Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:10173
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Message-ID: <40B8A953.4050608@actcom.net.il>
Date: Sat, 29 May 2004 18:16:35 +0300
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040519
MIME-Version: 1.0
To: internals@lists.php.net
References: <40B76426.8080107@php.net> <40B7A984.6070702@actcom.net.il> <40B7B4EB.4080208@php.net> <40B82E44.2000409@actcom.net.il> <40B843DA.3080403@leetspeak.org> <40B85C1B.6010305@actcom.net.il> <20040529141411.11566.qmail@pb1.pair.com>
In-Reply-To: <20040529141411.11566.qmail@pb1.pair.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] switch labels in sub-blocks
From: ilya79@actcom.net.il (Ilya Sher)

Sara Golemon wrote:
>>Well, now that I think I understand what is it for,
>>I'm pretty sure it's not very appropriate for PHP(,
>>unless someone will provides an example of the opposite
>>of course).
>>
>>It's kind of clarity vs efficiency.
>>The more the basic operation ("*to = *from++" in the
>>original) is getting bigger (slower) the efficiency gain becomes
>>smaller (correct?) so I would prefer clarity here.
>>
>>I'm not even sure real example in PHP will have close to 50%
>>speed gain.
>>
> 
> In the case of "Duff's Device" it certainly isn't applicable to PHP
That was my guess, you approved it.
>....It
> much for efficient for the engine to process a complex single opcode than to
> process many simple opcodes in succession.  That still doesn't speak to
> whether or not there aren't truly applicable examples.
It looks like it worked just fine for that
example in _C_.
> 
> Functionally the parser doesn't want to see overlapping structures like this
> and it feel non-trivial to implement.  But I havn't looked at the switch
> implementation close enough to be certain yet.
> 
> For the sake of readability I'm -1.
Agreed on that.
That's what I was originally talking about.
It was phrased as "messy".
> I'd sooner see goto implemented than
> this.  And I don't care for that either.
> 
> -Sara
>