reverse list - scheme

Question

I\'m trying to reverse a list, here\'s my code:

(define (reverse list)
  (if (null? list) 
     list
      (list (reverse (cdr list)) (car list))))
         


        

Answer 1

Tail recursive approach using a named let:

(define (reverse lst)
  (let loop ([lst lst] [lst-reversed '()])
    (if (empty? lst)
        lst-reversed
        (loop (rest lst) (cons (first lst) lst-reversed)))))

This is basically the same approach as having a helper function with an accumulator argument as in Oscar's answer, where the loop binding after let makes the let into an inner function you can call.