cast.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */


case OP_CAST: {
 /* pop type then value (args pushed in this order: value, typeName) */
 Value t = pop_value(vm);
 Value v = pop_value(vm);

 const char *tn = (t.type == VAL_STRING && t.s) ? t.s : NULL;
 Value out = make_nil();

 /* Normalize target name to lowercase into a small buffer */
 char target[32];
 int k = 0;
 if (tn) {
 const char *p = tn;
 while (*p && k < (int)sizeof(target) - 1) {
 char c = *p++;
 if (c >= 'A' && c <= 'Z') c = (char)(c - 'A' + 'a');
 target[k++] = c;
 }
 }
 target[k] = '\0';

 if (!tn) {
 out = make_nil();
 } else if (strcmp(target, "number") == 0) {
 if (v.type == VAL_INT) {
 out = make_int(v.i);
 } else if (v.type == VAL_STRING) {
 const char *s = v.s ? v.s : "";
 const char *p = s;
 while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')
 p++;
 char *endp = NULL;
 long long parsed = strtoll(p, &endp, 10);
 while (endp && (*endp == ' ' || *endp == '\t' || *endp == '\r' || *endp == '\n'))
 endp++;
 if (endp && *endp != '\0')
 out = make_int(0);
 else
 out = make_int((int64_t)parsed);
 } else {
 out = make_int(0);
 }
 } else if (strcmp(target, "string") == 0) {
 char *s = value_to_string_alloc(&v);
 out = make_string(s ? s : "");
 if (s) free(s);
 } else if (strcmp(target, "array") == 0) {
 if (v.type == VAL_ARRAY) {
 out = copy_value(&v);
 } else {
 Value tmp = deep_copy_value(&v);
 out = make_array_from_values(&tmp, 1);
 free_value(tmp);
 }
 } else if (strcmp(target, "map") == 0) {
 if (v.type == VAL_MAP) {
 out = copy_value(&v);
 } else {
 out = make_map_empty();
 }
 } else if (strcmp(target, "nil") == 0) {
 out = make_nil();
 } else if (strcmp(target, "function") == 0) {
 out = (v.type == VAL_FUNCTION) ? copy_value(&v) : make_nil();
 } else if (strcmp(target, "boolean") == 0) {
 out = make_int(value_is_truthy(&v) ? 1 : 0);
 } else {
 out = make_nil();
 }

 free_value(t);
 free_value(v);
 push_value(vm, out);
 break;
}