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define-syntax-rule
From: |
Andy Wingo |
Subject: |
define-syntax-rule |
Date: |
Fri, 02 Sep 2011 11:43:41 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) |
I just added the following to api-macros.texi:
@subsubsection Shorthands
One often ends up writing simple one-clause @code{syntax-rules} macros.
There is a convenient shorthand for this idiom, in the form of
@code{define-syntax-rule}.
@deffn {Syntax} define-syntax-rule (keyword . pattern) [docstring] template
Define @var{keyword} as a new @code{syntax-rules} macro with one clause.
@end deffn
Cast into this form, our @code{when} example is significantly shorter:
@example
(define-syntax-rule (when c e ...)
(if c (begin e ...)))
@end example
Happy hacking,
Andy
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