pluggable Y Combinator 2

• vallog: pluggable Y Combinator
• vallog: メモ化された Y Combinator
• vallog: Scheme 紙面プログラミング

さっきの続き。

• さあ、Yコンビネータ(不動点演算子)を使おう！ - よくわかりません

コードは以下のとおり。

	(define (make-trace)
	(lambda (f)
	(lambda (n)
	(format #t "\; call with : ~a\n" n)
	(f n))))
	(time ((Y (compose (make-trace) fib)) 5))
	;(time ((Y (compose (make-trace) fib)) 5))
	; real 0.000
	; user 0.000
	; sys 0.000
	; call with : 5
	; call with : 4
	; call with : 3
	; call with : 2
	; call with : 1
	; call with : 0
	; call with : 1
	; call with : 2
	; call with : 1
	; call with : 0
	; call with : 3
	; call with : 2
	; call with : 1
	; call with : 0
	; call with : 1
	8
	(time ((Y (compose (make-memoize)(compose (make-trace) fib))) 5))
	;(time ((Y (compose (make-memoize) (compose (make-trace) fib))) 5))
	; real 0.000
	; user 0.000
	; sys 0.000
	; call with : 5
	; call with : 4
	; call with : 3
	; call with : 2
	; call with : 1
	; call with : 0
	8

view raw trace.scm hosted with ❤ by GitHub

おもしろいな～。

• Gauche(Scheme) でデバッグをする4つの方法 - ひげぽん OSとか作っちゃうかMona-

追記

;(compose hoge (compose fuga ... は (compose hoge fuga ... で良かった。

(time ((Y (compose (make-memoize)(make-trace) fib)) 10))
;(time ((Y (compose (make-memoize) (make-trace) fib)) 10))
; real 0.000
; user 0.000
; sys 0.000
; call with : 10
; call with : 9
; call with : 8
; call with : 7
; call with : 6
; call with : 5
; call with : 4
; call with : 3
; call with : 2
; call with : 1
; call with : 0
89