.re: Another code review perhaps?

Martin Pomije wrote:

This is my solution to Ex. 6 on p. 97 of Paul Graham's "ANSI Common
Lisp"
 
<QUOTE>
Define iterative and recursive versions of a function that takes an
object and a list, and returns a new list in which the object appears
between each pair of elements in the original list:
 

(intersprerse '- '(a b c d))

 
(A - B - C - C)
<\QUOTE>
 
(I'll just ask about the iterative solution I developed.)
 
;;;;Ex. 6
(defun intersperse (element list)
  (let ((return-list (list (car list))))
    (do ((rest-input-list (cdr list) (cdr rest-input-list))
         (rest-return-list return-list (cddr rest-return-list)))
        ((not (consp rest-input-list)) return-list)
      (setf (cdr rest-return-list)
            (list element (car rest-input-list))))))

newLISP

(define (intersperse sep seq   , A B)
  (if (unify '(A B) (slice seq 0 2))
    (begin (bind $it)
           (append (list A sep) (intersperse sep (rest seq))))
    seq))

(intersperse '- '(a b c d e f))

(a - b - c - d - e - f)