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This commit is contained in:
Matthew Butterick 2016-04-29 19:31:42 -07:00
parent fb0522957a
commit 5a0e8982b7
1 changed files with 4 additions and 4 deletions
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8
beautiful-racket-lib/br/define.rkt
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@ -154,16 +154,16 @@
[(_ (syntax id) (syntax thing)) ; (define #'f1 #'42)
#'(br:define-cases (syntax id) [#'_ (syntax thing)])]
[(_ (sid:syntaxed-id stx-arg ...) expr ...) ; (define (#'f1 stx) expr ...)
[(_ (sid:syntaxed-id stx-arg ...) . exprs) ; (define (#'f1 stx) expr ...)
(raise-syntax-error 'define "definition of a syntax transformer must use lambda notation, because otherwise it's too easy to confuse the compile-time shape and the run-time shape" (syntax->datum #'sid.name))]
[(_ sid:syntaxed-id (λ (stx-arg ...) expr ...)) ; (define #'f1 (λ(stx) expr ...)
[(_ sid:syntaxed-id (λ (stx-arg ...) . exprs)) ; (define #'f1 (λ(stx) expr ...)
#:fail-when (not (= (length (syntax->datum #'(stx-arg ...))) 1))
(raise-syntax-error 'define "did not get exactly one argument for macro" (syntax->datum #'(stx-arg ...)))
(with-syntax ([(first-stx-arg other ...) #'(stx-arg ...)])
#'(define-syntax (sid.name first-stx-arg) expr ...))]
#'(define-syntax (sid.name first-stx-arg) . exprs))]
[(_ arg ...) #'(define arg ...)]))
[(_ . args) #'(define . args)]))
(module+ test
(require rackunit)