Re: [MIT-Scheme-devel] improving integration of VALUES and CALL-WITH-VALUES

[Taylor R Campbell]

   Date: Mon, 21 Sep 2009 09:54:47 -0700
   From: Joe Marshall <address@hidden>

   It'd be nice if the optimizations were rule-based rather than
   having these deep, ad-hoc conditionals.  Then the description of
   the transform would *be* the transform.

   Would it be possible to get the *parser to involved here to simplify
   this sort of stuff?

Well, *PARSER works only on strings.  The runtime's structure parser
works on more general sequences of objects, but whatever rule language
you use, it would have to be fairly sophisticated to capture many of
these rules.  I gave several simple examples, but actually the pattern
is doubly recursive: it descends down a tree of combinations whose
operators are procedures whose bodies are combinations (recursion #1),
*or* of combinations whose operators can be transformed according to
the same rule (recursion #2).  That ignores the complications of
declarations and sequences, too.

If you can come up with a nice rule language to express this, I'd be
happy to try it!  But I haven't tried to come up with one because I
don't think I'm clever enough to do so.