Hi,
why this does not work with DrRacket:
#lang racket
(define-syntax then
(syntax-rules ()
((_ ev) ev)
((_ ev ...) (begin ev ...))))
(define-syntax else
(syntax-rules ()
((_ ev) ev)
((_ ev ...) (begin ev ...))))
(if #f
(then
1
2
3)
(else
3
4
5))
(cond (#f 'never)
(else 'always))
. else: bad syntax in: else
it works with others schemes as in bigloo or kawa:
------------------------------------------------------------------------------
Bigloo (4.1a) ,--^,
`a practical Scheme compiler' _ ___/ /|/
Sam 26 sep 2015 04:59:46 CEST ,;'( )__, ) '
Inria -- Sophia Antipolis ;; // L__.
email: big...@lists-sop.inria.fr ' \ / '
url: http://www-sop.inria.fr/indes/fp/Bigloo ^ ^
------------------------------------------------------------------------------
1:=> (define-syntax then
(syntax-rules ()
((_ ev) ev)
((_ ev ...) (begin ev ...))))
#unspecified
1:=> (define-syntax else
(syntax-rules ()
((_ ev) ev)
((_ ev ...) (begin ev ...))))
#unspecified
1:=> (if #f
(then
1
2
3)
(else
3
4
5))
5
1:=> (cond (#f 'never)
(else 'always))
always
Damien
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