How to do a while loop in LISP

Question

I cannot get a simple while loop to work in lisp!

(loop (while (row >= 0))
      setf(row (- row 1))
      (collect (findIndex row col))

Answer 1

The correct form of the loop is the following:

(loop while (>= row 0) 
  do (setf row (- row 1))           ; or better: do (decf row)
  collect (findIndex row col))

For a detailed description of the loop syntax, see the manual.