source: trunk/abcl/src/org/armedbear/lisp/gentemp.lisp

;;; gentemp.lisp
;;;
;;; Copyright (C) 2003-2005 Peter Graves
;;; $Id: gentemp.lisp 15569 2022-03-19 12:50:18Z mevenson $
;;;
;;; 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.

;;; Adapted from CMUCL.

(in-package #:system)

(defvar *gentemp-counter* 0)

(defun gentemp (&optional (prefix "T") (package *package*))
  (require-type prefix 'string)
  (require-type package '(or package string symbol character))
  (loop
    (let ((name (format nil "~A~D" prefix (incf *gentemp-counter*))))
      (multiple-value-bind (symbol exists-p) (find-symbol name package)
        (unless exists-p
          (return (values (intern name package))))))))