(in-package :polyominos)

(defstruct action polyomino x y rot)

(defvar *action-stack* nil "Stack of preallocated actions.")

(defun reset-actions ()
  (setq *action-stack* (make-array 1000 :fill-pointer 1000))
  (map-into *action-stack* #'make-action))
  
(defun action-alloc ()
  (if (= 0 (length *action-stack*))
	(error 'stack-exhausted)
      (vector-pop *action-stack*)))

(defun action-release (action)
  (vector-push *action-stack* action))
      
;; $Id: //info.ravenbrook.com/user/ndl/lisp/contest/entries/anthony-juckel/solution1/actions.lisp#1 $