Can't we do better than a memo table? On Thursday, June 6, 2013, wrote:
> stamourv has updated `master' from 5ea3a1ce6d to 6e8c9ed15a. > http://git.racket-lang.org/plt/5ea3a1ce6d..6e8c9ed15a > > =====[ 2 Commits ]====================================================== > Directory summary: > 82.9% collects/racket/contract/private/ > 17.0% collects/scribblings/reference/ > > ~~~~~~~~~~ > > d1df869 Vincent St-Amour <stamo...@racket-lang.org <javascript:;>> > 2013-06-06 18:02 > : > | Document procedure-closure-contents-eq?. > : > M collects/scribblings/reference/procedures.scrbl | 5 +++++ > > ~~~~~~~~~~ > > 6e8c9ed Vincent St-Amour <stamo...@racket-lang.org <javascript:;>> > 2013-06-06 18:31 > : > | Memoize wrapped case-> range contracts. > | > | Fixes failing contract tests. > : > M collects/racket/contract/private/arrow.rkt | 21 +++++++++++++++------ > > =====[ Overall Diff ]=================================================== > > collects/racket/contract/private/arrow.rkt > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > --- OLD/collects/racket/contract/private/arrow.rkt > +++ NEW/collects/racket/contract/private/arrow.rkt > @@ -1712,12 +1712,21 @@ v4 todo: > "the domain of" > #:swap? #t))) > dom-ctcs+case-nums) > - (map (λ (f) > - (define p (f rng-blame)) > - (lambda args > - (with-continuation-mark > - contract-continuation-mark-key blame > - (apply p args)))) > + (map (let ([memo '()]) > + ;; to preserve > procedure-closure-contents-eq?ness of the > + ;; wrapped procedures, memoize with f > as the key. > + (λ (f) > + (define target > + (assoc f memo > procedure-closure-contents-eq?)) > + (if target > + (cdr target) > + (let* ([p (f rng-blame)] > + [new (lambda args > + > (with-continuation-mark > + > contract-continuation-mark-key blame > + (apply p args)))]) > + (set! memo (cons (cons f new) > memo)) > + new)))) > rng-ctcs))) > (define (chk val mtd?) > (cond > > collects/scribblings/reference/procedures.scrbl > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > --- OLD/collects/scribblings/reference/procedures.scrbl > +++ NEW/collects/scribblings/reference/procedures.scrbl > @@ -88,6 +88,11 @@ to the wrong number of arguments, the resulting error > hides the first > argument as if the procedure had been compiled with the > @indexed-racket['method-arity-error] syntax property.} > > +@defproc[(procedure-closure-contents-eq? [proc1 procedure?] > + [proc2 procedure?]) boolean?]{ > +Compares the contents of the closures of @racket[proc1] and @racket[proc2] > +for equality by comparing closure elements pointwise using @racket[eq?]} > + > @; ---------------------------------------- > @section{Keywords and Arity} > >
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