Re: [Boost-users] [Proto] Extracting types of sub-expression in transform

Subject: Re: [Boost-users] [Proto] Extracting types of sub-expression in transform
From: Joel de Guzman (joel_at_[hidden])
Date: 2008-10-20 12:10:06

Eric Niebler wrote:
> I want to learn this stuff, but the references you've provided so far 
> haven't helped. How badly do you want to see something like this in 
> Boost? Badly enough to jump in and get your hands dirty with some code? 
> Maybe you could help me to add two-level grammar support to Proto.

FWIW, there's an annex on this in the ISO EBNF documentation.
Here's the final draft:

     http://www.cl.cam.ac.uk/~mgk25/iso-14977.pdf

Annex A suggests how Extended BNF might be extended to define
a two-level grammar. I've had interest on this when I came
across that part. Nothing much there, just FYI...

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://spirit.sf.net