Oh nooo! (gotos)

[T. William Wells]

: while(rule = (Rule*)Queue_iter_next(&rule_iter)) {
:
:   while(rsym = (Symbol*)Queue_iter_next(&rsym_iter)) {
:    switch (derives(rsym)) {
:    case derives_nothing:
:      goto next_rule;
:    ....
:    }
:   }
:
: next_rule: continue;
:
: }

Look Ma, no goto!

	while(rule = (Rule*)Queue_iter_next(&rule_iter)) {
		while(rsym = (Symbol*)Queue_iter_next(&rsym_iter)) {
			switch (derives(rsym)) {
			case derives_nothing:
				break;
			.... (cases that want to loop use continue)
			}
			break;
		}
	}

I use this one all the time. And I do mean all the time. This is an
example of how I write the argument parser for my programs:

	init_program(argv[0]);
	list_ids_only = 0;
	all_users = 0;
	user_name = 0;
	sys_name = 0;
	kill_id = 0;
	interactive_kill = 0;
	show_machines = 0;
	show_procs = 0;
	show_queue = 0;
	no_kill = 0;
	opterr = 0;
	while (1) {
		switch (getopt(argc, argv, "aF:hik:Kmpqr:s:u:x:X")) {
		case EOF:                                       break;
		default:  usage("illegal option or missing option argument");
		case 'a': all_users = 1;                        continue;
		case 'F': set_directory(optarg);                continue;
		case 'h': uustat_help();
		case 'i': list_ids_only = 1;                    continue;
		case 'k': kill_id = optarg; func = my_unlink;   continue;
		case 'K': interactive_kill = 1;                 continue;
		case 'm': show_machines = 1;                    continue;
		case 'p': show_procs = 1;                       continue;
		case 'q': show_queue = 1;                       continue;
		case 'r': kill_id = optarg; func = my_touch;    continue;
		case 's': sys_name = optarg;                    continue;
		case 'u': user_name = optarg;                   continue;
		case 'x': Debug_level = atoi(optarg);           continue;
		case 'X': no_kill = 1;                          continue;
		}
		break;
	}

And here is how I code state machines:

	state = ST_INIT;
	while (1) {
		... get inpot
		switch (state) {
		case ST_INIT:
			... continue for the next state
			... break to exit the state machine
		...
		}
		break;
	}

Yes, I know all the limitations of this method. And yes, I have
already though of all the arguments for why one shouldn't do this. I
compared them with all the problems of using gotos and found this to
be preferable.

After seven years of C programming, I still haven't used a goto.

---
Bill                    { uunet | novavax | ankh | sunvice } !twwells!bill
bill at twwells.com