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Date: Tue, 12 Jun 2012 15:32:33 +1200
Message-ID: <CAMBQuvee2CQxtfECbm3HedtKgn1d1VJCkYzgtcMP00mnKxDROg@mail.gmail.com>
To: Nikita Popov <nikita.ppv@googlemail.com>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Generators in PHP
From: jevon@jevon.org (Jevon Wright)

I don't understand why you need to introduce two new keywords into the
language - * and yield. Could you not solve it like follows?

// Generator implements Iterable
class AllEvenNumbers extends Generator {
  private $i;

  public __construct() { $this->i = 0; }

  function generate() {
    return ($this->i++) * 2;
  }
}

That way I think you can persist state (as part of the class instance)
and implement rewind (per whichever way you do it - either caching the
output, or serialising the class instance) without having to introduce
yet more keywords.

If this is instead a discussion to specifically implement yield,
rather than simplifying the implementation of rewindable Iterators, it
might be more useful to frame the discussion in that way.

Jevon

On Wed, Jun 6, 2012 at 5:35 AM, Nikita Popov <nikita.ppv@googlemail.com> wrote:
> Hi internals!
>
> In the last few days I've created a proof of concept implementation
> for generators in PHP. It's not yet complete, but the basic
> functionality is there:
> https://github.com/nikic/php-src/tree/addGeneratorsSupport
>
> The implementation is outlined in the RFC-stub here:
> https://wiki.php.net/rfc/generators
>
> Before going any further I'd like to get some comments about what you
> think of adding generator support to PHP.
>
> If you don't know what generators are you should have a look at the
> "Introduction" section in the above RFC or in the Python documentation
> at http://wiki.python.org/moin/Generators.
>
> Nikita
>
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