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Add new simplification pass before render-test-list.

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Simplification expands match expanders and removes syntactic sugar.

Also, syntax errors are checked in the simplification phase, so better
error messages can be given.
This commit is contained in:
Sam Tobin-Hochstadt 2006-09-07 12:02:41 -04:00
parent 6034e5e0d5
commit 506c154ea8
3 changed files with 65 additions and 71 deletions
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6
collects/mzlib/private/match/gen-match.ss
View File

@ -13,6 +13,7 @@
"render-helpers.ss"
"reorder-tests.scm"
"tag-negate-tests.scm"
"simplify-patterns.ss"
"convert-pat.ss")
(require-for-template mzscheme
@ -85,7 +86,10 @@
let-bound)))
bv)))
(success-func sf bv)))))
(define test-list (render-test-list pat exp (lambda (x) x) stx))
(define test-list
(let* ([cert (lambda (x) x)]
[simplified-pat (simplify pat cert)])
(render-test-list simplified-pat exp cert stx)))
(cons test-list success))
;; gen-match : syntax list list syntax success-func -> syntax

54
collects/mzlib/private/match/render-test-list-impl.ss
View File

@ -220,34 +220,10 @@
,(syntax-object->datum ae))
ae (lambda (exp) #`(#,(cert #'pred?) #,exp)))))
;; syntax checking
((? anything ...)
(match:syntax-err
p
(if (zero? (length (syntax-e #'(anything ...))))
"a predicate pattern must have a predicate following the ?"
"syntax error in predicate pattern")))
((regexp reg-exp)
(regexp-matcher ae stx #'(? (lambda (x) (regexp-match reg-exp x))) cert))
((pregexp reg-exp)
(regexp-matcher ae stx #'(? (lambda (x) (pregexp-match-with-error reg-exp x))) cert))
((regexp reg-exp pat)
(regexp-matcher ae stx #'(app (lambda (x) (regexp-match reg-exp x)) pat) cert))
((pregexp reg-exp pat)
(regexp-matcher ae stx #'(app (lambda (x) (pregexp-match-with-error reg-exp x)) pat) cert))
;; app patterns just apply their operation.
((app op pat)
(render-test-list #'pat #`(#,(cert #'op) #,ae) cert stx))
;; syntax checking
((app . op)
(match:syntax-err
p
(if (zero? (length (syntax-e #'op)))
"an operation pattern must have a procedure following the app"
"there should be one pattern following the operator")))
[(and . pats) (map-append (lambda (pat) (render-test-list pat ae cert stx))
(syntax->list #'pats))]
@ -271,9 +247,6 @@
;; swap success and fail
(next-outer #'pat ae sf bv let-bound ks kf cert))))))
;; (cons a b) == (list-rest a b)
[(cons p1 p2) (render-test-list #'(list-rest p1 p2) ae cert stx)]
;; could try to catch syntax local value error and rethrow syntax error
((list-no-order pats ...)
(if (stx-null? (syntax (pats ...)))
@ -340,26 +313,18 @@
((hash-table pats ...)
;; must check the structure
(proper-hash-table-pattern? (syntax->list (syntax (pats ...))))
#;(proper-hash-table-pattern? (syntax->list (syntax (pats ...))))
(list
(shape-test
`(hash-table? ,(syntax-object->datum ae))
ae (lambda (exp) #`(hash-table? #,exp)))
(let ((mod-pat
(let ([mod-pat
(lambda (pat)
(syntax-case pat ()
((key value) (syntax (list key value)))
(ddk
(stx-dot-dot-k? (syntax ddk))
(syntax ddk))
(id
(and (pattern-var? (syntax id))
(not (stx-dot-dot-k? (syntax id))))
(syntax id))
(p (match:syntax-err
(syntax/loc stx p)
"poorly formed hash-table pattern"))))))
(syntax-case* pat (var) stx-equal?
[(var id) pat]
[(keypat valpat) (syntax/loc pat (list keypat valpat))]
[_ pat]))])
(make-act
'hash-table-pat
ae
@ -370,7 +335,7 @@
(hash-table-map #,(subst-bindings ae
let-bound)
(lambda (k v) (list k v)))))
#,(next-outer #`(list-no-order #,@(map mod-pat (syntax->list (syntax (pats ...)))))
#,(next-outer #`(list-no-order #,@(syntax-map mod-pat #'(pats ...)))
#`#,hash-name
sf
;; these tests have to be true
@ -385,11 +350,6 @@
ks
cert)))))))))
((hash-table . pats)
(match:syntax-err
p
"improperly formed hash table pattern"))
((struct struct-name (fields ...))
(identifier? (syntax struct-name))
(let*-values ([(field-pats) (syntax->list (syntax (fields ...)))]

76
collects/mzlib/private/match/simplify-patterns.ss
View File

@ -27,10 +27,21 @@
(provide simplify)
;; simplifies patterns by removing syntactic sugar and expanding match-expanders
;; simplify : syntax certifier-> syntax
(define (simplify stx cert)
(define (simplify stx cert)
;; convert and check sub patterns for hash-table patterns
(define (convert-hash-table-pat pat)
(syntax-case pat ()
[(p1 p2) #`(#,(simplify/i #'p1) #,(simplify/i #'p2))]
[i (and (identifier? #'i) (not (stx-dot-dot-k? #'i))) #'(var i)]
[_ (match:syntax-err pat "hash table subpattern must contain either two patterns or an identifier")]))
;; simple one-arg version, just passes the cert along
(define (simplify/i stx) (simplify stx cert))
(syntax-case*
stx
(_ list quote quasiquote vector box ? app and or not struct set! var
@ -65,54 +76,69 @@
[(quote data) stx]
;; transform quasi-patterns into regular patterns
[`quasi-pat (simplify (parse-quasi #'quasi-pat))]
[`quasi-pat (simplify/i (parse-quasi #'quasi-pat))]
;; predicate patterns with binders are redundant with and patterns
[(? pred pat . pats) (simplify/i (syntax/loc stx (and (? pred) pat . pats)))]
[(? pred) (quasisyntax/loc stx (? #,(cert #'pred)))]
[(? . anything)
(match:syntax-err
stx
(if (null? (syntax-e #'anything))
"a predicate pattern must have a predicate following the ?"
"syntax error in predicate pattern"))]
;; regexp patterns - FIXME: abstract here
[(regexp re) (simplify (syntax/loc stx (and (? string?) (? (lambda (x) (regexp-match re x))))))]
[(pregexp re) (simplify (syntax/loc stx (and (? string?) (? (lambda (x) (pregexp-match-with-error re x))))))]
[(regexp re pat) (simplify (syntax/loc stx (and (? string?) (app (lambda (x) (regexp-match re x)) pat))))]
[(pregexp re pat) (simplify (syntax/loc stx (and (? string?) (app (lambda (x) (pregexp-match-with-error re x)) pat))))]
[(regexp re) (simplify/i (syntax/loc stx (and (? string?) (? (lambda (x) (regexp-match re x))))))]
[(pregexp re) (simplify/i (syntax/loc stx (and (? string?) (? (lambda (x) (pregexp-match-with-error re x))))))]
[(regexp re pat) (simplify/i (syntax/loc stx (and (? string?) (app (lambda (x) (regexp-match re x)) pat))))]
[(pregexp re pat) (simplify/i (syntax/loc stx (and (? string?) (app (lambda (x) (pregexp-match-with-error re x)) pat))))]
[(regexp . re) (match:syntax-err stx "regexp pattern must have one or two subpatterns")]
[(pregexp . re) (match:syntax-err stx "pregexp pattern must have one or two subpatterns")]
;; cons is just list-rest with 2 arguments
[(cons p1 p2) (simplify (syntax/loc stx (list-rest p1 p2)))]
[(cons p1 p2) (simplify/i (syntax/loc stx (list-rest p1 p2)))]
[(cons . rest) (match:syntax-err stx "cons pattern must have exactly two subpatterns")]
;; aggregates
[(kw pats ...)
[(kw pats ...)
(memq (syntax-e #'kw) '(list vector list-rest list-no-order and or not))
(quasisyntax/loc stx (kw #,@(syntax-map simplify #'(pats ...))))]
(with-syntax ([(pats* ...) (syntax-map simplify/i #'(pats ...))])
(syntax/loc stx (kw pats* ...)))]
[(kw pats ... . rest)
(match:syntax-err stx (format "~a pattern must have a proper list of subpatterns" (syntax-e #'kw)))]
;; hash table patterns have their own syntax
[(hash-table (pat1 pat2) ...)
(with-syntax ([(pat1* ...) (syntax-map simplify #'(pat1 ...))]
[(pat2* ...) (syntax-map simplify #'(pat2 ...))])
(syntax/loc stx (hash-table (pat1* pat2*) ...)))]
[(hash-table (pat1 pat2) ... ooo)
[(hash-table pats ... ooo)
(stx-dot-dot-k? #'ooo)
(with-syntax ([(pat1* ...) (syntax-map simplify #'(pat1 ...))]
[(pat2* ...) (syntax-map simplify #'(pat2 ...))])
(syntax/loc stx (hash-table (pat1* pat2*) ... ooo)))]
(with-syntax
([(pats* ...) (syntax-map convert-hash-table-pat #'(pats ...))])
(syntax/loc stx (hash-table pats* ... ooo)))]
[(hash-table pats ...)
(with-syntax
([(pats* ...) (syntax-map convert-hash-table-pat #'(pats ...))])
(syntax/loc stx (hash-table pats* ...)))]
[(hash-table . rest) (match:syntax-err stx "syntax error in hash table pattern")]
;; struct patterns
[(struct st (pats ...)) (with-syntax ([(pats* ...) (syntax-map simplify #'(pats ...))]
[(struct st (pats ...)) (with-syntax ([(pats* ...) (syntax-map simplify/i #'(pats ...))]
[st* (cert #'st)])
(syntax/loc stx (struct st* (pats* ...))))]
[(struct . rest) (match:syntax-err stx "syntax error in struct pattern")]
[(struct . rest)
(match:syntax-err
stx
(if (null? (syntax-e #'rest))
(format "~a~n~a~n~a"
"a structure pattern must have the name "
"of a defined structure followed by a list of patterns "
"to match each field of that structure")
"syntax error in structure pattern"))]
[(box pat) (quasisyntax/loc stx (box #,(simplify #'pat)))]
[(box pat) (quasisyntax/loc stx (box #,(simplify/i #'pat)))]
[(box . rest) (match:syntax-err stx "syntax error in box pattern")]
[(app e pat) (quasisyntax/loc stx (app #,(cert #'e) #,(simplify #'pat)))]
[(app e pat) (quasisyntax/loc stx (app #,(cert #'e) #,(simplify/i #'pat)))]
[(app . rest) (match:syntax-err stx "syntax error in app pattern")]
[(set! id)
@ -125,9 +151,13 @@
stx]
[(get! . rest) (match:syntax-err stx "get! pattern must have one identifier")]
[(var . rest) (match:internal-err stx "var pattern found before simplification!")]
[(var id)
(identifier? #'id)
stx]
[(var . rest)
(match:syntax-err stx "var pattern must have one identifier")]
[_ stx])
[__ stx])
)