UpdateStringOfList,
    JIM_TYPE_NONE,
};

void FreeListInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    int i;

    for (i = 0; i < objPtr->internalRep.listValue.len; i++) {
        Jim_DecrRefCount(interp, objPtr->internalRep.listValue.ele[i]);
    }
    Jim_Free(objPtr->internalRep.listValue.ele);
}

void DupListInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    int i;
    JIM_NOTUSED(interp);

    dupPtr->internalRep.listValue.len = srcPtr->internalRep.listValue.len;
    dupPtr->internalRep.listValue.maxLen = srcPtr->internalRep.listValue.maxLen;
    dupPtr->internalRep.listValue.ele =
        Jim_Alloc(sizeof(Jim_Obj*)*srcPtr->internalRep.listValue.maxLen);
    memcpy(dupPtr->internalRep.listValue.ele, srcPtr->internalRep.listValue.ele,
            sizeof(Jim_Obj*)*srcPtr->internalRep.listValue.len);
    for (i = 0; i < dupPtr->internalRep.listValue.len; i++) {
        Jim_IncrRefCount(dupPtr->internalRep.listValue.ele[i]);
    }
    dupPtr->typePtr = &listObjType;
}

/* The following function checks if a given string can be encoded
 * into a list element without any kind of quoting, surrounded by braces,
 * or using escapes to quote. */
#define JIM_ELESTR_SIMPLE 0
#define JIM_ELESTR_BRACE 1
#define JIM_ELESTR_QUOTE 2
static int ListElementQuotingType(const char *s, int len)
{
    int i, level, trySimple = 1;

    /* Try with the SIMPLE case */
    if (len == 0) return JIM_ELESTR_BRACE;
    if (s[0] == '"' || s[0] == '{') {
        trySimple = 0;
        goto testbrace;
    }
    for (i = 0; i < len; i++) {
        switch(s[i]) {
        case ' ':
        case '$':
        case '"':
        case '[':
        case ']':
        case ';':
        case '\\':
        case '\r':
        case '\n':
        case '\t':
        case '\f':
        case '\v':
            trySimple = 0;
        case '{':
        case '}':
            goto testbrace;
        }
    }
    return JIM_ELESTR_SIMPLE;

testbrace:
    /* Test if it's possible to do with braces */
    if (s[len-1] == '\\' ||
        s[len-1] == ']') return JIM_ELESTR_QUOTE;
    level = 0;
    for (i = 0; i < len; i++) {
        switch(s[i]) {
        case '{': level++; break;
        case '}': level--;
              if (level < 0) return JIM_ELESTR_QUOTE;
              break;
        case '\\':
              if (s[i+1] == '\n')
                  return JIM_ELESTR_QUOTE;
              else
                  if (s[i+1] != '\0') i++;
              break;
        }
    }
    if (level == 0) {
        if (!trySimple) return JIM_ELESTR_BRACE;
        for (i = 0; i < len; i++) {
            switch(s[i]) {
            case ' ':
            case '$':
            case '"':
            case '[':
            case ']':
            case ';':
            case '\\':
            case '\r':
            case '\n':
            case '\t':
            case '\f':
            case '\v':
                return JIM_ELESTR_BRACE;
                break;
            }
        }
        return JIM_ELESTR_SIMPLE;
    }
    return JIM_ELESTR_QUOTE;
}

/* Returns the malloc-ed representation of a string
 * using backslash to quote special chars. */
char *BackslashQuoteString(const char *s, int len, int *qlenPtr)
{
    char *q = Jim_Alloc(len*2+1), *p;

    p = q;
    while(*s) {
        switch (*s) {
        case ' ':
        case '$':
        case '"':
        case '[':
        case ']':
        case '{':
        case '}':
        case ';':
        case '\\':
            *p++ = '\\';
            *p++ = *s++;
            break;
        case '\n': *p++ = '\\'; *p++ = 'n'; s++; break;
        case '\r': *p++ = '\\'; *p++ = 'r'; s++; break;
        case '\t': *p++ = '\\'; *p++ = 't'; s++; break;
        case '\f': *p++ = '\\'; *p++ = 'f'; s++; break;
        case '\v': *p++ = '\\'; *p++ = 'v'; s++; break;
        default:
            *p++ = *s++;
            break;
        }
    }
    *p = '\0';
    *qlenPtr = p-q;
    return q;
}

void UpdateStringOfList(struct Jim_Obj *objPtr)
{
    int i, bufLen, realLength;
    const char *strRep;
    char *p;
    int *quotingType;
    Jim_Obj **ele = objPtr->internalRep.listValue.ele;

    /* (Over) Estimate the space needed. */
    quotingType = Jim_Alloc(sizeof(int)*objPtr->internalRep.listValue.len+1);
    bufLen = 0;
    for (i = 0; i < objPtr->internalRep.listValue.len; i++) {
        int len;

        strRep = Jim_GetString(ele[i], &len);
        quotingType[i] = ListElementQuotingType(strRep, len);
        switch (quotingType[i]) {
        case JIM_ELESTR_SIMPLE: bufLen += len; break;
        case JIM_ELESTR_BRACE: bufLen += len+2; break;
        case JIM_ELESTR_QUOTE: bufLen += len*2; break;
        }
        bufLen++; /* elements separator. */
    }
    bufLen++;

    /* Generate the string rep. */
    p = objPtr->bytes = Jim_Alloc(bufLen+1);
    realLength = 0;
    for (i = 0; i < objPtr->internalRep.listValue.len; i++) {
        int len, qlen;
        const char *strRep = Jim_GetString(ele[i], &len);
        char *q;

        switch(quotingType[i]) {
        case JIM_ELESTR_SIMPLE:
            memcpy(p, strRep, len);
            p += len;
            realLength += len;
            break;
        case JIM_ELESTR_BRACE:
            *p++ = '{';
            memcpy(p, strRep, len);
            p += len;
            *p++ = '}';
            realLength += len+2;
            break;
        case JIM_ELESTR_QUOTE:
            q = BackslashQuoteString(strRep, len, &qlen);
            memcpy(p, q, qlen);
            Jim_Free(q);
            p += qlen;
            realLength += qlen;
            break;
        }
        /* Add a separating space */
        if (i+1 != objPtr->internalRep.listValue.len) {
            *p++ = ' ';
            realLength ++;
        }
    }
    *p = '\0'; /* nul term. */
    objPtr->length = realLength;
    Jim_Free(quotingType);
}

int SetListFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr)
{
    struct JimParserCtx parser;
    const char *str;
    int strLen;

    /* Get the string representation */
    str = Jim_GetString(objPtr, &strLen);

    /* Free the old internal repr just now and initialize the
     * new one just now. The string->list conversion can't fail. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &listObjType;
    objPtr->internalRep.listValue.len = 0;
    objPtr->internalRep.listValue.maxLen = 0;
    objPtr->internalRep.listValue.ele = NULL;

    /* Convert into a list */
    JimParserInit(&parser, str, strLen, 1);
    while(!JimParserEof(&parser)) {
        char *token;
        int tokenLen, type;
        Jim_Obj *elementPtr;

        JimParseList(&parser);
        if (JimParserTtype(&parser) != JIM_TT_STR &&
            JimParserTtype(&parser) != JIM_TT_ESC)
            continue;
        token = JimParserGetToken(&parser, &tokenLen, &type, NULL);
        elementPtr = Jim_NewStringObjNoAlloc(interp, token, tokenLen);
        ListAppendElement(objPtr, elementPtr);
    }
    return JIM_OK;
}

Jim_Obj *Jim_NewListObj(Jim_Interp *interp, Jim_Obj *const *elements, 
        int len)
{
    Jim_Obj *objPtr;
    int i;

    objPtr = Jim_NewObj(interp);
    objPtr->typePtr = &listObjType;
    objPtr->bytes = NULL;
    objPtr->internalRep.listValue.ele = NULL;
    objPtr->internalRep.listValue.len = 0;
    objPtr->internalRep.listValue.maxLen = 0;
    for (i = 0; i < len; i++) {
        ListAppendElement(objPtr, elements[i]);
    }
    return objPtr;
}

/* Return a vector of Jim_Obj with the elements of a Jim list, and the
 * length of the vector. Note that the user of this function should make
 * sure that the list object can't shimmer while the vector returned
 * is in use, this vector is the one stored inside the internal representation
 * of the list object. This function is not exported, extensions should
 * always access to the List object elements using Jim_ListIndex(). */
static void JimListGetElements(Jim_Interp *interp, Jim_Obj *listObj, int *argc,
        Jim_Obj ***listVec)
{
    Jim_ListLength(interp, listObj, argc);
    assert(listObj->typePtr == &listObjType);
    *listVec = listObj->internalRep.listValue.ele;
}

/* ListSortElements type values */
enum {JIM_LSORT_ASCII, JIM_LSORT_NOCASE, JIM_LSORT_ASCII_DECR,
      JIM_LSORT_NOCASE_DECR};

/* Sort the internal rep of a list. */
static int ListSortString(Jim_Obj **lhsObj, Jim_Obj **rhsObj)
{
    return Jim_StringCompareObj(*lhsObj, *rhsObj, 0);
}

static int ListSortStringDecr(Jim_Obj **lhsObj, Jim_Obj **rhsObj)
{
    return Jim_StringCompareObj(*lhsObj, *rhsObj, 0) * -1;
}

static int ListSortStringNoCase(Jim_Obj **lhsObj, Jim_Obj **rhsObj)
{
    return Jim_StringCompareObj(*lhsObj, *rhsObj, 1);
}

static int ListSortStringNoCaseDecr(Jim_Obj **lhsObj, Jim_Obj **rhsObj)
{
    return Jim_StringCompareObj(*lhsObj, *rhsObj, 1) * -1;
}

/* Sort a list *in place*. MUST be called with non-shared objects. */
static void ListSortElements(Jim_Interp *interp, Jim_Obj *listObjPtr, int type)
{
    typedef int (qsort_comparator)(const void *, const void *);
    int (*fn)(Jim_Obj**, Jim_Obj**);
    Jim_Obj **vector;
    int len;

    if (Jim_IsShared(listObjPtr))
        Jim_Panic("Jim_ListSortElements called with shared object");
    if (listObjPtr->typePtr != &listObjType)
        SetListFromAny(interp, listObjPtr);

    vector = listObjPtr->internalRep.listValue.ele;
    len = listObjPtr->internalRep.listValue.len;
    switch (type) {
        case JIM_LSORT_ASCII: fn = ListSortString;  break;
        case JIM_LSORT_NOCASE: fn = ListSortStringNoCase;  break;
        case JIM_LSORT_ASCII_DECR: fn = ListSortStringDecr;  break;
        case JIM_LSORT_NOCASE_DECR: fn = ListSortStringNoCaseDecr;  break;
        default:
            fn = NULL; /* avoid warning */
            Jim_Panic("ListSort called with invalid sort type");
    }
    qsort(vector, len, sizeof(Jim_Obj *), (qsort_comparator *)fn);
    Jim_InvalidateStringRep(listObjPtr);
}

/* This is the low-level function to append an element to a list.
 * The higher-level Jim_ListAppendElement() performs shared object
 * check and invalidate the string repr. This version is used
 * in the internals of the List Object and is not exported.
 *
 * NOTE: this function can be called only against objects
 * with internal type of List. */
void ListAppendElement(Jim_Obj *listPtr, Jim_Obj *objPtr)
{
    int requiredLen = listPtr->internalRep.listValue.len + 1;

    if (requiredLen > listPtr->internalRep.listValue.maxLen) {
        int maxLen = requiredLen * 2;

        listPtr->internalRep.listValue.ele =
            Jim_Realloc(listPtr->internalRep.listValue.ele,
                    sizeof(Jim_Obj*)*maxLen);
        listPtr->internalRep.listValue.maxLen = maxLen;
    }
    listPtr->internalRep.listValue.ele[listPtr->internalRep.listValue.len] =
        objPtr;
    listPtr->internalRep.listValue.len ++;
    Jim_IncrRefCount(objPtr);
}

/* This is the low-level function to insert elements into a list.
 * The higher-level Jim_ListInsertElements() performs shared object
 * check and invalidate the string repr. This version is used
 * in the internals of the List Object and is not exported.
 *
 * NOTE: this function can be called only against objects
 * with internal type of List. */
void ListInsertElements(Jim_Obj *listPtr, int index, int elemc,
        Jim_Obj *const *elemVec)
{
    int currentLen = listPtr->internalRep.listValue.len;
    int requiredLen = currentLen + elemc;
    int i;
    Jim_Obj **point;

    if (requiredLen > listPtr->internalRep.listValue.maxLen) {
        int maxLen = requiredLen * 2;

        listPtr->internalRep.listValue.ele =
            Jim_Realloc(listPtr->internalRep.listValue.ele,
                    sizeof(Jim_Obj*)*maxLen);
        listPtr->internalRep.listValue.maxLen = maxLen;
    }
    point = listPtr->internalRep.listValue.ele + index;
    memmove(point+elemc, point, (currentLen-index) * sizeof(Jim_Obj*));
    for (i=0; i < elemc; ++i) {
        point[i] = elemVec[i];
        Jim_IncrRefCount(point[i]);
    }
    listPtr->internalRep.listValue.len += elemc;
}

/* Appends every element of appendListPtr into listPtr.
 * Both have to be of the list type. */
void ListAppendList(Jim_Obj *listPtr, Jim_Obj *appendListPtr)
{
    int i, oldLen = listPtr->internalRep.listValue.len;
    int appendLen = appendListPtr->internalRep.listValue.len;
    int requiredLen = oldLen + appendLen;

    if (requiredLen > listPtr->internalRep.listValue.maxLen) {
        int maxLen = requiredLen * 2;

        listPtr->internalRep.listValue.ele =
            Jim_Realloc(listPtr->internalRep.listValue.ele,
                    sizeof(Jim_Obj*)*maxLen);
        listPtr->internalRep.listValue.maxLen = maxLen;
    }
    for (i = 0; i < appendLen; i++) {
        Jim_Obj *objPtr = appendListPtr->internalRep.listValue.ele[i];
        listPtr->internalRep.listValue.ele[oldLen+i] = objPtr;
        Jim_IncrRefCount(objPtr);
    }
    listPtr->internalRep.listValue.len += appendLen;
}

void Jim_ListAppendElement(Jim_Interp *interp, Jim_Obj *listPtr, Jim_Obj *objPtr)
{
    if (Jim_IsShared(listPtr))
        Jim_Panic("Jim_ListAppendElement called with shared object");
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    Jim_InvalidateStringRep(listPtr);
    ListAppendElement(listPtr, objPtr);
}

void Jim_ListAppendList(Jim_Interp *interp, Jim_Obj *listPtr, Jim_Obj *appendListPtr)
{
    if (Jim_IsShared(listPtr))
        Jim_Panic("Jim_ListAppendList called with shared object");
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    Jim_InvalidateStringRep(listPtr);
    ListAppendList(listPtr, appendListPtr);
}

void Jim_ListLength(Jim_Interp *interp, Jim_Obj *listPtr, int *intPtr)
{
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    *intPtr = listPtr->internalRep.listValue.len;
}

void Jim_ListInsertElements(Jim_Interp *interp, Jim_Obj *listPtr, int index,
        int objc, Jim_Obj *const *objVec)
{
    if (Jim_IsShared(listPtr))
        Jim_Panic("Jim_ListInsertElement called with shared object");
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    if (index >= 0 && index > listPtr->internalRep.listValue.len)
        index = listPtr->internalRep.listValue.len;
    else if (index < 0 ) 
        index = 0;
    Jim_InvalidateStringRep(listPtr);
    ListInsertElements(listPtr, index, objc, objVec);
}

int Jim_ListIndex(Jim_Interp *interp, Jim_Obj *listPtr, int index,
        Jim_Obj **objPtrPtr, int flags)
{
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    if ((index >= 0 && index >= listPtr->internalRep.listValue.len) ||
        (index < 0 && (-index-1) >= listPtr->internalRep.listValue.len)) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResultString(interp,
                "list index out of range", -1);
        }
        return JIM_ERR;
    }
    if (index < 0)
        index = listPtr->internalRep.listValue.len+index;
    *objPtrPtr = listPtr->internalRep.listValue.ele[index];
    return JIM_OK;
}

static int ListSetIndex(Jim_Interp *interp, Jim_Obj *listPtr, int index,
        Jim_Obj *newObjPtr, int flags)
{
    if (listPtr->typePtr != &listObjType)
        SetListFromAny(interp, listPtr);
    if ((index >= 0 && index >= listPtr->internalRep.listValue.len) ||
        (index < 0 && (-index-1) >= listPtr->internalRep.listValue.len)) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResultString(interp,
                "list index out of range", -1);
        }
        return JIM_ERR;
    }
    if (index < 0)
        index = listPtr->internalRep.listValue.len+index;
    Jim_DecrRefCount(interp, listPtr->internalRep.listValue.ele[index]);
    listPtr->internalRep.listValue.ele[index] = newObjPtr;
    Jim_IncrRefCount(newObjPtr);
    return JIM_OK;
}

/* Modify the list stored into the variable named 'varNamePtr'
 * setting the element specified by the 'indexc' indexes objects in 'indexv',
 * with the new element 'newObjptr'. */
int Jim_SetListIndex(Jim_Interp *interp, Jim_Obj *varNamePtr,
        Jim_Obj *const *indexv, int indexc, Jim_Obj *newObjPtr)
{
    Jim_Obj *varObjPtr, *objPtr, *listObjPtr;
    int shared, i, index;

    varObjPtr = objPtr = Jim_GetVariable(interp, varNamePtr, JIM_ERRMSG);
    if (objPtr == NULL)
        return JIM_ERR;
    if ((shared = Jim_IsShared(objPtr)))
        varObjPtr = objPtr = Jim_DuplicateObj(interp, objPtr);
    for (i = 0; i < indexc-1; i++) {
        listObjPtr = objPtr;
        if (Jim_GetIndex(interp, indexv[i], &index) != JIM_OK)
            goto err;
        if (Jim_ListIndex(interp, listObjPtr, index, &objPtr,
                    JIM_ERRMSG) != JIM_OK) {
            goto err;
        }
        if (Jim_IsShared(objPtr)) {
            objPtr = Jim_DuplicateObj(interp, objPtr);
            ListSetIndex(interp, listObjPtr, index, objPtr, JIM_NONE);
        }
        Jim_InvalidateStringRep(listObjPtr);
    }
    if (Jim_GetIndex(interp, indexv[indexc-1], &index) != JIM_OK)
        goto err;
    if (ListSetIndex(interp, objPtr, index, newObjPtr, JIM_ERRMSG) == JIM_ERR)
        goto err;
    Jim_InvalidateStringRep(objPtr);
    Jim_InvalidateStringRep(varObjPtr);
    if (Jim_SetVariable(interp, varNamePtr, varObjPtr) != JIM_OK)
        goto err;
    Jim_SetResult(interp, varObjPtr);
    return JIM_OK;
err:
    if (shared) {
        Jim_FreeNewObj(interp, varObjPtr);
    }
    return JIM_ERR;
}

Jim_Obj *Jim_ConcatObj(Jim_Interp *interp, int objc, Jim_Obj *const *objv)
{
    int i;

    /* If all the objects in objv are lists without string rep.
     * it's possible to return a list as result, that's the
     * concatenation of all the lists. */
    for (i = 0; i < objc; i++) {
        if (objv[i]->typePtr != &listObjType || objv[i]->bytes)
            break;
    }
    if (i == objc) {
        Jim_Obj *objPtr = Jim_NewListObj(interp, NULL, 0);
        for (i = 0; i < objc; i++)
            Jim_ListAppendList(interp, objPtr, objv[i]);
        return objPtr;
    } else {
        /* Else... we have to glue strings together */
        int len = 0, objLen;
        char *bytes, *p;

        /* Compute the length */
        for (i = 0; i < objc; i++) {
            Jim_GetString(objv[i], &objLen);
            len += objLen;
        }
        if (objc) len += objc-1;
        /* Create the string rep, and a stinrg object holding it. */
        p = bytes = Jim_Alloc(len+1);
        for (i = 0; i < objc; i++) {
            const char *s = Jim_GetString(objv[i], &objLen);
            while (objLen && (*s == ' ' || *s == '\t' || *s == '\n'))
            {
                s++; objLen--; len--;
            }
            while (objLen && (s[objLen-1] == ' ' ||
                s[objLen-1] == '\n' || s[objLen-1] == '\t')) {
                objLen--; len--;
            }
            memcpy(p, s, objLen);
            p += objLen;
            if (objLen && i+1 != objc) {
                *p++ = ' ';
            } else if (i+1 != objc) {
                /* Drop the space calcuated for this
                 * element that is instead null. */
                len--;
            }
        }
        *p = '\0';
        return Jim_NewStringObjNoAlloc(interp, bytes, len);
    }
}

/* Returns a list composed of the elements in the specified range.
 * first and start are directly accepted as Jim_Objects and
 * processed for the end?-index? case. */
Jim_Obj *Jim_ListRange(Jim_Interp *interp, Jim_Obj *listObjPtr, Jim_Obj *firstObjPtr, Jim_Obj *lastObjPtr)
{
    int first, last;
    int len, rangeLen;

    if (Jim_GetIndex(interp, firstObjPtr, &first) != JIM_OK ||
        Jim_GetIndex(interp, lastObjPtr, &last) != JIM_OK)
        return NULL;
    Jim_ListLength(interp, listObjPtr, &len); /* will convert into list */
    first = JimRelToAbsIndex(len, first);
    last = JimRelToAbsIndex(len, last);
    JimRelToAbsRange(len, first, last, &first, &last, &rangeLen);
    return Jim_NewListObj(interp,
            listObjPtr->internalRep.listValue.ele+first, rangeLen);
}

/* -----------------------------------------------------------------------------
 * Dict object
 * ---------------------------------------------------------------------------*/
static void FreeDictInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupDictInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static void UpdateStringOfDict(struct Jim_Obj *objPtr);
static int SetDictFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

/* Dict HashTable Type.
 *
 * Keys and Values are Jim objects. */

unsigned int JimObjectHTHashFunction(const void *key)
{
    const char *str;
    Jim_Obj *objPtr = (Jim_Obj*) key;
    int len, h;

    str = Jim_GetString(objPtr, &len);
    h = Jim_GenHashFunction((unsigned char*)str, len);
    return h;
}

int JimObjectHTKeyCompare(void *privdata, const void *key1, const void *key2)
{
    JIM_NOTUSED(privdata);

    return Jim_StringEqObj((Jim_Obj*)key1, (Jim_Obj*)key2, 0);
}

static void JimObjectHTKeyValDestructor(void *interp, void *val)
{
    Jim_Obj *objPtr = val;

    Jim_DecrRefCount(interp, objPtr);
}

static Jim_HashTableType JimDictHashTableType = {
    JimObjectHTHashFunction,            /* hash function */
    NULL,                               /* key dup */
    NULL,                               /* val dup */
    JimObjectHTKeyCompare,              /* key compare */
    (void(*)(void*, const void*))       /* ATTENTION: const cast */
        JimObjectHTKeyValDestructor,    /* key destructor */
    JimObjectHTKeyValDestructor         /* val destructor */
};

/* Note that while the elements of the dict may contain references,
 * the list object itself can't. This basically means that the
 * dict object string representation as a whole can't contain references
 * that are not presents in the single elements. */
static Jim_ObjType dictObjType = {
    "dict",
    FreeDictInternalRep,
    DupDictInternalRep,
    UpdateStringOfDict,
    JIM_TYPE_NONE,
};

void FreeDictInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    JIM_NOTUSED(interp);

    Jim_FreeHashTable(objPtr->internalRep.ptr);
    Jim_Free(objPtr->internalRep.ptr);
}

void DupDictInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    Jim_HashTable *ht, *dupHt;
    Jim_HashTableIterator *htiter;
    Jim_HashEntry *he;

    /* Create a new hash table */
    ht = srcPtr->internalRep.ptr;
    dupHt = Jim_Alloc(sizeof(*dupHt));
    Jim_InitHashTable(dupHt, &JimDictHashTableType, interp);
    if (ht->size != 0)
        Jim_ExpandHashTable(dupHt, ht->size);
    /* Copy every element from the source to the dup hash table */
    htiter = Jim_GetHashTableIterator(ht);
    while ((he = Jim_NextHashEntry(htiter)) != NULL) {
        const Jim_Obj *keyObjPtr = he->key;
        Jim_Obj *valObjPtr = he->val;

        Jim_IncrRefCount((Jim_Obj*)keyObjPtr);  /* ATTENTION: const cast */
        Jim_IncrRefCount(valObjPtr);
        Jim_AddHashEntry(dupHt, keyObjPtr, valObjPtr);
    }
    Jim_FreeHashTableIterator(htiter);

    dupPtr->internalRep.ptr = dupHt;
    dupPtr->typePtr = &dictObjType;
}

void UpdateStringOfDict(struct Jim_Obj *objPtr)
{
    int i, bufLen, realLength;
    const char *strRep;
    char *p;
    int *quotingType, objc;
    Jim_HashTable *ht;
    Jim_HashTableIterator *htiter;
    Jim_HashEntry *he;
    Jim_Obj **objv;

    /* Trun the hash table into a flat vector of Jim_Objects. */
    ht = objPtr->internalRep.ptr;
    objc = ht->used*2;
    objv = Jim_Alloc(objc*sizeof(Jim_Obj*));
    htiter = Jim_GetHashTableIterator(ht);
    i = 0;
    while ((he = Jim_NextHashEntry(htiter)) != NULL) {
        objv[i++] = (Jim_Obj*)he->key;  /* ATTENTION: const cast */
        objv[i++] = he->val;
    }
    Jim_FreeHashTableIterator(htiter);
    /* (Over) Estimate the space needed. */
    quotingType = Jim_Alloc(sizeof(int)*objc);
    bufLen = 0;
    for (i = 0; i < objc; i++) {
        int len;

        strRep = Jim_GetString(objv[i], &len);
        quotingType[i] = ListElementQuotingType(strRep, len);
        switch (quotingType[i]) {
        case JIM_ELESTR_SIMPLE: bufLen += len; break;
        case JIM_ELESTR_BRACE: bufLen += len+2; break;
        case JIM_ELESTR_QUOTE: bufLen += len*2; break;
        }
        bufLen++; /* elements separator. */
    }
    bufLen++;

    /* Generate the string rep. */
    p = objPtr->bytes = Jim_Alloc(bufLen+1);
    realLength = 0;
    for (i = 0; i < objc; i++) {
        int len, qlen;
        const char *strRep = Jim_GetString(objv[i], &len);
        char *q;

        switch(quotingType[i]) {
        case JIM_ELESTR_SIMPLE:
            memcpy(p, strRep, len);
            p += len;
            realLength += len;
            break;
        case JIM_ELESTR_BRACE:
            *p++ = '{';
            memcpy(p, strRep, len);
            p += len;
            *p++ = '}';
            realLength += len+2;
            break;
        case JIM_ELESTR_QUOTE:
            q = BackslashQuoteString(strRep, len, &qlen);
            memcpy(p, q, qlen);
            Jim_Free(q);
            p += qlen;
            realLength += qlen;
            break;
        }
        /* Add a separating space */
        if (i+1 != objc) {
            *p++ = ' ';
            realLength ++;
        }
    }
    *p = '\0'; /* nul term. */
    objPtr->length = realLength;
    Jim_Free(quotingType);
    Jim_Free(objv);
}

int SetDictFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr)
{
    struct JimParserCtx parser;
    Jim_HashTable *ht;
    Jim_Obj *objv[2];
    const char *str;
    int i, strLen;

    /* Get the string representation */
    str = Jim_GetString(objPtr, &strLen);

    /* Free the old internal repr just now and initialize the
     * new one just now. The string->list conversion can't fail. */
    Jim_FreeIntRep(interp, objPtr);
    ht = Jim_Alloc(sizeof(*ht));
    Jim_InitHashTable(ht, &JimDictHashTableType, interp);
    objPtr->typePtr = &dictObjType;
    objPtr->internalRep.ptr = ht;

    /* Convert into a dict */
    JimParserInit(&parser, str, strLen, 1);
    i = 0;
    while(!JimParserEof(&parser)) {
        char *token;
        int tokenLen, type;

        JimParseList(&parser);
        if (JimParserTtype(&parser) != JIM_TT_STR &&
            JimParserTtype(&parser) != JIM_TT_ESC)
            continue;
        token = JimParserGetToken(&parser, &tokenLen, &type, NULL);
        objv[i++] = Jim_NewStringObjNoAlloc(interp, token, tokenLen);
        if (i == 2) {
            i = 0;
            Jim_IncrRefCount(objv[0]);
            Jim_IncrRefCount(objv[1]);
            if (Jim_AddHashEntry(ht, objv[0], objv[1]) != JIM_OK) {
                Jim_HashEntry *he;
                he = Jim_FindHashEntry(ht, objv[0]);
                Jim_DecrRefCount(interp, objv[0]);
                /* ATTENTION: const cast */
                Jim_DecrRefCount(interp, (Jim_Obj*)he->val);
                he->val = objv[1];
            }
        }
    }
    if (i) {
        Jim_FreeNewObj(interp, objv[0]);
        objPtr->typePtr = NULL;
        Jim_FreeHashTable(ht);
        Jim_SetResultString(interp, "invalid dictionary value: must be a list with an even number of elements", -1);
        return JIM_ERR;
    }
    return JIM_OK;
}

/* Dict object API */

/* Add an element to a dict. objPtr must be of the "dict" type.
 * The higer-level exported function is Jim_DictAddElement().
 * If an element with the specified key already exists, the value
 * associated is replaced with the new one.
 *
 * if valueObjPtr == NULL, the key is instead removed if it exists. */
static void DictAddElement(Jim_Interp *interp, Jim_Obj *objPtr,
        Jim_Obj *keyObjPtr, Jim_Obj *valueObjPtr)
{
    Jim_HashTable *ht = objPtr->internalRep.ptr;

    if (valueObjPtr == NULL) { /* unset */
        Jim_DeleteHashEntry(ht, keyObjPtr);
        return;
    }
    Jim_IncrRefCount(keyObjPtr);
    Jim_IncrRefCount(valueObjPtr);
    if (Jim_AddHashEntry(ht, keyObjPtr, valueObjPtr) != JIM_OK) {
        Jim_HashEntry *he = Jim_FindHashEntry(ht, keyObjPtr);
        Jim_DecrRefCount(interp, keyObjPtr);
        /* ATTENTION: const cast */
        Jim_DecrRefCount(interp, (Jim_Obj*)he->val);
        he->val = valueObjPtr;
    }
}

/* Add an element, higher-level interface for DictAddElement().
 * If valueObjPtr == NULL, the key is removed if it exists. */
int Jim_DictAddElement(Jim_Interp *interp, Jim_Obj *objPtr,
        Jim_Obj *keyObjPtr, Jim_Obj *valueObjPtr)
{
    if (Jim_IsShared(objPtr))
        Jim_Panic("Jim_DictAddElement called with shared object");
    if (objPtr->typePtr != &dictObjType) {
        if (SetDictFromAny(interp, objPtr) != JIM_OK)
            return JIM_ERR;
    }
    DictAddElement(interp, objPtr, keyObjPtr, valueObjPtr);
    Jim_InvalidateStringRep(objPtr);
    return JIM_OK;
}

Jim_Obj *Jim_NewDictObj(Jim_Interp *interp, Jim_Obj *const *elements, int len)
{
    Jim_Obj *objPtr;
    int i;

    if (len % 2)
        Jim_Panic("Jim_NewDicObj() 'len' argument must be even");

    objPtr = Jim_NewObj(interp);
    objPtr->typePtr = &dictObjType;
    objPtr->bytes = NULL;
    objPtr->internalRep.ptr = Jim_Alloc(sizeof(Jim_HashTable));
    Jim_InitHashTable(objPtr->internalRep.ptr, &JimDictHashTableType, interp);
    for (i = 0; i < len; i += 2)
        DictAddElement(interp, objPtr, elements[i], elements[i+1]);
    return objPtr;
}

/* Return the value associated to the specified dict key */
int Jim_DictKey(Jim_Interp *interp, Jim_Obj *dictPtr, Jim_Obj *keyPtr,
        Jim_Obj **objPtrPtr, int flags)
{
    Jim_HashEntry *he;
    Jim_HashTable *ht;

    if (dictPtr->typePtr != &dictObjType) {
        if (SetDictFromAny(interp, dictPtr) != JIM_OK)
            return JIM_ERR;
    }
    ht = dictPtr->internalRep.ptr;
    if ((he = Jim_FindHashEntry(ht, keyPtr)) == NULL) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "key \"", Jim_GetString(keyPtr, NULL),
                    "\" not found in dictionary", NULL);
        }
        return JIM_ERR;
    }
    *objPtrPtr = he->val;
    return JIM_OK;
}

/* Return the value associated to the specified dict keys */
int Jim_DictKeysVector(Jim_Interp *interp, Jim_Obj *dictPtr,
        Jim_Obj *const *keyv, int keyc, Jim_Obj **objPtrPtr, int flags)
{
    Jim_Obj *objPtr;
    int i;

    if (keyc == 0) {
        *objPtrPtr = dictPtr;
        return JIM_OK;
    }

    for (i = 0; i < keyc; i++) {
        if (Jim_DictKey(interp, dictPtr, keyv[i], &objPtr, flags)
                != JIM_OK)
            return JIM_ERR;
        dictPtr = objPtr;
    }
    *objPtrPtr = objPtr;
    return JIM_OK;
}

/* Modify the dict stored into the variable named 'varNamePtr'
 * setting the element specified by the 'keyc' keys objects in 'keyv',
 * with the new value of the element 'newObjPtr'.
 *
 * If newObjPtr == NULL the operation is to remove the given key
 * from the dictionary. */
int Jim_SetDictKeysVector(Jim_Interp *interp, Jim_Obj *varNamePtr,
        Jim_Obj *const *keyv, int keyc, Jim_Obj *newObjPtr)
{
    Jim_Obj *varObjPtr, *objPtr, *dictObjPtr;
    int shared, i;

    varObjPtr = objPtr = Jim_GetVariable(interp, varNamePtr, JIM_ERRMSG);
    if (objPtr == NULL) {
        if (newObjPtr == NULL) /* Cannot remove a key from non existing var */
            return JIM_ERR;
        varObjPtr = objPtr = Jim_NewDictObj(interp, NULL, 0);
        if (Jim_SetVariable(interp, varNamePtr, objPtr) != JIM_OK) {
            Jim_FreeNewObj(interp, varObjPtr);
            return JIM_ERR;
        }
    }
    if ((shared = Jim_IsShared(objPtr)))
        varObjPtr = objPtr = Jim_DuplicateObj(interp, objPtr);
    for (i = 0; i < keyc-1; i++) {
        dictObjPtr = objPtr;

        /* Check if it's a valid dictionary */
        if (dictObjPtr->typePtr != &dictObjType) {
            if (SetDictFromAny(interp, dictObjPtr) != JIM_OK)
                goto err;
        }
        /* Check if the given key exists. */
        Jim_InvalidateStringRep(dictObjPtr);
        if (Jim_DictKey(interp, dictObjPtr, keyv[i], &objPtr,
            newObjPtr ? JIM_NONE : JIM_ERRMSG) == JIM_OK)
        {
            /* This key exists at the current level.
             * Make sure it's not shared!. */
            if (Jim_IsShared(objPtr)) {
                objPtr = Jim_DuplicateObj(interp, objPtr);
                DictAddElement(interp, dictObjPtr, keyv[i], objPtr);
            }
        } else {
            /* Key not found. If it's an [unset] operation
             * this is an error. Only the last key may not
             * exist. */
            if (newObjPtr == NULL)
                goto err;
            /* Otherwise set an empty dictionary
             * as key's value. */
            objPtr = Jim_NewDictObj(interp, NULL, 0);
            DictAddElement(interp, dictObjPtr, keyv[i], objPtr);
        }
    }
    if (Jim_DictAddElement(interp, objPtr, keyv[keyc-1], newObjPtr)
            != JIM_OK)
        goto err;
    Jim_InvalidateStringRep(objPtr);
    Jim_InvalidateStringRep(varObjPtr);
    if (Jim_SetVariable(interp, varNamePtr, varObjPtr) != JIM_OK)
        goto err;
    Jim_SetResult(interp, varObjPtr);
    return JIM_OK;
err:
    if (shared) {
        Jim_FreeNewObj(interp, varObjPtr);
    }
    return JIM_ERR;
}

/* -----------------------------------------------------------------------------
 * Index object
 * ---------------------------------------------------------------------------*/
static void UpdateStringOfIndex(struct Jim_Obj *objPtr);
static int SetIndexFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType indexObjType = {
    "index",
    NULL,
    NULL,
    UpdateStringOfIndex,
    JIM_TYPE_NONE,
};

void UpdateStringOfIndex(struct Jim_Obj *objPtr)
{
    int len;
    char buf[JIM_INTEGER_SPACE+1];

    if (objPtr->internalRep.indexValue >= 0)
        len = sprintf(buf, "%d", objPtr->internalRep.indexValue);
    else if (objPtr->internalRep.indexValue == -1)
        len = sprintf(buf, "end");
    else {
        len = sprintf(buf, "end%d", objPtr->internalRep.indexValue+1);
    }
    objPtr->bytes = Jim_Alloc(len+1);
    memcpy(objPtr->bytes, buf, len+1);
    objPtr->length = len;
}

int SetIndexFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    int index, end = 0;
    const char *str;

    /* Get the string representation */
    str = Jim_GetString(objPtr, NULL);
    /* Try to convert into an index */
    if (!strcmp(str, "end")) {
        index = 0;
        end = 1;
    } else {
        if (!strncmp(str, "end-", 4)) {
            str += 4;
            end = 1;
        }
        if (Jim_StringToIndex(str, &index) != JIM_OK) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "bad index \"", Jim_GetString(objPtr, NULL), "\": "
                    "must be integer or end?-integer?", NULL);
            return JIM_ERR;
        }
    }
    if (end) {
        if (index < 0)
            index = INT_MAX;
        else
            index = -(index+1);
    } else if (!end && index < 0)
        index = -INT_MAX;
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &indexObjType;
    objPtr->internalRep.indexValue = index;
    return JIM_OK;
}

int Jim_GetIndex(Jim_Interp *interp, Jim_Obj *objPtr, int *indexPtr)
{
    /* Avoid shimmering if the object is an integer. */
    if (objPtr->typePtr == &intObjType) {
        jim_wide val = objPtr->internalRep.wideValue;
        if (!(val < LONG_MIN) && !(val > LONG_MAX)) {
            *indexPtr = (val < 0) ? -INT_MAX : (long)val;;
            return JIM_OK;
        }
    }
    if (objPtr->typePtr != &indexObjType &&
        SetIndexFromAny(interp, objPtr) == JIM_ERR)
        return JIM_ERR;
    *indexPtr = objPtr->internalRep.indexValue;
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * Return Code Object.
 * ---------------------------------------------------------------------------*/

static int SetReturnCodeFromAny(Jim_Interp *interp, Jim_Obj *objPtr);

static Jim_ObjType returnCodeObjType = {
    "return-code",
    NULL,
    NULL,
    NULL,
    JIM_TYPE_NONE,
};

int SetReturnCodeFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    const char *str;
    int strLen, returnCode;
    jim_wide wideValue;

    /* Get the string representation */
    str = Jim_GetString(objPtr, &strLen);
    /* Try to convert into an integer */
    if (JimGetWideNoErr(interp, objPtr, &wideValue) != JIM_ERR)
        returnCode = (int) wideValue;
    else if (!JimStringCompare(str, strLen, "ok", 2, JIM_NOCASE))
        returnCode = JIM_OK;
    else if (!JimStringCompare(str, strLen, "error", 5, JIM_NOCASE))
        returnCode = JIM_ERR;
    else if (!JimStringCompare(str, strLen, "return", 6, JIM_NOCASE))
        returnCode = JIM_RETURN;
    else if (!JimStringCompare(str, strLen, "break", 5, JIM_NOCASE))
        returnCode = JIM_BREAK;
    else if (!JimStringCompare(str, strLen, "continue", 8, JIM_NOCASE))
        returnCode = JIM_CONTINUE;
    else if (!JimStringCompare(str, strLen, "eval", 4, JIM_NOCASE))
        returnCode = JIM_EVAL;
    else {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "expected return code but got '", str, "'",
                NULL);
        return JIM_ERR;
    }
    /* Free the old internal repr and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    objPtr->typePtr = &returnCodeObjType;
    objPtr->internalRep.returnCode = returnCode;
    return JIM_OK;
}

int Jim_GetReturnCode(Jim_Interp *interp, Jim_Obj *objPtr, int *intPtr)
{
    if (objPtr->typePtr != &returnCodeObjType &&
        SetReturnCodeFromAny(interp, objPtr) == JIM_ERR)
        return JIM_ERR;
    *intPtr = objPtr->internalRep.returnCode;
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * Expression Parsing
 * ---------------------------------------------------------------------------*/
static int JimParseExprOperator(struct JimParserCtx *pc);
static int JimParseExprNumber(struct JimParserCtx *pc);
static int JimParseExprIrrational(struct JimParserCtx *pc);

/* Exrp's Stack machine operators opcodes. */

/* Binary operators (numbers) */
#define JIM_EXPROP_BINARY_NUM_FIRST 0 /* first */
#define JIM_EXPROP_MUL 0
#define JIM_EXPROP_DIV 1
#define JIM_EXPROP_MOD 2
#define JIM_EXPROP_SUB 3
#define JIM_EXPROP_ADD 4
#define JIM_EXPROP_LSHIFT 5
#define JIM_EXPROP_RSHIFT 6
#define JIM_EXPROP_ROTL 7
#define JIM_EXPROP_ROTR 8
#define JIM_EXPROP_LT 9
#define JIM_EXPROP_GT 10
#define JIM_EXPROP_LTE 11
#define JIM_EXPROP_GTE 12
#define JIM_EXPROP_NUMEQ 13
#define JIM_EXPROP_NUMNE 14
#define JIM_EXPROP_BITAND 15
#define JIM_EXPROP_BITXOR 16
#define JIM_EXPROP_BITOR 17
#define JIM_EXPROP_LOGICAND 18
#define JIM_EXPROP_LOGICOR 19
#define JIM_EXPROP_LOGICAND_LEFT 20
#define JIM_EXPROP_LOGICOR_LEFT 21
#define JIM_EXPROP_POW 22
#define JIM_EXPROP_BINARY_NUM_LAST 22 /* last */

/* Binary operators (strings) */
#define JIM_EXPROP_STREQ 23
#define JIM_EXPROP_STRNE 24

/* Unary operators (numbers) */
#define JIM_EXPROP_NOT 25
#define JIM_EXPROP_BITNOT 26
#define JIM_EXPROP_UNARYMINUS 27
#define JIM_EXPROP_UNARYPLUS 28
#define JIM_EXPROP_LOGICAND_RIGHT 29
#define JIM_EXPROP_LOGICOR_RIGHT 30

/* Ternary operators */
#define JIM_EXPROP_TERNARY 31

/* Operands */
#define JIM_EXPROP_NUMBER 32
#define JIM_EXPROP_COMMAND 33
#define JIM_EXPROP_VARIABLE 34
#define JIM_EXPROP_DICTSUGAR 35
#define JIM_EXPROP_SUBST 36
#define JIM_EXPROP_STRING 37

/* Operators table */
typedef struct Jim_ExprOperator {
    const char *name;
    int precedence;
    int arity;
    int opcode;
} Jim_ExprOperator;

/* name - precedence - arity - opcode */
static struct Jim_ExprOperator Jim_ExprOperators[] = {
    {"!", 300, 1, JIM_EXPROP_NOT},
    {"~", 300, 1, JIM_EXPROP_BITNOT},
    {"unarymin", 300, 1, JIM_EXPROP_UNARYMINUS},
    {"unaryplus", 300, 1, JIM_EXPROP_UNARYPLUS},

    {"**", 250, 2, JIM_EXPROP_POW},

    {"*", 200, 2, JIM_EXPROP_MUL},
    {"/", 200, 2, JIM_EXPROP_DIV},
    {"%", 200, 2, JIM_EXPROP_MOD},

    {"-", 100, 2, JIM_EXPROP_SUB},
    {"+", 100, 2, JIM_EXPROP_ADD},

    {"<<<", 90, 3, JIM_EXPROP_ROTL},
    {">>>", 90, 3, JIM_EXPROP_ROTR},
    {"<<", 90, 2, JIM_EXPROP_LSHIFT},
    {">>", 90, 2, JIM_EXPROP_RSHIFT},

    {"<",  80, 2, JIM_EXPROP_LT},
    {">",  80, 2, JIM_EXPROP_GT},
    {"<=", 80, 2, JIM_EXPROP_LTE},
    {">=", 80, 2, JIM_EXPROP_GTE},

    {"==", 70, 2, JIM_EXPROP_NUMEQ},
    {"!=", 70, 2, JIM_EXPROP_NUMNE},

    {"eq", 60, 2, JIM_EXPROP_STREQ},
    {"ne", 60, 2, JIM_EXPROP_STRNE},

    {"&", 50, 2, JIM_EXPROP_BITAND},
    {"^", 49, 2, JIM_EXPROP_BITXOR},
    {"|", 48, 2, JIM_EXPROP_BITOR},

    {"&&", 10, 2, JIM_EXPROP_LOGICAND},
    {"||", 10, 2, JIM_EXPROP_LOGICOR},

    {"?", 5, 3, JIM_EXPROP_TERNARY},
    /* private operators */
    {NULL, 10, 2, JIM_EXPROP_LOGICAND_LEFT},
    {NULL, 10, 1, JIM_EXPROP_LOGICAND_RIGHT},
    {NULL, 10, 2, JIM_EXPROP_LOGICOR_LEFT},
    {NULL, 10, 1, JIM_EXPROP_LOGICOR_RIGHT},
};

#define JIM_EXPR_OPERATORS_NUM \
    (sizeof(Jim_ExprOperators)/sizeof(struct Jim_ExprOperator))

int JimParseExpression(struct JimParserCtx *pc)
{
    /* Discard spaces and quoted newline */
    while(*(pc->p) == ' ' ||
          *(pc->p) == '\t' ||
          *(pc->p) == '\r' ||
          *(pc->p) == '\n' ||
            (*(pc->p) == '\\' && *(pc->p+1) == '\n')) {
        pc->p++; pc->len--;
    }

    if (pc->len == 0) {
        pc->tstart = pc->tend = pc->p;
        pc->tline = pc->linenr;
        pc->tt = JIM_TT_EOL;
        pc->eof = 1;
        return JIM_OK;
    }
    switch(*(pc->p)) {
    case '(':
        pc->tstart = pc->tend = pc->p;
        pc->tline = pc->linenr;
        pc->tt = JIM_TT_SUBEXPR_START;
        pc->p++; pc->len--;
        break;
    case ')':
        pc->tstart = pc->tend = pc->p;
        pc->tline = pc->linenr;
        pc->tt = JIM_TT_SUBEXPR_END;
        pc->p++; pc->len--;
        break;
    case '[':
        return JimParseCmd(pc);
        break;
    case '$':
        if (JimParseVar(pc) == JIM_ERR)
            return JimParseExprOperator(pc);
        else
            return JIM_OK;
        break;
    case '-':
        if ((pc->tt == JIM_TT_NONE || pc->tt == JIM_TT_EXPR_OPERATOR) &&
            isdigit((int)*(pc->p+1)))
            return JimParseExprNumber(pc);
        else
            return JimParseExprOperator(pc);
        break;
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': case '.':
        return JimParseExprNumber(pc);
        break;
    case '"':
    case '{':
        /* Here it's possible to reuse the List String parsing. */
        pc->tt = JIM_TT_NONE; /* Make sure it's sensed as a new word. */
        return JimParseListStr(pc);
        break;
    case 'N': case 'I':
    case 'n': case 'i':
        if (JimParseExprIrrational(pc) == JIM_ERR)
            return JimParseExprOperator(pc);
        break;
    default:
        return JimParseExprOperator(pc);
        break;
    }
    return JIM_OK;
}

int JimParseExprNumber(struct JimParserCtx *pc)
{
    int allowdot = 1;

    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    if (*pc->p == '-') {
        pc->p++; pc->len--;
    }
    while (isdigit((int)*pc->p) || (allowdot && *pc->p == '.')) {
        if (*pc->p == '.')
            allowdot = 0;
        pc->p++; pc->len--;
        if (!allowdot && *pc->p == 'e' && *(pc->p+1) == '-') {
            pc->p += 2; pc->len -= 2;
        }
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_EXPR_NUMBER;
    return JIM_OK;
}

int JimParseExprIrrational(struct JimParserCtx *pc)
{
    const char *Tokens[] = {"NaN", "nan", "NAN", "Inf", "inf", "INF", NULL};
    const char **token;
    for (token = Tokens; *token != NULL; token++) {
        int len = strlen(*token);
        if (strncmp(*token, pc->p, len) == 0) {
            pc->tstart = pc->p;
            pc->tend = pc->p + len - 1;
            pc->p += len; pc->len -= len;
            pc->tline = pc->linenr;
            pc->tt = JIM_TT_EXPR_NUMBER;
            return JIM_OK;
        }
    }
    return JIM_ERR;
}

int JimParseExprOperator(struct JimParserCtx *pc)
{
    int i;
    int bestIdx = -1, bestLen = 0;

    /* Try to get the longest match. */
    for (i = 0; i < (signed)JIM_EXPR_OPERATORS_NUM; i++) {
        const char *opname;
        int oplen;

        opname = Jim_ExprOperators[i].name;
        if (opname == NULL) continue;
        oplen = strlen(opname);

        if (strncmp(opname, pc->p, oplen) == 0 && oplen > bestLen) {
            bestIdx = i;
            bestLen = oplen;
        }
    }
    if (bestIdx == -1) return JIM_ERR;
    pc->tstart = pc->p;
    pc->tend = pc->p + bestLen - 1;
    pc->p += bestLen; pc->len -= bestLen;
    pc->tline = pc->linenr;
    pc->tt = JIM_TT_EXPR_OPERATOR;
    return JIM_OK;
}

struct Jim_ExprOperator *JimExprOperatorInfo(const char *opname)
{
    int i;
    for (i = 0; i < (signed)JIM_EXPR_OPERATORS_NUM; i++)
        if (Jim_ExprOperators[i].name &&
            strcmp(opname, Jim_ExprOperators[i].name) == 0)
            return &Jim_ExprOperators[i];
    return NULL;
}

struct Jim_ExprOperator *JimExprOperatorInfoByOpcode(int opcode)
{
    int i;
    for (i = 0; i < (signed)JIM_EXPR_OPERATORS_NUM; i++)
        if (Jim_ExprOperators[i].opcode == opcode)
            return &Jim_ExprOperators[i];
    return NULL;
}

/* -----------------------------------------------------------------------------
 * Expression Object
 * ---------------------------------------------------------------------------*/
static void FreeExprInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupExprInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static int SetExprFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr);

static Jim_ObjType exprObjType = {
    "expression",
    FreeExprInternalRep,
    DupExprInternalRep,
    NULL,
    JIM_TYPE_REFERENCES,
};

/* Expr bytecode structure */
typedef struct ExprByteCode {
    int *opcode;        /* Integer array of opcodes. */
    Jim_Obj **obj;      /* Array of associated Jim Objects. */
    int len;            /* Bytecode length */
    int inUse;          /* Used for sharing. */
} ExprByteCode;

void FreeExprInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    int i;
    ExprByteCode *expr = (void*) objPtr->internalRep.ptr;

    expr->inUse--;
    if (expr->inUse != 0) return;
    for (i = 0; i < expr->len; i++)
        Jim_DecrRefCount(interp, expr->obj[i]);
    Jim_Free(expr->opcode);
    Jim_Free(expr->obj);
    Jim_Free(expr);
}

void DupExprInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    JIM_NOTUSED(interp);
    JIM_NOTUSED(srcPtr);

    /* Just returns an simple string. */
    dupPtr->typePtr = NULL;
}

/* Add a new instruction to an expression bytecode structure. */
static void ExprObjAddInstr(Jim_Interp *interp, ExprByteCode *expr,
        int opcode, char *str, int len)
{
    expr->opcode = Jim_Realloc(expr->opcode, sizeof(int)*(expr->len+1));
    expr->obj = Jim_Realloc(expr->obj, sizeof(Jim_Obj*)*(expr->len+1));
    expr->opcode[expr->len] = opcode;
    expr->obj[expr->len] = Jim_NewStringObjNoAlloc(interp, str, len);
    Jim_IncrRefCount(expr->obj[expr->len]);
    expr->len++;
}

/* Check if an expr program looks correct. */
static int ExprCheckCorrectness(ExprByteCode *expr)
{
    int i;
    int stacklen = 0;

    /* Try to check if there are stack underflows,
     * and make sure at the end of the program there is
     * a single result on the stack. */
    for (i = 0; i < expr->len; i++) {
        switch(expr->opcode[i]) {
        case JIM_EXPROP_NUMBER:
        case JIM_EXPROP_STRING:
        case JIM_EXPROP_SUBST:
        case JIM_EXPROP_VARIABLE:
        case JIM_EXPROP_DICTSUGAR:
        case JIM_EXPROP_COMMAND:
            stacklen++;
            break;
        case JIM_EXPROP_NOT:
        case JIM_EXPROP_BITNOT:
        case JIM_EXPROP_UNARYMINUS:
        case JIM_EXPROP_UNARYPLUS:
            /* Unary operations */
            if (stacklen < 1) return JIM_ERR;
            break;
        case JIM_EXPROP_ADD:
        case JIM_EXPROP_SUB:
        case JIM_EXPROP_MUL:
        case JIM_EXPROP_DIV:
        case JIM_EXPROP_MOD:
        case JIM_EXPROP_LT:
        case JIM_EXPROP_GT:
        case JIM_EXPROP_LTE:
        case JIM_EXPROP_GTE:
        case JIM_EXPROP_ROTL:
        case JIM_EXPROP_ROTR:
        case JIM_EXPROP_LSHIFT:
        case JIM_EXPROP_RSHIFT:
        case JIM_EXPROP_NUMEQ:
        case JIM_EXPROP_NUMNE:
        case JIM_EXPROP_STREQ:
        case JIM_EXPROP_STRNE:
        case JIM_EXPROP_BITAND:
        case JIM_EXPROP_BITXOR:
        case JIM_EXPROP_BITOR:
        case JIM_EXPROP_LOGICAND:
        case JIM_EXPROP_LOGICOR:
        case JIM_EXPROP_POW:
            /* binary operations */
            if (stacklen < 2) return JIM_ERR;
            stacklen--;
            break;
        default:
            Jim_Panic("Default opcode reached ExprCheckCorrectness");
            break;
        }
    }
    if (stacklen != 1) return JIM_ERR;
    return JIM_OK;
}

static void ExprShareLiterals(Jim_Interp *interp, ExprByteCode *expr,
        ScriptObj *topLevelScript)
{
    int i;

    return;
    for (i = 0; i < expr->len; i++) {
        Jim_Obj *foundObjPtr;

        if (expr->obj[i] == NULL) continue;
        foundObjPtr = ScriptSearchLiteral(interp, topLevelScript,
                NULL, expr->obj[i]);
        if (foundObjPtr != NULL) {
            Jim_IncrRefCount(foundObjPtr);
            Jim_DecrRefCount(interp, expr->obj[i]);
            expr->obj[i] = foundObjPtr;
        }
    }
}

/* This procedure converts every occurrence of || and && opereators
 * in lazy unary versions.
 *
 * a b || is converted into:
 *
 * a <offset> |L b |R
 *
 * a b && is converted into:
 *
 * a <offset> &L b &R
 *
 * "|L" checks if 'a' is true:
 *   1) if it is true pushes 1 and skips <offset> istructions to reach
 *      the opcode just after |R.
 *   2) if it is false does nothing.
 * "|R" checks if 'b' is true:
 *   1) if it is true pushes 1, otherwise pushes 0.
 *
 * "&L" checks if 'a' is true:
 *   1) if it is true does nothing.
 *   2) If it is false pushes 0 and skips <offset> istructions to reach
 *      the opcode just after &R
 * "&R" checks if 'a' is true:
 *      if it is true pushes 1, otherwise pushes 0.
 */
static void ExprMakeLazy(Jim_Interp *interp, ExprByteCode *expr)
{
    while (1) {
        int index = -1, leftindex, arity, i, offset;
        Jim_ExprOperator *op;

        /* Search for || or && */
        for (i = 0; i < expr->len; i++) {
            if (expr->opcode[i] == JIM_EXPROP_LOGICAND ||
                expr->opcode[i] == JIM_EXPROP_LOGICOR) {
                index = i;
                break;
            }
        }
        if (index == -1) return;
        /* Search for the end of the first operator */
        leftindex = index-1;
        arity = 1;
        while(arity) {
            switch(expr->opcode[leftindex]) {
            case JIM_EXPROP_NUMBER:
            case JIM_EXPROP_COMMAND:
            case JIM_EXPROP_VARIABLE:
            case JIM_EXPROP_DICTSUGAR:
            case JIM_EXPROP_SUBST:
            case JIM_EXPROP_STRING:
                break;
            default:
                op = JimExprOperatorInfoByOpcode(expr->opcode[i]);
                if (op == NULL) {
                    Jim_Panic("Default reached in ExprMakeLazy()");
                }
                arity += op->arity;
                break;
            }
            arity--;
            leftindex--;
        }
        leftindex++;
        expr->opcode = Jim_Realloc(expr->opcode, sizeof(int)*(expr->len+2));
        expr->obj = Jim_Realloc(expr->obj, sizeof(Jim_Obj*)*(expr->len+2));
        memmove(&expr->opcode[leftindex+2], &expr->opcode[leftindex],
                sizeof(int)*(expr->len-leftindex));
        memmove(&expr->obj[leftindex+2], &expr->obj[leftindex],
                sizeof(Jim_Obj*)*(expr->len-leftindex));
        expr->len += 2;
        index += 2;
        offset = (index-leftindex)-1;
        Jim_DecrRefCount(interp, expr->obj[index]);
        if (expr->opcode[index] == JIM_EXPROP_LOGICAND) {
            expr->opcode[leftindex+1] = JIM_EXPROP_LOGICAND_LEFT;
            expr->opcode[index] = JIM_EXPROP_LOGICAND_RIGHT;
            expr->obj[leftindex+1] = Jim_NewStringObj(interp, "&L", -1);
            expr->obj[index] = Jim_NewStringObj(interp, "&R", -1);
        } else {
            expr->opcode[leftindex+1] = JIM_EXPROP_LOGICOR_LEFT;
            expr->opcode[index] = JIM_EXPROP_LOGICOR_RIGHT;
            expr->obj[leftindex+1] = Jim_NewStringObj(interp, "|L", -1);
            expr->obj[index] = Jim_NewStringObj(interp, "|R", -1);
        }
        expr->opcode[leftindex] = JIM_EXPROP_NUMBER;
        expr->obj[leftindex] = Jim_NewIntObj(interp, offset);
        Jim_IncrRefCount(expr->obj[index]);
        Jim_IncrRefCount(expr->obj[leftindex]);
        Jim_IncrRefCount(expr->obj[leftindex+1]);
    }
}

/* This method takes the string representation of an expression
 * and generates a program for the Expr's stack-based VM. */
int SetExprFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr)
{
    int exprTextLen;
    const char *exprText = Jim_GetString(objPtr, &exprTextLen);
    struct JimParserCtx parser;
    int i, shareLiterals;
    ExprByteCode *expr = Jim_Alloc(sizeof(*expr));
    Jim_Stack stack;
    Jim_ExprOperator *op;

    /* Perform literal sharing with the current procedure
     * running only if this expression appears to be not generated
     * at runtime. */
    shareLiterals = objPtr->typePtr == &sourceObjType;

    expr->opcode = NULL;
    expr->obj = NULL;
    expr->len = 0;
    expr->inUse = 1;

    Jim_InitStack(&stack);
    JimParserInit(&parser, exprText, exprTextLen, 1);
    while(!JimParserEof(&parser)) {
        char *token;
        int len, type;

        if (JimParseExpression(&parser) != JIM_OK) {
            Jim_SetResultString(interp, "Syntax error in expression", -1);
            goto err;
        }
        token = JimParserGetToken(&parser, &len, &type, NULL);
        if (type == JIM_TT_EOL) {
            Jim_Free(token);
            break;
        }
        switch(type) {
        case JIM_TT_STR:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_STRING, token, len);
            break;
        case JIM_TT_ESC:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_SUBST, token, len);
            break;
        case JIM_TT_VAR:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_VARIABLE, token, len);
            break;
        case JIM_TT_DICTSUGAR:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_DICTSUGAR, token, len);
            break;
        case JIM_TT_CMD:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_COMMAND, token, len);
            break;
        case JIM_TT_EXPR_NUMBER:
            ExprObjAddInstr(interp, expr, JIM_EXPROP_NUMBER, token, len);
            break;
        case JIM_TT_EXPR_OPERATOR:
            op = JimExprOperatorInfo(token);
            while(1) {
                Jim_ExprOperator *stackTopOp;

                if (Jim_StackPeek(&stack) != NULL) {
                    stackTopOp = JimExprOperatorInfo(Jim_StackPeek(&stack));
                } else {
                    stackTopOp = NULL;
                }
                if (Jim_StackLen(&stack) && op->arity != 1 &&
                    stackTopOp && stackTopOp->precedence >= op->precedence)
                {
                    ExprObjAddInstr(interp, expr, stackTopOp->opcode,
                        Jim_StackPeek(&stack), -1);
                    Jim_StackPop(&stack);
                } else {
                    break;
                }
            }
            Jim_StackPush(&stack, token);
            break;
        case JIM_TT_SUBEXPR_START:
            Jim_StackPush(&stack, Jim_StrDup("("));
            Jim_Free(token);
            break;
        case JIM_TT_SUBEXPR_END:
            {
                int found = 0;
                while(Jim_StackLen(&stack)) {
                    char *opstr = Jim_StackPop(&stack);
                    if (!strcmp(opstr, "(")) {
                        Jim_Free(opstr);
                        found = 1;
                        break;
                    }
                    op = JimExprOperatorInfo(opstr);
                    ExprObjAddInstr(interp, expr, op->opcode, opstr, -1);
                }
                if (!found) {
                    Jim_SetResultString(interp,
                        "Unexpected close parenthesis", -1);
                    goto err;
                }
            }
            Jim_Free(token);
            break;
        default:
            Jim_Panic("Default reached in SetExprFromAny()");
            break;
        }
    }
    while (Jim_StackLen(&stack)) {
        char *opstr = Jim_StackPop(&stack);
        op = JimExprOperatorInfo(opstr);
        if (op == NULL && !strcmp(opstr, "(")) {
            Jim_Free(opstr);
            Jim_SetResultString(interp, "Missing close parenthesis", -1);
            goto err;
        }
        ExprObjAddInstr(interp, expr, op->opcode, opstr, -1);
    }
    /* Check program correctness. */
    if (ExprCheckCorrectness(expr) != JIM_OK) {
        Jim_SetResultString(interp, "Invalid expression", -1);
        goto err;
    }

    /* Free the stack used for the compilation. */
    Jim_FreeStackElements(&stack, Jim_Free);
    Jim_FreeStack(&stack);

    /* Convert || and && operators in unary |L |R and &L &R for lazyness */
    ExprMakeLazy(interp, expr);

    /* Perform literal sharing */
    if (shareLiterals && interp->framePtr->procBodyObjPtr) {
        Jim_Obj *bodyObjPtr = interp->framePtr->procBodyObjPtr;
        if (bodyObjPtr->typePtr == &scriptObjType) {
            ScriptObj *bodyScript = bodyObjPtr->internalRep.ptr;
            ExprShareLiterals(interp, expr, bodyScript);
        }
    }

    /* Free the old internal rep and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    Jim_SetIntRepPtr(objPtr, expr);
    objPtr->typePtr = &exprObjType;
    return JIM_OK;

err:    /* we jump here on syntax/compile errors. */
    Jim_FreeStackElements(&stack, Jim_Free);
    Jim_FreeStack(&stack);
    Jim_Free(expr->opcode);
    for (i = 0; i < expr->len; i++) {
        Jim_DecrRefCount(interp,expr->obj[i]);
    }
    Jim_Free(expr->obj);
    Jim_Free(expr);
    return JIM_ERR;
}

ExprByteCode *Jim_GetExpression(Jim_Interp *interp, Jim_Obj *objPtr)
{
    if (objPtr->typePtr != &exprObjType) {
        if (SetExprFromAny(interp, objPtr) != JIM_OK)
            return NULL;
    }
    return (ExprByteCode*) Jim_GetIntRepPtr(objPtr);
}

/* -----------------------------------------------------------------------------
 * Expressions evaluation.
 * Jim uses a specialized stack-based virtual machine for expressions,
 * that takes advantage of the fact that expr's operators
 * can't be redefined.
 *
 * Jim_EvalExpression() uses the bytecode compiled by
 * SetExprFromAny() method of the "expression" object.
 *
 * On success a Tcl Object containing the result of the evaluation
 * is stored into expResultPtrPtr (having refcount of 1), and JIM_OK is
 * returned.
 * On error the function returns a retcode != to JIM_OK and set a suitable
 * error on the interp.
 * ---------------------------------------------------------------------------*/
#define JIM_EE_STATICSTACK_LEN 10

int Jim_EvalExpression(Jim_Interp *interp, Jim_Obj *exprObjPtr,
        Jim_Obj **exprResultPtrPtr)
{
    ExprByteCode *expr;
    Jim_Obj **stack, *staticStack[JIM_EE_STATICSTACK_LEN];
    int stacklen = 0, i, error = 0, errRetCode = JIM_ERR;

    Jim_IncrRefCount(exprObjPtr);
    expr = Jim_GetExpression(interp, exprObjPtr);
    if (!expr) {
        Jim_DecrRefCount(interp, exprObjPtr);
        return JIM_ERR; /* error in expression. */
    }
    /* In order to avoid that the internal repr gets freed due to
     * shimmering of the exprObjPtr's object, we make the internal rep
     * shared. */
    expr->inUse++;

    /* The stack-based expr VM itself */

    /* Stack allocation. Expr programs have the feature that
     * a program of length N can't require a stack longer than
     * N. */
    if (expr->len > JIM_EE_STATICSTACK_LEN)
        stack = Jim_Alloc(sizeof(Jim_Obj*)*expr->len);
    else
        stack = staticStack;

    /* Execute every istruction */
    for (i = 0; i < expr->len; i++) {
        Jim_Obj *A, *B, *objPtr;
        jim_wide wA, wB, wC;
        double dA, dB, dC;
        const char *sA, *sB;
        int Alen, Blen, retcode;
        int opcode = expr->opcode[i];

        if (opcode == JIM_EXPROP_NUMBER || opcode == JIM_EXPROP_STRING) {
            stack[stacklen++] = expr->obj[i];
            Jim_IncrRefCount(expr->obj[i]);
        } else if (opcode == JIM_EXPROP_VARIABLE) {
            objPtr = Jim_GetVariable(interp, expr->obj[i], JIM_ERRMSG);
            if (objPtr == NULL) {
                error = 1;
                goto err;
            }
            stack[stacklen++] = objPtr;
            Jim_IncrRefCount(objPtr);
        } else if (opcode == JIM_EXPROP_SUBST) {
            if ((retcode = Jim_SubstObj(interp, expr->obj[i],
                        &objPtr, JIM_NONE)) != JIM_OK)
            {
                error = 1;
                errRetCode = retcode;
                goto err;
            }
            stack[stacklen++] = objPtr;
            Jim_IncrRefCount(objPtr);
        } else if (opcode == JIM_EXPROP_DICTSUGAR) {
            objPtr = Jim_ExpandDictSugar(interp, expr->obj[i]);
            if (objPtr == NULL) {
                error = 1;
                goto err;
            }
            stack[stacklen++] = objPtr;
            Jim_IncrRefCount(objPtr);
        } else if (opcode == JIM_EXPROP_COMMAND) {
            if ((retcode = Jim_EvalObj(interp, expr->obj[i])) != JIM_OK) {
                error = 1;
                errRetCode = retcode;
                goto err;
            }
            stack[stacklen++] = interp->result;
            Jim_IncrRefCount(interp->result);
        } else if (opcode >= JIM_EXPROP_BINARY_NUM_FIRST &&
                   opcode <= JIM_EXPROP_BINARY_NUM_LAST)
        {
            /* Note that there isn't to increment the
             * refcount of objects. the references are moved
             * from stack to A and B. */
            B = stack[--stacklen];
            A = stack[--stacklen];

            /* --- Integer --- */
            if ((A->typePtr == &doubleObjType && !A->bytes) ||
                (B->typePtr == &doubleObjType && !B->bytes) ||
                JimGetWideNoErr(interp, A, &wA) != JIM_OK ||
                JimGetWideNoErr(interp, B, &wB) != JIM_OK) {
                goto trydouble;
            }
            Jim_DecrRefCount(interp, A);
            Jim_DecrRefCount(interp, B);
            switch(expr->opcode[i]) {
            case JIM_EXPROP_ADD: wC = wA+wB; break;
            case JIM_EXPROP_SUB: wC = wA-wB; break;
            case JIM_EXPROP_MUL: wC = wA*wB; break;
            case JIM_EXPROP_LT: wC = wA<wB; break;
            case JIM_EXPROP_GT: wC = wA>wB; break;
            case JIM_EXPROP_LTE: wC = wA<=wB; break;
            case JIM_EXPROP_GTE: wC = wA>=wB; break;
            case JIM_EXPROP_LSHIFT: wC = wA<<wB; break;
            case JIM_EXPROP_RSHIFT: wC = wA>>wB; break;
            case JIM_EXPROP_NUMEQ: wC = wA==wB; break;
            case JIM_EXPROP_NUMNE: wC = wA!=wB; break;
            case JIM_EXPROP_BITAND: wC = wA&wB; break;
            case JIM_EXPROP_BITXOR: wC = wA^wB; break;
            case JIM_EXPROP_BITOR: wC = wA|wB; break;
            case JIM_EXPROP_POW: wC = JimPowWide(wA,wB); break;
            case JIM_EXPROP_LOGICAND_LEFT:
                if (wA == 0) {
                    i += (int)wB;
                    wC = 0;
                } else {
                    continue;
                }
                break;
            case JIM_EXPROP_LOGICOR_LEFT:
                if (wA != 0) {
                    i += (int)wB;
                    wC = 1;
                } else {
                    continue;
                }
                break;
            case JIM_EXPROP_DIV:
                if (wB == 0) goto divbyzero;
                wC = wA/wB;
                break;
            case JIM_EXPROP_MOD:
                if (wB == 0) goto divbyzero;
                wC = wA%wB;
                break;
            case JIM_EXPROP_ROTL: {
                /* uint32_t would be better. But not everyone has inttypes.h?*/
                unsigned long uA = (unsigned long)wA;
#ifdef _MSC_VER
                wC = _rotl(uA,(unsigned long)wB);
#else
                const unsigned int S = sizeof(unsigned long) * 8;
                wC = (unsigned long)((uA<<wB)|(uA>>(S-wB)));
#endif
                break;
            }
            case JIM_EXPROP_ROTR: {
                unsigned long uA = (unsigned long)wA;
#ifdef _MSC_VER
                wC = _rotr(uA,(unsigned long)wB);
#else
                const unsigned int S = sizeof(unsigned long) * 8;
                wC = (unsigned long)((uA>>wB)|(uA<<(S-wB)));
#endif
                break;
            }

            default:
                wC = 0; /* avoid gcc warning */
                break;
            }
            stack[stacklen] = Jim_NewIntObj(interp, wC);
            Jim_IncrRefCount(stack[stacklen]);
            stacklen++;
            continue;
trydouble:
            /* --- Double --- */
            if (Jim_GetDouble(interp, A, &dA) != JIM_OK ||
                Jim_GetDouble(interp, B, &dB) != JIM_OK) {
                Jim_DecrRefCount(interp, A);
                Jim_DecrRefCount(interp, B);
                error = 1;
                goto err;
            }
            Jim_DecrRefCount(interp, A);
            Jim_DecrRefCount(interp, B);
            switch(expr->opcode[i]) {
            case JIM_EXPROP_ROTL:
            case JIM_EXPROP_ROTR:
            case JIM_EXPROP_LSHIFT:
            case JIM_EXPROP_RSHIFT:
            case JIM_EXPROP_BITAND:
            case JIM_EXPROP_BITXOR:
            case JIM_EXPROP_BITOR:
            case JIM_EXPROP_MOD:
            case JIM_EXPROP_POW:
                Jim_SetResultString(interp,
                    "Got floating-point value where integer was expected", -1);
                error = 1;
                goto err;
                break;
            case JIM_EXPROP_ADD: dC = dA+dB; break;
            case JIM_EXPROP_SUB: dC = dA-dB; break;
            case JIM_EXPROP_MUL: dC = dA*dB; break;
            case JIM_EXPROP_LT: dC = dA<dB; break;
            case JIM_EXPROP_GT: dC = dA>dB; break;
            case JIM_EXPROP_LTE: dC = dA<=dB; break;
            case JIM_EXPROP_GTE: dC = dA>=dB; break;
            case JIM_EXPROP_NUMEQ: dC = dA==dB; break;
            case JIM_EXPROP_NUMNE: dC = dA!=dB; break;
            case JIM_EXPROP_LOGICAND_LEFT:
                if (dA == 0) {
                    i += (int)dB;
                    dC = 0;
                } else {
                    continue;
                }
                break;
            case JIM_EXPROP_LOGICOR_LEFT:
                if (dA != 0) {
                    i += (int)dB;
                    dC = 1;
                } else {
                    continue;
                }
                break;
            case JIM_EXPROP_DIV:
                if (dB == 0) goto divbyzero;
                dC = dA/dB;
                break;
            default:
                dC = 0; /* avoid gcc warning */
                break;
            }
            stack[stacklen] = Jim_NewDoubleObj(interp, dC);
            Jim_IncrRefCount(stack[stacklen]);
            stacklen++;
        } else if (opcode == JIM_EXPROP_STREQ || opcode == JIM_EXPROP_STRNE) {
            B = stack[--stacklen];
            A = stack[--stacklen];
            sA = Jim_GetString(A, &Alen);
            sB = Jim_GetString(B, &Blen);
            switch(expr->opcode[i]) {
            case JIM_EXPROP_STREQ:
                if (Alen == Blen && memcmp(sA, sB, Alen) ==0)
                    wC = 1;
                else
                    wC = 0;
                break;
            case JIM_EXPROP_STRNE:
                if (Alen != Blen || memcmp(sA, sB, Alen) != 0)
                    wC = 1;
                else
                    wC = 0;
                break;
            default:
                wC = 0; /* avoid gcc warning */
                break;
            }
            Jim_DecrRefCount(interp, A);
            Jim_DecrRefCount(interp, B);
            stack[stacklen] = Jim_NewIntObj(interp, wC);
            Jim_IncrRefCount(stack[stacklen]);
            stacklen++;
        } else if (opcode == JIM_EXPROP_NOT ||
                   opcode == JIM_EXPROP_BITNOT ||
                   opcode == JIM_EXPROP_LOGICAND_RIGHT ||
                   opcode == JIM_EXPROP_LOGICOR_RIGHT) {
            /* Note that there isn't to increment the
             * refcount of objects. the references are moved
             * from stack to A and B. */
            A = stack[--stacklen];

            /* --- Integer --- */
            if ((A->typePtr == &doubleObjType && !A->bytes) ||
                JimGetWideNoErr(interp, A, &wA) != JIM_OK) {
                goto trydouble_unary;
            }
            Jim_DecrRefCount(interp, A);
            switch(expr->opcode[i]) {
            case JIM_EXPROP_NOT: wC = !wA; break;
            case JIM_EXPROP_BITNOT: wC = ~wA; break;
            case JIM_EXPROP_LOGICAND_RIGHT:
            case JIM_EXPROP_LOGICOR_RIGHT: wC = (wA != 0); break;
            default:
                wC = 0; /* avoid gcc warning */
                break;
            }
            stack[stacklen] = Jim_NewIntObj(interp, wC);
            Jim_IncrRefCount(stack[stacklen]);
            stacklen++;
            continue;
trydouble_unary:
            /* --- Double --- */
            if (Jim_GetDouble(interp, A, &dA) != JIM_OK) {
                Jim_DecrRefCount(interp, A);
                error = 1;
                goto err;
            }
            Jim_DecrRefCount(interp, A);
            switch(expr->opcode[i]) {
            case JIM_EXPROP_NOT: dC = !dA; break;
            case JIM_EXPROP_LOGICAND_RIGHT:
            case JIM_EXPROP_LOGICOR_RIGHT: dC = (dA != 0); break;
            case JIM_EXPROP_BITNOT:
                Jim_SetResultString(interp,
                    "Got floating-point value where integer was expected", -1);
                error = 1;
                goto err;
                break;
            default:
                dC = 0; /* avoid gcc warning */
                break;
            }
            stack[stacklen] = Jim_NewDoubleObj(interp, dC);
            Jim_IncrRefCount(stack[stacklen]);
            stacklen++;
        } else {
            Jim_Panic("Unknown opcode in Jim_EvalExpression");
        }
    }
err:
    /* There is no need to decerement the inUse field because
     * this reference is transfered back into the exprObjPtr. */
    Jim_FreeIntRep(interp, exprObjPtr);
    exprObjPtr->typePtr = &exprObjType;
    Jim_SetIntRepPtr(exprObjPtr, expr);
    Jim_DecrRefCount(interp, exprObjPtr);
    if (!error) {
        *exprResultPtrPtr = stack[0];
        Jim_IncrRefCount(stack[0]);
        errRetCode = JIM_OK;
    }
    for (i = 0; i < stacklen; i++) {
        Jim_DecrRefCount(interp, stack[i]);
    }
    if (stack != staticStack)
        Jim_Free(stack);
    return errRetCode;
divbyzero:
    error = 1;
    Jim_SetResultString(interp, "Division by zero", -1);
    goto err;
}

int Jim_GetBoolFromExpr(Jim_Interp *interp, Jim_Obj *exprObjPtr, int *boolPtr)
{
    int retcode;
    jim_wide wideValue;
    double doubleValue;
    Jim_Obj *exprResultPtr;

    retcode = Jim_EvalExpression(interp, exprObjPtr, &exprResultPtr);
    if (retcode != JIM_OK)
        return retcode;
    if (JimGetWideNoErr(interp, exprResultPtr, &wideValue) != JIM_OK) {
        if (Jim_GetDouble(interp, exprResultPtr, &doubleValue) != JIM_OK)
        {
            Jim_DecrRefCount(interp, exprResultPtr);
            return JIM_ERR;
        } else {
            Jim_DecrRefCount(interp, exprResultPtr);
            *boolPtr = doubleValue != 0;
            return JIM_OK;
        }
    }
    Jim_DecrRefCount(interp, exprResultPtr);
    *boolPtr = wideValue != 0;
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * ScanFormat String Object
 * ---------------------------------------------------------------------------*/

/* This Jim_Obj will held a parsed representation of a format string passed to
 * the Jim_ScanString command. For error diagnostics, the scanformat string has
 * to be parsed in its entirely first and then, if correct, can be used for
 * scanning. To avoid endless re-parsing, the parsed representation will be
 * stored in an internal representation and re-used for performance reason. */
 
/* A ScanFmtPartDescr will held the information of /one/ part of the whole
 * scanformat string. This part will later be used to extract information
 * out from the string to be parsed by Jim_ScanString */
 
typedef struct ScanFmtPartDescr {
    char type;         /* Type of conversion (e.g. c, d, f) */
    char modifier;     /* Modify type (e.g. l - long, h - short */
    size_t  width;     /* Maximal width of input to be converted */
    int  pos;          /* -1 - no assign, 0 - natural pos, >0 - XPG3 pos */ 
    char *arg;         /* Specification of a CHARSET conversion */
    char *prefix;      /* Prefix to be scanned literally before conversion */
} ScanFmtPartDescr;

/* The ScanFmtStringObj will held the internal representation of a scanformat
 * string parsed and separated in part descriptions. Furthermore it contains
 * the original string representation of the scanformat string to allow for
 * fast update of the Jim_Obj's string representation part.
 *
 * As add-on the internal object representation add some scratch pad area
 * for usage by Jim_ScanString to avoid endless allocating and freeing of
 * memory for purpose of string scanning.
 *
 * The error member points to a static allocated string in case of a mal-
 * formed scanformat string or it contains '0' (NULL) in case of a valid
 * parse representation.
 *
 * The whole memory of the internal representation is allocated as a single
 * area of memory that will be internally separated. So freeing and duplicating
 * of such an object is cheap */

typedef struct ScanFmtStringObj {
    jim_wide        size;         /* Size of internal repr in bytes */
    char            *stringRep;   /* Original string representation */
    size_t          count;        /* Number of ScanFmtPartDescr contained */
    size_t          convCount;    /* Number of conversions that will assign */
    size_t          maxPos;       /* Max position index if XPG3 is used */
    const char      *error;       /* Ptr to error text (NULL if no error */
    char            *scratch;     /* Some scratch pad used by Jim_ScanString */
    ScanFmtPartDescr descr[1];    /* The vector of partial descriptions */
} ScanFmtStringObj;


static void FreeScanFmtInternalRep(Jim_Interp *interp, Jim_Obj *objPtr);
static void DupScanFmtInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr);
static void UpdateStringOfScanFmt(Jim_Obj *objPtr);

static Jim_ObjType scanFmtStringObjType = {
    "scanformatstring",
    FreeScanFmtInternalRep,
    DupScanFmtInternalRep,
    UpdateStringOfScanFmt,
    JIM_TYPE_NONE,
};

void FreeScanFmtInternalRep(Jim_Interp *interp, Jim_Obj *objPtr)
{
    JIM_NOTUSED(interp);
    Jim_Free((char*)objPtr->internalRep.ptr);
    objPtr->internalRep.ptr = 0;
}

void DupScanFmtInternalRep(Jim_Interp *interp, Jim_Obj *srcPtr, Jim_Obj *dupPtr)
{
    size_t size = (size_t)((ScanFmtStringObj*)srcPtr->internalRep.ptr)->size;
    ScanFmtStringObj *newVec = (ScanFmtStringObj*)Jim_Alloc(size);

    JIM_NOTUSED(interp);
    memcpy(newVec, srcPtr->internalRep.ptr, size);
    dupPtr->internalRep.ptr = newVec;
    dupPtr->typePtr = &scanFmtStringObjType;
}

void UpdateStringOfScanFmt(Jim_Obj *objPtr)
{
    char *bytes = ((ScanFmtStringObj*)objPtr->internalRep.ptr)->stringRep;

    objPtr->bytes = Jim_StrDup(bytes);
    objPtr->length = strlen(bytes);
}

/* SetScanFmtFromAny will parse a given string and create the internal
 * representation of the format specification. In case of an error
 * the error data member of the internal representation will be set
 * to an descriptive error text and the function will be left with
 * JIM_ERR to indicate unsucessful parsing (aka. malformed scanformat
 * specification */

static int SetScanFmtFromAny(Jim_Interp *interp, Jim_Obj *objPtr)
{
    ScanFmtStringObj *fmtObj;
    char *buffer;
    int maxCount, i, approxSize, lastPos = -1;
    const char *fmt = objPtr->bytes;
    int maxFmtLen = objPtr->length;
    const char *fmtEnd = fmt + maxFmtLen;
    int curr;

    Jim_FreeIntRep(interp, objPtr);
    /* Count how many conversions could take place maximally */
    for (i=0, maxCount=0; i < maxFmtLen; ++i)
        if (fmt[i] == '%')
            ++maxCount;
    /* Calculate an approximation of the memory necessary */
    approxSize = sizeof(ScanFmtStringObj)           /* Size of the container */
        + (maxCount + 1) * sizeof(ScanFmtPartDescr) /* Size of all partials */
        + maxFmtLen * sizeof(char) + 3 + 1          /* Scratch + "%n" + '\0' */
        + maxFmtLen * sizeof(char) + 1              /* Original stringrep */
        + maxFmtLen * sizeof(char)                  /* Arg for CHARSETs */
        + (maxCount +1) * sizeof(char)              /* '\0' for every partial */
        + 1;                                        /* safety byte */
    fmtObj = (ScanFmtStringObj*)Jim_Alloc(approxSize);
    memset(fmtObj, 0, approxSize);
    fmtObj->size = approxSize;
    fmtObj->maxPos = 0;
    fmtObj->scratch = (char*)&fmtObj->descr[maxCount+1];
    fmtObj->stringRep = fmtObj->scratch + maxFmtLen + 3 + 1;
    memcpy(fmtObj->stringRep, fmt, maxFmtLen);
    buffer = fmtObj->stringRep + maxFmtLen + 1;
    objPtr->internalRep.ptr = fmtObj;
    objPtr->typePtr = &scanFmtStringObjType;
    for (i=0, curr=0; fmt < fmtEnd; ++fmt) {
        int width=0, skip;
        ScanFmtPartDescr *descr = &fmtObj->descr[curr];
        fmtObj->count++;
        descr->width = 0;                   /* Assume width unspecified */ 
        /* Overread and store any "literal" prefix */
        if (*fmt != '%' || fmt[1] == '%') {
            descr->type = 0;
            descr->prefix = &buffer[i];
            for (; fmt < fmtEnd; ++fmt) {
                if (*fmt == '%') {
                    if (fmt[1] != '%') break;
                    ++fmt;
                }
                buffer[i++] = *fmt;
            }
            buffer[i++] = 0;
        } 
        /* Skip the conversion introducing '%' sign */
        ++fmt;      
        /* End reached due to non-conversion literal only? */
        if (fmt >= fmtEnd)
            goto done;
        descr->pos = 0;                     /* Assume "natural" positioning */
        if (*fmt == '*') {
            descr->pos = -1;       /* Okay, conversion will not be assigned */
            ++fmt;
        } else
            fmtObj->convCount++;    /* Otherwise count as assign-conversion */
        /* Check if next token is a number (could be width or pos */
        if (sscanf(fmt, "%d%n", &width, &skip) == 1) {
            fmt += skip;
            /* Was the number a XPG3 position specifier? */
            if (descr->pos != -1 && *fmt == '$') {
                int prev;
                ++fmt;
                descr->pos = width;
                width = 0;
                /* Look if "natural" postioning and XPG3 one was mixed */
                if ((lastPos == 0 && descr->pos > 0)
                        || (lastPos > 0 && descr->pos == 0)) {
                    fmtObj->error = "cannot mix \"%\" and \"%n$\" conversion specifiers";
                    return JIM_ERR;
                }
                /* Look if this position was already used */
                for (prev=0; prev < curr; ++prev) {
                    if (fmtObj->descr[prev].pos == -1) continue;
                    if (fmtObj->descr[prev].pos == descr->pos) {
                        fmtObj->error = "same \"%n$\" conversion specifier "
                            "used more than once";
                        return JIM_ERR;
                    }
                }
                /* Try to find a width after the XPG3 specifier */
                if (sscanf(fmt, "%d%n", &width, &skip) == 1) {
                    descr->width = width;
                    fmt += skip;
                }
                if (descr->pos > 0 && (size_t)descr->pos > fmtObj->maxPos)
                    fmtObj->maxPos = descr->pos;
            } else {
                /* Number was not a XPG3, so it has to be a width */
                descr->width = width;
            }
        }
        /* If positioning mode was undetermined yet, fix this */
        if (lastPos == -1)
            lastPos = descr->pos;
        /* Handle CHARSET conversion type ... */
        if (*fmt == '[') {
            int swapped = 1, beg = i, end, j;
            descr->type = '[';
            descr->arg = &buffer[i];
            ++fmt;
            if (*fmt == '^') buffer[i++] = *fmt++;
            if (*fmt == ']') buffer[i++] = *fmt++;
            while (*fmt && *fmt != ']') buffer[i++] = *fmt++;
            if (*fmt != ']') {
                fmtObj->error = "unmatched [ in format string";
                return JIM_ERR;
            } 
            end = i;
            buffer[i++] = 0;
            /* In case a range fence was given "backwards", swap it */
            while (swapped) {
                swapped = 0;
                for (j=beg+1; j < end-1; ++j) {
                    if (buffer[j] == '-' && buffer[j-1] > buffer[j+1]) {
                        char tmp = buffer[j-1];
                        buffer[j-1] = buffer[j+1];
                        buffer[j+1] = tmp;
                        swapped = 1;
                    }
                }
            }
        } else {
            /* Remember any valid modifier if given */
            if (strchr("hlL", *fmt) != 0)
                descr->modifier = tolower((int)*fmt++);
            
            descr->type = *fmt;
            if (strchr("efgcsndoxui", *fmt) == 0) {
                fmtObj->error = "bad scan conversion character";
                return JIM_ERR;
            } else if (*fmt == 'c' && descr->width != 0) {
                fmtObj->error = "field width may not be specified in %c "
                    "conversion";
                return JIM_ERR;
            } else if (*fmt == 'u' && descr->modifier == 'l') {
                fmtObj->error = "unsigned wide not supported";
                return JIM_ERR;
            }
        }
        curr++;
    }
done:
    if (fmtObj->convCount == 0) {
        fmtObj->error = "no any conversion specifier given";
        return JIM_ERR;
    }
    return JIM_OK;
}

/* Some accessor macros to allow lowlevel access to fields of internal repr */

#define FormatGetCnvCount(_fo_) \
    ((ScanFmtStringObj*)((_fo_)->internalRep.ptr))->convCount
#define FormatGetMaxPos(_fo_) \
    ((ScanFmtStringObj*)((_fo_)->internalRep.ptr))->maxPos
#define FormatGetError(_fo_) \
    ((ScanFmtStringObj*)((_fo_)->internalRep.ptr))->error

/* Some Bit testing/setting/cleaning routines. For now only used in handling
 * charsets ([a-z123]) within scanning. Later on perhaps a base for a 
 * bitvector implementation in Jim? */ 

static int JimTestBit(const char *bitvec, char ch)
{
    div_t pos = div(ch-1, 8);
    return bitvec[pos.quot] & (1 << pos.rem);
}

static void JimSetBit(char *bitvec, char ch)
{
    div_t pos = div(ch-1, 8);
    bitvec[pos.quot] |= (1 << pos.rem);
}

#if 0 /* currently not used */
static void JimClearBit(char *bitvec, char ch)
{
    div_t pos = div(ch-1, 8);
    bitvec[pos.quot] &= ~(1 << pos.rem);
}
#endif

/* JimScanAString is used to scan an unspecified string that ends with
 * next WS, or a string that is specified via a charset. The charset
 * is currently implemented in a way to only allow for usage with
 * ASCII. Whenever we will switch to UNICODE, another idea has to
 * be born :-/
 *
 * FIXME: Works only with ASCII */

static Jim_Obj *
JimScanAString(Jim_Interp *interp, const char *sdescr, const char *str)
{
    size_t i;
    Jim_Obj *result;
    char charset[256/8+1];  /* A Charset may contain max 256 chars */
    char *buffer = Jim_Alloc(strlen(str)+1), *anchor = buffer;

    /* First init charset to nothing or all, depending if a specified
     * or an unspecified string has to be parsed */
    memset(charset, (sdescr ? 0 : 255), sizeof(charset));
    if (sdescr) {
        /* There was a set description given, that means we are parsing
         * a specified string. So we have to build a corresponding 
         * charset reflecting the description */
        int notFlag = 0;
        /* Should the set be negated at the end? */
        if (*sdescr == '^') {
            notFlag = 1;
            ++sdescr;
        }
        /* Here '-' is meant literally and not to define a range */
        if (*sdescr == '-') {
            JimSetBit(charset, '-');
            ++sdescr;
        }
        while (*sdescr) {
            if (sdescr[1] == '-' && sdescr[2] != 0) {
                /* Handle range definitions */
                int i;
                for (i=sdescr[0]; i <= sdescr[2]; ++i)
                    JimSetBit(charset, i);
                sdescr += 3;
            } else {
                /* Handle verbatim character definitions */
                JimSetBit(charset, *sdescr++);
            }
        }
        /* Negate the charset if there was a NOT given */
        for (i=0; notFlag && i < sizeof(charset); ++i)
            charset[i] = ~charset[i];
    } 
    /* And after all the mess above, the real work begin ... */
    while (str && *str) {
        if (!sdescr && isspace((int)*str))
            break; /* EOS via WS if unspecified */
        if (JimTestBit(charset, *str)) *buffer++ = *str++;
        else break;             /* EOS via mismatch if specified scanning */
    }
    *buffer = 0;                /* Close the string properly ... */
    result = Jim_NewStringObj(interp, anchor, -1);
    Jim_Free(anchor);           /* ... and free it afer usage */
    return result;
}

/* ScanOneEntry will scan one entry out of the string passed as argument.
 * It use the sscanf() function for this task. After extracting and
 * converting of the value, the count of scanned characters will be
 * returned of -1 in case of no conversion tool place and string was
 * already scanned thru */

static int ScanOneEntry(Jim_Interp *interp, const char *str, long pos,
        ScanFmtStringObj *fmtObj, long index, Jim_Obj **valObjPtr)
{
#   define MAX_SIZE (sizeof(jim_wide) > sizeof(double) \
        ? sizeof(jim_wide)                             \
        : sizeof(double))
    char buffer[MAX_SIZE];
    char *value = buffer;
    const char *tok;
    const ScanFmtPartDescr *descr = &fmtObj->descr[index];
    size_t sLen = strlen(&str[pos]), scanned = 0;
    size_t anchor = pos;
    int i;

    /* First pessimiticly assume, we will not scan anything :-) */
    *valObjPtr = 0;
    if (descr->prefix) {
        /* There was a prefix given before the conversion, skip it and adjust
         * the string-to-be-parsed accordingly */
        for (i=0; str[pos] && descr->prefix[i]; ++i) {
            /* If prefix require, skip WS */
            if (isspace((int)descr->prefix[i]))
                while (str[pos] && isspace((int)str[pos])) ++pos;
            else if (descr->prefix[i] != str[pos]) 
                break;  /* Prefix do not match here, leave the loop */
            else
                ++pos;  /* Prefix matched so far, next round */
        }
        if (str[pos] == 0)
            return -1;  /* All of str consumed: EOF condition */
        else if (descr->prefix[i] != 0)
            return 0;   /* Not whole prefix consumed, no conversion possible */
    }
    /* For all but following conversion, skip leading WS */
    if (descr->type != 'c' && descr->type != '[' && descr->type != 'n')
        while (isspace((int)str[pos])) ++pos;
    /* Determine how much skipped/scanned so far */
    scanned = pos - anchor;
    if (descr->type == 'n') {
        /* Return pseudo conversion means: how much scanned so far? */
        *valObjPtr = Jim_NewIntObj(interp, anchor + scanned);
    } else if (str[pos] == 0) {
        /* Cannot scan anything, as str is totally consumed */
        return -1;
    } else {
        /* Processing of conversions follows ... */
        if (descr->width > 0) {
            /* Do not try to scan as fas as possible but only the given width.
             * To ensure this, we copy the part that should be scanned. */
            size_t tLen = descr->width > sLen ? sLen : descr->width;
            tok = Jim_StrDupLen(&str[pos], tLen);
        } else {
            /* As no width was given, simply refer to the original string */
            tok = &str[pos];
        }
        switch (descr->type) {
            case 'c':
                *valObjPtr = Jim_NewIntObj(interp, *tok);
                scanned += 1;
                break;
            case 'd': case 'o': case 'x': case 'u': case 'i': {
                char *endp;  /* Position where the number finished */
                int base = descr->type == 'o' ? 8
                    : descr->type == 'x' ? 16
                    : descr->type == 'i' ? 0
                    : 10;
                    
                do {
                    /* Try to scan a number with the given base */
                    if (descr->modifier == 'l')
#ifdef HAVE_LONG_LONG
                      *(jim_wide*)value = JimStrtoll(tok, &endp, base);
#else
                      *(jim_wide*)value = strtol(tok, &endp, base);
#endif
                    else
                      if (descr->type == 'u')
                        *(long*)value = strtoul(tok, &endp, base);
                      else
                        *(long*)value = strtol(tok, &endp, base);
                    /* If scanning failed, and base was undetermined, simply
                     * put it to 10 and try once more. This should catch the
                     * case where %i begin to parse a number prefix (e.g. 
                     * '0x' but no further digits follows. This will be
                     * handled as a ZERO followed by a char 'x' by Tcl */
                    if (endp == tok && base == 0) base = 10;
                    else break;
                } while (1);
                if (endp != tok) {
                    /* There was some number sucessfully scanned! */
                    if (descr->modifier == 'l')
                        *valObjPtr = Jim_NewIntObj(interp, *(jim_wide*)value);
                    else
                        *valObjPtr = Jim_NewIntObj(interp, *(long*)value);
                    /* Adjust the number-of-chars scanned so far */
                    scanned += endp - tok;
                } else {
                    /* Nothing was scanned. We have to determine if this
                     * happened due to e.g. prefix mismatch or input str
                     * exhausted */
                    scanned = *tok ? 0 : -1;
                }
                break;
            }
            case 's': case '[': {
                *valObjPtr = JimScanAString(interp, descr->arg, tok);
                scanned += Jim_Length(*valObjPtr);
                break;
            }
            case 'e': case 'f': case 'g': {
                char *endp;

                *(double*)value = strtod(tok, &endp);
                if (endp != tok) {
                    /* There was some number sucessfully scanned! */
                    *valObjPtr = Jim_NewDoubleObj(interp, *(double*)value);
                    /* Adjust the number-of-chars scanned so far */
                    scanned += endp - tok;
                } else {
                    /* Nothing was scanned. We have to determine if this
                     * happened due to e.g. prefix mismatch or input str
                     * exhausted */
                    scanned = *tok ? 0 : -1;
                }
                break;
            }
        }
        /* If a substring was allocated (due to pre-defined width) do not
         * forget to free it */
        if (tok != &str[pos])
            Jim_Free((char*)tok);
    }
    return scanned;
}

/* Jim_ScanString is the workhorse of string scanning. It will scan a given
 * string and returns all converted (and not ignored) values in a list back
 * to the caller. If an error occured, a NULL pointer will be returned */

Jim_Obj *Jim_ScanString(Jim_Interp *interp, Jim_Obj *strObjPtr,
        Jim_Obj *fmtObjPtr, int flags)
{
    size_t i, pos;
    int scanned = 1;
    const char *str = Jim_GetString(strObjPtr, 0);
    Jim_Obj *resultList = 0;
    Jim_Obj **resultVec;
    int resultc;
    Jim_Obj *emptyStr = 0;
    ScanFmtStringObj *fmtObj;

    /* If format specification is not an object, convert it! */
    if (fmtObjPtr->typePtr != &scanFmtStringObjType)
        SetScanFmtFromAny(interp, fmtObjPtr);
    fmtObj = (ScanFmtStringObj*)fmtObjPtr->internalRep.ptr;
    /* Check if format specification was valid */
    if (fmtObj->error != 0) {
        if (flags & JIM_ERRMSG)
            Jim_SetResultString(interp, fmtObj->error, -1);
        return 0;
    }
    /* Allocate a new "shared" empty string for all unassigned conversions */
    emptyStr = Jim_NewEmptyStringObj(interp);
    Jim_IncrRefCount(emptyStr);
    /* Create a list and fill it with empty strings up to max specified XPG3 */
    resultList = Jim_NewListObj(interp, 0, 0);
    if (fmtObj->maxPos > 0) {
        for (i=0; i < fmtObj->maxPos; ++i)
            Jim_ListAppendElement(interp, resultList, emptyStr);
        JimListGetElements(interp, resultList, &resultc, &resultVec);
    }
    /* Now handle every partial format description */
    for (i=0, pos=0; i < fmtObj->count; ++i) {
        ScanFmtPartDescr *descr = &(fmtObj->descr[i]);
        Jim_Obj *value = 0;
        /* Only last type may be "literal" w/o conversion - skip it! */
        if (descr->type == 0) continue;
        /* As long as any conversion could be done, we will proceed */
        if (scanned > 0)
            scanned = ScanOneEntry(interp, str, pos, fmtObj, i, &value);
        /* In case our first try results in EOF, we will leave */
        if (scanned == -1 && i == 0)
            goto eof;
        /* Advance next pos-to-be-scanned for the amount scanned already */
        pos += scanned;
        /* value == 0 means no conversion took place so take empty string */
        if (value == 0)
            value = Jim_NewEmptyStringObj(interp);
        /* If value is a non-assignable one, skip it */
        if (descr->pos == -1) {
            Jim_FreeNewObj(interp, value);
        } else if (descr->pos == 0)
            /* Otherwise append it to the result list if no XPG3 was given */
            Jim_ListAppendElement(interp, resultList, value);
        else if (resultVec[descr->pos-1] == emptyStr) {
            /* But due to given XPG3, put the value into the corr. slot */
            Jim_DecrRefCount(interp, resultVec[descr->pos-1]);
            Jim_IncrRefCount(value);
            resultVec[descr->pos-1] = value;
        } else {
            /* Otherwise, the slot was already used - free obj and ERROR */
            Jim_FreeNewObj(interp, value);
            goto err;
        }
    }
    Jim_DecrRefCount(interp, emptyStr);
    return resultList;
eof:
    Jim_DecrRefCount(interp, emptyStr);
    Jim_FreeNewObj(interp, resultList);
    return (Jim_Obj*)EOF;
err:
    Jim_DecrRefCount(interp, emptyStr);
    Jim_FreeNewObj(interp, resultList);
    return 0;
}

/* -----------------------------------------------------------------------------
 * Pseudo Random Number Generation
 * ---------------------------------------------------------------------------*/
static void JimPrngSeed(Jim_Interp *interp, const unsigned char *seed,
        int seedLen);

/* Initialize the sbox with the numbers from 0 to 255 */
static void JimPrngInit(Jim_Interp *interp)
{
    int i;
    unsigned int seed[256];

    interp->prngState = Jim_Alloc(sizeof(Jim_PrngState));
    for (i = 0; i < 256; i++)
        seed[i] = (rand() ^ time(NULL) ^ clock());
    JimPrngSeed(interp, (unsigned char*) seed, sizeof(int)*256);
}

/* Generates N bytes of random data */
static void JimRandomBytes(Jim_Interp *interp, void *dest, unsigned int len)
{
    Jim_PrngState *prng;
    unsigned char *destByte = (unsigned char*) dest;
    unsigned int si, sj, x;

    /* initialization, only needed the first time */
    if (interp->prngState == NULL)
        JimPrngInit(interp);
    prng = interp->prngState;
    /* generates 'len' bytes of pseudo-random numbers */
    for (x = 0; x < len; x++) {
        prng->i = (prng->i+1) & 0xff;
        si = prng->sbox[prng->i];
        prng->j = (prng->j + si) & 0xff;
        sj = prng->sbox[prng->j];
        prng->sbox[prng->i] = sj;
        prng->sbox[prng->j] = si;
        *destByte++ = prng->sbox[(si+sj)&0xff];
    }
}

/* Re-seed the generator with user-provided bytes */
static void JimPrngSeed(Jim_Interp *interp, const unsigned char *seed,
        int seedLen)
{
    int i;
    unsigned char buf[256];
    Jim_PrngState *prng;

    /* initialization, only needed the first time */
    if (interp->prngState == NULL)
        JimPrngInit(interp);
    prng = interp->prngState;

    /* Set the sbox[i] with i */
    for (i = 0; i < 256; i++)
        prng->sbox[i] = i;
    /* Now use the seed to perform a random permutation of the sbox */
    for (i = 0; i < seedLen; i++) {
        unsigned char t;

        t = prng->sbox[i&0xFF];
        prng->sbox[i&0xFF] = prng->sbox[seed[i]];
        prng->sbox[seed[i]] = t;
    }
    prng->i = prng->j = 0;
    /* discard the first 256 bytes of stream. */
    JimRandomBytes(interp, buf, 256);
}

/* -----------------------------------------------------------------------------
 * Dynamic libraries support (WIN32 not supported)
 * ---------------------------------------------------------------------------*/

#ifdef JIM_DYNLIB
#ifdef WIN32
#define RTLD_LAZY 0
void * dlopen(const char *path, int mode) 
{
    JIM_NOTUSED(mode);

    return (void *)LoadLibraryA(path);
}
int dlclose(void *handle)
{
    FreeLibrary((HANDLE)handle);
    return 0;
}
void *dlsym(void *handle, const char *symbol)
{
    return GetProcAddress((HMODULE)handle, symbol);
}
static char win32_dlerror_string[121];
const char *dlerror()
{
    FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(),
                   LANG_NEUTRAL, win32_dlerror_string, 120, NULL);
    return win32_dlerror_string;
}
#endif /* WIN32 */

int Jim_LoadLibrary(Jim_Interp *interp, const char *pathName)
{
    Jim_Obj *libPathObjPtr;
    int prefixc, i;
    void *handle;
    int (*onload)(Jim_Interp *interp);

    libPathObjPtr = Jim_GetGlobalVariableStr(interp, "jim_libpath", JIM_NONE);
    if (libPathObjPtr == NULL) {
        prefixc = 0;
        libPathObjPtr = NULL;
    } else {
        Jim_IncrRefCount(libPathObjPtr);
        Jim_ListLength(interp, libPathObjPtr, &prefixc);
    }

    for (i = -1; i < prefixc; i++) {
        if (i < 0) {
            handle = dlopen(pathName, RTLD_LAZY);
        } else {
            FILE *fp;
            char buf[JIM_PATH_LEN];
            const char *prefix;
            int prefixlen;
            Jim_Obj *prefixObjPtr;
            
            buf[0] = '\0';
            if (Jim_ListIndex(interp, libPathObjPtr, i,
                    &prefixObjPtr, JIM_NONE) != JIM_OK)
                continue;
            prefix = Jim_GetString(prefixObjPtr, NULL);
            prefixlen = strlen(prefix);
            if (prefixlen+strlen(pathName)+1 >= JIM_PATH_LEN)
                continue;
            if (prefixlen && prefix[prefixlen-1] == '/')
                sprintf(buf, "%s%s", prefix, pathName);
            else
                sprintf(buf, "%s/%s", prefix, pathName);
            fp = fopen(buf, "r");
            if (fp == NULL)
                continue;
            fclose(fp);
            handle = dlopen(buf, RTLD_LAZY);
        }
        if (handle == NULL) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "error loading extension \"", pathName,
                "\": ", dlerror(), NULL);
            if (i < 0)
                continue;
            goto err;
        }
        if ((onload = dlsym(handle, "Jim_OnLoad")) == NULL) {
            Jim_SetResultString(interp,
                    "No Jim_OnLoad symbol found on extension", -1);
            goto err;
        }
        if (onload(interp) == JIM_ERR) {
            dlclose(handle);
            goto err;
        }
        Jim_SetEmptyResult(interp);
        if (libPathObjPtr != NULL)
            Jim_DecrRefCount(interp, libPathObjPtr);
        return JIM_OK;
    }
err:
    if (libPathObjPtr != NULL)
        Jim_DecrRefCount(interp, libPathObjPtr);
    return JIM_ERR;
}
#else /* JIM_DYNLIB */
int Jim_LoadLibrary(Jim_Interp *interp, const char *pathName)
{
    JIM_NOTUSED(interp);
    JIM_NOTUSED(pathName);

    Jim_SetResultString(interp, "the Jim binary has no support for [load]", -1);
    return JIM_ERR;
}
#endif/* JIM_DYNLIB */

/* -----------------------------------------------------------------------------
 * Packages handling
 * ---------------------------------------------------------------------------*/

#define JIM_PKG_ANY_VERSION -1

/* Convert a string of the type "1.2" into an integer.
 * MAJOR.MINOR is converted as MAJOR*100+MINOR, so "1.2" is converted 
 * to the integer with value 102 */
static int JimPackageVersionToInt(Jim_Interp *interp, const char *v,
        int *intPtr, int flags)
{
    char *copy;
    jim_wide major, minor;
    char *majorStr, *minorStr, *p;

    if (v[0] == '\0') {
        *intPtr = JIM_PKG_ANY_VERSION;
        return JIM_OK;
    }

    copy = Jim_StrDup(v);
    p = strchr(copy, '.');
    if (p == NULL) goto badfmt;
    *p = '\0';
    majorStr = copy;
    minorStr = p+1;

    if (Jim_StringToWide(majorStr, &major, 10) != JIM_OK ||
        Jim_StringToWide(minorStr, &minor, 10) != JIM_OK)
        goto badfmt;
    *intPtr = (int)(major*100+minor);
    Jim_Free(copy);
    return JIM_OK;

badfmt:
    Jim_Free(copy);
    if (flags & JIM_ERRMSG) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "invalid package version '", v, "'", NULL);
    }
    return JIM_ERR;
}

#define JIM_MATCHVER_EXACT (1<<JIM_PRIV_FLAG_SHIFT)
static int JimPackageMatchVersion(int needed, int actual, int flags)
{
    if (needed == JIM_PKG_ANY_VERSION) return 1;
    if (flags & JIM_MATCHVER_EXACT) {
        return needed == actual;
    } else {
        return needed/100 == actual/100 && (needed <= actual);
    }
}

int Jim_PackageProvide(Jim_Interp *interp, const char *name, const char *ver,
        int flags)
{
    int intVersion;
    /* Check if the version format is ok */
    if (JimPackageVersionToInt(interp, ver, &intVersion, JIM_ERRMSG) != JIM_OK)
        return JIM_ERR;
    /* If the package was already provided returns an error. */
    if (Jim_FindHashEntry(&interp->packages, name) != NULL) {
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "package '", name, "' was already provided", NULL);
        }
        return JIM_ERR;
    }
    Jim_AddHashEntry(&interp->packages, name, (char*) ver);
    return JIM_OK;
}

#ifndef JIM_ANSIC

#ifndef WIN32
# include <sys/types.h>
# include <dirent.h>
#else
# include <io.h>
/* Posix dirent.h compatiblity layer for WIN32.
 * Copyright Kevlin Henney, 1997, 2003. All rights reserved.
 * Copyright Salvatore Sanfilippo ,2005.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose is hereby granted without fee, provided
 * that this copyright and permissions notice appear in all copies and
 * derivatives.
 *
 * This software is supplied "as is" without express or implied warranty.
 * This software was modified by Salvatore Sanfilippo for the Jim Interpreter.
 */

struct dirent {
    char *d_name;
};

typedef struct DIR {
    long                handle; /* -1 for failed rewind */
    struct _finddata_t  info;
    struct dirent       result; /* d_name null iff first time */
    char                *name;  /* null-terminated char string */
} DIR;

DIR *opendir(const char *name)
{
    DIR *dir = 0;

    if(name && name[0]) {
        size_t base_length = strlen(name);
        const char *all = /* search pattern must end with suitable wildcard */
            strchr("/\\", name[base_length - 1]) ? "*" : "/*";

        if((dir = (DIR *) Jim_Alloc(sizeof *dir)) != 0 &&
           (dir->name = (char *) Jim_Alloc(base_length + strlen(all) + 1)) != 0)
        {
            strcat(strcpy(dir->name, name), all);

            if((dir->handle = (long) _findfirst(dir->name, &dir->info)) != -1)
                dir->result.d_name = 0;
            else { /* rollback */
                Jim_Free(dir->name);
                Jim_Free(dir);
                dir = 0;
            }
        } else { /* rollback */
            Jim_Free(dir);
            dir   = 0;
            errno = ENOMEM;
        }
    } else {
        errno = EINVAL;
    }
    return dir;
}

int closedir(DIR *dir)
{
    int result = -1;

    if(dir) {
        if(dir->handle != -1)
            result = _findclose(dir->handle);
        Jim_Free(dir->name);
        Jim_Free(dir);
    }
    if(result == -1) /* map all errors to EBADF */
        errno = EBADF;
    return result;
}

struct dirent *readdir(DIR *dir)
{
    struct dirent *result = 0;

    if(dir && dir->handle != -1) {
        if(!dir->result.d_name || _findnext(dir->handle, &dir->info) != -1) {
            result         = &dir->result;
            result->d_name = dir->info.name;
        }
    } else {
        errno = EBADF;
    }
    return result;
}

#endif /* WIN32 */

static char *JimFindBestPackage(Jim_Interp *interp, char **prefixes,
        int prefixc, const char *pkgName, int pkgVer, int flags)
{
    int bestVer = -1, i;
    int pkgNameLen = strlen(pkgName);
    char *bestPackage = NULL;
    struct dirent *de;

    for (i = 0; i < prefixc; i++) {
        DIR *dir;
        char buf[JIM_PATH_LEN];
        int prefixLen;

        if (prefixes[i] == NULL) continue;
        strncpy(buf, prefixes[i], JIM_PATH_LEN);
        buf[JIM_PATH_LEN-1] = '\0';
        prefixLen = strlen(buf);
        if (prefixLen && buf[prefixLen-1] == '/')
            buf[prefixLen-1] = '\0';

        if ((dir = opendir(buf)) == NULL) continue;
        while ((de = readdir(dir)) != NULL) {
            char *fileName = de->d_name;
            int fileNameLen = strlen(fileName);

            if (strncmp(fileName, "jim-", 4) == 0 &&
                strncmp(fileName+4, pkgName, pkgNameLen) == 0 &&
                *(fileName+4+pkgNameLen) == '-' &&
                fileNameLen > 4 && /* note that this is not really useful */
                (strncmp(fileName+fileNameLen-4, ".tcl", 4) == 0 ||
                 strncmp(fileName+fileNameLen-4, ".dll", 4) == 0 ||
                 strncmp(fileName+fileNameLen-3, ".so", 3) == 0))
            {
                char ver[6]; /* xx.yy<nulterm> */
                char *p = strrchr(fileName, '.');
                int verLen, fileVer;

                verLen = p - (fileName+4+pkgNameLen+1);
                if (verLen < 3 || verLen > 5) continue;
                memcpy(ver, fileName+4+pkgNameLen+1, verLen);
                ver[verLen] = '\0';
                if (JimPackageVersionToInt(interp, ver, &fileVer, JIM_NONE)
                        != JIM_OK) continue;
                if (JimPackageMatchVersion(pkgVer, fileVer, flags) &&
                    (bestVer == -1 || bestVer < fileVer))
                {
                    bestVer = fileVer;
                    Jim_Free(bestPackage);
                    bestPackage = Jim_Alloc(strlen(buf)+strlen(fileName)+2);
                    sprintf(bestPackage, "%s/%s", buf, fileName);
                }
            }
        }
        closedir(dir);
    }
    return bestPackage;
}

#else /* JIM_ANSIC */

static char *JimFindBestPackage(Jim_Interp *interp, char **prefixes,
        int prefixc, const char *pkgName, int pkgVer, int flags)
{
    JIM_NOTUSED(interp);
    JIM_NOTUSED(prefixes);
    JIM_NOTUSED(prefixc);
    JIM_NOTUSED(pkgName);
    JIM_NOTUSED(pkgVer);
    JIM_NOTUSED(flags);
    return NULL;
}

#endif /* JIM_ANSIC */

/* Search for a suitable package under every dir specified by jim_libpath
 * and load it if possible. If a suitable package was loaded with success
 * JIM_OK is returned, otherwise JIM_ERR is returned. */
static int JimLoadPackage(Jim_Interp *interp, const char *name, int ver,
        int flags)
{
    Jim_Obj *libPathObjPtr;
    char **prefixes, *best;
    int prefixc, i, retCode = JIM_OK;

    libPathObjPtr = Jim_GetGlobalVariableStr(interp, "jim_libpath", JIM_NONE);
    if (libPathObjPtr == NULL) {
        prefixc = 0;
        libPathObjPtr = NULL;
    } else {
        Jim_IncrRefCount(libPathObjPtr);
        Jim_ListLength(interp, libPathObjPtr, &prefixc);
    }

    prefixes = Jim_Alloc(sizeof(char*)*prefixc);
    for (i = 0; i < prefixc; i++) {
            Jim_Obj *prefixObjPtr;
            if (Jim_ListIndex(interp, libPathObjPtr, i,
                    &prefixObjPtr, JIM_NONE) != JIM_OK)
            {
                prefixes[i] = NULL;
                continue;
            }
            prefixes[i] = Jim_StrDup(Jim_GetString(prefixObjPtr, NULL));
    }
    /* Scan every directory to find the "best" package. */
    best = JimFindBestPackage(interp, prefixes, prefixc, name, ver, flags);
    if (best != NULL) {
        char *p = strrchr(best, '.');
        /* Try to load/source it */
        if (p && strcmp(p, ".tcl") == 0) {
            retCode = Jim_EvalFile(interp, best);
        } else {
            retCode = Jim_LoadLibrary(interp, best);
        }
    } else {
        retCode = JIM_ERR;
    }
    Jim_Free(best);
    for (i = 0; i < prefixc; i++)
        Jim_Free(prefixes[i]);
    Jim_Free(prefixes);
    if (libPathObjPtr)
        Jim_DecrRefCount(interp, libPathObjPtr);
    return retCode;
}

const char *Jim_PackageRequire(Jim_Interp *interp, const char *name,
        const char *ver, int flags)
{
    Jim_HashEntry *he;
    int requiredVer;

    if (JimPackageVersionToInt(interp, ver, &requiredVer, JIM_ERRMSG) != JIM_OK)
        return NULL;
    he = Jim_FindHashEntry(&interp->packages, name);
    if (he == NULL) {
        /* Try to load the package. */
        if (JimLoadPackage(interp, name, requiredVer, flags) == JIM_OK) {
            he = Jim_FindHashEntry(&interp->packages, name);
            if (he == NULL) {
                return "?";
            }
            return he->val;
        }
        /* No way... return an error. */
        if (flags & JIM_ERRMSG) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "Can't find package '", name, "'", NULL);
        }
        return NULL;
    } else {
        int actualVer;
        if (JimPackageVersionToInt(interp, he->val, &actualVer, JIM_ERRMSG)
                != JIM_OK)
        {
            return NULL;
        }
        /* Check if version matches. */
        if (JimPackageMatchVersion(requiredVer, actualVer, flags) == 0) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                    "Package '", name, "' already loaded, but with version ",
                    he->val, NULL);
            return NULL;
        }
        return he->val;
    }
}

/* -----------------------------------------------------------------------------
 * Eval
 * ---------------------------------------------------------------------------*/
#define JIM_EVAL_SARGV_LEN 8 /* static arguments vector length */
#define JIM_EVAL_SINTV_LEN 8 /* static interpolation vector length */

static int JimCallProcedure(Jim_Interp *interp, Jim_Cmd *cmd, int argc,
        Jim_Obj *const *argv);

/* Handle calls to the [unknown] command */
static int JimUnknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
    Jim_Obj **v, *sv[JIM_EVAL_SARGV_LEN];
    int retCode;

    /* If the [unknown] command does not exists returns
     * just now */
    if (Jim_GetCommand(interp, interp->unknown, JIM_NONE) == NULL)
        return JIM_ERR;

    /* The object interp->unknown just contains
     * the "unknown" string, it is used in order to
     * avoid to lookup the unknown command every time
     * but instread to cache the result. */
    if (argc+1 <= JIM_EVAL_SARGV_LEN)
        v = sv;
    else
        v = Jim_Alloc(sizeof(Jim_Obj*)*(argc+1));
    /* Make a copy of the arguments vector, but shifted on
     * the right of one position. The command name of the
     * command will be instead the first argument of the
     * [unknonw] call. */
    memcpy(v+1, argv, sizeof(Jim_Obj*)*argc);
    v[0] = interp->unknown;
    /* Call it */
    retCode = Jim_EvalObjVector(interp, argc+1, v);
    /* Clean up */
    if (v != sv)
        Jim_Free(v);
    return retCode;
}

/* Eval the object vector 'objv' composed of 'objc' elements.
 * Every element is used as single argument.
 * Jim_EvalObj() will call this function every time its object
 * argument is of "list" type, with no string representation.
 *
 * This is possible because the string representation of a
 * list object generated by the UpdateStringOfList is made
 * in a way that ensures that every list element is a different
 * command argument. */
int Jim_EvalObjVector(Jim_Interp *interp, int objc, Jim_Obj *const *objv)
{
    int i, retcode;
    Jim_Cmd *cmdPtr;

    /* Incr refcount of arguments. */
    for (i = 0; i < objc; i++)
        Jim_IncrRefCount(objv[i]);
    /* Command lookup */
    cmdPtr = Jim_GetCommand(interp, objv[0], JIM_ERRMSG);
    if (cmdPtr == NULL) {
        retcode = JimUnknown(interp, objc, objv);
    } else {
        /* Call it -- Make sure result is an empty object. */
        Jim_SetEmptyResult(interp);
        if (cmdPtr->cmdProc) {
            interp->cmdPrivData = cmdPtr->privData;
            retcode = cmdPtr->cmdProc(interp, objc, objv);
        } else {
            retcode = JimCallProcedure(interp, cmdPtr, objc, objv);
            if (retcode == JIM_ERR) {
                JimAppendStackTrace(interp,
                    Jim_GetString(objv[0], NULL), "?", 1);
            }
        }
    }
    /* Decr refcount of arguments and return the retcode */
    for (i = 0; i < objc; i++)
        Jim_DecrRefCount(interp, objv[i]);
    return retcode;
}

/* Interpolate the given tokens into a unique Jim_Obj returned by reference
 * via *objPtrPtr. This function is only called by Jim_EvalObj().
 * The returned object has refcount = 0. */
int Jim_InterpolateTokens(Jim_Interp *interp, ScriptToken *token,
        int tokens, Jim_Obj **objPtrPtr)
{
    int totlen = 0, i, retcode;
    Jim_Obj **intv;
    Jim_Obj *sintv[JIM_EVAL_SINTV_LEN];
    Jim_Obj *objPtr;
    char *s;

    if (tokens <= JIM_EVAL_SINTV_LEN)
        intv = sintv;
    else
        intv = Jim_Alloc(sizeof(Jim_Obj*)*
                tokens);
    /* Compute every token forming the argument
     * in the intv objects vector. */
    for (i = 0; i < tokens; i++) {
        switch(token[i].type) {
        case JIM_TT_ESC:
        case JIM_TT_STR:
            intv[i] = token[i].objPtr;
            break;
        case JIM_TT_VAR:
            intv[i] = Jim_GetVariable(interp, token[i].objPtr, JIM_ERRMSG);
            if (!intv[i]) {
                retcode = JIM_ERR;
                goto err;
            }
            break;
        case JIM_TT_DICTSUGAR:
            intv[i] = Jim_ExpandDictSugar(interp, token[i].objPtr);
            if (!intv[i]) {
                retcode = JIM_ERR;
                goto err;
            }
            break;
        case JIM_TT_CMD:
            retcode = Jim_EvalObj(interp, token[i].objPtr);
            if (retcode != JIM_OK)
                goto err;
            intv[i] = Jim_GetResult(interp);
            break;
        default:
            Jim_Panic(
              "default token type reached "
              "in Jim_InterpolateTokens().");
            break;
        }
        Jim_IncrRefCount(intv[i]);
        /* Make sure there is a valid
         * string rep, and add the string
         * length to the total legnth. */
        Jim_GetString(intv[i], NULL);
        totlen += intv[i]->length;
    }
    /* Concatenate every token in an unique
     * object. */
    objPtr = Jim_NewStringObjNoAlloc(interp,
            NULL, 0);
    s = objPtr->bytes = Jim_Alloc(totlen+1);
    objPtr->length = totlen;
    for (i = 0; i < tokens; i++) {
        memcpy(s, intv[i]->bytes, intv[i]->length);
        s += intv[i]->length;
        Jim_DecrRefCount(interp, intv[i]);
    }
    objPtr->bytes[totlen] = '\0';
    /* Free the intv vector if not static. */
    if (tokens > JIM_EVAL_SINTV_LEN)
        Jim_Free(intv);
    *objPtrPtr = objPtr;
    return JIM_OK;
err:
    i--;
    for (; i >= 0; i--)
        Jim_DecrRefCount(interp, intv[i]);
    if (tokens > JIM_EVAL_SINTV_LEN)
        Jim_Free(intv);
    return retcode;
}

/* Helper of Jim_EvalObj() to perform argument expansion.
 * Basically this function append an argument to 'argv'
 * (and increments argc by reference accordingly), performing
 * expansion of the list object if 'expand' is non-zero, or
 * just adding objPtr to argv if 'expand' is zero. */
void Jim_ExpandArgument(Jim_Interp *interp, Jim_Obj ***argv,
        int *argcPtr, int expand, Jim_Obj *objPtr)
{
    if (!expand) {
        (*argv) = Jim_Realloc(*argv, sizeof(Jim_Obj*)*((*argcPtr)+1));
        /* refcount of objPtr not incremented because
         * we are actually transfering a reference from
         * the old 'argv' to the expanded one. */
        (*argv)[*argcPtr] = objPtr;
        (*argcPtr)++;
    } else {
        int len, i;

        Jim_ListLength(interp, objPtr, &len);
        (*argv) = Jim_Realloc(*argv, sizeof(Jim_Obj*)*((*argcPtr)+len));
        for (i = 0; i < len; i++) {
            (*argv)[*argcPtr] = objPtr->internalRep.listValue.ele[i];
            Jim_IncrRefCount(objPtr->internalRep.listValue.ele[i]);
            (*argcPtr)++;
        }
        /* The original object reference is no longer needed,
         * after the expansion it is no longer present on
         * the argument vector, but the single elements are
         * in its place. */
        Jim_DecrRefCount(interp, objPtr);
    }
}

int Jim_EvalObj(Jim_Interp *interp, Jim_Obj *scriptObjPtr)
{
    int i, j = 0, len;
    ScriptObj *script;
    ScriptToken *token;
    int *cs; /* command structure array */
    int retcode = JIM_OK;
    Jim_Obj *sargv[JIM_EVAL_SARGV_LEN], **argv = NULL, *tmpObjPtr;

    interp->errorFlag = 0;

    /* If the object is of type "list" and there is no
     * string representation for this object, we can call
     * a specialized version of Jim_EvalObj() */
    if (scriptObjPtr->typePtr == &listObjType &&
        scriptObjPtr->internalRep.listValue.len &&
        scriptObjPtr->bytes == NULL) {
        Jim_IncrRefCount(scriptObjPtr);
        retcode = Jim_EvalObjVector(interp,
                scriptObjPtr->internalRep.listValue.len,
                scriptObjPtr->internalRep.listValue.ele);
        Jim_DecrRefCount(interp, scriptObjPtr);
        return retcode;
    }

    Jim_IncrRefCount(scriptObjPtr); /* Make sure it's shared. */
    script = Jim_GetScript(interp, scriptObjPtr);
    /* Now we have to make sure the internal repr will not be
     * freed on shimmering.
     *
     * Think for example to this:
     *
     * set x {llength $x; ... some more code ...}; eval $x
     *
     * In order to preserve the internal rep, we increment the
     * inUse field of the script internal rep structure. */
    script->inUse++;

    token = script->token;
    len = script->len;
    cs = script->cmdStruct;
    i = 0; /* 'i' is the current token index. */

    /* Reset the interpreter result. This is useful to
     * return the emtpy result in the case of empty program. */
    Jim_SetEmptyResult(interp);

    /* Execute every command sequentially, returns on
     * error (i.e. if a command does not return JIM_OK) */
    while (i < len) {
        int expand = 0;
        int argc = *cs++; /* Get the number of arguments */
        Jim_Cmd *cmd;

        /* Set the expand flag if needed. */
        if (argc == -1) {
            expand++;
            argc = *cs++;
        }
        /* Allocate the arguments vector */
        if (argc <= JIM_EVAL_SARGV_LEN)
            argv = sargv;
        else
            argv = Jim_Alloc(sizeof(Jim_Obj*)*argc);
        /* Populate the arguments objects. */
        for (j = 0; j < argc; j++) {
            int tokens = *cs++;

            /* tokens is negative if expansion is needed.
             * for this argument. */
            if (tokens < 0) {
                tokens = (-tokens)-1;
                i++;
            }
            if (tokens == 1) {
                /* Fast path if the token does not
                 * need interpolation */
                switch(token[i].type) {
                case JIM_TT_ESC:
                case JIM_TT_STR:
                    argv[j] = token[i].objPtr;
                    break;
                case JIM_TT_VAR:
                    tmpObjPtr = Jim_GetVariable(interp, token[i].objPtr,
                            JIM_ERRMSG);
                    if (!tmpObjPtr) {
                        retcode = JIM_ERR;
                        goto err;
                    }
                    argv[j] = tmpObjPtr;
                    break;
                case JIM_TT_DICTSUGAR:
                    tmpObjPtr = Jim_ExpandDictSugar(interp, token[i].objPtr);
                    if (!tmpObjPtr) {
                        retcode = JIM_ERR;
                        goto err;
                    }
                    argv[j] = tmpObjPtr;
                    break;
                case JIM_TT_CMD:
                    retcode = Jim_EvalObj(interp, token[i].objPtr);
                    if (retcode != JIM_OK)
                        goto err;
                    argv[j] = Jim_GetResult(interp);
                    break;
                default:
                    Jim_Panic(
                      "default token type reached "
                      "in Jim_EvalObj().");
                    break;
                }
                Jim_IncrRefCount(argv[j]);
                i += 2;
            } else {
                /* For interpolation we call an helper
                 * function doing the work for us. */
                if ((retcode = Jim_InterpolateTokens(interp,
                        token+i, tokens, &tmpObjPtr)) != JIM_OK)
                {
                    goto err;
                }
                argv[j] = tmpObjPtr;
                Jim_IncrRefCount(argv[j]);
                i += tokens+1;
            }
        }
        /* Handle {expand} expansion */
        if (expand) {
            int *ecs = cs - argc;
            int eargc = 0;
            Jim_Obj **eargv = NULL;

            for (j = 0; j < argc; j++) {
                Jim_ExpandArgument( interp, &eargv, &eargc,
                        ecs[j] < 0, argv[j]);
            }
            if (argv != sargv)
                Jim_Free(argv);
            argc = eargc;
            argv = eargv;
            j = argc;
            if (argc == 0) {
                /* Nothing to do with zero args. */
                Jim_Free(eargv);
                continue;
            }
        }
        /* Lookup the command to call */
        cmd = Jim_GetCommand(interp, argv[0], JIM_ERRMSG);
        if (cmd != NULL) {
            /* Call it -- Make sure result is an empty object. */
            Jim_SetEmptyResult(interp);
            if (cmd->cmdProc) {
                interp->cmdPrivData = cmd->privData;
                retcode = cmd->cmdProc(interp, argc, argv);
            } else {
                retcode = JimCallProcedure(interp, cmd, argc, argv);
                if (retcode == JIM_ERR) {
                    JimAppendStackTrace(interp,
                        Jim_GetString(argv[0], NULL), script->fileName,
                        token[i-argc*2].linenr);
                }
            }
        } else {
            /* Call [unknown] */
            retcode = JimUnknown(interp, argc, argv);
        }
        if (retcode != JIM_OK) {
            i -= argc*2; /* point to the command name. */
            goto err;
        }
        /* Decrement the arguments count */
        for (j = 0; j < argc; j++) {
            Jim_DecrRefCount(interp, argv[j]);
        }

        if (argv != sargv) {
            Jim_Free(argv);
            argv = NULL;
        }
    }
    /* Note that we don't have to decrement inUse, because the
     * following code transfers our use of the reference again to
     * the script object. */
    j = 0; /* on normal termination, the argv array is already
          Jim_DecrRefCount-ed. */
err:
    /* Handle errors. */
    if (retcode == JIM_ERR && !interp->errorFlag) {
        interp->errorFlag = 1;
        JimSetErrorFileName(interp, script->fileName);
        JimSetErrorLineNumber(interp, token[i].linenr);
        JimResetStackTrace(interp);
    }
    Jim_FreeIntRep(interp, scriptObjPtr);
    scriptObjPtr->typePtr = &scriptObjType;
    Jim_SetIntRepPtr(scriptObjPtr, script);
    Jim_DecrRefCount(interp, scriptObjPtr);
    for (i = 0; i < j; i++) {
        Jim_DecrRefCount(interp, argv[i]);
    }
    if (argv != sargv)
        Jim_Free(argv);
    return retcode;
}

/* Call a procedure implemented in Tcl.
 * It's possible to speed-up a lot this function, currently
 * the callframes are not cached, but allocated and
 * destroied every time. What is expecially costly is
 * to create/destroy the local vars hash table every time.
 *
 * This can be fixed just implementing callframes caching
 * in JimCreateCallFrame() and JimFreeCallFrame(). */
int JimCallProcedure(Jim_Interp *interp, Jim_Cmd *cmd, int argc,
        Jim_Obj *const *argv)
{
    int i, retcode;
    Jim_CallFrame *callFramePtr;

    /* Check arity */
    if (argc < cmd->arityMin || (cmd->arityMax != -1 &&
        argc > cmd->arityMax)) {
        Jim_Obj *objPtr = Jim_NewEmptyStringObj(interp);
        Jim_AppendStrings(interp, objPtr,
            "wrong # args: should be \"", Jim_GetString(argv[0], NULL),
            (cmd->arityMin > 1) ? " " : "",
            Jim_GetString(cmd->argListObjPtr, NULL), "\"", NULL);
        Jim_SetResult(interp, objPtr);
        return JIM_ERR;
    }
    /* Check if there are too nested calls */
    if (interp->numLevels == interp->maxNestingDepth) {
        Jim_SetResultString(interp,
            "Too many nested calls. Infinite recursion?", -1);
        return JIM_ERR;
    }
    /* Create a new callframe */
    callFramePtr = JimCreateCallFrame(interp);
    callFramePtr->parentCallFrame = interp->framePtr;
    callFramePtr->argv = argv;
    callFramePtr->argc = argc;
    callFramePtr->procArgsObjPtr = cmd->argListObjPtr;
    callFramePtr->procBodyObjPtr = cmd->bodyObjPtr;
    callFramePtr->staticVars = cmd->staticVars;
    Jim_IncrRefCount(cmd->argListObjPtr);
    Jim_IncrRefCount(cmd->bodyObjPtr);
    interp->framePtr = callFramePtr;
    interp->numLevels ++;
    /* Set arguments */
    for (i = 0; i < cmd->arityMin-1; i++) {
        Jim_Obj *objPtr;

        Jim_ListIndex(interp, cmd->argListObjPtr, i, &objPtr, JIM_NONE);
        Jim_SetVariable(interp, objPtr, argv[i+1]);
    }
    if (cmd->arityMax == -1) {
        Jim_Obj *listObjPtr, *objPtr;

        listObjPtr = Jim_NewListObj(interp, argv+cmd->arityMin,
                argc-cmd->arityMin);
        Jim_ListIndex(interp, cmd->argListObjPtr, i, &objPtr, JIM_NONE);
        Jim_SetVariable(interp, objPtr, listObjPtr);
    }
    /* Eval the body */
    retcode = Jim_EvalObj(interp, cmd->bodyObjPtr);

    /* Destroy the callframe */
    interp->numLevels --;
    interp->framePtr = interp->framePtr->parentCallFrame;
    if (callFramePtr->vars.size != JIM_HT_INITIAL_SIZE) {
        JimFreeCallFrame(interp, callFramePtr, JIM_FCF_NONE);
    } else {
        JimFreeCallFrame(interp, callFramePtr, JIM_FCF_NOHT);
    }
    /* Handle the JIM_EVAL return code */
    if (retcode == JIM_EVAL && interp->evalRetcodeLevel != interp->numLevels) {
        int savedLevel = interp->evalRetcodeLevel;

        interp->evalRetcodeLevel = interp->numLevels;
        while (retcode == JIM_EVAL) {
            Jim_Obj *resultScriptObjPtr = Jim_GetResult(interp);
            Jim_IncrRefCount(resultScriptObjPtr);
            retcode = Jim_EvalObj(interp, resultScriptObjPtr);
            Jim_DecrRefCount(interp, resultScriptObjPtr);
        }
        interp->evalRetcodeLevel = savedLevel;
    }
    /* Handle the JIM_RETURN return code */
    if (retcode == JIM_RETURN) {
        retcode = interp->returnCode;
        interp->returnCode = JIM_OK;
    }
    return retcode;
}

int Jim_Eval(Jim_Interp *interp, const char *script)
{
    Jim_Obj *scriptObjPtr = Jim_NewStringObj(interp, script, -1);
    int retval;

    Jim_IncrRefCount(scriptObjPtr);
    retval = Jim_EvalObj(interp, scriptObjPtr);
    Jim_DecrRefCount(interp, scriptObjPtr);
    return retval;
}

/* Execute script in the scope of the global level */
int Jim_EvalGlobal(Jim_Interp *interp, const char *script)
{
    Jim_CallFrame *savedFramePtr;
    int retval;

    savedFramePtr = interp->framePtr;
    interp->framePtr = interp->topFramePtr;
    retval = Jim_Eval(interp, script);
    interp->framePtr = savedFramePtr;
    return retval;
}

int Jim_EvalObjBackground(Jim_Interp *interp, Jim_Obj *scriptObjPtr)
{
    Jim_CallFrame *savedFramePtr;
    int retval;

    savedFramePtr = interp->framePtr;
    interp->framePtr = interp->topFramePtr;
    retval = Jim_EvalObj(interp, scriptObjPtr);
    interp->framePtr = savedFramePtr;
    /* Try to report the error (if any) via the bgerror proc */
    if (retval != JIM_OK) {
        Jim_Obj *objv[2];

        objv[0] = Jim_NewStringObj(interp, "bgerror", -1);
        objv[1] = Jim_GetResult(interp);
        Jim_IncrRefCount(objv[0]);
        Jim_IncrRefCount(objv[1]);
        if (Jim_EvalObjVector(interp, 2, objv) != JIM_OK) {
            /* Report the error to stderr. */
            fprintf(stderr, "Background error:\n");
            Jim_PrintErrorMessage(interp);
        }
        Jim_DecrRefCount(interp, objv[0]);
        Jim_DecrRefCount(interp, objv[1]);
    }
    return retval;
}

int Jim_EvalFile(Jim_Interp *interp, const char *filename)
{
    char *prg = NULL;
    FILE *fp;
    int nread, totread, maxlen, buflen;
    int retval;
    Jim_Obj *scriptObjPtr;
    
    if ((fp = fopen(filename, "r")) == NULL) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "Error loading script \"", filename, "\": ",
            strerror(errno), NULL);
        return JIM_ERR;
    }
    buflen = 1024;
    maxlen = totread = 0;
    while (1) {
        if (maxlen < totread+buflen+1) {
            maxlen = totread+buflen+1;
            prg = Jim_Realloc(prg, maxlen);
        }
        if ((nread = fread(prg+totread, 1, buflen, fp)) == 0) break;
        totread += nread;
    }
    prg[totread] = '\0';
    fclose(fp);

    scriptObjPtr = Jim_NewStringObjNoAlloc(interp, prg, totread);
    JimSetSourceInfo(interp, scriptObjPtr, filename, 1);
    Jim_IncrRefCount(scriptObjPtr);
    retval = Jim_EvalObj(interp, scriptObjPtr);
    Jim_DecrRefCount(interp, scriptObjPtr);
    return retval;
}

/* -----------------------------------------------------------------------------
 * Subst
 * ---------------------------------------------------------------------------*/
static int JimParseSubstStr(struct JimParserCtx *pc)
{
    pc->tstart = pc->p;
    pc->tline = pc->linenr;
    while (*pc->p && *pc->p != '$' && *pc->p != '[') {
        pc->p++; pc->len--;
    }
    pc->tend = pc->p-1;
    pc->tt = JIM_TT_ESC;
    return JIM_OK;
}

static int JimParseSubst(struct JimParserCtx *pc, int flags)
{
    int retval;

    if (pc->len == 0) {
        pc->tstart = pc->tend = pc->p;
        pc->tline = pc->linenr;
        pc->tt = JIM_TT_EOL;
        pc->eof = 1;
        return JIM_OK;
    }
    switch(*pc->p) {
    case '[':
        retval = JimParseCmd(pc);
        if (flags & JIM_SUBST_NOCMD) {
            pc->tstart--;
            pc->tend++;
            pc->tt = (flags & JIM_SUBST_NOESC) ?
                JIM_TT_STR : JIM_TT_ESC;
        }
        return retval;
        break;
    case '$':
        if (JimParseVar(pc) == JIM_ERR) {
            pc->tstart = pc->tend = pc->p++; pc->len--;
            pc->tline = pc->linenr;
            pc->tt = JIM_TT_STR;
        } else {
            if (flags & JIM_SUBST_NOVAR) {
                pc->tstart--;
                if (flags & JIM_SUBST_NOESC)
                    pc->tt = JIM_TT_STR;
                else
                    pc->tt = JIM_TT_ESC;
                if (*pc->tstart == '{') {
                    pc->tstart--;
                    if (*(pc->tend+1))
                        pc->tend++;
                }
            }
        }
        break;
    default:
        retval = JimParseSubstStr(pc);
        if (flags & JIM_SUBST_NOESC)
            pc->tt = JIM_TT_STR;
        return retval;
        break;
    }
    return JIM_OK;
}

/* The subst object type reuses most of the data structures and functions
 * of the script object. Script's data structures are a bit more complex
 * for what is needed for [subst]itution tasks, but the reuse helps to
 * deal with a single data structure at the cost of some more memory
 * usage for substitutions. */
static Jim_ObjType substObjType = {
    "subst",
    FreeScriptInternalRep,
    DupScriptInternalRep,
    NULL,
    JIM_TYPE_REFERENCES,
};

/* This method takes the string representation of an object
 * as a Tcl string where to perform [subst]itution, and generates
 * the pre-parsed internal representation. */
int SetSubstFromAny(Jim_Interp *interp, struct Jim_Obj *objPtr, int flags)
{
    int scriptTextLen;
    const char *scriptText = Jim_GetString(objPtr, &scriptTextLen);
    struct JimParserCtx parser;
    struct ScriptObj *script = Jim_Alloc(sizeof(*script));

    script->len = 0;
    script->csLen = 0;
    script->commands = 0;
    script->token = NULL;
    script->cmdStruct = NULL;
    script->inUse = 1;
    script->substFlags = flags;
    script->fileName = NULL;

    JimParserInit(&parser, scriptText, scriptTextLen, 1);
    while(1) {
        char *token;
        int len, type, linenr;

        JimParseSubst(&parser, flags);
        if (JimParserEof(&parser)) break;
        token = JimParserGetToken(&parser, &len, &type, &linenr);
        ScriptObjAddToken(interp, script, token, len, type,
                NULL, linenr);
    }
    /* Free the old internal rep and set the new one. */
    Jim_FreeIntRep(interp, objPtr);
    Jim_SetIntRepPtr(objPtr, script);
    objPtr->typePtr = &scriptObjType;
    return JIM_OK;
}

ScriptObj *Jim_GetSubst(Jim_Interp *interp, Jim_Obj *objPtr, int flags)
{
    struct ScriptObj *script = Jim_GetIntRepPtr(objPtr);

    if (objPtr->typePtr != &substObjType || script->substFlags != flags)
        SetSubstFromAny(interp, objPtr, flags);
    return (ScriptObj*) Jim_GetIntRepPtr(objPtr);
}

/* Performs commands,variables,blackslashes substitution,
 * storing the result object (with refcount 0) into
 * resObjPtrPtr. */
int Jim_SubstObj(Jim_Interp *interp, Jim_Obj *substObjPtr,
        Jim_Obj **resObjPtrPtr, int flags)
{
    ScriptObj *script;
    ScriptToken *token;
    int i, len, retcode = JIM_OK;
    Jim_Obj *resObjPtr, *savedResultObjPtr;

    script = Jim_GetSubst(interp, substObjPtr, flags);
#ifdef JIM_OPTIMIZATION
    /* Fast path for a very common case with array-alike syntax,
     * that's: $foo($bar) */
    if (script->len == 1 && script->token[0].type == JIM_TT_VAR) {
        Jim_Obj *varObjPtr = script->token[0].objPtr;
        
        Jim_IncrRefCount(varObjPtr);
        resObjPtr = Jim_GetVariable(interp, varObjPtr, JIM_ERRMSG);
        if (resObjPtr == NULL) {
            Jim_DecrRefCount(interp, varObjPtr);
            return JIM_ERR;
        }
        Jim_DecrRefCount(interp, varObjPtr);
        *resObjPtrPtr = resObjPtr;
        return JIM_OK;
    }
#endif

    Jim_IncrRefCount(substObjPtr); /* Make sure it's shared. */
    /* In order to preserve the internal rep, we increment the
     * inUse field of the script internal rep structure. */
    script->inUse++;

    token = script->token;
    len = script->len;

    /* Save the interp old result, to set it again before
     * to return. */
    savedResultObjPtr = interp->result;
    Jim_IncrRefCount(savedResultObjPtr);
    
    /* Perform the substitution. Starts with an empty object
     * and adds every token (performing the appropriate
     * var/command/escape substitution). */
    resObjPtr = Jim_NewStringObj(interp, "", 0);
    for (i = 0; i < len; i++) {
        Jim_Obj *objPtr;

        switch(token[i].type) {
        case JIM_TT_STR:
        case JIM_TT_ESC:
            Jim_AppendObj(interp, resObjPtr, token[i].objPtr);
            break;
        case JIM_TT_VAR:
            objPtr = Jim_GetVariable(interp, token[i].objPtr, JIM_ERRMSG);
            if (objPtr == NULL) goto err;
            Jim_IncrRefCount(objPtr);
            Jim_AppendObj(interp, resObjPtr, objPtr);
            Jim_DecrRefCount(interp, objPtr);
            break;
        case JIM_TT_CMD:
            if (Jim_EvalObj(interp, token[i].objPtr) != JIM_OK)
                goto err;
            Jim_AppendObj(interp, resObjPtr, interp->result);
            break;
        default:
            Jim_Panic(
              "default token type (%d) reached "
              "in Jim_SubstObj().", token[i].type);
            break;
        }
    }
ok:
    if (retcode == JIM_OK)
        Jim_SetResult(interp, savedResultObjPtr);
    Jim_DecrRefCount(interp, savedResultObjPtr);
    /* Note that we don't have to decrement inUse, because the
     * following code transfers our use of the reference again to
     * the script object. */
    Jim_FreeIntRep(interp, substObjPtr);
    substObjPtr->typePtr = &scriptObjType;
    Jim_SetIntRepPtr(substObjPtr, script);
    Jim_DecrRefCount(interp, substObjPtr);
    *resObjPtrPtr = resObjPtr;
    return retcode;
err:
    Jim_FreeNewObj(interp, resObjPtr);
    retcode = JIM_ERR;
    goto ok;
}

/* -----------------------------------------------------------------------------
 * API Input/Export functions
 * ---------------------------------------------------------------------------*/

int Jim_GetApi(Jim_Interp *interp, const char *funcname, void *targetPtrPtr)
{
    Jim_HashEntry *he;

    he = Jim_FindHashEntry(&interp->stub, funcname);
    if (!he)
        return JIM_ERR;
    memcpy(targetPtrPtr, &he->val, sizeof(void*));
    return JIM_OK;
}

int Jim_RegisterApi(Jim_Interp *interp, const char *funcname, void *funcptr)
{
    return Jim_AddHashEntry(&interp->stub, funcname, funcptr);
}

#define JIM_REGISTER_API(name) \
    Jim_RegisterApi(interp, "Jim_" #name, (void *)Jim_ ## name)

void JimRegisterCoreApi(Jim_Interp *interp)
{
  interp->getApiFuncPtr = Jim_GetApi;
  JIM_REGISTER_API(Alloc);
  JIM_REGISTER_API(Free);
  JIM_REGISTER_API(Eval);
  JIM_REGISTER_API(EvalGlobal);
  JIM_REGISTER_API(EvalFile);
  JIM_REGISTER_API(EvalObj);
  JIM_REGISTER_API(EvalObjBackground);
  JIM_REGISTER_API(EvalObjVector);
  JIM_REGISTER_API(InitHashTable);
  JIM_REGISTER_API(ExpandHashTable);
  JIM_REGISTER_API(AddHashEntry);
  JIM_REGISTER_API(ReplaceHashEntry);
  JIM_REGISTER_API(DeleteHashEntry);
  JIM_REGISTER_API(FreeHashTable);
  JIM_REGISTER_API(FindHashEntry);
  JIM_REGISTER_API(ResizeHashTable);
  JIM_REGISTER_API(GetHashTableIterator);
  JIM_REGISTER_API(NextHashEntry);
  JIM_REGISTER_API(NewObj);
  JIM_REGISTER_API(FreeObj);
  JIM_REGISTER_API(InvalidateStringRep);
  JIM_REGISTER_API(InitStringRep);
  JIM_REGISTER_API(DuplicateObj);
  JIM_REGISTER_API(GetString);
  JIM_REGISTER_API(Length);
  JIM_REGISTER_API(InvalidateStringRep);
  JIM_REGISTER_API(NewStringObj);
  JIM_REGISTER_API(NewStringObjNoAlloc);
  JIM_REGISTER_API(AppendString);
  JIM_REGISTER_API(AppendObj);
  JIM_REGISTER_API(AppendStrings);
  JIM_REGISTER_API(StringEqObj);
  JIM_REGISTER_API(StringMatchObj);
  JIM_REGISTER_API(StringRangeObj);
  JIM_REGISTER_API(FormatString);
  JIM_REGISTER_API(CompareStringImmediate);
  JIM_REGISTER_API(NewReference);
  JIM_REGISTER_API(GetReference);
  JIM_REGISTER_API(SetFinalizer);
  JIM_REGISTER_API(GetFinalizer);
  JIM_REGISTER_API(CreateInterp);
  JIM_REGISTER_API(FreeInterp);
  JIM_REGISTER_API(CreateCommand);
  JIM_REGISTER_API(CreateProcedure);
  JIM_REGISTER_API(DeleteCommand);
  JIM_REGISTER_API(RenameCommand);
  JIM_REGISTER_API(GetCommand);
  JIM_REGISTER_API(SetVariable);
  JIM_REGISTER_API(SetVariableStr);
  JIM_REGISTER_API(SetGlobalVariableStr);
  JIM_REGISTER_API(SetVariableStrWithStr);
  JIM_REGISTER_API(SetVariableLink);
  JIM_REGISTER_API(GetVariable);
  JIM_REGISTER_API(GetCallFrameByLevel);
  JIM_REGISTER_API(Collect);
  JIM_REGISTER_API(CollectIfNeeded);
  JIM_REGISTER_API(GetIndex);
  JIM_REGISTER_API(NewListObj);
  JIM_REGISTER_API(ListAppendElement);
  JIM_REGISTER_API(ListAppendList);
  JIM_REGISTER_API(ListLength);
  JIM_REGISTER_API(ListIndex);
  JIM_REGISTER_API(SetListIndex);
  JIM_REGISTER_API(ConcatObj);
  JIM_REGISTER_API(NewDictObj);
  JIM_REGISTER_API(DictKey);
  JIM_REGISTER_API(DictKeysVector);
  JIM_REGISTER_API(GetIndex);
  JIM_REGISTER_API(GetReturnCode);
  JIM_REGISTER_API(EvalExpression);
  JIM_REGISTER_API(GetBoolFromExpr);
  JIM_REGISTER_API(GetWide);
  JIM_REGISTER_API(GetLong);
  JIM_REGISTER_API(SetWide);
  JIM_REGISTER_API(NewIntObj);
  JIM_REGISTER_API(GetDouble);
  JIM_REGISTER_API(SetDouble);
  JIM_REGISTER_API(NewDoubleObj);
  JIM_REGISTER_API(WrongNumArgs);
  JIM_REGISTER_API(SetDictKeysVector);
  JIM_REGISTER_API(SubstObj);
  JIM_REGISTER_API(RegisterApi);
  JIM_REGISTER_API(PrintErrorMessage);
  JIM_REGISTER_API(InteractivePrompt);
  JIM_REGISTER_API(RegisterCoreCommands);
  JIM_REGISTER_API(GetSharedString);
  JIM_REGISTER_API(ReleaseSharedString);
  JIM_REGISTER_API(Panic);
  JIM_REGISTER_API(StrDup);
  JIM_REGISTER_API(UnsetVariable);
  JIM_REGISTER_API(GetVariableStr);
  JIM_REGISTER_API(GetGlobalVariable);
  JIM_REGISTER_API(GetGlobalVariableStr);
  JIM_REGISTER_API(GetAssocData);
  JIM_REGISTER_API(SetAssocData);
  JIM_REGISTER_API(DeleteAssocData);
  JIM_REGISTER_API(GetEnum);
  JIM_REGISTER_API(ScriptIsComplete);
  JIM_REGISTER_API(PackageRequire);
  JIM_REGISTER_API(PackageProvide);
  JIM_REGISTER_API(InitStack);
  JIM_REGISTER_API(FreeStack);
  JIM_REGISTER_API(StackLen);
  JIM_REGISTER_API(StackPush);
  JIM_REGISTER_API(StackPop);
  JIM_REGISTER_API(StackPeek);
  JIM_REGISTER_API(FreeStackElements);
}

/* -----------------------------------------------------------------------------
 * Core commands utility functions
 * ---------------------------------------------------------------------------*/
void Jim_WrongNumArgs(Jim_Interp *interp, int argc, Jim_Obj *const *argv, 
        const char *msg)
{
    int i;
    Jim_Obj *objPtr = Jim_NewEmptyStringObj(interp);

    Jim_AppendString(interp, objPtr, "wrong # args: should be \"", -1);
    for (i = 0; i < argc; i++) {
        Jim_AppendObj(interp, objPtr, argv[i]);
        if (!(i+1 == argc && msg[0] == '\0'))
            Jim_AppendString(interp, objPtr, " ", 1);
    }
    Jim_AppendString(interp, objPtr, msg, -1);
    Jim_AppendString(interp, objPtr, "\"", 1);
    Jim_SetResult(interp, objPtr);
}

static Jim_Obj *JimCommandsList(Jim_Interp *interp, Jim_Obj *patternObjPtr)
{
    Jim_HashTableIterator *htiter;
    Jim_HashEntry *he;
    Jim_Obj *listObjPtr = Jim_NewListObj(interp, NULL, 0);
    const char *pattern;
    int patternLen;
    
    pattern = patternObjPtr ? Jim_GetString(patternObjPtr, &patternLen) : NULL;
    htiter = Jim_GetHashTableIterator(&interp->commands);
    while ((he = Jim_NextHashEntry(htiter)) != NULL) {
        if (pattern && !JimStringMatch(pattern, patternLen, he->key, 
                    strlen((const char*)he->key), 0))
            continue;
        Jim_ListAppendElement(interp, listObjPtr,
                Jim_NewStringObj(interp, he->key, -1));
    }
    Jim_FreeHashTableIterator(htiter);
    return listObjPtr;
}

#define JIM_VARLIST_GLOBALS 0
#define JIM_VARLIST_LOCALS 1
#define JIM_VARLIST_VARS 2

static Jim_Obj *JimVariablesList(Jim_Interp *interp, Jim_Obj *patternObjPtr,
        int mode)
{
    Jim_HashTableIterator *htiter;
    Jim_HashEntry *he;
    Jim_Obj *listObjPtr = Jim_NewListObj(interp, NULL, 0);
    const char *pattern;
    int patternLen;
    
    pattern = patternObjPtr ? Jim_GetString(patternObjPtr, &patternLen) : NULL;
    if (mode == JIM_VARLIST_GLOBALS) {
        htiter = Jim_GetHashTableIterator(&interp->topFramePtr->vars);
    } else {
        /* For [info locals], if we are at top level an emtpy list
         * is returned. I don't agree, but we aim at compatibility (SS) */
        if (mode == JIM_VARLIST_LOCALS &&
            interp->framePtr == interp->topFramePtr)
            return listObjPtr;
        htiter = Jim_GetHashTableIterator(&interp->framePtr->vars);
    }
    while ((he = Jim_NextHashEntry(htiter)) != NULL) {
        Jim_Var *varPtr = (Jim_Var*) he->val;
        if (mode == JIM_VARLIST_LOCALS) {
            if (varPtr->linkFramePtr != NULL)
                continue;
        }
        if (pattern && !JimStringMatch(pattern, patternLen, he->key, 
                    strlen((const char*)he->key), 0))
            continue;
        Jim_ListAppendElement(interp, listObjPtr,
                Jim_NewStringObj(interp, he->key, -1));
    }
    Jim_FreeHashTableIterator(htiter);
    return listObjPtr;
}

static int JimInfoLevel(Jim_Interp *interp, Jim_Obj *levelObjPtr,
        Jim_Obj **objPtrPtr)
{
    Jim_CallFrame *targetCallFrame;

    if (JimGetCallFrameByInteger(interp, levelObjPtr, &targetCallFrame)
            != JIM_OK)
        return JIM_ERR;
    /* No proc call at toplevel callframe */
    if (targetCallFrame == interp->topFramePtr) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "bad level \"",
                Jim_GetString(levelObjPtr, NULL), "\"", NULL);
        return JIM_ERR;
    }
    *objPtrPtr = Jim_NewListObj(interp,
            targetCallFrame->argv,
            targetCallFrame->argc);
    return JIM_OK;
}

/* -----------------------------------------------------------------------------
 * Core commands
 * ---------------------------------------------------------------------------*/

/* fake [puts] -- not the real puts, just for debugging. */
static int Jim_PutsCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    const char *str;
    int len, nonewline = 0;
    
    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "-nonewline string");
        return JIM_ERR;
    }
    if (argc == 3) {
        if (!Jim_CompareStringImmediate(interp, argv[1], "-nonewline"))
        {
            Jim_SetResultString(interp, "The second argument must "
                    "be -nonewline", -1);
            return JIM_OK;
        } else {
            nonewline = 1;
            argv++;
        }
    }
    str = Jim_GetString(argv[1], &len);
    fwrite(str, 1, len, stdout);
    if (!nonewline) printf("\n");
    return JIM_OK;
}

/* Helper for [+] and [*] */
static int Jim_AddMulHelper(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv, int op)
{
    jim_wide wideValue, res;
    double doubleValue, doubleRes;
    int i;

    res = (op == JIM_EXPROP_ADD) ? 0 : 1;
    
    for (i = 1; i < argc; i++) {
        if (Jim_GetWide(interp, argv[i], &wideValue) != JIM_OK)
            goto trydouble;
        if (op == JIM_EXPROP_ADD)
            res += wideValue;
        else
            res *= wideValue;
    }
    Jim_SetResult(interp, Jim_NewIntObj(interp, res));
    return JIM_OK;
trydouble:
    doubleRes = (double) res;
    for (;i < argc; i++) {
        if (Jim_GetDouble(interp, argv[i], &doubleValue) != JIM_OK)
            return JIM_ERR;
        if (op == JIM_EXPROP_ADD)
            doubleRes += doubleValue;
        else
            doubleRes *= doubleValue;
    }
    Jim_SetResult(interp, Jim_NewDoubleObj(interp, doubleRes));
    return JIM_OK;
}

/* Helper for [-] and [/] */
static int Jim_SubDivHelper(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv, int op)
{
    jim_wide wideValue, res = 0;
    double doubleValue, doubleRes = 0;
    int i = 2;

    /* The arity = 2 case is different. For [- x] returns -x,
     * while [/ x] returns 1/x. */
    if (argc == 2) {
        if (Jim_GetWide(interp, argv[1], &wideValue) != JIM_OK) {
            if (Jim_GetDouble(interp, argv[1], &doubleValue) !=
                    JIM_OK)
            {
                return JIM_ERR;
            } else {
                if (op == JIM_EXPROP_SUB)
                    doubleRes = -doubleValue;
                else
                    doubleRes = 1.0/doubleValue;
                Jim_SetResult(interp, Jim_NewDoubleObj(interp,
                            doubleRes));
                return JIM_OK;
            }
        }
        if (op == JIM_EXPROP_SUB) {
            res = -wideValue;
            Jim_SetResult(interp, Jim_NewIntObj(interp, res));
        } else {
            doubleRes = 1.0/wideValue;
            Jim_SetResult(interp, Jim_NewDoubleObj(interp,
                        doubleRes));
        }
        return JIM_OK;
    } else {
        if (Jim_GetWide(interp, argv[1], &res) != JIM_OK) {
            if (Jim_GetDouble(interp, argv[1], &doubleRes)
                    != JIM_OK) {
                return JIM_ERR;
            } else {
                goto trydouble;
            }
        }
    }
    for (i = 2; i < argc; i++) {
        if (Jim_GetWide(interp, argv[i], &wideValue) != JIM_OK) {
            doubleRes = (double) res;
            goto trydouble;
        }
        if (op == JIM_EXPROP_SUB)
            res -= wideValue;
        else
            res /= wideValue;
    }
    Jim_SetResult(interp, Jim_NewIntObj(interp, res));
    return JIM_OK;
trydouble:
    for (;i < argc; i++) {
        if (Jim_GetDouble(interp, argv[i], &doubleValue) != JIM_OK)
            return JIM_ERR;
        if (op == JIM_EXPROP_SUB)
            doubleRes -= doubleValue;
        else
            doubleRes /= doubleValue;
    }
    Jim_SetResult(interp, Jim_NewDoubleObj(interp, doubleRes));
    return JIM_OK;
}


/* [+] */
static int Jim_AddCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    return Jim_AddMulHelper(interp, argc, argv, JIM_EXPROP_ADD);
}

/* [*] */
static int Jim_MulCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    return Jim_AddMulHelper(interp, argc, argv, JIM_EXPROP_MUL);
}

/* [-] */
static int Jim_SubCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    return Jim_SubDivHelper(interp, argc, argv, JIM_EXPROP_SUB);
}

/* [/] */
static int Jim_DivCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    return Jim_SubDivHelper(interp, argc, argv, JIM_EXPROP_DIV);
}

/* [set] */
static int Jim_SetCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?newValue?");
        return JIM_ERR;
    }
    if (argc == 2) {
        Jim_Obj *objPtr;
        objPtr = Jim_GetVariable(interp, argv[1], JIM_ERRMSG);
        if (!objPtr)
            return JIM_ERR;
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    }
    /* argc == 3 case. */
    if (Jim_SetVariable(interp, argv[1], argv[2]) != JIM_OK)
        return JIM_ERR;
    Jim_SetResult(interp, argv[2]);
    return JIM_OK;
}

/* [unset] */
static int Jim_UnsetCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int i;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?varName ...?");
        return JIM_ERR;
    }
    for (i = 1; i < argc; i++) {
        if (Jim_UnsetVariable(interp, argv[i], JIM_ERRMSG) != JIM_OK)
            return JIM_ERR;
    }
    return JIM_OK;
}

/* [incr] */
static int Jim_IncrCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    jim_wide wideValue, increment = 1;
    Jim_Obj *intObjPtr;

    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?increment?");
        return JIM_ERR;
    }
    if (argc == 3) {
        if (Jim_GetWide(interp, argv[2], &increment) != JIM_OK)
            return JIM_ERR;
    }
    intObjPtr = Jim_GetVariable(interp, argv[1], JIM_ERRMSG);
    if (!intObjPtr) return JIM_ERR;
    if (Jim_GetWide(interp, intObjPtr, &wideValue) != JIM_OK)
        return JIM_ERR;
    if (Jim_IsShared(intObjPtr)) {
        intObjPtr = Jim_NewIntObj(interp, wideValue+increment);
        if (Jim_SetVariable(interp, argv[1], intObjPtr) != JIM_OK) {
            Jim_FreeNewObj(interp, intObjPtr);
            return JIM_ERR;
        }
    } else {
        Jim_SetWide(interp, intObjPtr, wideValue+increment);
        /* The following step is required in order to invalidate the
         * string repr of "FOO" if the var name is on the form of "FOO(IDX)" */
        if (Jim_SetVariable(interp, argv[1], intObjPtr) != JIM_OK) {
            return JIM_ERR;
        }
    }
    Jim_SetResult(interp, intObjPtr);
    return JIM_OK;
}

/* [while] */
static int Jim_WhileCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "condition body");
        return JIM_ERR;
    }
    /* Try to run a specialized version of while if the expression
     * is in one of the following forms:
     *
     *   $a < CONST, $a < $b
     *   $a <= CONST, $a <= $b
     *   $a > CONST, $a > $b
     *   $a >= CONST, $a >= $b
     *   $a != CONST, $a != $b
     *   $a == CONST, $a == $b
     *   $a
     *   !$a
     *   CONST
     */

#ifdef JIM_OPTIMIZATION
    {
        ExprByteCode *expr;
        Jim_Obj *varAObjPtr = NULL, *varBObjPtr = NULL, *objPtr;
        int exprLen, retval;

        /* STEP 1 -- Check if there are the conditions to run the specialized
         * version of while */
        
        if ((expr = Jim_GetExpression(interp, argv[1])) == NULL) goto noopt;
        if (expr->len <= 0 || expr->len > 3) goto noopt;
        switch(expr->len) {
        case 1:
            if (expr->opcode[0] != JIM_EXPROP_VARIABLE &&
                expr->opcode[0] != JIM_EXPROP_NUMBER)
                goto noopt;
            break;
        case 2:
            if (expr->opcode[1] != JIM_EXPROP_NOT ||
                expr->opcode[0] != JIM_EXPROP_VARIABLE)
                goto noopt;
            break;
        case 3:
            if (expr->opcode[0] != JIM_EXPROP_VARIABLE ||
                (expr->opcode[1] != JIM_EXPROP_NUMBER &&
                 expr->opcode[1] != JIM_EXPROP_VARIABLE))
                goto noopt;
            switch(expr->opcode[2]) {
            case JIM_EXPROP_LT:
            case JIM_EXPROP_LTE:
            case JIM_EXPROP_GT:
            case JIM_EXPROP_GTE:
            case JIM_EXPROP_NUMEQ:
            case JIM_EXPROP_NUMNE:
                /* nothing to do */
                break;
            default:
                goto noopt;
            }
            break;
        default:
            Jim_Panic("Unexpected default reached in Jim_WhileCoreCommand()");
            break;
        }

        /* STEP 2 -- conditions meet. Initialization. Take different
         * branches for different expression lengths. */
        exprLen = expr->len;

        if (exprLen == 1) {
            jim_wide wideValue;

            if (expr->opcode[0] == JIM_EXPROP_VARIABLE) {
                varAObjPtr = expr->obj[0];
                Jim_IncrRefCount(varAObjPtr);
            } else {
                if (Jim_GetWide(interp, expr->obj[0], &wideValue) != JIM_OK)
                    goto noopt;
            }
            while (1) {
                if (varAObjPtr) {
                    if (!(objPtr =
                               Jim_GetVariable(interp, varAObjPtr, JIM_NONE)) ||
                        Jim_GetWide(interp, objPtr, &wideValue) != JIM_OK)
                    {
                        Jim_DecrRefCount(interp, varAObjPtr);
                        goto noopt;
                    }
                }
                if (!wideValue) break;
                if ((retval = Jim_EvalObj(interp, argv[2])) != JIM_OK) {
                    switch(retval) {
                    case JIM_BREAK:
                        if (varAObjPtr)
                            Jim_DecrRefCount(interp, varAObjPtr);
                        goto out;
                        break;
                    case JIM_CONTINUE:
                        continue;
                        break;
                    default:
                        if (varAObjPtr)
                            Jim_DecrRefCount(interp, varAObjPtr);
                        return retval;
                    }
                }
            }
            if (varAObjPtr)
                Jim_DecrRefCount(interp, varAObjPtr);
        } else if (exprLen == 3) {
            jim_wide wideValueA, wideValueB, cmpRes = 0;
            int cmpType = expr->opcode[2];

            varAObjPtr = expr->obj[0];
            Jim_IncrRefCount(varAObjPtr);
            if (expr->opcode[1] == JIM_EXPROP_VARIABLE) {
                varBObjPtr = expr->obj[1];
                Jim_IncrRefCount(varBObjPtr);
            } else {
                if (Jim_GetWide(interp, expr->obj[1], &wideValueB) != JIM_OK)
                    goto noopt;
            }
            while (1) {
                if (!(objPtr = Jim_GetVariable(interp, varAObjPtr, JIM_NONE)) ||
                    Jim_GetWide(interp, objPtr, &wideValueA) != JIM_OK)
                {
                    Jim_DecrRefCount(interp, varAObjPtr);
                    if (varBObjPtr)
                        Jim_DecrRefCount(interp, varBObjPtr);
                    goto noopt;
                }
                if (varBObjPtr) {
                    if (!(objPtr =
                               Jim_GetVariable(interp, varBObjPtr, JIM_NONE)) ||
                        Jim_GetWide(interp, objPtr, &wideValueB) != JIM_OK)
                    {
                        Jim_DecrRefCount(interp, varAObjPtr);
                        if (varBObjPtr)
                            Jim_DecrRefCount(interp, varBObjPtr);
                        goto noopt;
                    }
                }
                switch(cmpType) {
                case JIM_EXPROP_LT:
                    cmpRes = wideValueA < wideValueB; break;
                case JIM_EXPROP_LTE:
                    cmpRes = wideValueA <= wideValueB; break;
                case JIM_EXPROP_GT:
                    cmpRes = wideValueA > wideValueB; break;
                case JIM_EXPROP_GTE:
                    cmpRes = wideValueA >= wideValueB; break;
                case JIM_EXPROP_NUMEQ:
                    cmpRes = wideValueA == wideValueB; break;
                case JIM_EXPROP_NUMNE:
                    cmpRes = wideValueA != wideValueB; break;
                }
                if (!cmpRes) break;
                if ((retval = Jim_EvalObj(interp, argv[2])) != JIM_OK) {
                    switch(retval) {
                    case JIM_BREAK:
                        Jim_DecrRefCount(interp, varAObjPtr);
                        if (varBObjPtr)
                            Jim_DecrRefCount(interp, varBObjPtr);
                        goto out;
                        break;
                    case JIM_CONTINUE:
                        continue;
                        break;
                    default:
                        Jim_DecrRefCount(interp, varAObjPtr);
                        if (varBObjPtr)
                            Jim_DecrRefCount(interp, varBObjPtr);
                        return retval;
                    }
                }
            }
            Jim_DecrRefCount(interp, varAObjPtr);
            if (varBObjPtr)
                Jim_DecrRefCount(interp, varBObjPtr);
        } else {
            /* TODO: case for len == 2 */
            goto noopt;
        }
        Jim_SetEmptyResult(interp);
        return JIM_OK;
    }
noopt:
#endif

    /* The general purpose implementation of while starts here */
    while (1) {
        int boolean, retval;

        if ((retval = Jim_GetBoolFromExpr(interp, argv[1],
                        &boolean)) != JIM_OK)
            return retval;
        if (!boolean) break;
        if ((retval = Jim_EvalObj(interp, argv[2])) != JIM_OK) {
            switch(retval) {
            case JIM_BREAK:
                goto out;
                break;
            case JIM_CONTINUE:
                continue;
                break;
            default:
                return retval;
            }
        }
    }
out:
    Jim_SetEmptyResult(interp);
    return JIM_OK;
}

/* [for] */
static int Jim_ForCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int retval;

    if (argc != 5) {
        Jim_WrongNumArgs(interp, 1, argv, "start test next body");
        return JIM_ERR;
    }
    /* Check if the for is on the form:
     *      for {set i CONST} {$i < CONST} {incr i}
     *      for {set i CONST} {$i < $j} {incr i}
     *      for {set i CONST} {$i <= CONST} {incr i}
     *      for {set i CONST} {$i <= $j} {incr i}
     * XXX: NOTE: if variable traces are implemented, this optimization
     * need to be modified to check for the proc epoch at every variable
     * update. */
#ifdef JIM_OPTIMIZATION
    {
        ScriptObj *initScript, *incrScript;
        ExprByteCode *expr;
        jim_wide start, stop, currentVal;
        unsigned jim_wide procEpoch = interp->procEpoch;
        Jim_Obj *varNamePtr, *stopVarNamePtr = NULL, *objPtr;
        int cmpType;
        struct Jim_Cmd *cmdPtr;

        /* Do it only if there aren't shared arguments */
        if (argv[1] == argv[2] || argv[2] == argv[3] || argv[1] == argv[3])
            goto evalstart;
        initScript = Jim_GetScript(interp, argv[1]);
        expr = Jim_GetExpression(interp, argv[2]);
        incrScript = Jim_GetScript(interp, argv[3]);

        /* Ensure proper lengths to start */
        if (initScript->len != 6) goto evalstart;
        if (incrScript->len != 4) goto evalstart;
        if (expr->len != 3) goto evalstart;
        /* Ensure proper token types. */
        if (initScript->token[2].type != JIM_TT_ESC ||
            initScript->token[4].type != JIM_TT_ESC ||
            incrScript->token[2].type != JIM_TT_ESC ||
            expr->opcode[0] != JIM_EXPROP_VARIABLE ||
            (expr->opcode[1] != JIM_EXPROP_NUMBER &&
             expr->opcode[1] != JIM_EXPROP_VARIABLE) ||
            (expr->opcode[2] != JIM_EXPROP_LT &&
             expr->opcode[2] != JIM_EXPROP_LTE))
            goto evalstart;
        cmpType = expr->opcode[2];
        /* Initialization command must be [set] */
        cmdPtr = Jim_GetCommand(interp, initScript->token[0].objPtr, JIM_NONE);
        if (cmdPtr == NULL || cmdPtr->cmdProc != Jim_SetCoreCommand)
            goto evalstart;
        /* Update command must be incr */
        cmdPtr = Jim_GetCommand(interp, incrScript->token[0].objPtr, JIM_NONE);
        if (cmdPtr == NULL || cmdPtr->cmdProc != Jim_IncrCoreCommand)
            goto evalstart;
        /* set, incr, expression must be about the same variable */
        if (!Jim_StringEqObj(initScript->token[2].objPtr,
                            incrScript->token[2].objPtr, 0))
            goto evalstart;
        if (!Jim_StringEqObj(initScript->token[2].objPtr,
                            expr->obj[0], 0))
            goto evalstart;
        /* Check that the initialization and comparison are valid integers */
        if (Jim_GetWide(interp, initScript->token[4].objPtr, &start) == JIM_ERR)
            goto evalstart;
        if (expr->opcode[1] == JIM_EXPROP_NUMBER &&
            Jim_GetWide(interp, expr->obj[1], &stop) == JIM_ERR)
        {
            goto evalstart;
        }

        /* Initialization */
        varNamePtr = expr->obj[0];
        if (expr->opcode[1] == JIM_EXPROP_VARIABLE) {
            stopVarNamePtr = expr->obj[1];
            Jim_IncrRefCount(stopVarNamePtr);
        }
        Jim_IncrRefCount(varNamePtr);

        /* --- OPTIMIZED FOR --- */
        /* Start to loop */
        objPtr = Jim_NewIntObj(interp, start);
        if (Jim_SetVariable(interp, varNamePtr, objPtr) != JIM_OK) {
            Jim_DecrRefCount(interp, varNamePtr);
            if (stopVarNamePtr) Jim_DecrRefCount(interp, stopVarNamePtr);
            Jim_FreeNewObj(interp, objPtr);
            goto evalstart;
        }
        while (1) {
            /* === Check condition === */
            /* Common code: */
            objPtr = Jim_GetVariable(interp, varNamePtr, JIM_NONE);
            if (objPtr == NULL ||
                Jim_GetWide(interp, objPtr, &currentVal) != JIM_OK)
            {
                Jim_DecrRefCount(interp, varNamePtr);
                if (stopVarNamePtr) Jim_DecrRefCount(interp, stopVarNamePtr);
                goto testcond;
            }
            /* Immediate or Variable? get the 'stop' value if the latter. */
            if (stopVarNamePtr) {
                objPtr = Jim_GetVariable(interp, stopVarNamePtr, JIM_NONE);
                if (objPtr == NULL ||
                    Jim_GetWide(interp, objPtr, &stop) != JIM_OK)
                {
                    Jim_DecrRefCount(interp, varNamePtr);
                    Jim_DecrRefCount(interp, stopVarNamePtr);
                    goto testcond;
                }
            }
            if (cmpType == JIM_EXPROP_LT) {
                if (currentVal >= stop) break;
            } else {
                if (currentVal > stop) break;
            }
            /* Eval body */
            if ((retval = Jim_EvalObj(interp, argv[4])) != JIM_OK) {
                switch(retval) {
                case JIM_BREAK:
                    if (stopVarNamePtr)
                        Jim_DecrRefCount(interp, stopVarNamePtr);
                    Jim_DecrRefCount(interp, varNamePtr);
                    goto out;
                case JIM_CONTINUE:
                    /* nothing to do */
                    break;
                default:
                    if (stopVarNamePtr)
                        Jim_DecrRefCount(interp, stopVarNamePtr);
                    Jim_DecrRefCount(interp, varNamePtr);
                    return retval;
                }
            }
            /* If there was a change in procedures/command continue
             * with the usual [for] command implementation */
            if (procEpoch != interp->procEpoch) {
                if (stopVarNamePtr)
                    Jim_DecrRefCount(interp, stopVarNamePtr);
                Jim_DecrRefCount(interp, varNamePtr);
                goto evalnext;
            }
            /* Increment */
            objPtr = Jim_GetVariable(interp, varNamePtr, JIM_ERRMSG);
            if (objPtr->refCount == 1 && objPtr->typePtr == &intObjType) {
                objPtr->internalRep.wideValue ++;
                Jim_InvalidateStringRep(objPtr);
            } else {
                Jim_Obj *auxObjPtr;

                if (Jim_GetWide(interp, objPtr, &currentVal) == JIM_ERR) {
                    if (stopVarNamePtr)
                        Jim_DecrRefCount(interp, stopVarNamePtr);
                    Jim_DecrRefCount(interp, varNamePtr);
                    goto evalnext;
                }
                auxObjPtr = Jim_NewIntObj(interp, currentVal+1);
                if (Jim_SetVariable(interp, varNamePtr, auxObjPtr) == JIM_ERR) {
                    if (stopVarNamePtr)
                        Jim_DecrRefCount(interp, stopVarNamePtr);
                    Jim_DecrRefCount(interp, varNamePtr);
                    Jim_FreeNewObj(interp, auxObjPtr);
                    goto evalnext;
                }
            }
        }
        if (stopVarNamePtr)
            Jim_DecrRefCount(interp, stopVarNamePtr);
        Jim_DecrRefCount(interp, varNamePtr);
        Jim_SetEmptyResult(interp);
        return JIM_OK;
    }
#endif
evalstart:
    /* Eval start */
    if ((retval = Jim_EvalObj(interp, argv[1])) != JIM_OK)
        return retval;
    while (1) {
        int boolean;
testcond:
        /* Test the condition */
        if ((retval = Jim_GetBoolFromExpr(interp, argv[2], &boolean))
                != JIM_OK)
            return retval;
        if (!boolean) break;
        /* Eval body */
        if ((retval = Jim_EvalObj(interp, argv[4])) != JIM_OK) {
            switch(retval) {
            case JIM_BREAK:
                goto out;
                break;
            case JIM_CONTINUE:
                /* Nothing to do */
                break;
            default:
                return retval;
            }
        }
evalnext:
        /* Eval next */
        if ((retval = Jim_EvalObj(interp, argv[3])) != JIM_OK) {
            switch(retval) {
            case JIM_BREAK:
                goto out;
                break;
            case JIM_CONTINUE:
                continue;
                break;
            default:
                return retval;
            }
        }
    }
out:
    Jim_SetEmptyResult(interp);
    return JIM_OK;
}

/* foreach + lmap implementation. */
static int JimForeachMapHelper(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv, int doMap)
{
    int result = JIM_ERR, i, nbrOfLists, *listsIdx, *listsEnd;
    int nbrOfLoops = 0;
    Jim_Obj *emptyStr, *script, *mapRes = NULL;

    if (argc < 4 || argc % 2 != 0) {
        Jim_WrongNumArgs(interp, 1, argv, "varList list ?varList list ...? script");
        return JIM_ERR;
    }
    if (doMap) {
        mapRes = Jim_NewListObj(interp, NULL, 0);
        Jim_IncrRefCount(mapRes);
    }
    emptyStr = Jim_NewEmptyStringObj(interp);
    Jim_IncrRefCount(emptyStr);
    script = argv[argc-1];            /* Last argument is a script */
    nbrOfLists = (argc - 1 - 1) / 2;  /* argc - 'foreach' - script */
    listsIdx = (int*)Jim_Alloc(nbrOfLists * sizeof(int));
    listsEnd = (int*)Jim_Alloc(nbrOfLists*2 * sizeof(int));
    /* Initialize iterators and remember max nbr elements each list */
    memset(listsIdx, 0, nbrOfLists * sizeof(int));
    /* Remember lengths of all lists and calculate how much rounds to loop */
    for (i=0; i < nbrOfLists*2; i += 2) {
        div_t cnt;
        int count;
        Jim_ListLength(interp, argv[i+1], &listsEnd[i]);
        Jim_ListLength(interp, argv[i+2], &listsEnd[i+1]);
        if (listsEnd[i] == 0) {
            Jim_SetResultString(interp, "foreach varlist is empty", -1);
            goto err;
        }
        cnt = div(listsEnd[i+1], listsEnd[i]);
        count = cnt.quot + (cnt.rem ? 1 : 0);
        if (count > nbrOfLoops)
            nbrOfLoops = count;
    }
    for (; nbrOfLoops-- > 0; ) {
        for (i=0; i < nbrOfLists; ++i) {
            int varIdx = 0, var = i * 2;
            while (varIdx < listsEnd[var]) {
                Jim_Obj *varName, *ele;
                int lst = i * 2 + 1;
                if (Jim_ListIndex(interp, argv[var+1], varIdx, &varName, JIM_ERRMSG)
                        != JIM_OK)
                        goto err;
                if (listsIdx[i] < listsEnd[lst]) {
                    if (Jim_ListIndex(interp, argv[lst+1], listsIdx[i], &ele, JIM_ERRMSG)
                        != JIM_OK)
                        goto err;
                    if (Jim_SetVariable(interp, varName, ele) != JIM_OK) {
                        Jim_SetResultString(interp, "couldn't set loop variable: ", -1);
                        goto err;
                    }
                    ++listsIdx[i];  /* Remember next iterator of current list */ 
                } else if (Jim_SetVariable(interp, varName, emptyStr) != JIM_OK) {
                    Jim_SetResultString(interp, "couldn't set loop variable: ", -1);
                    goto err;
                }
                ++varIdx;  /* Next variable */
            }
        }
        switch (result = Jim_EvalObj(interp, script)) {
            case JIM_OK:
                if (doMap)
                    Jim_ListAppendElement(interp, mapRes, interp->result);
                break;
            case JIM_CONTINUE:
                break;
            case JIM_BREAK:
                goto out;
                break;
            default:
                goto err;
        }
    }
out:
    result = JIM_OK;
    if (doMap)
        Jim_SetResult(interp, mapRes);
    else
        Jim_SetEmptyResult(interp);
err:
    if (doMap)
        Jim_DecrRefCount(interp, mapRes);
    Jim_DecrRefCount(interp, emptyStr);
    Jim_Free(listsIdx);
    Jim_Free(listsEnd);
    return result;
}

/* [foreach] */
static int Jim_ForeachCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    return JimForeachMapHelper(interp, argc, argv, 0);
}

/* [lmap] */
static int Jim_LmapCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    return JimForeachMapHelper(interp, argc, argv, 1);
}

/* [if] */
static int Jim_IfCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int boolean, retval, current = 1, falsebody = 0;
    if (argc >= 3) {
        while (1) {
            /* Far not enough arguments given! */
            if (current >= argc) goto err;
            if ((retval = Jim_GetBoolFromExpr(interp,
                        argv[current++], &boolean))
                    != JIM_OK)
                return retval;
            /* There lacks something, isn't it? */
            if (current >= argc) goto err;
            if (Jim_CompareStringImmediate(interp, argv[current],
                        "then")) current++;
            /* Tsk tsk, no then-clause? */
            if (current >= argc) goto err;
            if (boolean)
                return Jim_EvalObj(interp, argv[current]);
             /* Ok: no else-clause follows */
            if (++current >= argc) return JIM_OK;
            falsebody = current++;
            if (Jim_CompareStringImmediate(interp, argv[falsebody],
                        "else")) {
                /* IIICKS - else-clause isn't last cmd? */
                if (current != argc-1) goto err;
                return Jim_EvalObj(interp, argv[current]);
            } else if (Jim_CompareStringImmediate(interp,
                        argv[falsebody], "elseif"))
                /* Ok: elseif follows meaning all the stuff
                 * again (how boring...) */
                continue;
            /* OOPS - else-clause is not last cmd?*/
            else if (falsebody != argc-1)
                goto err;
            return Jim_EvalObj(interp, argv[falsebody]);
        }
        return JIM_OK;
    }
err:
    Jim_WrongNumArgs(interp, 1, argv, "condition ?then? trueBody ?elseif ...? ?else? falseBody");
    return JIM_ERR;
}

enum {SWITCH_EXACT, SWITCH_GLOB, SWITCH_RE, SWITCH_CMD, SWITCH_UNKNOWN};

/* [switch] */
static int Jim_SwitchCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int retcode = JIM_ERR, matchOpt = SWITCH_EXACT, opt=1, patCount, i;
    Jim_Obj *command = 0, *const *caseList = 0, *strObj;
    Jim_Obj *script = 0;
    if (argc < 3) goto wrongnumargs;
    for (opt=1; opt < argc; ++opt) {
        const char *option = Jim_GetString(argv[opt], 0);
        if (*option != '-') break;
        else if (strncmp(option, "--", 2) == 0) { ++opt; break; }
        else if (strncmp(option, "-exact", 2) == 0) matchOpt = SWITCH_EXACT;
        else if (strncmp(option, "-glob", 2) == 0) matchOpt = SWITCH_GLOB;
        else if (strncmp(option, "-regexp", 2) == 0) matchOpt = SWITCH_RE;
        else if (strncmp(option, "-command", 2) == 0) { matchOpt = SWITCH_CMD;
            if ((argc - opt) < 2) goto wrongnumargs;
            command = argv[++opt]; 
        } else {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "bad option \"", option, "\": must be -exact, -glob, "
                "-regexp, -command procname or --", 0);
            goto err;            
        }
        if ((argc - opt) < 2) goto wrongnumargs;
    }
    strObj = argv[opt++];
    patCount = argc - opt;
    if (patCount == 1) {
        Jim_Obj **vector;
        JimListGetElements(interp, argv[opt], &patCount, &vector);
        caseList = vector;
    } else
        caseList = &argv[opt];
    if (patCount == 0 || patCount % 2 != 0) goto wrongnumargs;
    for (i=0; script == 0 && i < patCount; i += 2) {
        Jim_Obj *patObj = caseList[i];
        if (!Jim_CompareStringImmediate(interp, patObj, "default")
            || i < (patCount-2)) {
            switch (matchOpt) {
                case SWITCH_EXACT:
                    if (Jim_StringEqObj(strObj, patObj, 0))
                        script = caseList[i+1];
                    break;
                case SWITCH_GLOB:
                    if (Jim_StringMatchObj(patObj, strObj, 0))
                        script = caseList[i+1];
                    break;
                case SWITCH_RE:
                    command = Jim_NewStringObj(interp, "regexp", -1);
                    /* Fall thru intentionally */
                case SWITCH_CMD: {
                    Jim_Obj *parms[] = {command, patObj, strObj};
                    int rc = Jim_EvalObjVector(interp, 3, parms);
                    long matching;
                    /* After the execution of a command we need to
                     * make sure to reconvert the object into a list
                     * again. Only for the single-list style [switch]. */
                    if (argc-opt == 1) {
                        Jim_Obj **vector;
                        JimListGetElements(interp, argv[opt], &patCount,
                                &vector);
                        caseList = vector;
                    }
                    /* command is here already decref'd */
                    if (rc != JIM_OK) {
                        retcode = rc;
                        goto err;
                    }
                    rc = Jim_GetLong(interp, Jim_GetResult(interp), &matching);
                    if (rc != JIM_OK) {
                        retcode = rc;
                        goto err;
                    }
                    if (matching)
                        script = caseList[i+1];
                    break;
                }
                default:
                    Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
                    Jim_AppendStrings(interp, Jim_GetResult(interp),
                        "internal error: no such option implemented", 0);
                    goto err;
            }
        } else {
          script = caseList[i+1];
        }
    }
    for(; i < patCount && Jim_CompareStringImmediate(interp, script, "-");
        i += 2)
        script = caseList[i+1];
    if (script && Jim_CompareStringImmediate(interp, script, "-")) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "no body specified for pattern \"",
            Jim_GetString(caseList[i-2], 0), "\"", 0);
        goto err;
    }
    retcode = JIM_OK;
    Jim_SetEmptyResult(interp);
    if (script != 0)
        retcode = Jim_EvalObj(interp, script);
    return retcode;
wrongnumargs:
    Jim_WrongNumArgs(interp, 1, argv, "?options? string "
        "pattern body ... ?default body?   or   "
        "{pattern body ?pattern body ...?}");
err:
    return retcode;        
}

/* [list] */
static int Jim_ListCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Obj *listObjPtr;

    listObjPtr = Jim_NewListObj(interp, argv+1, argc-1);
    Jim_SetResult(interp, listObjPtr);
    return JIM_OK;
}

/* [lindex] */
static int Jim_LindexCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Obj *objPtr, *listObjPtr;
    int i;
    int index;

    if (argc < 3) {
        Jim_WrongNumArgs(interp, 1, argv, "list index ?...?");
        return JIM_ERR;
    }
    objPtr = argv[1];
    Jim_IncrRefCount(objPtr);
    for (i = 2; i < argc; i++) {
        listObjPtr = objPtr;
        if (Jim_GetIndex(interp, argv[i], &index) != JIM_OK) {
            Jim_DecrRefCount(interp, listObjPtr);
            return JIM_ERR;
        }
        if (Jim_ListIndex(interp, listObjPtr, index, &objPtr,
                    JIM_NONE) != JIM_OK) {
            /* Returns an empty object if the index
             * is out of range. */
            Jim_DecrRefCount(interp, listObjPtr);
            Jim_SetEmptyResult(interp);
            return JIM_OK;
        }
        Jim_IncrRefCount(objPtr);
        Jim_DecrRefCount(interp, listObjPtr);
    }
    Jim_SetResult(interp, objPtr);
    Jim_DecrRefCount(interp, objPtr);
    return JIM_OK;
}

/* [llength] */
static int Jim_LlengthCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int len;

    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "list");
        return JIM_ERR;
    }
    Jim_ListLength(interp, argv[1], &len);
    Jim_SetResult(interp, Jim_NewIntObj(interp, len));
    return JIM_OK;
}

/* [lappend] */
static int Jim_LappendCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Obj *listObjPtr;
    int shared, i;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?value value ...?");
        return JIM_ERR;
    }
    listObjPtr = Jim_GetVariable(interp, argv[1], JIM_NONE);
    if (!listObjPtr) {
        /* Create the list if it does not exists */
        listObjPtr = Jim_NewListObj(interp, NULL, 0);
        if (Jim_SetVariable(interp, argv[1], listObjPtr) != JIM_OK) {
            Jim_FreeNewObj(interp, listObjPtr);
            return JIM_ERR;
        }
    }
    shared = Jim_IsShared(listObjPtr);
    if (shared)
        listObjPtr = Jim_DuplicateObj(interp, listObjPtr);
    for (i = 2; i < argc; i++)
        Jim_ListAppendElement(interp, listObjPtr, argv[i]);
    if (Jim_SetVariable(interp, argv[1], listObjPtr) != JIM_OK) {
        if (shared)
            Jim_FreeNewObj(interp, listObjPtr);
        return JIM_ERR;
    }
    Jim_SetResult(interp, listObjPtr);
    return JIM_OK;
}

/* [linsert] */
static int Jim_LinsertCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int index, len;
    Jim_Obj *listPtr;

    if (argc < 4) {
        Jim_WrongNumArgs(interp, 1, argv, "list index element "
            "?element ...?");
        return JIM_ERR;
    }
    listPtr = argv[1];
    if (Jim_IsShared(listPtr))
        listPtr = Jim_DuplicateObj(interp, listPtr);
    if (Jim_GetIndex(interp, argv[2], &index) != JIM_OK)
        goto err;
    Jim_ListLength(interp, listPtr, &len);
    if (index >= len)
        index = len;
    else if (index < 0)
        index = len + index + 1;
    Jim_ListInsertElements(interp, listPtr, index, argc-3, &argv[3]);
    Jim_SetResult(interp, listPtr);
    return JIM_OK;
err:
    if (listPtr != argv[1]) {
        Jim_FreeNewObj(interp, listPtr);
    }
    return JIM_ERR;
}

/* [lset] */
static int Jim_LsetCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc < 3) {
        Jim_WrongNumArgs(interp, 1, argv, "listVar ?index...? newVal");
        return JIM_ERR;
    } else if (argc == 3) {
        if (Jim_SetVariable(interp, argv[1], argv[2]) != JIM_OK)
            return JIM_ERR;
        Jim_SetResult(interp, argv[2]);
        return JIM_OK;
    }
    if (Jim_SetListIndex(interp, argv[1], argv+2, argc-3, argv[argc-1])
            == JIM_ERR) return JIM_ERR;
    return JIM_OK;
}

/* [lsort] */
static int Jim_LsortCoreCommand(Jim_Interp *interp, int argc, Jim_Obj *const argv[])
{
    const char *options[] = {
        "-ascii", "-nocase", "-increasing", "-decreasing", NULL
    };
    enum {OPT_ASCII, OPT_NOCASE, OPT_INCREASING, OPT_DECREASING};
    Jim_Obj *resObj;
    int i, lsortType = JIM_LSORT_ASCII; /* default sort type */
    int decreasing = 0;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "?options? list");
        return JIM_ERR;
    }
    for (i = 1; i < (argc-1); i++) {
        int option;

        if (Jim_GetEnum(interp, argv[i], options, &option, "option", JIM_ERRMSG)
                != JIM_OK)
            return JIM_ERR;
        switch(option) {
        case OPT_ASCII: lsortType = JIM_LSORT_ASCII; break;
        case OPT_NOCASE: lsortType = JIM_LSORT_NOCASE; break;
        case OPT_INCREASING: decreasing = 0; break;
        case OPT_DECREASING: decreasing = 1; break;
        }
    }
    if (decreasing) {
        switch(lsortType) {
        case JIM_LSORT_ASCII: lsortType = JIM_LSORT_ASCII_DECR; break;
        case JIM_LSORT_NOCASE: lsortType = JIM_LSORT_NOCASE_DECR; break;
        }
    }
    resObj = Jim_DuplicateObj(interp, argv[argc-1]);
    ListSortElements(interp, resObj, lsortType);
    Jim_SetResult(interp, resObj);
    return JIM_OK;
}

/* [append] */
static int Jim_AppendCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Obj *stringObjPtr;
    int shared, i;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?value value ...?");
        return JIM_ERR;
    }
    if (argc == 2) {
        stringObjPtr = Jim_GetVariable(interp, argv[1], JIM_ERRMSG);
        if (!stringObjPtr) return JIM_ERR;
    } else {
        stringObjPtr = Jim_GetVariable(interp, argv[1], JIM_NONE);
        if (!stringObjPtr) {
            /* Create the string if it does not exists */
            stringObjPtr = Jim_NewEmptyStringObj(interp);
            if (Jim_SetVariable(interp, argv[1], stringObjPtr)
                    != JIM_OK) {
                Jim_FreeNewObj(interp, stringObjPtr);
                return JIM_ERR;
            }
        }
    }
    shared = Jim_IsShared(stringObjPtr);
    if (shared)
        stringObjPtr = Jim_DuplicateObj(interp, stringObjPtr);
    for (i = 2; i < argc; i++)
        Jim_AppendObj(interp, stringObjPtr, argv[i]);
    if (Jim_SetVariable(interp, argv[1], stringObjPtr) != JIM_OK) {
        if (shared)
            Jim_FreeNewObj(interp, stringObjPtr);
        return JIM_ERR;
    }
    Jim_SetResult(interp, stringObjPtr);
    return JIM_OK;
}

/* [debug] */
static int Jim_DebugCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    const char *options[] = {
        "refcount", "objcount", "objects", "invstr", "scriptlen", "exprlen",
        "exprbc",
        NULL
    };
    enum {
        OPT_REFCOUNT, OPT_OBJCOUNT, OPT_OBJECTS, OPT_INVSTR, OPT_SCRIPTLEN,
        OPT_EXPRLEN, OPT_EXPRBC
    };
    int option;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "option ?...?");
        return JIM_ERR;
    }
    if (Jim_GetEnum(interp, argv[1], options, &option, "option",
                JIM_ERRMSG) != JIM_OK)
        return JIM_ERR;
    if (option == OPT_REFCOUNT) {
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "object");
            return JIM_ERR;
        }
        Jim_SetResult(interp, Jim_NewIntObj(interp, argv[2]->refCount));
        return JIM_OK;
    } else if (option == OPT_OBJCOUNT) {
        int freeobj = 0, liveobj = 0;
        char buf[256];
        Jim_Obj *objPtr;

        if (argc != 2) {
            Jim_WrongNumArgs(interp, 2, argv, "");
            return JIM_ERR;
        }
        /* Count the number of free objects. */
        objPtr = interp->freeList;
        while (objPtr) {
            freeobj++;
            objPtr = objPtr->nextObjPtr;
        }
        /* Count the number of live objects. */
        objPtr = interp->liveList;
        while (objPtr) {
            liveobj++;
            objPtr = objPtr->nextObjPtr;
        }
        /* Set the result string and return. */
        sprintf(buf, "free %d used %d", freeobj, liveobj);
        Jim_SetResultString(interp, buf, -1);
        return JIM_OK;
    } else if (option == OPT_OBJECTS) {
        Jim_Obj *objPtr, *listObjPtr, *subListObjPtr;
        /* Count the number of live objects. */
        objPtr = interp->liveList;
        listObjPtr = Jim_NewListObj(interp, NULL, 0);
        while (objPtr) {
            char buf[128];
            const char *type = objPtr->typePtr ?
                objPtr->typePtr->name : "";
            subListObjPtr = Jim_NewListObj(interp, NULL, 0);
            sprintf(buf, "%p", objPtr);
            Jim_ListAppendElement(interp, subListObjPtr,
                Jim_NewStringObj(interp, buf, -1));
            Jim_ListAppendElement(interp, subListObjPtr,
                Jim_NewStringObj(interp, type, -1));
            Jim_ListAppendElement(interp, subListObjPtr,
                Jim_NewIntObj(interp, objPtr->refCount));
            Jim_ListAppendElement(interp, subListObjPtr, objPtr);
            Jim_ListAppendElement(interp, listObjPtr, subListObjPtr);
            objPtr = objPtr->nextObjPtr;
        }
        Jim_SetResult(interp, listObjPtr);
        return JIM_OK;
    } else if (option == OPT_INVSTR) {
        Jim_Obj *objPtr;

        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "object");
            return JIM_ERR;
        }
        objPtr = argv[2];
        if (objPtr->typePtr != NULL)
            Jim_InvalidateStringRep(objPtr);
        Jim_SetEmptyResult(interp);
        return JIM_OK;
    } else if (option == OPT_SCRIPTLEN) {
        ScriptObj *script;
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "script");
            return JIM_ERR;
        }
        script = Jim_GetScript(interp, argv[2]);
        Jim_SetResult(interp, Jim_NewIntObj(interp, script->len));
        return JIM_OK;
    } else if (option == OPT_EXPRLEN) {
        ExprByteCode *expr;
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "expression");
            return JIM_ERR;
        }
        expr = Jim_GetExpression(interp, argv[2]);
        if (expr == NULL)
            return JIM_ERR;
        Jim_SetResult(interp, Jim_NewIntObj(interp, expr->len));
        return JIM_OK;
    } else if (option == OPT_EXPRBC) {
        Jim_Obj *objPtr;
        ExprByteCode *expr;
        int i;

        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "expression");
            return JIM_ERR;
        }
        expr = Jim_GetExpression(interp, argv[2]);
        if (expr == NULL)
            return JIM_ERR;
        objPtr = Jim_NewListObj(interp, NULL, 0);
        for (i = 0; i < expr->len; i++) {
            const char *type;
            Jim_ExprOperator *op;

            switch(expr->opcode[i]) {
            case JIM_EXPROP_NUMBER: type = "number"; break;
            case JIM_EXPROP_COMMAND: type = "command"; break;
            case JIM_EXPROP_VARIABLE: type = "variable"; break;
            case JIM_EXPROP_DICTSUGAR: type = "dictsugar"; break;
            case JIM_EXPROP_SUBST: type = "subst"; break;
            case JIM_EXPROP_STRING: type = "string"; break;
            default:
                op = JimExprOperatorInfo(Jim_GetString(expr->obj[i], NULL));
                if (op == NULL) {
                    type = "private";
                } else {
                    type = "operator";
                }
                break;
            }
            Jim_ListAppendElement(interp, objPtr,
                    Jim_NewStringObj(interp, type, -1));
            Jim_ListAppendElement(interp, objPtr, expr->obj[i]);
        }
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else {
        Jim_SetResultString(interp,
            "bad option. Valid options are refcount, "
            "objcount, objects, invstr", -1);
        return JIM_ERR;
    }
    return JIM_OK; /* unreached */
}

/* [eval] */
static int Jim_EvalCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc == 2) {
        return Jim_EvalObj(interp, argv[1]);
    } else if (argc > 2) {
        Jim_Obj *objPtr;
        int retcode;

        objPtr = Jim_ConcatObj(interp, argc-1, argv+1);
        Jim_IncrRefCount(objPtr);
        retcode = Jim_EvalObj(interp, objPtr);
        Jim_DecrRefCount(interp, objPtr);
        return retcode;
    } else {
        Jim_WrongNumArgs(interp, 1, argv, "script ?...?");
        return JIM_ERR;
    }
}

/* [uplevel] */
static int Jim_UplevelCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc >= 2) {
        int retcode, newLevel, oldLevel;
        Jim_CallFrame *savedCallFrame, *targetCallFrame;
        Jim_Obj *objPtr;
        const char *str;

        /* Save the old callframe pointer */
        savedCallFrame = interp->framePtr;

        /* Lookup the target frame pointer */
        str = Jim_GetString(argv[1], NULL);
        if ((str[0] >= '0' && str[0] <= '9') || str[0] == '#')
        {
            if (Jim_GetCallFrameByLevel(interp, argv[1],
                        &targetCallFrame,
                        &newLevel) != JIM_OK)
                return JIM_ERR;
            argc--;
            argv++;
        } else {
            if (Jim_GetCallFrameByLevel(interp, NULL,
                        &targetCallFrame,
                        &newLevel) != JIM_OK)
                return JIM_ERR;
        }
        if (argc < 2) {
            argc++;
            argv--;
            Jim_WrongNumArgs(interp, 1, argv,
                    "?level? command ?arg ...?");
            return JIM_ERR;
        }
        /* Eval the code in the target callframe. */
        interp->framePtr = targetCallFrame;
        oldLevel = interp->numLevels;
        interp->numLevels = newLevel;
        if (argc == 2) {
            retcode = Jim_EvalObj(interp, argv[1]);
        } else {
            objPtr = Jim_ConcatObj(interp, argc-1, argv+1);
            Jim_IncrRefCount(objPtr);
            retcode = Jim_EvalObj(interp, objPtr);
            Jim_DecrRefCount(interp, objPtr);
        }
        interp->numLevels = oldLevel;
        interp->framePtr = savedCallFrame;
        return retcode;
    } else {
        Jim_WrongNumArgs(interp, 1, argv, "?level? command ?arg ...?");
        return JIM_ERR;
    }
}

/* [expr] */
static int Jim_ExprCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Obj *exprResultPtr;
    int retcode;

    if (argc == 2) {
        retcode = Jim_EvalExpression(interp, argv[1], &exprResultPtr);
    } else if (argc > 2) {
        Jim_Obj *objPtr;

        objPtr = Jim_ConcatObj(interp, argc-1, argv+1);
        Jim_IncrRefCount(objPtr);
        retcode = Jim_EvalExpression(interp, objPtr, &exprResultPtr);
        Jim_DecrRefCount(interp, objPtr);
    } else {
        Jim_WrongNumArgs(interp, 1, argv, "expression ?...?");
        return JIM_ERR;
    }
    if (retcode != JIM_OK) return retcode;
    Jim_SetResult(interp, exprResultPtr);
    Jim_DecrRefCount(interp, exprResultPtr);
    return JIM_OK;
}

/* [break] */
static int Jim_BreakCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc != 1) {
        Jim_WrongNumArgs(interp, 1, argv, "");
        return JIM_ERR;
    }
    return JIM_BREAK;
}

/* [continue] */
static int Jim_ContinueCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    if (argc != 1) {
        Jim_WrongNumArgs(interp, 1, argv, "");
        return JIM_ERR;
    }
    return JIM_CONTINUE;
}

/* [return] */
static int Jim_ReturnCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc == 1) {
        return JIM_RETURN;
    } else if (argc == 2) {
        Jim_SetResult(interp, argv[1]);
        interp->returnCode = JIM_OK;
        return JIM_RETURN;
    } else if (argc == 3 || argc == 4) {
        int returnCode;
        if (Jim_GetReturnCode(interp, argv[2], &returnCode) == JIM_ERR)
            return JIM_ERR;
        interp->returnCode = returnCode;
        if (argc == 4)
            Jim_SetResult(interp, argv[3]);
        return JIM_RETURN;
    } else {
        Jim_WrongNumArgs(interp, 1, argv, "?-code code? ?result?");
        return JIM_ERR;
    }
    return JIM_RETURN; /* unreached */
}

/* [tailcall] */
static int Jim_TailcallCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    Jim_Obj *objPtr;

    objPtr = Jim_NewListObj(interp, argv+1, argc-1);
    Jim_SetResult(interp, objPtr);
    return JIM_EVAL;
}

/* [proc] */
static int Jim_ProcCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int argListLen;
    int arityMin, arityMax;

    if (argc != 4 && argc != 5) {
        Jim_WrongNumArgs(interp, 1, argv, "name arglist ?statics? body");
        return JIM_ERR;
    }
    Jim_ListLength(interp, argv[2], &argListLen);
    arityMin = arityMax = argListLen+1;
    if (argListLen) {
        const char *str;
        int len;
        Jim_Obj *lastArgPtr;
        
        Jim_ListIndex(interp, argv[2], argListLen-1, &lastArgPtr, JIM_NONE);
        str = Jim_GetString(lastArgPtr, &len);
        if (len == 4 && memcmp(str, "args", 4) == 0) {
            arityMin--;
            arityMax = -1;
        }
    }
    if (argc == 4) {
        return Jim_CreateProcedure(interp, Jim_GetString(argv[1], NULL),
                argv[2], NULL, argv[3], arityMin, arityMax);
    } else {
        return Jim_CreateProcedure(interp, Jim_GetString(argv[1], NULL),
                argv[2], argv[3], argv[4], arityMin, arityMax);
    }
}

/* [concat] */
static int Jim_ConcatCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_SetResult(interp, Jim_ConcatObj(interp, argc-1, argv+1));
    return JIM_OK;
}

/* [upvar] */
static int Jim_UpvarCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    const char *str;
    int i;
    Jim_CallFrame *targetCallFrame;

    /* Lookup the target frame pointer */
    str = Jim_GetString(argv[1], NULL);
    if (argc > 3 && 
        ((str[0] >= '0' && str[0] <= '9') || str[0] == '#'))
    {
        if (Jim_GetCallFrameByLevel(interp, argv[1],
                    &targetCallFrame, NULL) != JIM_OK)
            return JIM_ERR;
        argc--;
        argv++;
    } else {
        if (Jim_GetCallFrameByLevel(interp, NULL,
                    &targetCallFrame, NULL) != JIM_OK)
            return JIM_ERR;
    }
    /* Check for arity */
    if (argc < 3 || ((argc-1)%2) != 0) {
        Jim_WrongNumArgs(interp, 1, argv, "?level? otherVar localVar ?otherVar localVar ...?");
        return JIM_ERR;
    }
    /* Now... for every other/local couple: */
    for (i = 1; i < argc; i += 2) {
        if (Jim_SetVariableLink(interp, argv[i+1], argv[i],
                targetCallFrame) != JIM_OK) return JIM_ERR;
    }
    return JIM_OK;
}

/* [global] */
static int Jim_GlobalCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int i;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "varName ?varName ...?");
        return JIM_ERR;
    }
    /* Link every var to the toplevel having the same name */
    if (interp->numLevels == 0) return JIM_OK; /* global at toplevel... */
    for (i = 1; i < argc; i++) {
        if (Jim_SetVariableLink(interp, argv[i], argv[i],
                interp->topFramePtr) != JIM_OK) return JIM_ERR;
    }
    return JIM_OK;
}

/* does the [string map] operation. On error NULL is returned,
 * otherwise a new string object with the result, having refcount = 0,
 * is returned. */
static Jim_Obj *JimStringMap(Jim_Interp *interp, Jim_Obj *mapListObjPtr,
        Jim_Obj *objPtr, int nocase)
{
    int numMaps;
    const char **key, *str, *noMatchStart = NULL;
    Jim_Obj **value;
    int *keyLen, strLen, i;
    Jim_Obj *resultObjPtr;
    
    Jim_ListLength(interp, mapListObjPtr, &numMaps);
    if (numMaps % 2) {
        Jim_SetResultString(interp,
                "list must contain an even number of elements", -1);
        return NULL;
    }
    /* Initialization */
    numMaps /= 2;
    key = Jim_Alloc(sizeof(char*)*numMaps);
    keyLen = Jim_Alloc(sizeof(int)*numMaps);
    value = Jim_Alloc(sizeof(Jim_Obj*)*numMaps);
    resultObjPtr = Jim_NewStringObj(interp, "", 0);
    for (i = 0; i < numMaps; i++) {
        Jim_Obj *eleObjPtr;

        Jim_ListIndex(interp, mapListObjPtr, i*2, &eleObjPtr, JIM_NONE);
        key[i] = Jim_GetString(eleObjPtr, &keyLen[i]);
        Jim_ListIndex(interp, mapListObjPtr, i*2+1, &eleObjPtr, JIM_NONE);
        value[i] = eleObjPtr;
    }
    str = Jim_GetString(objPtr, &strLen);
    /* Map it */
    while(strLen) {
        for (i = 0; i < numMaps; i++) {
            if (strLen >= keyLen[i] && keyLen[i]) {
                if (!JimStringCompare(str, keyLen[i], key[i], keyLen[i],
                            nocase))
                {
                    if (noMatchStart) {
                        Jim_AppendString(interp, resultObjPtr,
                                noMatchStart, str-noMatchStart);
                        noMatchStart = NULL;
                    }
                    Jim_AppendObj(interp, resultObjPtr, value[i]);
                    str += keyLen[i];
                    strLen -= keyLen[i];
                    break;
                }
            }
        }
        if (i == numMaps) { /* no match */
            if (noMatchStart == NULL)
                noMatchStart = str;
            str ++;
            strLen --;
        }
    }
    if (noMatchStart) {
        Jim_AppendString(interp, resultObjPtr,
            noMatchStart, str-noMatchStart);
    }
    Jim_Free((void*)key);
    Jim_Free(keyLen);
    Jim_Free(value);
    return resultObjPtr;
}

/* [string] */
static int Jim_StringCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int option;
    const char *options[] = {
        "length", "compare", "match", "equal", "range", "map", "repeat",
        "index", "first", "tolower", "toupper", NULL
    };
    enum {
        OPT_LENGTH, OPT_COMPARE, OPT_MATCH, OPT_EQUAL, OPT_RANGE,
        OPT_MAP, OPT_REPEAT, OPT_INDEX, OPT_FIRST, OPT_TOLOWER, OPT_TOUPPER
    };

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "option ?arguments ...?");
        return JIM_ERR;
    }
    if (Jim_GetEnum(interp, argv[1], options, &option, "option",
                JIM_ERRMSG) != JIM_OK)
        return JIM_ERR;

    if (option == OPT_LENGTH) {
        int len;

        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "string");
            return JIM_ERR;
        }
        Jim_GetString(argv[2], &len);
        Jim_SetResult(interp, Jim_NewIntObj(interp, len));
        return JIM_OK;
    } else if (option == OPT_COMPARE) {
        int nocase = 0;
        if ((argc != 4 && argc != 5) ||
            (argc == 5 && Jim_CompareStringImmediate(interp,
                argv[2], "-nocase") == 0)) {
            Jim_WrongNumArgs(interp, 2, argv, "string1 string2");
            return JIM_ERR;
        }
        if (argc == 5) {
            nocase = 1;
            argv++;
        }
        Jim_SetResult(interp, Jim_NewIntObj(interp,
                    Jim_StringCompareObj(argv[2],
                            argv[3], nocase)));
        return JIM_OK;
    } else if (option == OPT_MATCH) {
        int nocase = 0;
        if ((argc != 4 && argc != 5) ||
            (argc == 5 && Jim_CompareStringImmediate(interp,
                argv[2], "-nocase") == 0)) {
            Jim_WrongNumArgs(interp, 2, argv, "?-nocase? pattern "
                    "string");
            return JIM_ERR;
        }
        if (argc == 5) {
            nocase = 1;
            argv++;
        }
        Jim_SetResult(interp,
            Jim_NewIntObj(interp, Jim_StringMatchObj(argv[2],
                    argv[3], nocase)));
        return JIM_OK;
    } else if (option == OPT_EQUAL) {
        if (argc != 4) {
            Jim_WrongNumArgs(interp, 2, argv, "string1 string2");
            return JIM_ERR;
        }
        Jim_SetResult(interp,
            Jim_NewIntObj(interp, Jim_StringEqObj(argv[2],
                    argv[3], 0)));
        return JIM_OK;
    } else if (option == OPT_RANGE) {
        Jim_Obj *objPtr;

        if (argc != 5) {
            Jim_WrongNumArgs(interp, 2, argv, "string first last");
            return JIM_ERR;
        }
        objPtr = Jim_StringRangeObj(interp, argv[2], argv[3], argv[4]);
        if (objPtr == NULL)
            return JIM_ERR;
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else if (option == OPT_MAP) {
        int nocase = 0;
        Jim_Obj *objPtr;

        if ((argc != 4 && argc != 5) ||
            (argc == 5 && Jim_CompareStringImmediate(interp,
                argv[2], "-nocase") == 0)) {
            Jim_WrongNumArgs(interp, 2, argv, "?-nocase? mapList "
                    "string");
            return JIM_ERR;
        }
        if (argc == 5) {
            nocase = 1;
            argv++;
        }
        objPtr = JimStringMap(interp, argv[2], argv[3], nocase);
        if (objPtr == NULL)
            return JIM_ERR;
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else if (option == OPT_REPEAT) {
        Jim_Obj *objPtr;
        jim_wide count;

        if (argc != 4) {
            Jim_WrongNumArgs(interp, 2, argv, "string count");
            return JIM_ERR;
        }
        if (Jim_GetWide(interp, argv[3], &count) != JIM_OK)
            return JIM_ERR;
        objPtr = Jim_NewStringObj(interp, "", 0);
        while (count--) {
            Jim_AppendObj(interp, objPtr, argv[2]);
        }
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else if (option == OPT_INDEX) {
        int index, len;
        const char *str;

        if (argc != 4) {
            Jim_WrongNumArgs(interp, 2, argv, "string index");
            return JIM_ERR;
        }
        if (Jim_GetIndex(interp, argv[3], &index) != JIM_OK)
            return JIM_ERR;
        str = Jim_GetString(argv[2], &len);
        if (index != INT_MIN && index != INT_MAX)
            index = JimRelToAbsIndex(len, index);
        if (index < 0 || index >= len) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            return JIM_OK;
        } else {
            Jim_SetResult(interp, Jim_NewStringObj(interp, str+index, 1));
            return JIM_OK;
        }
    } else if (option == OPT_FIRST) {
        int index = 0, l1, l2;
        const char *s1, *s2;

        if (argc != 4 && argc != 5) {
            Jim_WrongNumArgs(interp, 2, argv, "subString string ?startIndex?");
            return JIM_ERR;
        }
        s1 = Jim_GetString(argv[2], &l1);
        s2 = Jim_GetString(argv[3], &l2);
        if (argc == 5) {
            if (Jim_GetIndex(interp, argv[4], &index) != JIM_OK)
                return JIM_ERR;
            index = JimRelToAbsIndex(l2, index);
        }
        Jim_SetResult(interp, Jim_NewIntObj(interp,
                    JimStringFirst(s1, l1, s2, l2, index)));
        return JIM_OK;
    } else if (option == OPT_TOLOWER) {
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "string");
            return JIM_ERR;
        }
        Jim_SetResult(interp, JimStringToLower(interp, argv[2]));
    } else if (option == OPT_TOUPPER) {
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "string");
            return JIM_ERR;
        }
        Jim_SetResult(interp, JimStringToUpper(interp, argv[2]));
    }
    return JIM_OK;
}

/* [time] */
static int Jim_TimeCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    long i, count = 1;
    jim_wide start, elapsed;
    char buf [256];
    const char *fmt = "%" JIM_WIDE_MODIFIER " microseconds per iteration";

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "script ?count?");
        return JIM_ERR;
    }
    if (argc == 3) {
        if (Jim_GetLong(interp, argv[2], &count) != JIM_OK)
            return JIM_ERR;
    }
    if (count < 0)
        return JIM_OK;
    i = count;
    start = JimClock();
    while (i-- > 0) {
        int retval;

        if ((retval = Jim_EvalObj(interp, argv[1])) != JIM_OK)
            return retval;
    }
    elapsed = JimClock() - start;
    sprintf(buf, fmt, elapsed/count);
    Jim_SetResultString(interp, buf, -1);
    return JIM_OK;
}

/* [exit] */
static int Jim_ExitCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    long exitCode = 0;

    if (argc > 2) {
        Jim_WrongNumArgs(interp, 1, argv, "?exitCode?");
        return JIM_ERR;
    }
    if (argc == 2) {
        if (Jim_GetLong(interp, argv[1], &exitCode) != JIM_OK)
            return JIM_ERR;
    }
    exit(exitCode);
    return JIM_OK; /* unreached */
}

/* [catch] */
static int Jim_CatchCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int exitCode = 0;

    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "script ?varName?");
        return JIM_ERR;
    }
    exitCode = Jim_EvalObj(interp, argv[1]);
    if (argc == 3) {
        if (Jim_SetVariable(interp, argv[2], Jim_GetResult(interp))
                != JIM_OK)
            return JIM_ERR;
    }
    Jim_SetResult(interp, Jim_NewIntObj(interp, exitCode));
    return JIM_OK;
}

/* [ref] */
static int Jim_RefCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc != 3 && argc != 4) {
        Jim_WrongNumArgs(interp, 1, argv, "string tag ?finalizer?");
        return JIM_ERR;
    }
    if (argc == 3) {
        Jim_SetResult(interp, Jim_NewReference(interp, argv[1], argv[2], NULL));
    } else {
        Jim_SetResult(interp, Jim_NewReference(interp, argv[1], argv[2],
                    argv[3]));
    }
    return JIM_OK;
}

/* [getref] */
static int Jim_GetrefCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Reference *refPtr;

    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "reference");
        return JIM_ERR;
    }
    if ((refPtr = Jim_GetReference(interp, argv[1])) == NULL)
        return JIM_ERR;
    Jim_SetResult(interp, refPtr->objPtr);
    return JIM_OK;
}

/* [setref] */
static int Jim_SetrefCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    Jim_Reference *refPtr;

    if (argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "reference newValue");
        return JIM_ERR;
    }
    if ((refPtr = Jim_GetReference(interp, argv[1])) == NULL)
        return JIM_ERR;
    Jim_IncrRefCount(argv[2]);
    Jim_DecrRefCount(interp, refPtr->objPtr);
    refPtr->objPtr = argv[2];
    Jim_SetResult(interp, argv[2]);
    return JIM_OK;
}

/* [collect] */
static int Jim_CollectCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc != 1) {
        Jim_WrongNumArgs(interp, 1, argv, "");
        return JIM_ERR;
    }
    Jim_SetResult(interp, Jim_NewIntObj(interp, Jim_Collect(interp)));
    return JIM_OK;
}

/* [finalize] reference ?newValue? */
static int Jim_FinalizeCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "reference ?finalizerProc?");
        return JIM_ERR;
    }
    if (argc == 2) {
        Jim_Obj *cmdNamePtr;

        if (Jim_GetFinalizer(interp, argv[1], &cmdNamePtr) != JIM_OK)
            return JIM_ERR;
        if (cmdNamePtr != NULL) /* otherwise the null string is returned. */
            Jim_SetResult(interp, cmdNamePtr);
    } else {
        if (Jim_SetFinalizer(interp, argv[1], argv[2]) != JIM_OK)
            return JIM_ERR;
        Jim_SetResult(interp, argv[2]);
    }
    return JIM_OK;
}

/* TODO */
/* [info references] (list of all the references/finalizers) */

/* [rename] */
static int Jim_RenameCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    const char *oldName, *newName;

    if (argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "oldName newName");
        return JIM_ERR;
    }
    oldName = Jim_GetString(argv[1], NULL);
    newName = Jim_GetString(argv[2], NULL);
    if (Jim_RenameCommand(interp, oldName, newName) != JIM_OK) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "can't rename \"", oldName, "\": ",
            "command doesn't exist", NULL);
        return JIM_ERR;
    }
    return JIM_OK;
}

/* [dict] */
static int Jim_DictCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int option;
    const char *options[] = {
        "create", "get", "set", "unset", "exists", NULL
    };
    enum {
        OPT_CREATE, OPT_GET, OPT_SET, OPT_UNSET, OPT_EXIST
    };

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "option ?arguments ...?");
        return JIM_ERR;
    }

    if (Jim_GetEnum(interp, argv[1], options, &option, "option",
                JIM_ERRMSG) != JIM_OK)
        return JIM_ERR;

    if (option == OPT_CREATE) {
        Jim_Obj *objPtr;

        if (argc % 2) {
            Jim_WrongNumArgs(interp, 2, argv, "?key value ...?");
            return JIM_ERR;
        }
        objPtr = Jim_NewDictObj(interp, argv+2, argc-2);
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else if (option == OPT_GET) {
        Jim_Obj *objPtr;

        if (Jim_DictKeysVector(interp, argv[2], argv+3, argc-3, &objPtr,
                JIM_ERRMSG) != JIM_OK)
            return JIM_ERR;
        Jim_SetResult(interp, objPtr);
        return JIM_OK;
    } else if (option == OPT_SET) {
        if (argc < 5) {
            Jim_WrongNumArgs(interp, 2, argv, "varName key ?key ...? value");
            return JIM_ERR;
        }
        return Jim_SetDictKeysVector(interp, argv[2], argv+3, argc-4,
                    argv[argc-1]);
    } else if (option == OPT_UNSET) {
        if (argc < 4) {
            Jim_WrongNumArgs(interp, 2, argv, "varName key ?key ...?");
            return JIM_ERR;
        }
        return Jim_SetDictKeysVector(interp, argv[2], argv+3, argc-3,
                    NULL);
    } else if (option == OPT_EXIST) {
        Jim_Obj *objPtr;
        int exists;

        if (Jim_DictKeysVector(interp, argv[2], argv+3, argc-3, &objPtr,
                JIM_ERRMSG) == JIM_OK)
            exists = 1;
        else
            exists = 0;
        Jim_SetResult(interp, Jim_NewIntObj(interp, exists));
        return JIM_OK;
    } else {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
            "bad option \"", Jim_GetString(argv[1], NULL), "\":",
            " must be create, get, set", NULL);
        return JIM_ERR;
    }
    return JIM_OK;
}

/* [load] */
static int Jim_LoadCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "libaryFile");
        return JIM_ERR;
    }
    return Jim_LoadLibrary(interp, Jim_GetString(argv[1], NULL));
}

/* [subst] */
static int Jim_SubstCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int i, flags = 0;
    Jim_Obj *objPtr;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv,
            "?-nobackslashes? ?-nocommands? ?-novariables? string");
        return JIM_ERR;
    }
    i = argc-2;
    while(i--) {
        if (Jim_CompareStringImmediate(interp, argv[i+1],
                    "-nobackslashes"))
            flags |= JIM_SUBST_NOESC;
        else if (Jim_CompareStringImmediate(interp, argv[i+1],
                    "-novariables"))
            flags |= JIM_SUBST_NOVAR;
        else if (Jim_CompareStringImmediate(interp, argv[i+1],
                    "-nocommands"))
            flags |= JIM_SUBST_NOCMD;
        else {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "bad option \"", Jim_GetString(argv[i+1], NULL),
                "\": must be -nobackslashes, -nocommands, or "
                "-novariables", NULL);
            return JIM_ERR;
        }
    }
    if (Jim_SubstObj(interp, argv[argc-1], &objPtr, flags) != JIM_OK)
        return JIM_ERR;
    Jim_SetResult(interp, objPtr);
    return JIM_OK;
}

/* [info] */
static int Jim_InfoCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int cmd, result = JIM_OK;
    static const char *commands[] = {
        "body", "commands", "exists", "globals", "level", "locals",
        "vars", "version", "complete", "args", NULL
    };
    enum {INFO_BODY, INFO_COMMANDS, INFO_EXISTS, INFO_GLOBALS, INFO_LEVEL,
          INFO_LOCALS, INFO_VARS, INFO_VERSION, INFO_COMPLETE, INFO_ARGS};
    
    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "command ?args ...?");
        return JIM_ERR;
    }
    if (Jim_GetEnum(interp, argv[1], commands, &cmd, "command", JIM_ERRMSG)
        != JIM_OK) {
        return JIM_ERR;
    }
    
    if (cmd == INFO_COMMANDS) {
        if (argc != 2 && argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "?pattern?");
            return JIM_ERR;
        }
        if (argc == 3)
            Jim_SetResult(interp,JimCommandsList(interp, argv[2]));
        else
            Jim_SetResult(interp, JimCommandsList(interp, NULL));
    } else if (cmd == INFO_EXISTS) {
        Jim_Obj *exists;
        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "varName");
            return JIM_ERR;
        }
        exists = Jim_GetVariable(interp, argv[2], 0);
        Jim_SetResult(interp, Jim_NewIntObj(interp, exists != 0));
    } else if (cmd == INFO_GLOBALS || cmd == INFO_LOCALS || cmd == INFO_VARS) {
        int mode;
        switch (cmd) {
            case INFO_GLOBALS: mode = JIM_VARLIST_GLOBALS; break;
            case INFO_LOCALS:  mode = JIM_VARLIST_LOCALS; break;
            case INFO_VARS:    mode = JIM_VARLIST_VARS; break;
            default: mode = 0; /* avoid warning */; break;
        }
        if (argc != 2 && argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "?pattern?");
            return JIM_ERR;
        }
        if (argc == 3)
            Jim_SetResult(interp,JimVariablesList(interp, argv[2], mode));
        else
            Jim_SetResult(interp, JimVariablesList(interp, NULL, mode));
    } else if (cmd == INFO_LEVEL) {
        Jim_Obj *objPtr;
        switch (argc) {
            case 2:
                Jim_SetResult(interp,
                              Jim_NewIntObj(interp, interp->numLevels));
                break;
            case 3:
                if (JimInfoLevel(interp, argv[2], &objPtr) != JIM_OK)
                    return JIM_ERR;
                Jim_SetResult(interp, objPtr);
                break;
            default:
                Jim_WrongNumArgs(interp, 2, argv, "?levelNum?");
                return JIM_ERR;
        }
    } else if (cmd == INFO_BODY || cmd == INFO_ARGS) {
        Jim_Cmd *cmdPtr;

        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "procname");
            return JIM_ERR;
        }
        if ((cmdPtr = Jim_GetCommand(interp, argv[2], JIM_ERRMSG)) == NULL)
            return JIM_ERR;
        if (cmdPtr->cmdProc != NULL) {
            Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
            Jim_AppendStrings(interp, Jim_GetResult(interp),
                "command \"", Jim_GetString(argv[2], NULL),
                "\" is not a procedure", NULL);
            return JIM_ERR;
        }
        if (cmd == INFO_BODY)
            Jim_SetResult(interp, cmdPtr->bodyObjPtr);
        else
            Jim_SetResult(interp, cmdPtr->argListObjPtr);
    } else if (cmd == INFO_VERSION) {
        char buf[(JIM_INTEGER_SPACE * 2) + 1];
        sprintf(buf, "%d.%d", 
                JIM_VERSION / 100, JIM_VERSION % 100);
        Jim_SetResultString(interp, buf, -1);
    } else if (cmd == INFO_COMPLETE) {
        const char *s;
        int len;

        if (argc != 3) {
            Jim_WrongNumArgs(interp, 2, argv, "script");
            return JIM_ERR;
        }
        s = Jim_GetString(argv[2], &len);
        Jim_SetResult(interp,
                Jim_NewIntObj(interp, Jim_ScriptIsComplete(s, len, NULL)));
    }
    return result;
}

/* [split] */
static int Jim_SplitCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    const char *str, *splitChars, *noMatchStart;
    int splitLen, strLen, i;
    Jim_Obj *resObjPtr;

    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "string ?splitChars?");
        return JIM_ERR;
    }
    /* Init */
    if (argc == 2) {
        splitChars = " \n\t\r";
        splitLen = 4;
    } else {
        splitChars = Jim_GetString(argv[2], &splitLen);
    }
    str = Jim_GetString(argv[1], &strLen);
    if (!strLen) return JIM_OK;
    noMatchStart = str;
    resObjPtr = Jim_NewListObj(interp, NULL, 0);
    /* Split */
    if (splitLen) {
        while (strLen) {
            for (i = 0; i < splitLen; i++) {
                if (*str == splitChars[i]) {
                    Jim_Obj *objPtr;

                    objPtr = Jim_NewStringObj(interp, noMatchStart,
                            (str-noMatchStart));
                    Jim_ListAppendElement(interp, resObjPtr, objPtr);
                    noMatchStart = str+1;
                    break;
                }
            }
            str ++;
            strLen --;
        }
        Jim_ListAppendElement(interp, resObjPtr,
                Jim_NewStringObj(interp, noMatchStart, (str-noMatchStart)));
    } else {
        /* This handles the special case of splitchars eq {}. This
         * is trivial but we want to perform object sharing as Tcl does. */
        Jim_Obj *objCache[256];
        const unsigned char *u = (unsigned char*) str;
        memset(objCache, 0, sizeof(objCache));
        for (i = 0; i < strLen; i++) {
            int c = u[i];
            
            if (objCache[c] == NULL)
                objCache[c] = Jim_NewStringObj(interp, (char*)u+i, 1);
            Jim_ListAppendElement(interp, resObjPtr, objCache[c]);
        }
    }
    Jim_SetResult(interp, resObjPtr);
    return JIM_OK;
}

/* [join] */
static int Jim_JoinCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    const char *joinStr;
    int joinStrLen, i, listLen;
    Jim_Obj *resObjPtr;

    if (argc != 2 && argc != 3) {
        Jim_WrongNumArgs(interp, 1, argv, "list ?joinString?");
        return JIM_ERR;
    }
    /* Init */
    if (argc == 2) {
        joinStr = " ";
        joinStrLen = 1;
    } else {
        joinStr = Jim_GetString(argv[2], &joinStrLen);
    }
    Jim_ListLength(interp, argv[1], &listLen);
    resObjPtr = Jim_NewStringObj(interp, NULL, 0);
    /* Split */
    for (i = 0; i < listLen; i++) {
        Jim_Obj *objPtr;

        Jim_ListIndex(interp, argv[1], i, &objPtr, JIM_NONE);
        Jim_AppendObj(interp, resObjPtr, objPtr);
        if (i+1 != listLen) {
            Jim_AppendString(interp, resObjPtr, joinStr, joinStrLen);
        }
    }
    Jim_SetResult(interp, resObjPtr);
    return JIM_OK;
}

/* [format] */
static int Jim_FormatCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    Jim_Obj *objPtr;

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "formatString ?arg arg ...?");
        return JIM_ERR;
    }
    objPtr = Jim_FormatString(interp, argv[1], argc-2, argv+2);
    if (objPtr == NULL)
        return JIM_ERR;
    Jim_SetResult(interp, objPtr);
    return JIM_OK;
}

/* [scan] */
static int Jim_ScanCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    Jim_Obj *listPtr, **outVec;
    int outc, i, count = 0;

    if (argc < 3) {
        Jim_WrongNumArgs(interp, 1, argv, "string formatString ?varName ...?");
        return JIM_ERR;
    } 
    if (argv[2]->typePtr != &scanFmtStringObjType)
        SetScanFmtFromAny(interp, argv[2]);
    if (FormatGetError(argv[2]) != 0) {
        Jim_SetResultString(interp, FormatGetError(argv[2]), -1);
        return JIM_ERR;
    }
    if (argc > 3) {
        int maxPos = FormatGetMaxPos(argv[2]);
        int count = FormatGetCnvCount(argv[2]);
        if (maxPos > argc-3) {
            Jim_SetResultString(interp, "\"%n$\" argument index out of range", -1);
            return JIM_ERR;
        } else if (count != 0 && count < argc-3) {
            Jim_SetResultString(interp, "variable is not assigned by any "
                "conversion specifiers", -1);
            return JIM_ERR;
        } else if (count > argc-3) {
            Jim_SetResultString(interp, "different numbers of variable names and "
                "field specifiers", -1);
            return JIM_ERR;
        }
    } 
    listPtr = Jim_ScanString(interp, argv[1], argv[2], JIM_ERRMSG);
    if (listPtr == 0)
        return JIM_ERR;
    if (argc > 3) {
        int len = 0;
        if (listPtr != 0 && listPtr != (Jim_Obj*)EOF)
            Jim_ListLength(interp, listPtr, &len);
        if (listPtr == (Jim_Obj*)EOF || len == 0) { // XXX
            Jim_SetResult(interp, Jim_NewIntObj(interp, -1));
            return JIM_OK;
        }
        JimListGetElements(interp, listPtr, &outc, &outVec);
        for (i = 0; i < outc; ++i) {
            if (Jim_Length(outVec[i]) > 0) {
                ++count;
                if (Jim_SetVariable(interp, argv[3+i], outVec[i]) != JIM_OK)
                    goto err;
            }
        }
        Jim_FreeNewObj(interp, listPtr);
        Jim_SetResult(interp, Jim_NewIntObj(interp, count));
    } else {
        if (listPtr == (Jim_Obj*)EOF) {
            Jim_SetResult(interp, Jim_NewListObj(interp, 0, 0));
            return JIM_OK;
        }
        Jim_SetResult(interp, listPtr);
    }
    return JIM_OK;
err:
    Jim_FreeNewObj(interp, listPtr);
    return JIM_ERR;
}

/* [error] */
static int Jim_ErrorCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "message");
        return JIM_ERR;
    }
    Jim_SetResult(interp, argv[1]);
    return JIM_ERR;
}

/* [lrange] */
static int Jim_LrangeCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    Jim_Obj *objPtr;

    if (argc != 4) {
        Jim_WrongNumArgs(interp, 1, argv, "list first last");
        return JIM_ERR;
    }
    if ((objPtr = Jim_ListRange(interp, argv[1], argv[2], argv[3])) == NULL)
        return JIM_ERR;
    Jim_SetResult(interp, objPtr);
    return JIM_OK;
}

/* [env] */
static int Jim_EnvCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    const char *key;
    char *val;

    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "varName");
        return JIM_ERR;
    }
    key = Jim_GetString(argv[1], NULL);
    val = getenv(key);
    if (val == NULL) {
        Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
        Jim_AppendStrings(interp, Jim_GetResult(interp),
                "environment variable \"",
                key, "\" does not exist", NULL);
        return JIM_ERR;
    }
    Jim_SetResult(interp, Jim_NewStringObj(interp, val, -1));
    return JIM_OK;
}

/* [source] */
static int Jim_SourceCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    int retval;

    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "fileName");
        return JIM_ERR;
    }
    retval = Jim_EvalFile(interp, Jim_GetString(argv[1], NULL));
    if (retval == JIM_RETURN)
        return JIM_OK;
    return retval;
}

/* [lreverse] */
static int Jim_LreverseCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    Jim_Obj *revObjPtr, **ele;
    int len;

    if (argc != 2) {
        Jim_WrongNumArgs(interp, 1, argv, "list");
        return JIM_ERR;
    }
    JimListGetElements(interp, argv[1], &len, &ele);
    len--;
    revObjPtr = Jim_NewListObj(interp, NULL, 0);
    while (len >= 0)
        ListAppendElement(revObjPtr, ele[len--]);
    Jim_SetResult(interp, revObjPtr);
    return JIM_OK;
}

static int JimRangeLen(jim_wide start, jim_wide end, jim_wide step)
{
    jim_wide len;

    if (step == 0) return -1;
    if (start == end) return 0;
    else if (step > 0 && start > end) return -1;
    else if (step < 0 && end > start) return -1;
    len = end-start;
    if (len < 0) len = -len; /* abs(len) */
    if (step < 0) step = -step; /* abs(step) */
    len = 1 + ((len-1)/step);
    /* We can truncate safely to INT_MAX, the range command
     * will always return an error for a such long range
     * because Tcl lists can't be so long. */
    if (len > INT_MAX) len = INT_MAX;
    return (int)((len < 0) ? -1 : len);
}

/* [range] */
static int Jim_RangeCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    jim_wide start = 0, end, step = 1;
    int len, i;
    Jim_Obj *objPtr;

    if (argc < 2 || argc > 4) {
        Jim_WrongNumArgs(interp, 1, argv, "?start? end ?step?");
        return JIM_ERR;
    }
    if (argc == 2) {
        if (Jim_GetWide(interp, argv[1], &end) != JIM_OK)
            return JIM_ERR;
    } else {
        if (Jim_GetWide(interp, argv[1], &start) != JIM_OK ||
            Jim_GetWide(interp, argv[2], &end) != JIM_OK)
            return JIM_ERR;
        if (argc == 4 && Jim_GetWide(interp, argv[3], &step) != JIM_OK)
            return JIM_ERR;
    }
    if ((len = JimRangeLen(start, end, step)) == -1) {
        Jim_SetResultString(interp, "Invalid (infinite?) range specified", -1);
        return JIM_ERR;
    }
    objPtr = Jim_NewListObj(interp, NULL, 0);
    for (i = 0; i < len; i++)
        ListAppendElement(objPtr, Jim_NewIntObj(interp, start+i*step));
    Jim_SetResult(interp, objPtr);
    return JIM_OK;
}

/* [rand] */
static int Jim_RandCoreCommand(Jim_Interp *interp, int argc,
        Jim_Obj *const *argv)
{
    jim_wide min = 0, max, len, maxMul;

    if (argc < 1 || argc > 3) {
        Jim_WrongNumArgs(interp, 1, argv, "?min? max");
        return JIM_ERR;
    }
    if (argc == 1) {
        max = JIM_WIDE_MAX;
    } else if (argc == 2) {
        if (Jim_GetWide(interp, argv[1], &max) != JIM_OK)
            return JIM_ERR;
    } else if (argc == 3) {
        if (Jim_GetWide(interp, argv[1], &min) != JIM_OK ||
            Jim_GetWide(interp, argv[2], &max) != JIM_OK)
            return JIM_ERR;
    }
    len = max-min;
    if (len < 0) {
        Jim_SetResultString(interp, "Invalid arguments (max < min)", -1);
        return JIM_ERR;
    }
    maxMul = JIM_WIDE_MAX - (len ? (JIM_WIDE_MAX%len) : 0);
    while (1) {
        jim_wide r;

        JimRandomBytes(interp, &r, sizeof(jim_wide));
        if (r < 0 || r >= maxMul) continue;
        r = (len == 0) ? 0 : r%len;
        Jim_SetResult(interp, Jim_NewIntObj(interp, min+r));
        return JIM_OK;
    }
}

/* [package] */
static int Jim_PackageCoreCommand(Jim_Interp *interp, int argc, 
        Jim_Obj *const *argv)
{
    int option;
    const char *options[] = {
        "require", "provide", NULL
    };
    enum {OPT_REQUIRE, OPT_PROVIDE};

    if (argc < 2) {
        Jim_WrongNumArgs(interp, 1, argv, "option ?arguments ...?");
        return JIM_ERR;
    }
    if (Jim_GetEnum(interp, argv[1], options, &option, "option",
                JIM_ERRMSG) != JIM_OK)
        return JIM_ERR;

    if (option == OPT_REQUIRE) {
        int exact = 0;
        const char *ver;

        if (Jim_CompareStringImmediate(interp, argv[2], "-exact")) {
            exact = 1;
            argv++;
            argc--;
        }
        if (argc != 3 && argc != 4) {
            Jim_WrongNumArgs(interp, 2, argv, "?-exact? package ?version?");
            return JIM_ERR;
        }
        ver = Jim_PackageRequire(interp, Jim_GetString(argv[2], NULL),
                argc == 4 ? Jim_GetString(argv[3], NULL) : "",
                JIM_ERRMSG);
        if (ver == NULL)
            return JIM_ERR;
        Jim_SetResultString(interp, ver, -1);
    } else if (option == OPT_PROVIDE) {
        if (argc != 4) {
            Jim_WrongNumArgs(interp, 2, argv, "package version");
            return JIM_ERR;
        }
        return Jim_PackageProvide(interp, Jim_GetString(argv[2], NULL),
                    Jim_GetString(argv[3], NULL), JIM_ERRMSG);
    }
    return JIM_OK;
}

static struct {
    const char *name;
    Jim_CmdProc cmdProc;
} Jim_CoreCommandsTable[] = {
    {"set", Jim_SetCoreCommand},
    {"unset", Jim_UnsetCoreCommand},
    {"puts", Jim_PutsCoreCommand},
    {"+", Jim_AddCoreCommand},
    {"*", Jim_MulCoreCommand},
    {"-", Jim_SubCoreCommand},
    {"/", Jim_DivCoreCommand},
    {"incr", Jim_IncrCoreCommand},
    {"while", Jim_WhileCoreCommand},
    {"for", Jim_ForCoreCommand},
    {"foreach", Jim_ForeachCoreCommand},
    {"lmap", Jim_LmapCoreCommand},
    {"if", Jim_IfCoreCommand},
    {"switch", Jim_SwitchCoreCommand},
    {"list", Jim_ListCoreCommand},
    {"lindex", Jim_LindexCoreCommand},
    {"lset", Jim_LsetCoreCommand},
    {"llength", Jim_LlengthCoreCommand},
    {"lappend", Jim_LappendCoreCommand},
    {"linsert", Jim_LinsertCoreCommand},
    {"lsort", Jim_LsortCoreCommand},
    {"append", Jim_AppendCoreCommand},
    {"debug", Jim_DebugCoreCommand},
    {"eval", Jim_EvalCoreCommand},
    {"uplevel", Jim_UplevelCoreCommand},
    {"expr", Jim_ExprCoreCommand},
    {"break", Jim_BreakCoreCommand},
    {"continue", Jim_ContinueCoreCommand},
    {"proc", Jim_ProcCoreCommand},
    {"concat", Jim_ConcatCoreCommand},
    {"return", Jim_ReturnCoreCommand},
    {"upvar", Jim_UpvarCoreCommand},
    {"global", Jim_GlobalCoreCommand},
    {"string", Jim_StringCoreCommand},
    {"time", Jim_TimeCoreCommand},
    {"exit", Jim_ExitCoreCommand},
    {"catch", Jim_CatchCoreCommand},
    {"ref", Jim_RefCoreCommand},
    {"getref", Jim_GetrefCoreCommand},
    {"setref", Jim_SetrefCoreCommand},
    {"finalize", Jim_FinalizeCoreCommand},
    {"collect", Jim_CollectCoreCommand},
    {"rename", Jim_RenameCoreCommand},
    {"dict", Jim_DictCoreCommand},
    {"load", Jim_LoadCoreCommand},
    {"subst", Jim_SubstCoreCommand},
    {"info", Jim_InfoCoreCommand},
    {"split", Jim_SplitCoreCommand},
    {"join", Jim_JoinCoreCommand},
    {"format", Jim_FormatCoreCommand},
    {"scan", Jim_ScanCoreCommand},
    {"error", Jim_ErrorCoreCommand},
    {"lrange", Jim_LrangeCoreCommand},
    {"env", Jim_EnvCoreCommand},
    {"source", Jim_SourceCoreCommand},
    {"lreverse", Jim_LreverseCoreCommand},
    {"range", Jim_RangeCoreCommand},
    {"rand", Jim_RandCoreCommand},
    {"package", Jim_PackageCoreCommand},
    {"tailcall", Jim_TailcallCoreCommand},
    {NULL, NULL},
};

/* Some Jim core command is actually a procedure written in Jim itself. */
static void Jim_RegisterCoreProcedures(Jim_Interp *interp)
{
    Jim_Eval(interp, (char*)
"proc lambda {arglist args} {\n"
"    set name [ref {} function lambdaFinalizer]\n"
"    uplevel 1 [list proc $name $arglist {expand}$args]\n"
"    return $name\n"
"}\n"
"proc lambdaFinalizer {name val} {\n"
"    rename $name {}\n"
"}\n"
    );
}

void Jim_RegisterCoreCommands(Jim_Interp *interp)
{
    int i = 0;

    while(Jim_CoreCommandsTable[i].name != NULL) {
        Jim_CreateCommand(interp, 
                Jim_CoreCommandsTable[i].name,
                Jim_CoreCommandsTable[i].cmdProc,
                NULL, NULL);
        i++;
    }
    Jim_RegisterCoreProcedures(interp);
}

/* -----------------------------------------------------------------------------
 * Interactive prompt
 * ---------------------------------------------------------------------------*/
void Jim_PrintErrorMessage(Jim_Interp *interp)
{
    int len, i;

    fprintf(stderr, "Runtime error, file \"%s\", line %d:\n",
            interp->errorFileName, interp->errorLine);
    fprintf(stderr, "    %s\n", Jim_GetString(interp->result, NULL));
    Jim_ListLength(interp, interp->stackTrace, &len);
    for (i = 0; i < len; i+= 3) {
        Jim_Obj *objPtr;
        const char *proc, *file, *line;

        Jim_ListIndex(interp, interp->stackTrace, i, &objPtr, JIM_NONE);
        proc = Jim_GetString(objPtr, NULL);
        Jim_ListIndex(interp, interp->stackTrace, i+1, &objPtr,
                JIM_NONE);
        file = Jim_GetString(objPtr, NULL);
        Jim_ListIndex(interp, interp->stackTrace, i+2, &objPtr,
                JIM_NONE);
        line = Jim_GetString(objPtr, NULL);
        fprintf(stderr, "In procedure '%s' called at file \"%s\", line %s\n",
                proc, file, line);
    }
}

int Jim_InteractivePrompt(Jim_Interp *interp)
{
    int retcode = JIM_OK;
    Jim_Obj *scriptObjPtr;

    printf("Welcome to Jim version %d.%d, "
           "Copyright (c) 2005 Salvatore Sanfilippo\n",
           JIM_VERSION / 100, JIM_VERSION % 100);
    printf("CVS ID: $Id: jim.c,v 1.163 2005/09/19 15:47:15 antirez Exp $\n");
    Jim_SetVariableStrWithStr(interp, "jim_interactive", "1");
    while (1) {
        char buf[1024];
        const char *result;
        const char *retcodestr[] = {
            "ok", "error", "return", "break", "continue", "eval"
        };
        int reslen;

        if (retcode != 0) {
            if (retcode >= 2 && retcode <= 5)
                printf("[%s] . ", retcodestr[retcode]);
            else
                printf("[%d] . ", retcode);
        } else
            printf(". ");
        fflush(stdout);
        scriptObjPtr = Jim_NewStringObj(interp, "", 0);
        Jim_IncrRefCount(scriptObjPtr);
        while(1) {
            const char *str;
            char state;
            int len;

            if (fgets(buf, 1024, stdin) == NULL) {
                Jim_DecrRefCount(interp, scriptObjPtr);
                goto out;
            }
            Jim_AppendString(interp, scriptObjPtr, buf, -1);
            str = Jim_GetString(scriptObjPtr, &len);
            if (Jim_ScriptIsComplete(str, len, &state))
                break;
            printf("%c> ", state);
            fflush(stdout);
        }
        retcode = Jim_EvalObj(interp, scriptObjPtr);
        Jim_DecrRefCount(interp, scriptObjPtr);
        result = Jim_GetString(Jim_GetResult(interp), &reslen);
        if (retcode == JIM_ERR) {
            Jim_PrintErrorMessage(interp);
        } else {
            if (reslen) {
                fwrite(result, 1, reslen, stdout);
                printf("\n");
            }
        }
    }
out:
    return 0;
}
