[gambit-list] Intermixing syntax-rules and define-macro

Patrick Li patrickli.2001 at gmail.com
Thu Sep 27 18:34:45 EDT 2012


Hello,

I am having some issues with the subtleties of the low-level define-macro
system. The problem seems to be that the identifiers created by
syntax-rules are not equivalent to the identifiers created by define-macro.
I would really appreciate some help on this.

Here is a small example:

(define-syntax multi-let
  (syntax-rules ()
    ((multi-let (vars ...) body ...)
     (let* [(vars '()) ...] ;; Declare the variables
       ($set vars) ...    ;; Set them to "initial"
       body ...))))

(define-macro ($set var)
  `(set! ,var "initial"))   ;; Set the variable to "initial"


And here is what happens when I try to use it:
> (multi-let (x y z) x)
*** ERROR IN #<procedure #2> -- Unbound variable: x

Thank you very much! For my use case, I am unable to stick completely to
using define-syntax thus have to deal with how to intermix these two
systems properly.
  -Patrick
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