Function AR_REVERSE

src/arithmetic/string_funcs/string_funcs.c:122–148

incase the parameter type is 1. string - returns a string in which the order of all characters in the original string have been reversed. 2. array - returns an array in which the order of all elements in the original array have been reversed.

// 1. string - returns a string in which the order of all characters in the original string have been reversed.
// 2. array  - returns an array in which the order of all elements in the original array have been reversed.
SIValue AR_REVERSE(SIValue *argv, int argc, void *private_data) {
	if(SIValue_IsNull(argv[0])) return SI_NullVal();

	SIValue value = argv[0];
	if(SI_TYPE(value) == T_STRING) {
		// string reverse
		char *str = value.stringval;
		size_t str_len = strlen(str);
		char *reverse = rm_malloc((str_len + 1) * sizeof(char));

		char *reverse_i = reverse + str_len;
		utf8proc_int32_t c;
		utf8proc_ssize_t w;
		while(str[0] != 0) {
			w = utf8proc_iterate((const utf8proc_uint8_t *)str, -1, &c);
			str += w;
			reverse_i -= w;
			utf8proc_encode_char(c, (utf8proc_uint8_t *)reverse_i);
		}
		reverse[str_len] = '\0';
		return SI_TransferStringVal(reverse);
	} else {
		SIValue reverse = SI_CloneValue(value);
		array_reverse(reverse.array);
		return reverse;
	}
}

// returns a substring of the original string, beginning with a 0-based index start and length.
SIValue AR_SUBSTRING(SIValue *argv, int argc, void *private_data) {