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Scheme 方案替代模型_Scheme_Racket - Fatal编程技术网
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Scheme 方案替代模型

scheme racket

Scheme 方案替代模型,scheme,racket,Scheme,Racket,关于程序： (define (double fn) (lambda (x) (fn (fn x)))) 打电话时： (((double (double double)) 1+) 0) 这是否正确： (double (lambda (x) (double (double x) 1+) 0)) ((lambda (x) (double^4 x) 1+) 0) ((double^4 1+) 0) (16+ 0)

关于程序：

(define (double fn) (lambda (x) (fn (fn x))))
打电话时：

(((double (double double)) 1+) 0)
这是否正确：

(double (lambda (x) (double (double x) 1+) 0))
        ((lambda (x) (double^4 x) 1+) 0)
                ((double^4 1+) 0)
                 (16+ 0)
                    16   

(((double double (double double) double) 1+) 0)
  (double (double (lambda (x) (double (double x) 1+) 0)))
    (double (lambda (x) (double^4 1+) 0))
            ((lambda (x) (double^16 x) 1+) 0)
                         ((double^16 1+) 0)
                              (256+ 0)
                                256
同样，在呼叫时：

(((((double double) double) double) 1+) 0)
这是否正确：

(double (lambda (x) (double (double x) 1+) 0))
        ((lambda (x) (double^4 x) 1+) 0)
                ((double^4 1+) 0)
                 (16+ 0)
                    16   

(((double double (double double) double) 1+) 0)
  (double (double (lambda (x) (double (double x) 1+) 0)))
    (double (lambda (x) (double^4 1+) 0))
            ((lambda (x) (double^16 x) 1+) 0)
                         ((double^16 1+) 0)
                              (256+ 0)
                                256
我推荐DrRacket中的步进器。它允许您一次显示一个步骤。它甚至允许你回去

首先，我选择了语言“HTDP:advancedwithlambda”。 然后我进入了这个程序：

(define (double fn) 
  (lambda (x) (fn (fn x))))

(((double (double double)) add1) 0)
最后我点击了步进按钮。

什么是
1+/code>，
16+/code>，
256+/code>，
double^4
和
double^16
？可能的重复