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Date: Fri, 8 Jun 2012 13:24:49 +0200
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To: Gustavo Lopes <glopes@nebm.ist.utl.pt>
Cc: internals PHP <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Generators in PHP
From: nikita.ppv@googlemail.com (Nikita Popov)

On Thu, Jun 7, 2012 at 10:46 AM, Gustavo Lopes <glopes@nebm.ist.utl.pt> wrote:
> I mean how do you deal with "return $foo" in the body of the generator? Does
> it work like a final yield? Is the return value ignored?
Currently there will be a fatal error if return statements (with
values) are used in the generator. In the future I'd like to use the
return value as the result of a yield from / yield* expression, as it
is currently done in Python and JavaScript. This is particularly
useful if you are delegating control to another coroutine. This way
you can for example break down a coroutine-based parser into several
functions (instead of having one big ugly function).

> Are you planning on any internal API for functions to implement generators
> (though I really haven't thought how that would work)?
I don't think that this is possible. Generators require that the
execution context is suspended in some way and we have to that control
only over userland code, not internal C code.

Nikita