SICP学习笔记 2.3.1 引号 SICPLispScheme函数式编程
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2022-05-28 21:49:26
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练习2.53
(a b c) ((george)) ((y1 y2)) (y1 y2) #f #f (red shoes blue socks)
练习2.54
(define (equal? a b) (cond ((and (null? a) (null? b)) true) ((null? a) false) ((null? b) false) (else (and (eq? (car a) (car b)) (equal? (cdr a) (cdr b))))))
练习2.55
;; 'a 即为 (quote a) 1 ]=> (quote a) ;Value: a ;; 因此 ''abracadabra 等价于 (quote (quote abracadabra)) 1 ]=> (quote (quote abracadabra)) ;Value: (quote abracadabra) 1 ]=> ''abracadabra ;Value: (quote abracadabra) 1 ]=> (car (quote (quote abracadabra))) ;Value: quote