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Date: Sun, 09 Sep 2007 19:48:46 +0100
To: Stanislav Malyshev <stas@zend.com>
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Subject: Re:  Re: [PHP-DEV] constant folding optimization
From: nlopess@php.net (Nuno Lopes)

>> Well we don't support that syntax at this moment. If you are saying  
>> that we could add support for such syntax.. it does seem a good  
>> idea, but in that case we would need to modify a few rules of the  
>> grammar (like adding a const_expr production, and allow  
>> static_scalar derive it, etc..).
>
> Right, that's what I had in mind. That doesn't seem to break  
> anything and allows also a little more freedom. let's see if anyone  
> objects.

I tried implementing this and it seems much more complicated than what  
I though. I modified the static_scalar rule of the grammar and I got  
hundreds of reduce/reduce and shift/reduce ambiguities. Ignoring the  
warnings, well.. didn't work (the parser then couldn't process the  
run-tests.php script).

Nuno

P.S.: I already spoted a few more places where we can produce better  
byte-code (including more simple constant folding).. but one thing at  
a time :)