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[honu] always keep parsing a unary operator

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This commit is contained in:
Jon Rafkind 2012-04-23 17:17:58 -06:00
parent 4799d08022
commit 40a3161570
1 changed files with 19 additions and 18 deletions
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37
collects/honu/core/private/parse2.rkt
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@ -418,24 +418,25 @@
#f)])
(do-parse unparsed precedence left parsed))
#;
(do-parse #'(rest ...) new-precedence
(lambda (stuff)
(if current
(if binary-transformer
(left (binary-transformer current stuff))
(error '#'head "cannot be used as a binary operator"))
(if unary-transformer
(left (unary-transformer stuff))
(error '#'head "cannot be used as a unary operator"))))
#f)
(values (left current) stream)
#;
(do-parse #'(head rest ...)
0
(lambda (x) x)
(left final)))]
;; if we have a unary transformer then we have to keep parsing
(if unary-transformer
(if current
(values (left current) stream)
(do-parse #'(rest ...) new-precedence
(lambda (stuff)
(define right (parse-all stuff))
(define output (unary-transformer right))
;; apply the left function because
;; we just went ahead with parsing without
;; caring about precedence
(with-syntax ([out (left (parse-all output))])
#'out))
#f))
;; otherwise we have a binary transformer (or no transformer..??)
;; so we must have made a recursive call to parse, just return the
;; left hand
(values (left current) stream))
)]
#;
[(stopper? #'head)