add contract to make-caching-proc

10 years ago · baa670aa8f
parent 966563a968
commit baa670aa8f
1 changed files with 3 additions and 2 deletions
--- a/cache.rkt
+++ b/cache.rkt
@ -1,8 +1,9 @@
 #lang racket/base
-(require (for-syntax racket/base))
+(require (for-syntax racket/base) racket/contract)
 (provide (all-defined-out))

-(define (make-caching-proc base-proc) 
+(define/contract (make-caching-proc base-proc) 
+  (procedure? . -> . procedure?)
  (let ([cache (make-hash)])
    (λ args
      (hash-ref! cache args (λ () (apply base-proc args))))))