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fix a broken pattern-expander example (#2197)

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pattern expanders shouldn't use `syntax-protect` on their results, and so they shouldn't use `syntax-rules`
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yjqww6 2018-07-29 00:18:40 +08:00 committed by Alex Knauth
parent a447b5bf6b
commit 759c71e158
1 changed files with 4 additions and 3 deletions
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pkgs/racket-doc/syntax/scribblings/parse/patterns.scrbl
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@ -1151,9 +1151,10 @@ Returns a @tech{pattern expander} that uses @racket[proc] to transform the patte
@examples[#:eval the-eval @examples[#:eval the-eval
(define-syntax ~maybe (define-syntax ~maybe
(pattern-expander (pattern-expander
(syntax-rules () (lambda (stx)
[(~maybe pat ...) (syntax-case stx ()
(~optional (~seq pat ...))]))) [(~maybe pat ...)
#'(~optional (~seq pat ...))]))))
]} ]}
@defthing[prop:pattern-expander (struct-type-property/c (-> pattern-expander? (-> syntax? syntax?)))]{ @defthing[prop:pattern-expander (struct-type-property/c (-> pattern-expander? (-> syntax? syntax?)))]{