CHICKEN Scheme

Summary

bound variables get stripped incorrectly

Metadata

Id: 4035fb553674ebd4c62d696ae378423ccd19d544
Trac id: 618
Type: defect
Reporter: felix
Owner: felix
Cc:
Status: closed
Component: expander
Estimated difficulty:
Resolution: fixed
Priority: major
Milestone: 4.9.0
Version: 4.7.x
Changetime: 2012-09-24 21:47:48 UTC
Created: 2011-06-23 19:11:42 UTC
Keywords: syntax strip-syntax

Description

Matthew Flatt reports:

The following program prints a gensym in v4.7.0 and 4aaea216cc9887, but I think it should print the symbol 'x:

  (define-syntax c 
    (syntax-rules () 
      [(_) 
       (let ([x 10]) 
         (let-syntax ([z (syntax-rules ()
                           [(_) (quote x)])])
           (write (z))
           (newline)))]))
 
  (c)

I wrote the example because I'm suspicious of "compiler.scm" treating `##core#quote' and `##core#syntax` the same. Maybe `##sys#strip-syntax` in "expand.scm" is supposed to do different things in quote and syntax mode; the comment "if se is given, retain bound vars" in `##sys#strip-syntax` suggests that it had two modes at some point in the past.