🚀 go-pugleaf

Scott MacHaffie <machaffi@cs.washington.edu> wrote:
>Unconditional loops have a serious problem: you have to read all of the
>code inside the loop to find out when (or if) it terminates.

Well, not if you undent the terminating conditions properly:
	loop
	    do_stuff();
	break cleanup() when (done);
	    do_more_stuff();
	end loop;

Unfortunately this isn't convenient in most languages.  C doesn't have
an inverted if statement, so undenting is confusing:
	for (;;) {
	    do_stuff();
	if (done) { cleanup(); break; }
	    do_more_stuff();
	}
The last brace looks like it closes the if statement.  I usually just
mark break statements with a /*BREAK*/ off to the right somewhere.

Ada has "EXIT loop WHEN condition;" which you can undent, but doesn't
provide for a cleanup clause.  But you often don't need one anyway.
--
Felix Lee	flee@shire.cs.psu.edu	*!psuvax1!flee