You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
sugar/cache.rkt

16 lines
526 B
Racket

#lang racket/base
(require (for-syntax racket/base) racket/contract)
(provide (all-defined-out))
(define/contract (make-caching-proc base-proc)
(procedure? . -> . procedure?)
(let ([cache (make-hash)])
(λ args
(hash-ref! cache args (λ () (apply base-proc args))))))
(define-syntax (define/caching stx)
(syntax-case stx ()
[(_ (name arg ... . rest-arg) body ...)
#'(define/caching name (λ(arg ... . rest-arg) body ...))]
[(_ name body ...)
#'(define name (make-caching-proc body ...))]))