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

char *mu_parse_escape(const char *prog_name, const char *src) {
	size_t size = 0;
	size_t src_len = strlen(src);

	for (size_t i = 0; i < src_len; i++) {
		size++;
		size -= (src[i] == '\\');
	}

	char *buf = malloc(size + 1);
	if (buf == NULL) {
		if (prog_name)
			fprintf(stderr, "%s: malloc: %s\n", prog_name, strerror(errno));

		return NULL;
	}

	size = 0;
	for (size_t i = 0; i < src_len; i++) {
		char c = src[i];
		if (c == '\\' && i < src_len) {
			switch (src[i + 1]) {
				case 'n':
					c = '\n';
					break;

				case 'a':
					c = '\a';
					break;

				case 't':
					c = '\t';
					break;

				case 'b':
					c = '\b';
					break;

				case 'e':
					c = '\033';
					break;

				case 'r':
					c = '\r';
					break;

				case 'f':
					c = '\f';
					break;

				case 'v':
					c = '\v';
					break;

				default:
					c = '\\';
			}

			i++;
		}

		buf[size] = c;
		size++;
	}

	buf[size + 1] = '\0';
	return buf;
}