Archive for the ‘Scheme’ Category

PLT Scheme 4.0 is out!

Monday, June 16th, 2008

PLT website

Typed Scheme is fun:

[-]View Code SCHEME
  #lang typed-scheme
  (define-struct: Nothing ())
  (define-struct: (a) Just ([v : a]))  
 
  (define-type-alias (Maybe a) (U Nothing (Just a)))  
 
  (: find (Number (Listof Number) -> (Maybe Number)))
  (define (find v l)
  (cond [(null? l) (make-Nothing)]
        [(= v (car l)) (make-Just v)]
        [else (find v (cdr l))]))

Though I couldn’t even deconstruct a value returned by this function & docs are very scarce. And I really doubt the idea, but nevertheless it’s fun =)

Posted in Programming, Scheme | 2 Comments »