source: trunk/third/evolution/e-util/e-sexp.c @ 18142

/* 
 * Copyright 2000 Ximian (www.ximian.com).
 *
 * A simple, extensible s-exp evaluation engine.
 *
 * Author : 
 *  Michael Zucchi <notzed@ximian.com>

 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU General Public 
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

/*
  The following built-in s-exp's are supported:

  list = (and list*)
        perform an intersection of a number of lists, and return that.

  bool = (and bool*)
        perform a boolean AND of boolean values.

  list = (or list*)
        perform a union of a number of lists, returning the new list.

  bool = (or bool*)
        perform a boolean OR of boolean values.

  int = (+ int*)
        Add integers.

  string = (+ string*)
        Concat strings.

  time_t = (+ time_t*)
        Add time_t values.

  int = (- int int*)
        Subtract integers from the first.

  time_t = (- time_t*)
        Subtract time_t values from the first.

  int = (cast-int string|int|bool)
        Cast to an integer value.

  string = (cast-string string|int|bool)
        Cast to an string value.

  Comparison operators:

  bool = (< int int)
  bool = (> int int)
  bool = (= int int)

  bool = (< string string)
  bool = (> string string)
  bool = (= string string)

  bool = (< time_t time_t)
  bool = (> time_t time_t)
  bool = (= time_t time_t)
        Perform a comparision of 2 integers, 2 string values, or 2 time values.

  Function flow:

  type = (if bool function)
  type = (if bool function function)
        Choose a flow path based on a boolean value

  type = (begin  func func func)
        Execute a sequence.  The last function return is the return type.
*/

#include "e-sexp.h"

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

#include <glib.h>
#include "e-memory.h"
#define p(x)                    /* parse debug */
#define r(x)                    /* run debug */
#define d(x)                    /* general debug */


static struct _ESExpTerm * parse_list(ESExp *f, int gotbrace);
static struct _ESExpTerm * parse_value(ESExp *f);

static void parse_dump_term(struct _ESExpTerm *t, int depth);

#ifdef E_SEXP_IS_GTK_OBJECT
static GtkObjectClass *parent_class;
#endif

static GScannerConfig scanner_config =
{
        ( " \t\r\n")            /* cset_skip_characters */,
        ( G_CSET_a_2_z
          "_+-<=>?"
          G_CSET_A_2_Z)         /* cset_identifier_first */,
        ( G_CSET_a_2_z
          "_0123456789-<>?"
          G_CSET_A_2_Z
          G_CSET_LATINS
          G_CSET_LATINC )       /* cset_identifier_nth */,
        ( ";\n" )               /* cpair_comment_single */,
  
        FALSE                   /* case_sensitive */,
  
        TRUE                    /* skip_comment_multi */,
        TRUE                    /* skip_comment_single */,
        TRUE                    /* scan_comment_multi */,
        TRUE                    /* scan_identifier */,
        TRUE                    /* scan_identifier_1char */,
        FALSE                   /* scan_identifier_NULL */,
        TRUE                    /* scan_symbols */,
        FALSE                   /* scan_binary */,
        TRUE                    /* scan_octal */,
        TRUE                    /* scan_float */,
        TRUE                    /* scan_hex */,
        FALSE                   /* scan_hex_dollar */,
        TRUE                    /* scan_string_sq */,
        TRUE                    /* scan_string_dq */,
        TRUE                    /* numbers_2_int */,
        FALSE                   /* int_2_float */,
        FALSE                   /* identifier_2_string */,
        TRUE                    /* char_2_token */,
        FALSE                   /* symbol_2_token */,
        FALSE                   /* scope_0_fallback */,
};

/* jumps back to the caller of f->failenv, only to be called from inside a callback */
void
e_sexp_fatal_error(struct _ESExp *f, char *why, ...)
{
        va_list args;

        if (f->error)
                g_free(f->error);
        
        va_start(args, why);
        f->error = g_strdup_vprintf(why, args);
        va_end(args);

        longjmp(f->failenv, 1);
}

const char *
e_sexp_error(struct _ESExp *f)
{
        return f->error;
}

struct _ESExpResult *
e_sexp_result_new(struct _ESExp *f, int type)
{
        struct _ESExpResult *r = e_memchunk_alloc0(f->result_chunks);
        r->type = type;
        return r;
}

void
e_sexp_result_free(struct _ESExp *f, struct _ESExpResult *t)
{
        if (t == NULL)
                return;

        switch(t->type) {
        case ESEXP_RES_ARRAY_PTR:
                g_ptr_array_free(t->value.ptrarray, TRUE);
                break;
        case ESEXP_RES_BOOL:
        case ESEXP_RES_INT:
        case ESEXP_RES_TIME:
                break;
        case ESEXP_RES_STRING:
                g_free(t->value.string);
                break;
        case ESEXP_RES_UNDEFINED:
                break;
        default:
                g_assert_not_reached();
        }
        e_memchunk_free(f->result_chunks, t);
}

/* used in normal functions if they have to abort, and free their arguments */
void
e_sexp_resultv_free(struct _ESExp *f, int argc, struct _ESExpResult **argv)
{
        int i;

        for (i=0;i<argc;i++) {
                e_sexp_result_free(f, argv[i]);
        }
}

/* implementations for the builtin functions */

/* can you tell, i dont like glib? */
/* we can only itereate a hashtable from a called function */
struct _glib_sux_donkeys {
        int count;
        GPtrArray *uids;
};

/* ok, store any values that are in all sets */
static void
g_lib_sux_htand(char *key, int value, struct _glib_sux_donkeys *fuckup)
{
        if (value == fuckup->count) {
                g_ptr_array_add(fuckup->uids, key);
        }
}

/* or, store all unique values */
static void
g_lib_sux_htor(char *key, int value, struct _glib_sux_donkeys *fuckup)
{
        g_ptr_array_add(fuckup->uids, key);
}

static ESExpResult *
term_eval_and(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r, *r1;
        GHashTable *ht = g_hash_table_new(g_str_hash, g_str_equal);
        struct _glib_sux_donkeys lambdafoo;
        int type=-1;
        int bool = TRUE;
        int i;
        
        r(printf("( and\n"));

        r = e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
        
        for (i=0;bool && i<argc;i++) {
                r1 = e_sexp_term_eval(f, argv[i]);
                if (type == -1)
                        type = r1->type;
                if (type != r1->type) {
                        e_sexp_result_free(f, r);
                        e_sexp_result_free(f, r1);
                        g_hash_table_destroy(ht);
                        e_sexp_fatal_error(f, "Invalid types in AND");
                } else if (r1->type == ESEXP_RES_ARRAY_PTR) {
                        char **a1;
                        int l1, j;
                        
                        a1 = (char **)r1->value.ptrarray->pdata;
                        l1 = r1->value.ptrarray->len;
                        for (j=0;j<l1;j++) {
                                int n;
                                n = (int)g_hash_table_lookup(ht, a1[j]);
                                g_hash_table_insert(ht, a1[j], (void *)n+1);
                        }
                } else if (r1->type == ESEXP_RES_BOOL) {
                        bool = bool && r1->value.bool;
                }
                e_sexp_result_free(f, r1);
        }
        
        if (type == ESEXP_RES_ARRAY_PTR) {
                lambdafoo.count = argc;
                lambdafoo.uids = g_ptr_array_new();
                g_hash_table_foreach(ht, (GHFunc)g_lib_sux_htand, &lambdafoo);
                r->type = ESEXP_RES_ARRAY_PTR;
                r->value.ptrarray = lambdafoo.uids;
        } else if (type == ESEXP_RES_BOOL) {
                r->type = ESEXP_RES_BOOL;
                r->value.bool = bool;
        }
        
        g_hash_table_destroy(ht);
        
        return r;
}

static ESExpResult *
term_eval_or(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r, *r1;
        GHashTable *ht = g_hash_table_new(g_str_hash, g_str_equal);
        struct _glib_sux_donkeys lambdafoo;
        int type = -1;
        int bool = FALSE;
        int i;
        
        r(printf("(or \n"));

        r = e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
        
        for (i=0;!bool && i<argc;i++) {
                r1 = e_sexp_term_eval(f, argv[i]);
                if (type == -1)
                        type = r1->type;
                if (r1->type != type) {
                        e_sexp_result_free(f, r);
                        e_sexp_result_free(f, r1);
                        g_hash_table_destroy(ht);
                        e_sexp_fatal_error(f, "Invalid types in OR");
                } else if (r1->type == ESEXP_RES_ARRAY_PTR) {
                        char **a1;
                        int l1, j;
                        
                        a1 = (char **)r1->value.ptrarray->pdata;
                        l1 = r1->value.ptrarray->len;
                        for (j=0;j<l1;j++) {
                                g_hash_table_insert(ht, a1[j], (void *)1);
                        }
                } else if (r1->type == ESEXP_RES_BOOL) {
                        bool |= r1->value.bool;                         
                }
                e_sexp_result_free(f, r1);
        }
        
        if (type == ESEXP_RES_ARRAY_PTR) {
                lambdafoo.count = argc;
                lambdafoo.uids = g_ptr_array_new();
                g_hash_table_foreach(ht, (GHFunc)g_lib_sux_htor, &lambdafoo);
                r->type = ESEXP_RES_ARRAY_PTR;
                r->value.ptrarray = lambdafoo.uids;
        } else if (type == ESEXP_RES_BOOL) {
                r->type = ESEXP_RES_BOOL;
                r->value.bool = bool;
        }
        g_hash_table_destroy(ht);
        
        return r;
}

static ESExpResult *
term_eval_not(struct _ESExp *f, int argc, struct _ESExpResult **argv, void *data)
{
        int res = TRUE;
        ESExpResult *r;

        if (argc>0) {
                if (argv[0]->type == ESEXP_RES_BOOL
                    && argv[0]->value.bool)
                        res = FALSE;
        }
        r = e_sexp_result_new(f, ESEXP_RES_BOOL);
        r->value.bool = res;
        return r;
}

/* this should support all arguments ...? */
static ESExpResult *
term_eval_lt(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r, *r1, *r2;

        r = e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
        
        if (argc == 2) {
                r1 = e_sexp_term_eval(f, argv[0]);
                r2 = e_sexp_term_eval(f, argv[1]);
                if (r1->type != r2->type) {
                        e_sexp_result_free(f, r1);
                        e_sexp_result_free(f, r2);
                        e_sexp_result_free(f, r);
                        e_sexp_fatal_error(f, "Incompatible types in compare <");
                } else if (r1->type == ESEXP_RES_INT) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = r1->value.number < r2->value.number;
                } else if (r1->type == ESEXP_RES_TIME) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = r1->value.time < r2->value.time;
                } else if (r1->type == ESEXP_RES_STRING) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = strcmp(r1->value.string, r2->value.string) < 0;
                }
                e_sexp_result_free(f, r1);
                e_sexp_result_free(f, r2);
        }
        return r;
}

/* this should support all arguments ...? */
static ESExpResult *
term_eval_gt(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r, *r1, *r2;

        r = e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
        
        if (argc == 2) {
                r1 = e_sexp_term_eval(f, argv[0]);
                r2 = e_sexp_term_eval(f, argv[1]);
                if (r1->type != r2->type) {
                        e_sexp_result_free(f, r1);
                        e_sexp_result_free(f, r2);
                        e_sexp_result_free(f, r);
                        e_sexp_fatal_error(f, "Incompatible types in compare >");
                } else if (r1->type == ESEXP_RES_INT) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = r1->value.number > r2->value.number;
                } else if (r1->type == ESEXP_RES_TIME) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = r1->value.time > r2->value.time;
                } else if (r1->type == ESEXP_RES_STRING) {
                        r->type = ESEXP_RES_BOOL;
                        r->value.bool = strcmp(r1->value.string, r2->value.string) > 0;
                }
                e_sexp_result_free(f, r1);
                e_sexp_result_free(f, r2);
        }
        return r;
}

/* this should support all arguments ...? */
static ESExpResult *
term_eval_eq(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r, *r1, *r2;

        r = e_sexp_result_new(f, ESEXP_RES_BOOL);
        
        if (argc == 2) {
                r1 = e_sexp_term_eval(f, argv[0]);
                r2 = e_sexp_term_eval(f, argv[1]);
                if (r1->type != r2->type) {
                        r->value.bool = FALSE;
                } else if (r1->type == ESEXP_RES_INT) {
                        r->value.bool = r1->value.number == r2->value.number;
                } else if (r1->type == ESEXP_RES_BOOL) {
                        r->value.bool = r1->value.bool == r2->value.bool;
                } else if (r1->type == ESEXP_RES_TIME) {
                        r->value.bool = r1->value.time == r2->value.time;
                } else if (r1->type == ESEXP_RES_STRING) {
                        r->value.bool = strcmp(r1->value.string, r2->value.string) == 0;
                }
                e_sexp_result_free(f, r1);
                e_sexp_result_free(f, r2);
        }
        return r;
}

static ESExpResult *
term_eval_plus(struct _ESExp *f, int argc, struct _ESExpResult **argv, void *data)
{
        struct _ESExpResult *r=NULL;
        int type;
        int i;

        if (argc>0) {
                type = argv[0]->type;
                switch(type) {
                case ESEXP_RES_INT: {
                        int total = argv[0]->value.number;
                        for (i=1;i<argc && argv[i]->type == ESEXP_RES_INT;i++) {
                                total += argv[i]->value.number;
                        }
                        if (i<argc) {
                                e_sexp_resultv_free(f, argc, argv);
                                e_sexp_fatal_error(f, "Invalid types in (+ ints)");
                        }
                        r = e_sexp_result_new(f, ESEXP_RES_INT);
                        r->value.number = total;
                        break; }
                case ESEXP_RES_STRING: {
                        GString *s = g_string_new(argv[0]->value.string);
                        for (i=1;i<argc && argv[i]->type == ESEXP_RES_STRING;i++) {
                                g_string_append(s, argv[i]->value.string);
                        }
                        if (i<argc) {
                                e_sexp_resultv_free(f, argc, argv);
                                e_sexp_fatal_error(f, "Invalid types in (+ strings)");
                        }
                        r = e_sexp_result_new(f, ESEXP_RES_STRING);
                        r->value.string = s->str;
                        g_string_free(s, FALSE);
                        break; }
                case ESEXP_RES_TIME: {
                        time_t total;

                        total = argv[0]->value.time;

                        for (i = 1; i < argc && argv[i]->type == ESEXP_RES_TIME; i++)
                                total += argv[i]->value.time;

                        if (i < argc) {
                                e_sexp_resultv_free (f, argc, argv);
                                e_sexp_fatal_error (f, "Invalid types in (+ time_t)");
                        }

                        r = e_sexp_result_new (f, ESEXP_RES_TIME);
                        r->value.time = total;
                        break; }
                }
        }

        if (!r) {
                r = e_sexp_result_new(f, ESEXP_RES_INT);
                r->value.number = 0;
        }
        return r;
}

static ESExpResult *
term_eval_sub(struct _ESExp *f, int argc, struct _ESExpResult **argv, void *data)
{
        struct _ESExpResult *r=NULL;
        int type;
        int i;

        if (argc>0) {
                type = argv[0]->type;
                switch(type) {
                case ESEXP_RES_INT: {
                        int total = argv[0]->value.number;
                        for (i=1;i<argc && argv[i]->type == ESEXP_RES_INT;i++) {
                                total -= argv[i]->value.number;
                        }
                        if (i<argc) {
                                e_sexp_resultv_free(f, argc, argv);
                                e_sexp_fatal_error(f, "Invalid types in -");
                        }
                        r = e_sexp_result_new(f, ESEXP_RES_INT);
                        r->value.number = total;
                        break; }
                case ESEXP_RES_TIME: {
                        time_t total;

                        total = argv[0]->value.time;

                        for (i = 1; i < argc && argv[i]->type == ESEXP_RES_TIME; i++)
                                total -= argv[i]->value.time;

                        if (i < argc) {
                                e_sexp_resultv_free (f, argc, argv);
                                e_sexp_fatal_error (f, "Invalid types in (- time_t)");
                        }

                        r = e_sexp_result_new (f, ESEXP_RES_TIME);
                        r->value.time = total;
                        break; }
                }
        }

        if (!r) {
                r = e_sexp_result_new(f, ESEXP_RES_INT);
                r->value.number = 0;
        }
        return r;
}

/* cast to int */
static ESExpResult *
term_eval_castint(struct _ESExp *f, int argc, struct _ESExpResult **argv, void *data)
{
        struct _ESExpResult *r;

        if (argc != 1)
                e_sexp_fatal_error(f, "Incorrect argument count to (int )");

        r = e_sexp_result_new(f, ESEXP_RES_INT);
        switch (argv[0]->type) {
        case ESEXP_RES_INT:
                r->value.number = argv[0]->value.number;
                break;
        case ESEXP_RES_BOOL:
                r->value.number = argv[0]->value.bool != 0;
                break;
        case ESEXP_RES_STRING:
                r->value.number = strtoul(argv[0]->value.string, 0, 10);
                break;
        default:
                e_sexp_result_free(f, r);
                e_sexp_fatal_error(f, "Invalid type in (cast-int )");
        }

        return r;
}

/* cast to string */
static ESExpResult *
term_eval_caststring(struct _ESExp *f, int argc, struct _ESExpResult **argv, void *data)
{
        struct _ESExpResult *r;

        if (argc != 1)
                e_sexp_fatal_error(f, "Incorrect argument count to (cast-string )");

        r = e_sexp_result_new(f, ESEXP_RES_STRING);
        switch (argv[0]->type) {
        case ESEXP_RES_INT:
                r->value.string = g_strdup_printf("%d", argv[0]->value.number);
                break;
        case ESEXP_RES_BOOL:
                r->value.string = g_strdup_printf("%d", argv[0]->value.bool != 0);
                break;
        case ESEXP_RES_STRING:
                r->value.string = g_strdup(argv[0]->value.string);
                break;
        default:
                e_sexp_result_free(f, r);
                e_sexp_fatal_error(f, "Invalid type in (int )");
        }

        return r;
}

/* implements 'if' function */
static ESExpResult *
term_eval_if(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r;
        int doit;

        if (argc >=2 && argc<=3) {
                r = e_sexp_term_eval(f, argv[0]);
                doit = (r->type == ESEXP_RES_BOOL && r->value.bool);
                e_sexp_result_free(f, r);
                if (doit) {
                        return e_sexp_term_eval(f, argv[1]);
                } else if (argc>2) {
                        return e_sexp_term_eval(f, argv[2]);
                }
        }
        return e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
}

/* implements 'begin' statement */
static ESExpResult *
term_eval_begin(struct _ESExp *f, int argc, struct _ESExpTerm **argv, void *data)
{
        struct _ESExpResult *r=NULL;
        int i;

        for (i=0;i<argc;i++) {
                if (r)
                        e_sexp_result_free(f, r);
                r = e_sexp_term_eval(f, argv[i]);
        }
        if (r)
                return r;
        else
                return e_sexp_result_new(f, ESEXP_RES_UNDEFINED);
}


/* this must only be called from inside term evaluation callbacks! */
struct _ESExpResult *
e_sexp_term_eval(struct _ESExp *f, struct _ESExpTerm *t)
{
        struct _ESExpResult *r = NULL;
        int i;
        struct _ESExpResult **argv;

        g_return_val_if_fail(t != NULL, NULL);

        r(printf("eval term :\n"));
        r(parse_dump_term(t, 0));

        switch (t->type) {
        case ESEXP_TERM_STRING:
                r(printf(" (string \"%s\")\n", t->value.string));
                r = e_sexp_result_new(f, ESEXP_RES_STRING);
                /* erk, this shoul;dn't need to strdup this ... */
                r->value.string = g_strdup(t->value.string);
                break;
        case ESEXP_TERM_INT:
                r(printf(" (int %d)\n", t->value.number));
                r = e_sexp_result_new(f, ESEXP_RES_INT);
                r->value.number = t->value.number;
                break;
        case ESEXP_TERM_BOOL:
                r(printf(" (int %d)\n", t->value.number));
                r = e_sexp_result_new(f, ESEXP_RES_BOOL);
                r->value.bool = t->value.bool;
                break;
        case ESEXP_TERM_TIME:
                r(printf(" (time_t %d)\n", t->value.time));
                r = e_sexp_result_new (f, ESEXP_RES_TIME);
                r->value.time = t->value.time;
                break;
        case ESEXP_TERM_IFUNC:
                if (t->value.func.sym->f.ifunc)
                        r = t->value.func.sym->f.ifunc(f, t->value.func.termcount, t->value.func.terms, t->value.func.sym->data);
                break;
        case ESEXP_TERM_FUNC:
                /* first evaluate all arguments to result types */
                argv = alloca(sizeof(argv[0]) * t->value.func.termcount);
                for (i=0;i<t->value.func.termcount;i++) {
                        argv[i] = e_sexp_term_eval(f, t->value.func.terms[i]);
                }
                /* call the function */
                if (t->value.func.sym->f.func)
                        r = t->value.func.sym->f.func(f, t->value.func.termcount, argv, t->value.func.sym->data);

                e_sexp_resultv_free(f, t->value.func.termcount, argv);
                break;
        default:
                e_sexp_fatal_error(f, "Unknown type in parse tree: %d", t->type);
        }

        if (r==NULL)
                r = e_sexp_result_new(f, ESEXP_RES_UNDEFINED);

        return r;
}

#ifdef TESTER
static void
eval_dump_result(ESExpResult *r, int depth)
{
        int i;
        
        if (r==NULL) {
                printf("null result???\n");
                return;
        }

        for (i=0;i<depth;i++)
                printf("   ");

        switch (r->type) {
        case ESEXP_RES_ARRAY_PTR:
                printf("array pointers\n");
                break;
        case ESEXP_RES_INT:
                printf("int: %d\n", r->value.number);
                break;
        case ESEXP_RES_STRING:
                printf("string: '%s'\n", r->value.string);
                break;
        case ESEXP_RES_BOOL:
                printf("bool: %c\n", r->value.bool?'t':'f');
                break;
        case ESEXP_RES_TIME:
                printf("time_t: %ld\n", (long) r->value.time);
                break;
        case ESEXP_RES_UNDEFINED:
                printf(" <undefined>\n");
                break;
        }
        printf("\n");
}
#endif

static void
parse_dump_term(struct _ESExpTerm *t, int depth)
{
        int i;

        if (t==NULL) {
                printf("null term??\n");
                return;
        }

        for (i=0;i<depth;i++)
                printf("   ");
        
        switch (t->type) {
        case ESEXP_TERM_STRING:
                printf(" \"%s\"", t->value.string);
                break;
        case ESEXP_TERM_INT:
                printf(" %d", t->value.number);
                break;
        case ESEXP_TERM_BOOL:
                printf(" #%c", t->value.bool?'t':'f');
                break;
        case ESEXP_TERM_TIME:
                printf(" %ld", (long) t->value.time);
                break;
        case ESEXP_TERM_IFUNC:
        case ESEXP_TERM_FUNC:
                printf(" (function %s\n", t->value.func.sym->name);
                /*printf(" [%d] ", t->value.func.termcount);*/
                for (i=0;i<t->value.func.termcount;i++) {
                        parse_dump_term(t->value.func.terms[i], depth+1);
                }
                for (i=0;i<depth;i++)
                        printf("   ");
                printf(" )");
                break;
        case ESEXP_TERM_VAR:
                printf(" (variable %s )\n", t->value.var->name);
                break;
        default:
                printf("unknown type: %d\n", t->type);
        }

        printf("\n");
}

/*
  PARSER
*/

static struct _ESExpTerm *
parse_term_new(struct _ESExp *f, int type)
{
        struct _ESExpTerm *s = e_memchunk_alloc0(f->term_chunks);
        s->type = type;
        return s;
}

static void
parse_term_free(struct _ESExp *f, struct _ESExpTerm *t)
{
        int i;

        if (t==NULL) {
                return;
        }
        
        switch (t->type) {
        case ESEXP_TERM_INT:
        case ESEXP_TERM_BOOL:
        case ESEXP_TERM_TIME:
        case ESEXP_TERM_VAR:
                break;

        case ESEXP_TERM_STRING:
                g_free(t->value.string);
                break;

        case ESEXP_TERM_FUNC:
        case ESEXP_TERM_IFUNC:
                for (i=0;i<t->value.func.termcount;i++) {
                        parse_term_free(f, t->value.func.terms[i]);
                }
                g_free(t->value.func.terms);
                break;

        default:
                printf("parse_term_free: unknown type: %d\n", t->type);
        }
        e_memchunk_free(f->term_chunks, t);
}

static struct _ESExpTerm **
parse_values(ESExp *f, int *len)
{
        int token;
        struct _ESExpTerm **terms;
        int i, size = 0;
        GScanner *gs = f->scanner;
        GSList *list = NULL, *l;

        p(printf("parsing values\n"));

        while ( (token = g_scanner_peek_next_token(gs)) != G_TOKEN_EOF
                && token != ')') {
                list = g_slist_prepend(list, parse_value(f));
                size++;
        }

        /* go over the list, and put them backwards into the term array */
        terms = g_malloc(size * sizeof(*terms));
        l = list;
        for (i=size-1;i>=0;i--) {
                g_assert(l);
                g_assert(l->data);
                terms[i] = l->data;
                l = g_slist_next(l);
        }
        g_slist_free(list);

        p(printf("found %d subterms\n", size));
        *len = size;
        
        p(printf("done parsing values\n"));
        return terms;
}

static struct _ESExpTerm *
parse_value(ESExp *f)
{
        int token, negative = FALSE;
        struct _ESExpTerm *t = NULL;
        GScanner *gs = f->scanner;
        struct _ESExpSymbol *s;
        
        p(printf("parsing value\n"));
        
        token = g_scanner_get_next_token(gs);
        switch(token) {
        case G_TOKEN_LEFT_PAREN:
                p(printf("got brace, its a list!\n"));
                return parse_list(f, TRUE);
        case G_TOKEN_STRING:
                p(printf("got string\n"));
                t = parse_term_new(f, ESEXP_TERM_STRING);
                t->value.string = g_strdup(g_scanner_cur_value(gs).v_string);
                break;
        case '-':
                p(printf ("got negative int?\n"));
                token = g_scanner_get_next_token (gs);
                if (token != G_TOKEN_INT) {
                        e_sexp_fatal_error (f, "Invalid format for a integer value");
                        return NULL;
                }
                
                negative = TRUE;
                /* fall through... */
        case G_TOKEN_INT:
                t = parse_term_new(f, ESEXP_TERM_INT);
                t->value.number = g_scanner_cur_value(gs).v_int;
                if (negative)
                        t->value.number = -t->value.number;
                p(printf("got int\n"));
                break;
        case '#': {
                char *str;
                
                p(printf("got bool?\n"));
                token = g_scanner_get_next_token(gs);
                if (token != G_TOKEN_IDENTIFIER) {
                        e_sexp_fatal_error (f, "Invalid format for a boolean value");
                        return NULL;
                }
                
                str = g_scanner_cur_value (gs).v_identifier;
                
                g_assert (str != NULL);
                if (!(strlen (str) == 1 && (str[0] == 't' || str[0] == 'f'))) {
                        e_sexp_fatal_error (f, "Invalid format for a boolean value");
                        return NULL;
                }
                
                t = parse_term_new(f, ESEXP_TERM_BOOL);
                t->value.bool = (str[0] == 't');
                break; }
        case G_TOKEN_SYMBOL:
                s = g_scanner_cur_value(gs).v_symbol;
                switch (s->type) {
                case ESEXP_TERM_FUNC:
                case ESEXP_TERM_IFUNC:
                                /* this is basically invalid, since we can't use function
                                   pointers, but let the runtime catch it ... */
                        t = parse_term_new(f, s->type);
                        t->value.func.sym = s;
                        t->value.func.terms = parse_values(f, &t->value.func.termcount);
                        break;
                case ESEXP_TERM_VAR:
                        t = parse_term_new(f, s->type);
                        t->value.var = s;
                        break;
                default:
                        e_sexp_fatal_error(f, "Invalid symbol type: %s: %d", s->name, s->type);
                }
                break;
        case G_TOKEN_IDENTIFIER:
                e_sexp_fatal_error(f, "Unknown identifier: %s", g_scanner_cur_value(gs).v_identifier);
                break;
        default:
                e_sexp_fatal_error(f, "Unexpected token encountered: %d", token);
        }
        p(printf("done parsing value\n"));
        return t;
}

/* FIXME: this needs some robustification */
static struct _ESExpTerm *
parse_list(ESExp *f, int gotbrace)
{
        int token;
        struct _ESExpTerm *t = NULL;
        GScanner *gs = f->scanner;

        p(printf("parsing list\n"));
        if (gotbrace)
                token = '(';
        else
                token = g_scanner_get_next_token(gs);
        if (token =='(') {
                token = g_scanner_get_next_token(gs);
                switch(token) {
                case G_TOKEN_SYMBOL: {
                        struct _ESExpSymbol *s;

                        s = g_scanner_cur_value(gs).v_symbol;
                        p(printf("got funciton: %s\n", s->name));
                        t = parse_term_new(f, s->type);
                        p(printf("created new list %p\n", t));
                        /* if we have a variable, find out its base type */
                        while (s->type == ESEXP_TERM_VAR) {
                                s = ((ESExpTerm *)(s->data))->value.var;
                        }
                        if (s->type == ESEXP_TERM_FUNC
                            || s->type == ESEXP_TERM_IFUNC) {
                                t->value.func.sym = s;
                                t->value.func.terms = parse_values(f, &t->value.func.termcount);
                        } else {
                                parse_term_free(f, t);
                                e_sexp_fatal_error(f, "Trying to call variable as function: %s", s->name);
                        }
                        break; }
                case G_TOKEN_IDENTIFIER:
                        e_sexp_fatal_error(f, "Unknown identifier: %s", g_scanner_cur_value(gs).v_identifier);
                        break;
                default:
                        e_sexp_fatal_error(f, "Unexpected token encountered: %d", token);
                }
                token = g_scanner_get_next_token(gs);
                if (token != ')') {
                        e_sexp_fatal_error(f, "Missing ')'");
                }
        } else {
                e_sexp_fatal_error(f, "Missing '('");
        }

        p(printf("returning list %p\n", t));
        return t;
}

static void e_sexp_finalise(void *);

#ifdef E_SEXP_IS_GTK_OBJECT
static void
e_sexp_class_init (ESExpClass *class)
{
        GtkObjectClass *object_class;
        
        object_class = (GtkObjectClass *) class;

        object_class->finalize = e_sexp_finalise;

        parent_class = gtk_type_class (gtk_object_get_type ());
}
#endif

/* 'builtin' functions */
static struct {
        char *name;
        ESExpFunc *func;
        int type;               /* set to 1 if a function can perform shortcut evaluation, or
                                   doesn't execute everything, 0 otherwise */
} symbols[] = {
        { "and", (ESExpFunc *)term_eval_and, 1 },
        { "or", (ESExpFunc *)term_eval_or, 1 },
        { "not", (ESExpFunc *)term_eval_not, 0 },
        { "<", (ESExpFunc *)term_eval_lt, 1 },
        { ">", (ESExpFunc *)term_eval_gt, 1 },
        { "=", (ESExpFunc *)term_eval_eq, 1 },
        { "+", (ESExpFunc *)term_eval_plus, 0 },
        { "-", (ESExpFunc *)term_eval_sub, 0 },
        { "cast-int", (ESExpFunc *)term_eval_castint, 0 },
        { "cast-string", (ESExpFunc *)term_eval_caststring, 0 },
        { "if", (ESExpFunc *)term_eval_if, 1 },
        { "begin", (ESExpFunc *)term_eval_begin, 1 },
};

static void
free_symbol(void *key, void *value, void *data)
{
        struct _ESExpSymbol *s = value;

        g_free(s->name);
        g_free(s);
}

static void
e_sexp_finalise(void *o)
{
        ESExp *s = (ESExp *)o;

        if (s->tree) {
                parse_term_free(s, s->tree);
                s->tree = NULL;
        }

        e_memchunk_destroy(s->term_chunks);
        e_memchunk_destroy(s->result_chunks);

        g_scanner_scope_foreach_symbol(s->scanner, 0, free_symbol, 0);
        g_scanner_destroy(s->scanner);

#ifdef E_SEXP_IS_GTK_OBJECT
        ((GtkObjectClass *)(parent_class))->finalize((GtkObject *)o);
#endif
}

static void
e_sexp_init (ESExp *s)
{
        int i;

        s->scanner = g_scanner_new(&scanner_config);
        s->term_chunks = e_memchunk_new(16, sizeof(struct _ESExpTerm));
        s->result_chunks = e_memchunk_new(16, sizeof(struct _ESExpResult));

        /* load in builtin symbols? */
        for(i=0;i<sizeof(symbols)/sizeof(symbols[0]);i++) {
                if (symbols[i].type == 1) {
                        e_sexp_add_ifunction(s, 0, symbols[i].name, (ESExpIFunc *)symbols[i].func, &symbols[i]);
                } else {
                        e_sexp_add_function(s, 0, symbols[i].name, symbols[i].func, &symbols[i]);
                }
        }

#ifndef E_SEXP_IS_GTK_OBJECT
        s->refcount = 1;
#endif
}

#ifdef E_SEXP_IS_GTK_OBJECT
guint
e_sexp_get_type (void)
{
        static guint type = 0;
        
        if (!type) {
                GtkTypeInfo type_info = {
                        "ESExp",
                        sizeof (ESExp),
                        sizeof (ESExpClass),
                        (GtkClassInitFunc) e_sexp_class_init,
                        (GtkObjectInitFunc) e_sexp_init,
                        (GtkArgSetFunc) NULL,
                        (GtkArgGetFunc) NULL
                };
                
                type = gtk_type_unique (gtk_object_get_type (), &type_info);
        }
        
        return type;
}
#endif

ESExp *
e_sexp_new (void)
{
#ifdef E_SEXP_IS_GTK_OBJECT
        ESExp *f = E_SEXP ( gtk_type_new (e_sexp_get_type ()));
#else
        ESExp *f = g_malloc0(sizeof(*f));
        e_sexp_init(f);
#endif

        return f;
}

#ifndef E_SEXP_IS_GTK_OBJECT
void            e_sexp_ref              (ESExp *f)
{
        f->refcount++;
}

void            e_sexp_unref            (ESExp *f)
{
        f->refcount--;
        if (f->refcount == 0) {
                e_sexp_finalise(f);
                g_free(f);
        }
}
#endif

void
e_sexp_add_function(ESExp *f, int scope, char *name, ESExpFunc *func, void *data)
{
        struct _ESExpSymbol *s;

        g_return_if_fail(FILTER_IS_SEXP(f));
        g_return_if_fail(name != NULL);

        s = g_malloc0(sizeof(*s));
        s->name = g_strdup(name);
        s->f.func = func;
        s->type = ESEXP_TERM_FUNC;
        s->data = data;
        g_scanner_scope_add_symbol(f->scanner, scope, s->name, s);
}

void
e_sexp_add_ifunction(ESExp *f, int scope, char *name, ESExpIFunc *ifunc, void *data)
{
        struct _ESExpSymbol *s;

        g_return_if_fail(FILTER_IS_SEXP(f));
        g_return_if_fail(name != NULL);

        s = g_malloc0(sizeof(*s));
        s->name = g_strdup(name);
        s->f.ifunc = ifunc;
        s->type = ESEXP_TERM_IFUNC;
        s->data = data;
        g_scanner_scope_add_symbol(f->scanner, scope, s->name, s);
}

void
e_sexp_add_variable(ESExp *f, int scope, char *name, ESExpTerm *value)
{
        struct _ESExpSymbol *s;

        g_return_if_fail(FILTER_IS_SEXP(f));
        g_return_if_fail(name != NULL);

        s = g_malloc0(sizeof(*s));
        s->name = g_strdup(name);
        s->type = ESEXP_TERM_VAR;
        s->data = value;
        g_scanner_scope_add_symbol(f->scanner, scope, s->name, s);
}

void
e_sexp_remove_symbol(ESExp *f, int scope, char *name)
{
        int oldscope;
        struct _ESExpSymbol *s;

        g_return_if_fail(FILTER_IS_SEXP(f));
        g_return_if_fail(name != NULL);

        oldscope = g_scanner_set_scope(f->scanner, scope);
        s = g_scanner_lookup_symbol(f->scanner, name);
        g_scanner_scope_remove_symbol(f->scanner, scope, name);
        g_scanner_set_scope(f->scanner, oldscope);
        if (s) {
                g_free(s->name);
                g_free(s);
        }
}

int
e_sexp_set_scope(ESExp *f, int scope)
{
        g_return_val_if_fail(FILTER_IS_SEXP(f), 0);

        return g_scanner_set_scope(f->scanner, scope);
}

void
e_sexp_input_text(ESExp *f, const char *text, int len)
{
        g_return_if_fail(FILTER_IS_SEXP(f));
        g_return_if_fail(text != NULL);

        g_scanner_input_text(f->scanner, text, len);
}

void
e_sexp_input_file (ESExp *f, int fd)
{
        g_return_if_fail(FILTER_IS_SEXP(f));

        g_scanner_input_file(f->scanner, fd);
}

/* returns -1 on error */
int
e_sexp_parse(ESExp *f)
{
        g_return_val_if_fail(FILTER_IS_SEXP(f), -1);

        if (setjmp(f->failenv)) {
                g_warning("Error in parsing: %s", f->error);
                return -1;
        }

        if (f->tree)
                parse_term_free(f, f->tree);

        f->tree = parse_value (f);

        return 0;
}

/* returns NULL on error */
struct _ESExpResult *
e_sexp_eval(ESExp *f)
{
        g_return_val_if_fail(FILTER_IS_SEXP(f), NULL);
        g_return_val_if_fail(f->tree != NULL, NULL);

        if (setjmp(f->failenv)) {
                g_warning("Error in execution: %s", f->error);
                return NULL;
        }

        return e_sexp_term_eval(f, f->tree);
}

/**
 * e_sexp_encode_bool:
 * @s: 
 * @state: 
 * 
 * Encode a bool into an s-expression @s.  Bools are
 * encoded using #t #f syntax.
 **/
void
e_sexp_encode_bool(GString *s, gboolean state)
{
        if (state)
                g_string_append(s, " #t");
        else
                g_string_append(s, " #f");
}

/**
 * e_sexp_encode_string:
 * @s: Destination string.
 * @string: String expression.
 * 
 * Add a c string @string to the s-expression stored in
 * the gstring @s.  Quotes are added, and special characters
 * are escaped appropriately.
 **/
void
e_sexp_encode_string(GString *s, const char *string)
{
        char c;
        const char *p;

        if (string == NULL)
                p = "";
        else
                p = string;
        g_string_append(s, " \"");
        while ( (c = *p++) ) {
                if (c=='\\' || c=='\"' || c=='\'')
                        g_string_append_c(s, '\\');
                g_string_append_c(s, c);
        }
        g_string_append(s, "\"");
}

#ifdef TESTER
int main(int argc, char **argv)
{
        ESExp *f;
        char *t = "(+ \"foo\" \"\\\"\" \"bar\" \"\\\\ blah \\x \")";
        ESExpResult *r;

        gtk_init(&argc, &argv);

        f = e_sexp_new();

        e_sexp_add_variable(f, 0, "test", NULL);

        e_sexp_input_text(f, t, strlen(t));
        e_sexp_parse(f);

        if (f->tree) {
                parse_dump_term(f->tree, 0);
        }

        r = e_sexp_eval(f);
        if (r) {
                eval_dump_result(r, 0);
        } else {
                printf("no result?|\n");
        }

        return 0;
}
#endif