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Ingy döt Net 2013-10-27 22:24:23 +00:00
parent 6f050a029e
commit 776bba907c
3887 changed files with 59894 additions and 7280 deletions
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8
Task/Y-combinator/Racket/y-combinator-1.rkt Normal file
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#lang lazy
(define Y (λ(f)((λ(x)(f (x x)))(λ(x)(f (x x))))))
(define Fact
(Y (λ(fact) (λ(n) (if (zero? n) 1 (* n (fact (- n 1))))))))
(define Fib
(Y (λ(fib) (λ(n) (if (<= n 1) n (+ (fib (- n 1)) (fib (- n 2))))))))

3
Task/Y-combinator/Racket/y-combinator-2.rkt Normal file
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#lang racket
(define Y (λ(b)((λ(f)(b(λ(x)((f f) x))))
(λ(f)(b(λ(x)((f f) x)))))))

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Task/Y-combinator/Racket/y-combinator-3.rkt Normal file
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#lang typed/racket
(: make-recursive : (All (S T) ((S -> T) -> (S -> T)) -> (S -> T)))
(define-type Tau (All (S T) (Rec this (this -> (S -> T)))))
(define (make-recursive f)
((lambda: ([x : (Tau S T)]) (f (lambda (z) ((x x) z))))
(lambda: ([x : (Tau S T)]) (f (lambda (z) ((x x) z))))))
(: fact : Number -> Number)
(define fact (make-recursive
(lambda: ([fact : (Number -> Number)])
(lambda: ([n : Number])
(if (zero? n)
1
(* n (fact (- n 1))))))))
(fact 5)