Summary

Support "fender" in syntax-rules

Metadata

• Id: ab8b67168474f1443b7828f3f149dd9c225b7f95
• Trac id: 337
• Type: enhancement
• Reporter: kon
• Owner:
• Cc: kon
• Status: closed
• Component: expander
• Estimated difficulty:
• Resolution: wontfix
• Priority: not urgent at all
• Milestone:
• Version: 4.5.x
• Changetime: 2013-05-25 14:55:00 UTC
• Created: 2010-08-16 22:42:22 UTC
• Keywords:

Description

• Allow optional "fender" in `syntax-rules'

 * <pattern> <fender> <template>

 * <fender> is an <s-expr> that must evaluate to "true"

 * <fender> is evaluated as (and <fender> #t)

+ Useful since an er-transformer would otherwise be necessary for very common tasks.

- Muddies syntax-rules in that a procedural element is introduced

---

- (identifier? obj)

(define (identifier? obj)

 (let ((sans (strip-syntax obj)))
   (and (symbol? sans) (not (keyword? sans)) ) )

-(bound-identifier=? id1 id2)

-(free-identifier=? id1 id2)

Changes and comments

[2011-02-05 15:36:11 UTC] sjamaan removed milestone 4.7.0

[2013-05-25 14:55:00 UTC] sjamaan changed status from new to closed

[2013-05-25 14:55:00 UTC] sjamaan set resolution to wontfix

[2013-05-25 14:55:00 UTC] sjamaan wrote:

Personally, I think this doesn't belong in syntax-rules. It's complex enough as it is, and we'll add more features piled on by R7RS soon, too.

This could be an egg.