Dirty macros with define-syntax? Re: An Advanced Syntax-Rules Primer for the Mildly Insane

["Brian D. Carlstrom" <bdc@zurich.ai.mit.edu>]

Antti Karttunen writes:
 > I guess I will use scsh in my project, but unfortunately
 > it has only define-syntax, not define-macro.

define-syntax does not have to be used with syntax-rules. You can
provide a functon to do explicit s-exp based conversion.

A search with  
  find . -name '*.scm' | xargs grep rename | grep compare
gives some examples, like from scsh/cig/cig.scm:
  ;;; This section defines the Scheme-side macro processor.
  
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;; (define-syntax define-foreign define-foreign-expander)
  
  (define (define-foreign-expander form rename compare)
I tried to find a simple example but...