Scheme-CPS

给出斐波那契数列计算函数，普通版和CPS版

#lang SCHEME
(define (fib n)
  (if (< n 2) n
      (+ (fib (- n 1))
         (fib (- n 2)))))
(define (fib-cps n k)
  (if (< n 2)
      (k n)
      (fib-cps (- n 1)
               (lambda (fib-n-1)
                 (fib-cps (- n 2)
                          (lambda (fib-n-2)
                            (k (+ fib-n-1 fib-n-2))))))))
(define (k n) n)

命令行调用如下

Welcome to DrRacket, version 6.5 [3m].
Language: SCHEME, with debugging; memory limit: 128 MB.
> display (fib-cps 6 k)
#<procedure:display>
8
> 

嗯，再看一下阶乘的例子，毕竟两个是成双出现，呵呵

(define (fact n)
  (if (= n 0) 1
      (* n (fact (- n 1)))))

k函数的定义同上。