;;; map.lisp
;;;
;;; Copyright (C) 2005 Peter Graves
;;; $Id$
;;;
;;; This program is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU General Public License
;;; as published by the Free Software Foundation; either version 2
;;; of the License, or (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
;;;
;;; As a special exception, the copyright holders of this library give you
;;; permission to link this library with independent modules to produce an
;;; executable, regardless of the license terms of these independent
;;; modules, and to copy and distribute the resulting executable under
;;; terms of your choice, provided that you also meet, for each linked
;;; independent module, the terms and conditions of the license of that
;;; module. An independent module is a module which is not derived from
;;; or based on this library. If you modify this library, you may extend
;;; this exception to your version of the library, but you are not
;;; obligated to do so. If you do not wish to do so, delete this
;;; exception statement from your version.
(in-package #:system)
(defun map (result-type function sequence &rest more-sequences)
(let* ((sequences (cons sequence more-sequences))
(limit (apply #'min (mapcar #'length sequences))))
(declare (type index limit))
(cond ((null result-type)
(dotimes (i limit nil)
(apply function (mapcar #'(lambda (z) (elt z i)) sequences))))
((eq result-type 'LIST)
(let (result)
(dotimes (i limit (nreverse result))
(push (apply function (mapcar #'(lambda (z) (elt z i)) sequences))
result))))
(t
(let ((result (case result-type
(STRING
(make-string limit))
(VECTOR
(make-array limit))
(t
(make-sequence result-type limit)))))
(dotimes (i limit result)
(setf (elt result i)
(apply function (mapcar #'(lambda (z) (elt z i)) sequences)))))))))