module/slib/macrotst.scm

   1 ;;;"macrotst.scm" Test for R4RS Macros
   2 ;;; From Revised^4 Report on the Algorithmic Language Scheme
   3 ;;; Editors: William Clinger and Jonathon Rees
   4 ;
   5 ; We intend this report to belong to the entire Scheme community, and so
   6 ; we grant permission to copy it in whole or in part without fee.  In
   7 ; particular, we encourage implementors of Scheme to use this report as
   8 ; a starting point for manuals and other documentation, modifying it as
   9 ; necessary.
  10
  11 ;;; To run this code type
  12 ;;; (require 'macro)
  13 ;;; (macro:load "macrotst.scm")
  14
  15 (write "this code should print now, outer, and 7") (newline)
  16
  17 (write
  18  (let-syntax ((when (syntax-rules ()
  19                                   ((when test stmt1 stmt2 ...)
  20                                    (if test
  21                                        (begin stmt1
  22                                               stmt2 ...))))))
  23    (let ((if #t))
  24      (when if (set! if 'now))
  25      if)))
  26 (newline)
  27 ;;;                     ==> now
  28
  29 (write
  30  (let ((x 'outer))
  31    (let-syntax ((m (syntax-rules () ((m) x))))
  32      (let ((x 'inner))
  33        (m)))))
  34 (newline)
  35 ;;;                     ==> outer
  36 (write
  37  (letrec-syntax
  38   ((or (syntax-rules ()
  39          ((or) #f)
  40          ((or e) e)
  41          ((or e1 e2 ...)
  42           (let ((temp e1))
  43             (if temp temp (or e2 ...)))))))
  44   (let ((x #f)
  45         (y 7)
  46         (temp 8)
  47         (let odd?)
  48         (if even?))
  49     (or x
  50         (let temp)
  51         (if y)
  52         y))))
  53 (newline)
  54 ;;;                     ==> 7