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Date: Wed, 30 Nov 2005 17:17:39 +0100
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To: Sara Golemon <pollita@php.net>
Cc: "Dmitry Stogov" <dmitry@zend.com>, internals@lists.php.net
References: <2B.E1.14828.4130D834@pb1.pair.com> <000001c5f584$77823f80$e902a8c0@thinkpad> <002c01c5f5bf$f55e8c20$7d051fac@stumpy>
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Subject: Re: [PHP-DEV] Labeled Break (nothing at all whatsoever to do with
	GOTO)
From: jochem@iamjochem.com (Jochem Maas)

Sara Golemon wrote:

...

> Your take is spot-on.  This isn't an extension of functionality, just a 
> "numbered breaks with a name" which is something I've heard requested 
> from several corners (including @zend.com) as a "wouldn't it be nice..."
> 

I wonder if the need for labelled breaks/continues might dissapear (in practice)
if those people who could most do with them are given 'goto' (without the
no-go-backwards limitation) instead? Everytime I see heavily nested 'break n'
statements it makes me wince and the only times there seems to be no
real/decent alternative to such nesting is when building some kind of
state machine ... state machines being one of the few concrete examples
to support the implementation of 'goto' in the first place, no?

...

> Since you'd like the label to be moved out of zend_brk_cont_element, 
> then perhaps we can allow this syntax to pull double duty...

devils advocate:
what happens when I want to place a 'goto' label just before a while or foreach
loop (upon which I haven't put a label)? I ask because I assume that the following 2
statements should be identical no:?

<?php
LABEL: while(1) {
/* ..etc */
?>

<?php
LABEL:
while(1) {
/* ..etc */
?>



> LABEL: whlie(1) {
>  break LABEL; <-- el->brk
>  continue LABEL;  <-- el->cont
>  goto LABEL;  <-- opline->u.opline_num
>  break OTHERLABEL; <-- error
>  continue OTHERLABEL; <-- error
>  goto OTHERLABEL; <-- opline->u.opline_num
> }
> OTHERLABEL:
> nonBreakContainerStatement();
> 
>> This construct has logic and make sense, but I am not sure that we should
>> incrise complication of PHP compiler without any serious benefits.
>> Readability is the only one benefit of this patch.
>>
> So the question is:  How serious is the gain in 
> readability/maintainability?
> 
> -Sara