colon-pipes.arc

; colon-pipes.arc
;
; Copyright 2011 Ross Angle. However, you can use this for whatever
; you want. Don't bother giving me credit.
;
;
; This was made based on an idea expressed at
; <http://arclanguage.org/item?id=13450> and again at
; <http://arclanguage.org/item?id=14870>. Instead of writing this:
;
;  (accum acc
;    (each x args
;      (acc (* 2 x))))
;
; You can write this:
;
;  (// accum acc :
;     each x args :
;       acc : * 2 x)

(mac // body
  (aif (pos ': body)
    (let (before (nil . after)) (split body it)
      `(,@before (// ,@after)))
    body))