Exercise 2.22. Louis Reasoner tries to rewrite the first square-list procedure of exercise 2.21 so that it evolves an iterative process:
(define (square-list items)
(define (iter things answer)
(if (null? things)
answer
(iter (cdr things)
(cons (square (car things))
answer))))
(iter items nil))
Unfortunately, defining square-list this way produces the answer list in the reverse order of the one desired. Why?
Louis then tries to fix his bug by interchanging the arguments to cons:
(define (square-list items)
(define (iter things answer)
(if (null? things)
answer
(iter (cdr things)
(cons answer
(square (car things))))))
(iter items nil))
This doesn’t work either. Explain.