int
fsm_main(const char *s)
{
	const char *p;

	enum {
		S0, S1, S2, S3, S4, S5
	} state;

	state = S0;

	for (p = s; *p != '\0'; p++) {
		switch (state) {
		case S0: /* start */
			switch ((unsigned char) *p) {
			case '\t':
			case ' ': break;
			case 'a':
			case 'b':
			case 'c':
			case 'd':
			case 'e':
			case 'f':
			case 'g':
			case 'h':
			case 'i':
			case 'j':
			case 'k':
			case 'l':
			case 'm':
			case 'n':
			case 'o':
			case 'p':
			case 'q':
			case 'r':
			case 's':
			case 't':
			case 'u':
			case 'v':
			case 'w':
			case 'x':
			case 'y':
			case 'z': state = S1; break;
			default:  return -1; /* leaf */
			}
			break;

		case S1: /* e.g. "a" */
			switch ((unsigned char) *p) {
			case 'a':
			case 'b':
			case 'c':
			case 'd':
			case 'e':
			case 'f':
			case 'g':
			case 'h':
			case 'i':
			case 'j':
			case 'k':
			case 'l':
			case 'm':
			case 'n':
			case 'o':
			case 'p':
			case 'q':
			case 'r':
			case 's':
			case 't':
			case 'u':
			case 'v':
			case 'w':
			case 'x':
			case 'y':
			case 'z': break;
			case '=': state = S2; break;
			case '\t':
			case ' ': state = S3; break;
			default:  return -1; /* leaf */
			}
			break;

		case S2: /* e.g. "a=" */
			switch ((unsigned char) *p) {
			case '\t':
			case ' ': break;
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9': state = S4; break;
			default:  return -1; /* leaf */
			}
			break;

		case S3: /* e.g. "a\\x09" */
			switch ((unsigned char) *p) {
			case '=': state = S2; break;
			case '\t':
			case ' ': break;
			default:  return -1; /* leaf */
			}
			break;

		case S4: /* e.g. "a=0" */
			switch ((unsigned char) *p) {
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9': break;
			case '\t':
			case ' ': state = S5; break;
			default:  return -1; /* leaf */
			}
			break;

		case S5: /* e.g. "a=0" */
			switch ((unsigned char) *p) {
			case '\t':
			case ' ': break;
			default:  return -1; /* leaf */
			}
			break;

		default:
			; /* unreached */
		}
	}

	/* end states */
	switch (state) {
	case S4: return 0x1; /* "[ \t]*[a-z]+[ \t]*=[ \t]*[0-9]+[ \t]*" */
	case S5: return 0x1; /* "[ \t]*[a-z]+[ \t]*=[ \t]*[0-9]+[ \t]*" */
	default: return -1; /* unexpected EOT */
	}
}