Wade Humeniuk wrote:

John Connors wrote:

Yet Another Noob Question.

What are the characteristics of each implementation?

How can I tell which I should be writing in what context...

(defun find-indicies (lst tst)
(let ((li 0))
(labels ((qpred (a)
(incf li)
(if (funcall tst a)
(1- li)
nil)))
(remove nil (mapcar #'qpred lst)))))

(defun find-indices (lst tst)
(loop
for el in lst
counting t into index
if (funcall tst el)
collect index))

You are allergic to loop

(defun find-indices (list test)
(loop for element in list
for index from 1
when (funcall test element) collect index))

newLISP

(define (find-indices lst test)
(index test lst))

(find-indices '(200 209 250 257 260 263) odd?)
===>
(1 3 5)

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