racket/collects/scheme/contract/private/object.ss
Stevie Strickland d820493feb First cut of converting object-contract to share a common base that
object/c will also use.

svn: r18274
2010-02-22 21:55:32 +00:00

121 lines
4.4 KiB
Scheme

#lang scheme/base
(require "arrow.ss"
"guts.ss"
scheme/private/class-internal
scheme/stxparam)
(require (for-syntax scheme/base))
(provide mixin-contract
make-mixin-contract
is-a?/c
subclass?/c
implementation?/c
object-contract)
(define-for-syntax (parse-object-contract stx args)
(let loop ([args (syntax->list args)]
[mtds '()]
[flds '()])
(cond
[(null? args) (list mtds flds)]
[else (syntax-case (car args) (field)
[(field id ctc)
(identifier? #'id)
(loop (cdr args) mtds (cons #'(id ctc) flds))]
[(field . rst)
(raise-syntax-error #f "malformed field specification" stx (car args))]
[(id ctc)
(identifier? #'id)
(loop (cdr args) (cons #`(id ctc) mtds) flds)]
[_
(raise-syntax-error #f "malformed object-contract clause" stx (car args))])])))
(define-struct object-contract (methods method-ctcs fields field-ctcs)
#:omit-define-syntaxes
#:property prop:contract
(build-contract-property
#:projection
(λ (ctc)
(λ (blame)
(λ (val)
(make-wrapper-object val blame
(object-contract-methods ctc) (object-contract-method-ctcs ctc)
(object-contract-fields ctc) (object-contract-field-ctcs ctc)))))
#:name
(λ (ctc) `(object-contract ,@(map (λ (fld ctc) (build-compound-type-name 'field fld ctc))
(object-contract-fields ctc)
(object-contract-field-ctcs ctc))
,@(map (λ (mtd ctc) (build-compound-type-name mtd ctc))
(object-contract-methods ctc)
(object-contract-method-ctcs ctc))))
#:first-order
(λ (ctc)
(λ (val)
(check-object-contract val #f (object-contract-methods ctc) (object-contract-fields ctc))))))
(define-syntax (object-contract stx)
(syntax-case stx ()
[(_ spec ...)
(with-syntax ([(((method-id method-ctc) ...)
((field-id field-ctc) ...))
(parse-object-contract stx #'(spec ...))])
(with-syntax ([(method-name ...) (map (λ (x) (string->symbol (format "~a method" (syntax-e x))))
(syntax->list #'(method-id ...)))])
#'(build-object-contract '(method-id ...)
(syntax-parameterize ((making-a-method #t)) (list (let ([method-name method-ctc]) method-name) ...))
'(field-id ...)
(list field-ctc ...))))]))
(define (build-object-contract methods method-ctcs fields field-ctcs)
(make-object-contract methods
(map (λ (x) (coerce-contract 'object-contract x)) method-ctcs)
fields
(map (λ (x) (coerce-contract 'object-contract x)) field-ctcs)))
(define (make-mixin-contract . %/<%>s)
(->d ([c% (and/c (flat-contract class?)
(apply and/c (map sub/impl?/c %/<%>s)))])
()
[res (subclass?/c c%)]))
(define (subclass?/c %)
(unless (class? %)
(error 'subclass?/c "expected <class>, given: ~e" %))
(let ([name (object-name %)])
(flat-named-contract
`(subclass?/c ,(or name 'unknown%))
(lambda (x) (subclass? x %)))))
(define (implementation?/c <%>)
(unless (interface? <%>)
(error 'implementation?/c "expected <interface>, given: ~e" <%>))
(let ([name (object-name <%>)])
(flat-named-contract
`(implementation?/c ,(or name 'unknown<%>))
(lambda (x) (implementation? x <%>)))))
(define (sub/impl?/c %/<%>)
(cond
[(interface? %/<%>) (implementation?/c %/<%>)]
[(class? %/<%>) (subclass?/c %/<%>)]
[else (error 'make-mixin-contract "unknown input ~e" %/<%>)]))
(define (is-a?/c <%>)
(unless (or (interface? <%>)
(class? <%>))
(error 'is-a?/c "expected <interface> or <class>, given: ~e" <%>))
(let ([name (object-name <%>)])
(flat-named-contract
(cond
[name
`(is-a?/c ,name)]
[(class? <%>)
`(is-a?/c unknown%)]
[else `(is-a?/c unknown<%>)])
(lambda (x) (is-a? x <%>)))))
(define mixin-contract (->d ([c% class?]) () [res (subclass?/c c%)]))