racket/collects/scheme/match/parse-legacy.ss
Eli Barzilay fac8cf7328 minor
svn: r9127
2008-04-01 20:37:55 +00:00

74 lines
2.4 KiB
Scheme

#lang scheme/base
(require (for-template scheme/base)
syntax/boundmap
syntax/stx
scheme/struct-info
"patterns.ss"
"compiler.ss"
"parse-helper.ss"
"parse-quasi.ss"
(only-in srfi/1 delete-duplicates))
(provide parse/legacy/cert)
(define (parse/legacy/cert stx cert)
(define (parse stx) (parse/legacy/cert stx cert))
(syntax-case* stx (not $ ? and or = quasiquote quote)
(lambda (x y) (eq? (syntax-e x) (syntax-e y)))
[(expander args ...)
(and (identifier? #'expander)
(match-expander?
(syntax-local-value (cert #'expander) (lambda () #f))))
(match-expander-transform
parse/legacy/cert cert #'expander stx match-expander-legacy-xform
"This expander only works with the standard match syntax")]
[(and p ...)
(make-And (map parse (syntax->list #'(p ...))))]
[(or p ...)
(let ([ps (map parse (syntax->list #'(p ...)))])
(all-vars ps stx)
(make-Or ps))]
[(not p ...)
;; nots are conjunctions of negations
(let ([ps (map (compose make-Not parse) (syntax->list #'(p ...)))])
(make-And ps))]
[bx
(box? (syntax-e #'bx))
(make-Box (parse (unbox (syntax-e #'bx))))]
[#(es ...)
(ormap ddk? (syntax->list #'(es ...)))
(make-And (list (make-Pred #'vector?)
(make-App #'vector->list
(parse (syntax/loc stx (es ...))))))]
[#(es ...)
(make-Vector (map parse (syntax->list #'(es ...))))]
[($ s . pats)
(parse-struct stx cert parse #'s #'pats)]
[(? p q1 qs ...)
(make-And (cons (make-Pred (cert #'p))
(map parse (syntax->list #'(q1 qs ...)))))]
[(? p)
(make-Pred (cert #'p))]
[(= f p)
(make-App #'f (parse (cert #'p)))]
[(quasiquote p)
(parse-quasi #'p cert parse/legacy/cert)]
[(quote . rest)
(parse-quote stx parse)]
[() (make-Null (make-Dummy #f))]
[(..)
(ddk? #'..)
(raise-syntax-error 'match "incorrect use of ... in pattern" stx #'..)]
[(p .. . rest)
(ddk? #'..)
(dd-parse parse #'p #'.. #'rest)]
[(e . es)
(make-Pair (parse #'e) (parse (syntax/loc stx es)))]
[x
(identifier? #'x)
(parse-id #'x)]
[v
(or (parse-literal (syntax-e #'v))
(raise-syntax-error 'match "syntax error in pattern" stx))]))