Re: Re: [PHP-DEV] [VOTE] Generators

On 2012-08-30 20:39, Derick Rethans wrote:

On Wed, 29 Aug 2012, Gustavo Lopes wrote:

On Wed, 29 Aug 2012 22:10:52 +0200, Derick Rethans <derick@php.net> wrote:

Nothing in the core throws an exception, why would this?!

This is not accurate. All the iterators throw exceptions on similar situations. Generators are iterators, so I see no deviation from the norm here.

Nothing shows that they are. In any example I saw, I don't even see any OO syntax/functionality. For me, "yield" is a core syntax *keyword*, and hence: no exceptions. cheers, Derick I'm generally of the same opinion as you - issue a warning and skip the second loop - but for the fact that the "idiomatic" use

<?php foreach(generator() as $k => $item) {

    ...

} ?> is equivalent to the more explicit "manual" use <?php $generator = generator(); $generator->rewind(); while($generator->valid()) {

    $k = $generator->key();
    $item = $generator->current();
    ...
    $generator->next();

} ?> Since explicit control of generators can be useful, they won't necessarily be wrapped in the foreach() idiom; would not exceptions be the expected behaviour then? There might be a compromise - trigger a warning in idiomatic use, an exception in manual use - but that leaves a nasty taste in the mouth and would just cause more problems later.