Re: [boost] Interest in DSL framework

From: Andreas Pokorny (andreas.pokorny_at_[hidden])
Date: 2006-08-08 15:36:16

On Sun, Aug 06, 2006 at 09:51:27PM -0700, Eric Niebler <eric_at_[hidden]> wrote:
> >> The library lacks a proper documentation, and requires some interface changes
> >> to simplify attribute update operations. Before working on that, I wanted to see
> >> if there is interest at all. 
> >>  
> >> I used the framework to implement a matrix library with a signle frontend and 
> >> multiple backends, that could be picked and combined on a by expression basis. 
> > 
> > I'm interested. I'd like to see some examples; especially on how
> > the "rule system" works. I am also interested to know how a domain
> > can be adapted for use by 2 or more libraries: xpressive and spirit
> > being main examples. IOTW, in the future, spirit and xpressive
> > parts can be shared.
> 
> Joel, Hartmut Kaiser and I have spent a lot of time working out the 
> details of an expression template system that would work for xpressive, 
> Spirit-2 and Hartmut's Karma library. The discussions were public on 
> spirit-devel. Search the archives for "Spirit-2 and Subversion", 
> "Scanner Busines, R.I.P.", "Proto Compiler Visitors", "Fusion-ifying 
> proto parse trees", and "segmented fusion - a-ha!"
> 
> In particular, this is the message where the strategy to unify all the 
> ET libraries really crystallized:
> 
> http://permalink.gmane.org/gmane.comp.parsers.spirit.devel/2620
> 
> It would be great if you could share your thoughts on how you would 
> approach these problems with your new ET library.

I did not yet manage to read all email, but from what I read, you seem to 
plan using segmented sequences to encode the complete expression tree. The 
framework instead stores the expression tree mainly in a fusion map.
But I think it makes sense to support both encoding variantes. With
segmented sequences attributes will not work, and probably not required. 

> > To be honest, right now, for Spirit-2, I am inclined to use Eric's
> > proto. It's been there for quite some time now and is quite mature.
> > But, like your library, there are no docs yet (as far as I know).
> > I'm not sure when Eric will have the time to get it outside xpressive
> > as a standalone ET library, for review. At any rate, it would be
> > interesting if you can form a collaboration with him. So, instead
> > of having 2 separate ET entries, we can just have one that has the
> > the best of both. Is that possible at all? Or is your library too
> > different from Proto?
> 
> 
> I too would be interested in hearing more about your ideas and helping 
> to build a unified ET framework for boost.

unified .. thats the reason why I intended to call the library
Boost.Unification :) 

Regards
Andreas Pokorny