[PHP-BUG] Req #69988 [NEW]: foreach ... as long as ...

From:             w-p at dds dot nl
Operating system: 
PHP version:      Irrelevant
Package:          PHP Language Specification
Bug Type:         Feature/Change Request
Bug description:foreach ... as long as ...

Description:
------------
In many languages, as in PHP, the is a loop to iterate over all elements
of a collection. Many languages also provide a mechanism to prematurely
shut this loop down.

That is odd. By using a foreach loop, the programmer communicates that
he will use the loop for all the elements. But he doesn't. A common case
is looking for an element in a collection in a way that the collection
itself does not support. Upon finding the element, the loop is
prematurely terminated.

The problem is that the shut-down of the loop is in fact a go-to
statement (go to the first statement after the loop) and severely
frustrates refactoring. Exit, break and return statements (the hidden
go-to's) cannot be safely taken out of a method and be extracted to
another one.

It would be better if there was a loop statement that provides the loop
the programmer is actually after: a foreach-with-condition loop. This
communicates the intention better, and can always be indented properly
(how do you indent a hidden go-to statement?)

Off course, there are more uses than looking up something. Like
performing actions on only those elements where it makes sense, for
example spell-checking on only those elements that have text. In any
case, we would have a structure statement that communicates what the
loop is doing.

In the example below, I wrote "as long as" in keywords. This is so
unlike the rest of PHP that I expect that a symbol would be less out of
place. I am thinking of a questing mark or a double question mark.

Test script:
---------------
$objResult = NULL;
$blnFound = FALSE;
foreach($arrElements => $objElement as long as (! $blnFound)):
        if($objElement->FullName()=='What I am looking for'):
           $objResult = $objElement;
           $blnFound = TRUE;
        endif;
endforeach;
return $objResult;



-- 
Edit bug report at https://bugs.php.net/bug.php?id=69988&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=69988&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=69988&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=69988&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=69988&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=69988&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=69988&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=69988&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=69988&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=69988&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=69988&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=69988&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=69988&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=69988&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=69988&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=69988&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=69988&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=69988&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=69988&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=69988&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=69988&r=mysqlcfg