Re: Codeboost and Transformers - Transformers

31 May 2004

Otto Skrove Bagge wrote:
...
  Nicolas Despres &lt;despre_n(a)lrde.epita.fr&gt;
writes:

 Hello,

We met each other at the fifth Stratego Users Days. I'm part of the
Transformers team. We try to find a way to bridge the gap between
Codeboost and Transformers.  I mean, we think about writing a stratego
filter to convert Transformers AST to Codeboost AST. Thus, we could glue
Transformers front-end with Codeboost back-end.

Transformers release 0.1 is available on the web at
http://www.lrde.epita.fr/cgi-bin/twiki/view/Projects/TransformersReleases

Have you planed a next release for CodeBoost soon ?  

 Yes, there is a new release, but it has not been annouced yet (since there
 really aren't any external users to announce it to, I haven't bothered).
 You can get it at
 http://download.codeboost.org/codeboost/codeboost-0.3.0.tar.gz

 The subversion repository is also publicly available (svn checkout
 https://svn.cs.uu.nl:12443/repos/codeboost/trunk)

 I had a look at Transformers a while ago, and I think it would be a great
 idea to have a bridge between Transformers and CodeBoost (especially if
 some of you guys are willing to write it...).  I'm currently redesigning
 the abstract syntax, so it may be a waste of time to write a converter for
 the 3.0 AST.  However, I noticed that your abstract syntax seems to follow
 the standard grammar quite closely; for example, it preserves the extra
 productions used for operator precedence.  A good starting point might be
 to (design and) convert to an intermediate form which doesn't have these
 'unnecessary' constructors.  I believe it would then be easy to convert to
 CodeBoost's format (whatever it might end up looking like), and perhaps
 also interface with other C++ transformation tools.

 The 3.0 abstract syntax is poorly documented.  There is a bit of
 documentation in my thesis (available from the CodeBoost web page), and
 some recent changes are explained in the NEWS file.  I'm trying to do a
 better job with the new and improved version.  Note that while we in
 earlier versions of CodeBoost considered it important to preserve as much
 syntactic information as possible (e.g., whether the branches of an 'if'
 are compound statements or not, or whether some variables are declared in a
 single declaration (int a,b;) or in a sequence of declarations (int a; int
 b;)), we no longer feel this is important.  This means that the CodeBoost
 abstract syntax is more like a high-level intermediate than an abstract
 representation of C++.

 By the way, I did some experiments with Transformers on the Sophus library
 code (the code CodeBoost is designed to optimise), but I encountered
 problems with ambiguities (which was kind of expected, since some type
 information was missing).  Also, it seemed to be a bit too slow to be
 usable for us at the moment.  I expect both problems can be solved without
 too much trouble.

 -otto

-- 
Nicolas Desprès
nicolas.despres(a)lrde.epita.fr