Lisp Function Definitions and Sorting Algorithms, Exercises of Computer Programming

Download Lisp Function Definitions and Sorting Algorithms and more Exercises Computer Programming in PDF only on Docsity! Hypothetical “Implementation” of pairs (define cons (lambda (a b) (lambda (x) (if x a b)))) (define (car p) (p #t)) Do type analysis on the above. p is located inside a single open paren and is followed by a Boolean. It must therefore be a procedure which takes in a Boolean and returns something (we don’t know what). (define (cdr p) (p #f)) (car (cons 1 2)) => 1 (cdr (cons 1 2)) => 2 ((lambda (p) (p #t)) ((lambda (a b) (lambda (x) (if x a b)))) 1 (2)) ((lambda (p) (p #t)) (lambda (x) (if x 1 2))) ((lambda (x) (if x 1 2)) #t) (if #t 1 2) => 1 Three arguments of cons (define cons3 (lambda (a b c) (lambda (x) (if (= x 0) a (if (= x 4 2) b c))))) (define (car p) (p 0)) (define (cdr p) (p 42)) (define (cgr p) (p 7)) Docsity.com