wrapping `define-syntax'

[Julian Graham]

Hi Guilers,

For the purpose of some experiments I've been doing with integrating
R6RS libraries, I've been trying to figure out ways to wrap
`define-syntax' so that I can do things like add bindings to a
module's eval closure before evaluating a macro definition.  As part
of this mechanism, I need to be able to save the original transformer
for `define-syntax' so that I can delegate to it.  When I run the
following code (either in master or Andy Wingo's "syncase" branch)...

  (use-modules (ice-9 syncase))
  (define canonical-define-syntax (@ (ice-9 syncase) define-syntax))
  (canonical-define-syntax foo (syntax-rules () ((_) 'foo)))

...I get:

  ERROR: In procedure vm-run:
  ERROR: VM: Stack overflow

I've also tried doing:

  (define canonical-define-syntax
    (procedure->memoizing-macro (macro-transformer (@ (ice-9 syncase)
define-syntax))))

...which produces, when I try to use it:

  ERROR: unknown kind of macro

So I'm curious: regardless of whether what I'm trying to do is a good
idea, is it feasible -- and if so, what's the right way to do it?


Regards,
Julian