Re: [Boost-users] Proto transform : fold & fold_tree use case

From: Joel FALCOU (joel.falcou_at_[hidden])
Date: 2008-06-17 13:21:29

Eric Niebler a écrit :
> Hi Joel, I would have an easier time understanding what you were trying 
> to accomplish if you could give an example of an expression you'd like 
> to transform and the desired result of the transform.

Yeah I kinda guessed after posting this. Here is a link to a paper 
presenting what I am currently porting to proto :

http://www.ief.u-psud.fr/~falcou/pub/falcou-PARCO-2007.pdf

Quaff is a parallel programming DSL that maps user defined functor class 
to a process network structure.

Basically, take the principles of this paper and just say that instead 
of having pipe() and par() function, you have operator | and &.
The old version of quaff ran on a hand-made expression template system 
that was - well - a piece of crap.

Now, I want to use proto to leverage most of the ET + semantic code.
I tried to do so in a straight forward way (aka making a apply_rule 
transform that mapped a proto expression contents to my semantic rule 
meta-function) but it failed cause when I was mixing pipe and par (ie | 
and &), the numbering of PID and insertion of elements went awkward. I 
also guess i don't have to use mpl::vector then build a boost::tupel out 
of them thanks to fusion, but considering my first failure, I stepped back.

If more info than the paper is needed, I'll have to check with my 
co-worker to know which code is "safe" to publish here ;)

Thanks for the help.

-- 
Joel FALCOU
Research Engineer @ Institut d'Electronique Fondamentale
Université PARIS SUD XI
France