[gambit-list] Alexpander improvements and gambit error locations

Álvaro Castro-Castilla alvaro.castro.castilla at gmail.com
Thu Jan 3 17:42:25 EST 2013

Great, very useful information. I have it integrated and works well and
fast. I was transforming all ((lambda (x) ...) val) from macro expansiono
into (let ((x val)) ...)
Of course this was "making up" lets where there shouldn't. I will
deactivate this.

On Thu, Jan 3, 2013 at 8:43 PM, Marc Feeley <feeley at iro.umontreal.ca> wrote:

> On 2012-12-19, at 6:56 AM, Álvaro Castro-Castilla <
> alvaro.castro.castilla at gmail.com> wrote:
> > Hi,
> >
> > I've managed to get Alexpander in a quite usable state, I'm happy with
> it. It's fast and stable, and I managed to make keywords work, so I can use
> functions defined with ##define in DSSSL extensions, and namespaces for
> modules (I couldn't do these with psyntax). I also can mix low-level
> macros, in a second stage, which is good enough, since these are mostly
> used for very specific stuff related to FFI code generation and compilation
> helpers. High-level syntax is done in syntax-rules in my code.
> >
> > What I see as a main issue with Alexpander, however, are code locations
> of errors. Specially, those related to LET and other basic forms which are
> expanded to fundamental lambdas. That turns the code around all the time
> making it more difficult to locate the original source of the error.
> >
> > The basic compilation process involves generating intermediate files,
> expanded with Alexpander and then compiling them with Gambit.
> >
> > I believe that if this is improved (at least avoiding alexpander
> expansion of let/let*/letrec forms), the resulting syntax system is
> satisfactory. It could even be made to be compatible with Blackhole's
> module system, alghouth my alternative allows me the finer control for
> cross-compilation (Android) that I couldn't achieve in Blackhole after some
> time hacking it.
> >
> > Any ideas for improving this? I've tried hacking Alexpander removing the
> redefinitions and making them stubs, but no luck. I'll dive further into
> Alexpander if I don't find any other solution.
> > What are the consecuences of expanding let/let*/letrec, etc, to lambdas
> besides code locations? (am I missing any optimizations or some structure
> used by Gambit for better code generation?)
> The Gambit compiler's internal representation handles all the "let" forms
> using a call to a lambda-expression.  So you will get exactly the same
> optimizations down the line whether you use (let ((x X)) ...) or ((lambda
> (x) ...) X).
> Marc
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.iro.umontreal.ca/pipermail/gambit-list/attachments/20130103/492144ad/attachment.htm>

More information about the Gambit-list mailing list