Re: Labeled Break (nothing at all whatsoever to do with GOTO)

On Tue, 2005-11-29 at 20:40, Sara Golemon wrote: > But first, this word from our sponsor: > Group A wants anything resembling goto to burn in the fires of hell > Group B wants full non-crippled goto or nothing at all > Group C wants partial goto (non-backward jumping) or nothing at all > Groups B and C both (generally) want it called either GOTO or JUMP, not > BREAK > > Since no group this size will ever come to an agreement on something this > divisive, I'd like to turn the topic to a completely different language > feature which (might) please enough people to get a rousing consensus. > > Actual labeled breaks. Not the break+jump that was proposed earlier in the > guise of a break statement, but an actual straightforward, no funny-business > labeled break which does no more and no less than the current break N; > construct, but allows the use of identifier labels rather than numbers which > may change as the result of the addition or removal of break containers. > > http://libssh2.org/patches/true_labeled_break.diff > > Usage: > > while FOO ($condition) { > /* statements */ > break FOO; > /* more statements */ > } > > Or a stacked example: > > for FOO(;;) { > while BAR (true) { > foreach BAZ ($arr as $val) { > switch Foof ($value) { > default: > do Plop { > break FOO; > } while (false); > } > } > } > } > > Notes on this implementation: > > * Labels can't be repeated in an ancestral line. For example, the parser > will throw an ERROR on the following: > while FOO(true) { > while FOO(true) { > break FOO; > } > } > > * Labels can be repeated by siblings. I'm not married to this, and it > certainly has WTF potential. This behavior is easily modified to throw an > error. I left it permissable because there was no technical reason to > disallow it. For example, the following is okay: > while FOO(true) { > break; > } > while FOO(true) { > break FOO; > } > > * Labeled breaks also apply to continue; For example: > foreach FOO($arr as $key => $val) { > if ($key % 2) continue FOO; > if (empty(%key)) break FOO; > } Hello, I represent group B (not in any way officially or anything else that might give my words an iota of weight), but I (*cough cough*) WE think that the above break system would make a terrible system for finite state machines. Additionally at this time I'd like to make clear that we are in support for full uncrippled break WITHIN scope. Group A can feel free to travel to the burning fires of hell and have a barbecue, and group C should join us so that at least they get what they want as a subset. As an aside, from what I've read, the multitude were in favour of unrestricted goto. Quite a few were in favour of none at all (but not as many as in group B) and those in favour of none at all had a large subset that were in favour of unrestricted goto in the event that group B should get their way :) Cheers, Rob. -- .------------------------------------------------------------. | InterJinn Application Framework - http://www.interjinn.com | :------------------------------------------------------------: | An application and templating framework for PHP. Boasting | | a powerful, scalable system for accessing system services | | such as forms, properties, sessions, and caches. InterJinn | | also provides an extremely flexible architecture for | | creating re-usable components quickly and easily. | `------------------------------------------------------------'