| Reporter's email: |
dyoo at hashcollision dot org |
| Number: |
12508 |
| Category: |
macro-stepper |
| Synopsis: |
Macro stepper does not fully expand out uses of certain user macros under Standard Macro hiding |
| Class: |
sw-bug |
| Responsible: |
ryanc |
| Notify-List: |
|
| Severity: |
serious |
| Priority: |
medium |
| State: |
open |
| Confidential: |
no |
| Arrival-Date: |
Sun Jan 22 22:08:01 -0500 2012 |
| Closed-Date: |
|
| Last-Modified: |
Wed Feb 01 17:24:25 -0500 2012 |
| Originator: |
Danny Yoo |
| Organization: |
plt
|
| Submitter-Id: |
unknown |
| Release: |
5.2.0.901 |
| Environment: |
Linux i686 / Mozilla/5.0 (X11; Linux i686) AppleWebKit/534.30 (KHTML, like Gecko) Chrome/12.0.742.124 Safari/534.30
|
| Description: |
The following program, when macro expanded using standard Macro hiding, does not fully expand out uses of the user-defined macro:
---
#lang racket
(define-syntax myor
(syntax-rules ()
[(_ e) e]
[(_ e1 . es)
(let ([r e1]) (if r r (myor . es)))]))
(define (nonzero? r)
(myor (negative? r)
(positive? r)))
---
Under Standard macro hiding, this expands out up to:
---
(module anonymous-module racket
(#%module-begin
(define-syntax myor (syntax-rules () [(_ e) e] [(_ e1 . es) (let ([r e1]) (if r r (myor . es)))]))
(define (nonzero? r) (let ([r (negative? r)]) (if r r (myor (positive? r)))))))
---
where the second 'myor' still exists there.
There may be a relationship with the syntax tainting mechanisms that syntax-rules enforces. When the module is written using syntax-case rather than syntax-rules, then the macro expands out as expected.
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| Fix: |
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| Release-Note: |
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