Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:62842
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain zend.com designates 212.199.177.89 as permitted sender)
Message-ID: <504836A3.20904@zend.com>
Date: Thu, 6 Sep 2012 09:37:39 +0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120828 Thunderbird/15.0
MIME-Version: 1.0
To: Nikita Popov <nikita.ppv@gmail.com>
CC: PHP internals <internals@lists.php.net>
References: <CAF+90c-+Hgcv5B4+eGDS+jEj6oNoyefBWO-M=kvThaVdckz62g@mail.gmail.com>
In-Reply-To: <CAF+90c-+Hgcv5B4+eGDS+jEj6oNoyefBWO-M=kvThaVdckz62g@mail.gmail.com>
Content-Type: text/plain; charset="ISO-8859-1"; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] Moving to an AST-based parsing/compilation process
From: dmitry@zend.com (Dmitry Stogov)

Hi Nikita,

Personally, I don't see any reason to build AST. As you mentioned 
yourself, it will be slower and will require more memory. On the other 
hand AST itself would allow to perform only very basic optimizations. 
Most of them can be easily done on VM opcode level as well.

Also, as it's not an easy task, the old "ugly hacks" will be replaced 
with new mistakes, which would require new "hacks" in the future :)

The only real advantage could be an ability to expose AST to PHP 
scripts, but only few people may need it.

Thanks. Dmitry.

On 09/04/2012 11:57 PM, Nikita Popov wrote:
> Hey folks!
>
> Some people asked me what the advantages of using an AST-based
> parsing/compilation process are, so I put together a few quick notes
> in an RFC:
>
> https://wiki.php.net/rfc/ast_based_parsing_compilation_process
>
> It would be nice to get a few comments from other core devs on this.
>
> Nikita
>