Re: shootout: implementing an interpreter

B. Pym wrote:

Kent M. Pitman wrote:
 

(defun shrug (list)
  (loop for (x . sublist-and-more) on list
        for more = (member x sublist-and-more)
        when more
         collect `(g ,x ,(ldiff sublist-and-more more))))
=> SHRUG
 
(shrug '(a b c a d b d))
=> ((G A (B C)) (G B (C A D)) (G D (B)))

 
 
newLISP
 
(define (shrug xs  (x (pop xs)))
  (and xs
    (if (match (list '* x '*) xs)
      (cons (list 'g x ($it 0)) (shrug xs))
      (shrug xs))))
 
(shrug '(a b c a d b d))
 
((g a (b c)) (g b (c a d)) (g d (b)))

Shorter:

(define (shrug xs  (x (pop xs)))
  (and xs
    (if (find x xs)
      (cons (list 'g x (0 $it xs)) (shrug xs))
      (shrug xs))))
-