compilation: Expanding macros didn't do what I thought...

[Rob Browning]

I'm trying to create a guile function that will take a scheme form and
then expand all macros contained within it - at least all macros that
aren't "normal scheme" -- i.e. aren't stuff that hobbit would already
know about like "quote".

I thought I was making progress, but then hit a snag.  The code below
works for many cases, including a syntax-case/rules definitions and
define-macro definitions, but it goes into an infinite loop if it hits
eval-case (i.e. mmacros), which get returned unaffected by
macroexpand.  Now of course, I can skip them by just checking if the
output of macroexpand is eq? to the input, but that doesn't really
address the problem.  I need *everything* to be expanded before I hand
the code to hobbit.

Further, I'm wondering how acros, mmacros, and macros *should* be
treated compilation-wise -- most particularly mmacros...

To some extent, I'm kind of blundering around in the dark here, which
has been kinda fun for a while, but is there any documentation really
explaining how guile's current read/expansion/evaluation process
works?

(define-module (ice-9 simple-compile)
  :use-module (ice-9 syncase)
  :export (compile-form))

(define internal-eval (nested-ref the-scm-module '(app modules guile eval)))

(define (expand-all-macros x)
  (cond
   ((null? x) x)
   ((and (pair? x)
         (symbol? (car x))
         (defined? (car x))
         (macro? (internal-eval (car x) (interaction-environment)))
         (not (primitive-macro?
               (internal-eval (car x) (interaction-environment)))))
    (write (list 'expanding-macro (car x))) (newline)
    (expand-all-macros (macroexpand x)))
   ((pair? x)
    (cons (expand-all-macros (car x))
          (expand-all-macros (cdr x))))
   (else x)))

(export expand-all-macros)
    
(define (make-compilable-form x)
  (let ((sc-expanded-form (if (and (pair? x)
                                   (equal? (car x) "noexpand"))
                              (cadr x)
                              (sc-expand x))))

    (expand-all-macros sc-expanded-form)))

Thanks

-- 
Rob Browning <address@hidden> PGP=E80E0D04F521A094 532B97F5D64E3930