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Date: Mon, 3 Nov 2008 16:41:29 +0100
Reply-To: Marcus Boerger <helly@php.net>
Message-ID: <154582775.20081103164129@marcus-boerger.de>
To: Ionut Gabriel Stan <ionut.g.stan@gmail.com>
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Subject: Re: [PHP-DEV] [RFC] Iteration tools
From: helly@php.net (Marcus Boerger)

Hello Ionut,

  some remarks about your proposal:

1) You can turn any array into a Traversable using
(Recursive)ArrayIterator. Though this solution is still slow. The issue is
that the c-level code needs to verify the current pointer every single time
it uses it and that means traversing the array from the beginning. That
said we might want to:
a) Optimize that for cases where we don't have to. Basically when nothing
else is pointing to the array (refcount==1) we know when the array can be
changed and do not have to verify it always.
b) provide a lower level array to traversable mechanism that operates on
the current pointer provided by the array itself. That way having no need
to verify that pointer at all.

2) Ther are iterator_apply(), iterator_to_array(), iterator_count()
The first can be used for a lot of the things you were looking for,
especially when used together with lambdas. Also not that you can use it to
pass the iterator itself to the function being called easily.

Still a few of the things you mention can be implemented faster in the same
way iterator_apply() was done. In fact the code can be based on the lovel
c-implementation provided.

marcus

Monday, November 3, 2008, 4:07:14 PM, you wrote:

> Hello everybody,

> As a result of the advice given in the thread "array_key_exists BC 
> break", I have written an
> RFC concerning some higher order functions that, I believe, could a 
> helpful addition to the language.

> Please note that I'm a userland developer and have no clue about PHP 
> internals so please
> forgive any stupidities I might have said in the RFC and make the 
> appropriate corrections.
> That also means that, if positive feedback is received, this RFC needs a 
> developer with PHP
> internals knowledge to implement it.

> The RFC can be found here:  http://wiki.php.net/rfc/iteration-tools

> Hoping that I've made sense in what I wrote there, please feel free to 
> comment as you like.

> Regards,
> Ionut





Best regards,
 Marcus