pos

[procedure] pos test seq (o start 0)

(def pos (test seq (o start 0))
  (let f (testify test)
    (if (alist seq)
        ((afn (seq n)
           (if (no seq)   
                nil
               (f (car seq)) 
                n
               (self (cdr seq) (+ n 1))))
         (nthcdr start seq) 
         start)
        (recstring [if (f (seq _)) _] seq start))))