view lisp/config.el @ 5067:7d7ae8db0341

add functions `stable-union' and `stable-intersection' to do stable set operations -------------------- ChangeLog entries follow: -------------------- lisp/ChangeLog addition: 2010-02-22 Ben Wing <ben@xemacs.org> * cl-seq.el: * cl-seq.el (stable-union): New. * cl-seq.el (stable-intersection): New. New functions to do stable set operations, i.e. preserve the order of the elements in the argument lists, and prefer LIST1 over LIST2 when ordering the combined result. The result looks as much like LIST1 as possible, followed (in the case of `stable-union') by any necessary elements from LIST2, in order. This is contrary to `union' and `intersection', which are not required to be order- preserving and are not -- they prefer LIST2 and output results in backwards order.
author Ben Wing <ben@xemacs.org>
date Mon, 22 Feb 2010 21:23:02 -0600
parents 3ecd8885ac67
children 308d34e9f07d
line wrap: on
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;;; config.el --- access configuration parameters

;; Copyright (C) 1997 Sun Microsystems, Inc.

;; Author:   Martin Buchholz
;; Keywords: configure

;; This file is part of XEmacs.

;; XEmacs 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, or (at your option)
;; any later version.

;; XEmacs 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 XEmacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Synched up with: not in FSF.

;;; Commentary:

;;; Code:


(defvar config-value-file (expand-file-name "config.values" doc-directory)
  "File containing configuration parameters and their values.")

(defvar config-value-hash-table nil
  "Hash table to store configuration parameters and their values.")

;;;###autoload
(defun config-value-hash-table ()
  "Return hash table of configuration parameters and their values."
  (when (null config-value-hash-table)
    (setq config-value-hash-table (make-hash-table :size 300))
    (save-excursion
      (let ((buf (get-buffer-create " *Config*")))
	(set-buffer buf)
	(erase-buffer)
	(insert-file-contents config-value-file)
	(goto-char (point-min))
	(condition-case nil
	    (while t
	      (let* ((key (read buf))
		     (value (read buf))
		     (prev (gethash key config-value-hash-table)))
		(cond ((null prev)
		       (puthash key value config-value-hash-table))
		      ((atom prev)
		       (puthash key (list prev value) config-value-hash-table))
		      (t
		       (nconc prev (list value))))))
	  (end-of-file nil)))
      (kill-buffer " *Config*")))
  config-value-hash-table)

;;;###autoload
(defun config-value (config-symbol)
  "Return the value of the configuration parameter CONFIG_SYMBOL."
  (gethash config-symbol (config-value-hash-table)))

(provide 'config)
;;; config.el ends here