问题
I'm trying to make a procedure called map-odd-mapper where I take a proc that can then be applied to a list
ex:
((make-odd-mapper add-one) (list 14 38 29 10 57))
(15 30 58)
I was thinking of putting it as a let function as in (define (make-odd-mapper f) (let (..........something using ret-odds to allow for the indices so that you can get the odd numbers....
ret-odds is defined as (define (ret-odds lst) (if (null? lst) null (cons (car lst) (if (null? (cdr lst)) null (ret-odds (cdr (cdr lst))))))) the point of this is just to make a proc which will allow me to apply a procedure such as add-one to a list of odd indices....
回答1:
This problem can be broken down into two smaller ones. At the risk of being pedantic: can you describe what these two smaller problems would be, and provide test cases for them?
回答2:
(define (make-odd-mapper f) (lambda (lst) (ret-odds (map f lst))))
来源：https://stackoverflow.com/questions/5364838/trying-to-make-a-procedure-called-map-odd-mapper-in-scheme