racket/collects/scheme/match.ss
Sam Tobin-Hochstadt b7127dc9c7 Add new match implementation.
Does not yet work:
 - some errors about car of ()
 - some match-expander certification errors

svn: r9049
2008-03-21 23:54:58 +00:00

23 lines
692 B
Scheme

(module match scheme/base
(require scheme/match/match
(for-syntax scheme/base))
(provide (except-out (all-from-out scheme/match/match)
define-match-expander)
(rename-out [define-match-expander* define-match-expander]))
(define-for-syntax (no-old-match-form stx)
(raise-syntax-error
#f
"works only for constructor-based `match' form"
stx))
(define-syntax define-match-expander*
(syntax-rules ()
[(_ id expr) (define-match-expander id expr)]
[(_ id expr expr2) (define-match-expander id
expr
no-old-match-form
expr2)])))