(backup-extract-version-start): New variable.

[gnu-emacs] / lisp / loadhist.el

diff --git a/lisp/loadhist.el b/lisp/loadhist.el
index d541a70140599c67b77ade269ab46b63ddf489ee..726ae22e8dad441c4a51c65fb4f07ba365090416 100644 (file)
--- a/lisp/loadhist.el
+++ b/lisp/loadhist.el
@@ -1,5 +1,6 @@
 ;;; loadhist.el --- lisp functions for working with feature groups
-;;; Copyright (C) 1995 Free Software Foundation, Inc.
+
+;; Copyright (C) 1995 Free Software Foundation, Inc.
 
 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
 ;; Version: 1.0
@@ -18,8 +19,9 @@
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING.  If not, write to
-;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
 
 ;;; Commentary:
 
@@ -53,7 +55,7 @@ Actually, return the load argument, if any; this is sometimes the name of a
 Lisp file without an extension.  If the feature came from an eval-buffer on
 a buffer with no associated file, or an eval-region, return nil."
   (if (not (featurep feature))
-      (error "%s is not a currently loaded feature." (symbol-name feature))
+      (error "%s is not a currently loaded feature" (symbol-name feature))
     (car (feature-symbols feature))))
 
 (defun file-provides (file)
@@ -78,7 +80,7 @@ a buffer with no associated file, or an eval-region, return nil."
     requires
     ))
 
-(defun set-intersect (p q)
+(defun file-set-intersect (p q)
   ;; Return the set intersection of two lists
   (let ((ret nil))
     (mapcar
@@ -93,39 +95,54 @@ This can include FILE itself."
   (let ((provides (file-provides file)) (dependents nil))
     (mapcar
      (function (lambda (x) 
-                (if (set-intersect provides (file-requires (car x)))
+                (if (file-set-intersect provides (file-requires (car x)))
                     (setq dependents (cons (car x) dependents)))))
      load-history)
     dependents
     ))
 
+(defun read-feature (prompt)
+  "Read a feature name \(string\) from the minibuffer,
+prompting with PROMPT and completing from `features', and
+return the feature \(symbol\)."
+  (intern (completing-read prompt
+                          (mapcar (function (lambda (feature)
+                                              (list (symbol-name feature))))
+                                  features)
+                          nil t)))
+
 ;;;###autoload
 (defun unload-feature (feature &optional force)
   "Unload the library that provided FEATURE, restoring all its autoloads.
 If the feature is required by any other loaded code, and optional FORCE
 is nil, raise an error."
-  (interactive "SFeature: ")
+  (interactive (list (read-feature "Feature: ")))
   (if (not (featurep feature))
-      (error "%s is not a currently loaded feature." (symbol-name feature)))
+      (error "%s is not a currently loaded feature" (symbol-name feature)))
   (if (not force)
       (let* ((file (feature-file feature))
             (dependents (delete file (copy-sequence (file-dependents file)))))
        (if dependents
-           (error "Loaded libraries %s depend on %s."
+           (error "Loaded libraries %s depend on %s"
                   (prin1-to-string dependents) file)
            )))
   (let* ((flist (feature-symbols feature)) (file (car flist)))
     (mapcar
      (function (lambda (x) 
                 (cond ((stringp x) nil)
-                      ((consp x) nil)
+                      ((consp x)
+                       ;; Remove any feature names that this file provided.
+                       (if (eq (car x) 'provide)
+                           (setq features (delq (cdr x) features))))
                       ((boundp x) (makunbound x))
                       ((fboundp x)
                        (fmakunbound x)
                        (let ((aload (get x 'autoload)))
-                         (if aload (fset x (cons 'autoload aload)))))))
-              )
-     (cdr flist))))
+                         (if aload (fset x (cons 'autoload aload))))))))
+     (cdr flist))
+    ;; Delete the load-history element for this file.
+    (let ((elt (assoc file load-history)))
+      (setq load-history (delq elt load-history)))))
 
 (provide 'loadhist)