Commands to add/delete file/directory-local variables.

(read-file-local-variable, read-file-local-variable-value)
(read-file-local-variable-mode, modify-file-local-variable)
(modify-file-local-variable-prop-line)
(modify-dir-local-variable): New functions.
(add-file-local-variable, delete-file-local-variable)
(add-file-local-variable-prop-line, delete-file-local-variable-prop-line)
(add-dir-local-variable, delete-dir-local-variable)
(copy-file-locals-to-dir-locals, copy-dir-locals-to-file-locals)
(copy-dir-locals-to-file-locals-prop-line): New commands.

2 files changed, 426 insertions, 0 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 42b40e1442f..dea01f1eea3 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,16 @@
+2009-08-04  Juri Linkov  <juri@jurta.org>
+
+        * files.el: Commands to add/delete file/directory-local variables.
+        (read-file-local-variable, read-file-local-variable-value)
+        (read-file-local-variable-mode, modify-file-local-variable)
+        (modify-file-local-variable-prop-line)
+        (modify-dir-local-variable): New functions.
+        (add-file-local-variable, delete-file-local-variable)
+        (add-file-local-variable-prop-line, delete-file-local-variable-prop-line)
+        (add-dir-local-variable, delete-dir-local-variable)
+        (copy-file-locals-to-dir-locals, copy-dir-locals-to-file-locals)
+        (copy-dir-locals-to-file-locals-prop-line): New commands.
+
 2009-08-04  Chong Yidong  <cyd@stupidchicken.com>
 
         * abbrev.el (insert-abbrev-table-description): Prettify output.
diff --git a/lisp/files.el b/lisp/files.el
index 5f256a016ca..ae28ee2610f 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -3407,6 +3407,419 @@ and `file-local-variables-alist', without applying them."
             (hack-local-variables-filter variables dir-name)))))))
 
 
+;;; Commands to add/delete file-local/directory-local variables.
+
+(defun read-file-local-variable (prompt)
+  "Read file-local variable using PROMPT and completion.
+Intended to be used in the `interactive' spec of
+`add-file-local-variable', `delete-file-local-variable',
+`add-dir-local-variable', `delete-dir-local-variable'."
+  (let (default variable)
+    (setq default (variable-at-point))
+    (setq default (and (symbolp default) (boundp default)
+                       (symbol-name default)))
+    (setq variable
+          (completing-read
+           (if default
+               (format "%s (default %s): " prompt default)
+             (format "%s: " prompt))
+           obarray
+           (lambda (sym)
+             (or (user-variable-p sym)
+                 (memq sym '(mode eval coding unibyte))))
+           nil nil nil default nil))
+    (and (stringp variable) (intern variable))))
+
+(defun read-file-local-variable-value (variable)
+  "Read value of file-local VARIABLE using completion.
+Intended to be used in the `interactive' spec of
+`add-file-local-variable' and `add-dir-local-variable'."
+  (let (default value)
+    (cond
+     ((eq variable 'mode)
+      (setq default (and (symbolp major-mode) (symbol-name major-mode)))
+      (setq value
+            (completing-read
+             (if default
+                 (format "Add %s with value (default %s): " variable default)
+               (format "Add %s with value: " variable))
+             obarray
+             (lambda (sym)
+               (and (string-match-p "-mode\\'" (symbol-name sym))
+                    (not (string-match-p "-minor-mode\\'" (symbol-name sym)))))
+             nil nil nil default nil))
+      (and (stringp value)
+           (intern (replace-regexp-in-string "-mode\\'" "" value))))
+     ((eq variable 'eval)
+      (let ((minibuffer-completing-symbol t))
+        (read-from-minibuffer (format "Add %s with expression: " variable)
+                              nil read-expression-map t
+                              'read-expression-history)))
+     ((eq variable 'coding)
+      (setq default (and (symbolp buffer-file-coding-system)
+                         (symbol-name buffer-file-coding-system)))
+      (read-coding-system
+       (if default
+           (format "Add %s with value (default %s): " variable default)
+         (format "Add %s with value: " variable))
+       default))
+     (t
+      (read (read-string (format "Add %s with value: " variable)
+                         nil 'set-variable-value-history
+                         (format "%S" (symbol-value variable))))))))
+
+(defun read-file-local-variable-mode ()
+  "Read per-directory file-local variable's mode using completion.
+Intended to be used in the `interactive' spec of
+`add-dir-local-variable', `delete-dir-local-variable'."
+  (let* ((default (and (symbolp major-mode) (symbol-name major-mode)))
+         (mode
+          (completing-read
+           (if default
+               (format "Mode or subdirectory (default %s): " default)
+             (format "Mode or subdirectory: "))
+           obarray
+           (lambda (sym)
+             (and (string-match-p "-mode\\'" (symbol-name sym))
+                  (not (string-match-p "-minor-mode\\'" (symbol-name sym)))))
+           nil nil nil default nil)))
+    (cond
+     ((equal mode "nil") nil)
+     ((and (stringp mode) (fboundp (intern mode))) (intern mode))
+     (t mode))))
+
+(defun modify-file-local-variable (variable value op)
+  "Modify file-local VARIABLE in Local Variables depending on operation OP.
+
+If OP is `add-or-replace' then delete all existing settings of
+VARIABLE (except `mode' and `eval') and add a new file-local VARIABLE
+with VALUE to the Local Variables list.
+
+If there is no Local Variables list in the current file buffer and OP
+is not `delete' then this function adds the first line containing the
+string `Local Variables:' and the last line containing the string `End:'.
+
+If OP is `delete' then delete all existing settings of VARIABLE
+from the Local Variables list ignoring the input argument VALUE."
+  (catch 'exit
+    (let ((beg (point)) end replaced-pos)
+      (unless enable-local-variables
+        (throw 'exit (message "File-local variables are disabled")))
+
+      ;; Look for "Local variables:" line in last page.
+      (widen)
+      (goto-char (point-max))
+      (search-backward "\n\^L" (max (- (point-max) 3000) (point-min)) 'move)
+
+      ;; Add "Local variables:" list if not found.
+      (unless (let ((case-fold-search t))
+                (search-forward "Local Variables:" nil t))
+
+        ;; Don't add "Local variables:" list for the deletion operation.
+        (when (eq op 'delete)
+          (throw 'exit (progn (goto-char beg)
+                              (message "Local Variables not found"))))
+
+        (goto-char (point-max))
+        (let ((comment-style 'plain)
+              (comment-start (or comment-start ";;; ")))
+          (comment-region
+           (prog1 (setq beg (point))
+             (insert "\nLocal Variables:\nEnd:\n"))
+           (point)))
+
+        (unless (let ((case-fold-search t))
+                  (goto-char beg)
+                  (search-forward "Local Variables:" nil t))
+          (throw 'exit (message "Can't add file-local variables"))))
+
+      ;; prefix is what comes before "local variables:" in its line.
+      ;; suffix is what comes after "local variables:" in its line.
+      (let* ((prefix (buffer-substring (line-beginning-position)
+                                       (match-beginning 0)))
+             (suffix (buffer-substring (point) (line-end-position)))
+             (prefix-re (concat "^" (regexp-quote prefix)))
+             (suffix-re (concat (regexp-quote suffix) "$")))
+
+        ;; Find or add missing "End:".
+        (forward-line 1)
+        (setq beg (point))
+        (save-excursion
+          (unless (let ((case-fold-search t))
+                    (re-search-forward
+                     (concat prefix-re "[ \t]*End:[ \t]*" suffix-re)
+                     nil t))
+            (save-excursion
+              (insert (format "%sEnd:%s\n" prefix suffix))))
+          (beginning-of-line)
+          (setq end (point-marker)))
+
+        ;; Find and delete all existing variable/value pairs.
+        (when (member op '(add-or-replace delete))
+          (if (and (eq op 'add-or-replace) (memq variable '(mode eval)))
+              (goto-char end)
+            (goto-char beg)
+            (while (re-search-forward
+                    (format "%s%S:.*%s" prefix-re variable suffix-re) end t)
+              (delete-region (match-beginning 0) (1+ (match-end 0)))
+              (setq replaced-pos (point)))))
+
+        ;; Add a new variable/value pair.  Add `mode' to the start, add new
+        ;; variable to the end, and add a replaced variable to its last location.
+        (when (eq op 'add-or-replace)
+          (cond
+           ((eq variable 'mode) (goto-char beg))
+           ((null replaced-pos) (goto-char end))
+           (replaced-pos (goto-char replaced-pos)))
+          (insert (format "%s%S: %S%s\n" prefix variable value suffix)))))))
+
+(defun add-file-local-variable (variable value)
+  "Add file-local VARIABLE with its VALUE to the Local Variables list.
+
+This command deletes all existing settings of VARIABLE (except `mode'
+and `eval') and adds a new file-local VARIABLE with VALUE to the
+Local Variables list.
+
+If there is no Local Variables list in the current file buffer
+then this function adds the first line containing the string
+`Local Variables:' and the last line containing the string `End:'."
+  (interactive
+   (let ((variable (read-file-local-variable "Add file-local variable")))
+     (list variable (read-file-local-variable-value variable))))
+  (modify-file-local-variable variable value 'add-or-replace))
+
+(defun delete-file-local-variable (variable)
+  "Delete all settings of file-local VARIABLE from the Local Variables list."
+  (interactive
+   (list (read-file-local-variable "Delete file-local variable")))
+  (modify-file-local-variable variable nil 'delete))
+
+(defun modify-file-local-variable-prop-line (variable value op)
+  "Modify file-local VARIABLE in the -*- line depending on operation OP.
+
+If OP is `add-or-replace' then delete all existing settings of
+VARIABLE (except `mode' and `eval') and add a new file-local VARIABLE
+with VALUE to the -*- line.
+
+If there is no -*- line at the beginning of the current file buffer
+and OP is not `delete' then this function adds the -*- line.
+
+If OP is `delete' then delete all existing settings of VARIABLE
+from the -*- line ignoring the input argument VALUE."
+  (catch 'exit
+    (let ((beg (point)) end replaced-pos)
+      (unless enable-local-variables
+        (throw 'exit (message "File-local variables are disabled")))
+
+      ;; Find the -*- line at the beginning of the current buffer.
+      (widen)
+      (goto-char (point-min))
+      (setq end (set-auto-mode-1))
+
+      (if end
+          (setq beg (point) end (copy-marker end))
+
+        ;; Add the -*- line if not found.
+        ;; Don't add the -*- line for the deletion operation.
+        (when (eq op 'delete)
+          (throw 'exit (progn (goto-char beg)
+                              (message "The -*- line not found"))))
+
+        (goto-char (point-min))
+
+        ;; Skip interpreter magic line "#!"
+        (when (looking-at "^\\(#!\\|'\\\\\"\\)")
+          (forward-line 1))
+
+        (let ((comment-style 'plain)
+              (comment-start (or comment-start ";;; ")))
+          (comment-region
+           (prog1 (point)
+             (insert "-*-")
+             (setq beg (point-marker))
+             (setq end (point-marker))
+             (insert "-*-\n"))
+           (point))))
+
+      (cond
+       ((looking-at "[ \t]*\\([^ \t\n\r:;]+\\)\\([ \t]*-\\*-\\)")
+        ;; Simple form: "-*- MODENAME -*-".
+        (if (eq variable 'mode)
+            ;; Replace or delete MODENAME
+            (progn
+              (when (member op '(add-or-replace delete))
+                (delete-region (match-beginning 1) (match-end 1)))
+              (when (eq op 'add-or-replace)
+                (goto-char (match-beginning 1))
+                (insert (format "%S" value))))
+          ;; Else, turn `MODENAME' into `mode:MODENAME'
+          ;; and add `;VARIABLE:VALUE'
+          (goto-char (match-beginning 2))
+          (insert (format "; %S: %S " variable value))
+          (goto-char (match-beginning 1))
+          (insert " mode: ")))
+
+       (t
+        ;; Hairy form: '-*-' [ <variable> ':' <value> ';' ]* '-*-'
+        ;; Find and delete all existing variable/value pairs.
+        (when (member op '(add-or-replace delete))
+          (if (and (eq op 'add-or-replace) (memq variable '(mode eval)))
+              (goto-char end)
+            (goto-char beg)
+            (while (< (point) end)
+              (or (looking-at "[ \t]*\\([^ \t\n:]+\\)[ \t]*:[ \t]*")
+                  (throw 'exit (message "Malformed -*- line")))
+              (goto-char (match-end 0))
+              (let ((key (intern (match-string 1)))
+                    (val (save-restriction
+                           (narrow-to-region (point) end)
+                           (let ((read-circle nil))
+                             (read (current-buffer))))))
+                (skip-chars-forward " \t;")
+                (when (eq key variable)
+                  (delete-region (match-beginning 0) (point))
+                  (setq replaced-pos (point)))))))
+        ;; Add a new variable/value pair.  Add `mode' to the start, add new
+        ;; variable to the end, and add a replaced variable to its last location.
+        (when (eq op 'add-or-replace)
+          (cond
+           ((eq variable 'mode) (goto-char beg))
+           ((null replaced-pos) (goto-char end) (insert "; "))
+           (replaced-pos (goto-char replaced-pos)))
+          (insert (format "%S: %S" variable value))
+          (cond
+           ((eq variable 'mode) (insert "; "))
+           (replaced-pos (insert "; ") ))))))))
+
+(defun add-file-local-variable-prop-line (variable value)
+  "Add file-local VARIABLE with its VALUE to the -*- line.
+
+This command deletes all existing settings of VARIABLE (except `mode'
+and `eval') and adds a new file-local VARIABLE with VALUE to
+the -*- line.
+
+If there is no -*- line at the beginning of the current file buffer
+then this function adds it."
+  (interactive
+   (let ((variable (read-file-local-variable "Add -*- file-local variable")))
+     (list variable (read-file-local-variable-value variable))))
+  (modify-file-local-variable-prop-line variable value 'add-or-replace))
+
+(defun delete-file-local-variable-prop-line (variable)
+  "Delete all settings of file-local VARIABLE from the -*- line."
+  (interactive
+   (list (read-file-local-variable "Delete -*- file-local variable")))
+  (modify-file-local-variable-prop-line variable nil 'delete))
+
+(defun modify-dir-local-variable (mode variable value op)
+  "Modify directory-local VARIABLE in .dir-locals.el depending on operation OP.
+
+If OP is `add-or-replace' then delete all existing settings of
+VARIABLE (except `mode' and `eval') and add a new directory-local VARIABLE
+with VALUE to the MODE alist where MODE can be a mode name symbol or
+a subdirectory name.
+
+If .dir-locals.el was not found and OP is not `delete' then create
+this file in the current directory.
+
+If OP is `delete' then delete all existing settings of VARIABLE
+from the the MODE alist ignoring the input argument VALUE."
+  (catch 'exit
+    (unless enable-local-variables
+      (throw 'exit (message "Directory-local variables are disabled")))
+
+    (let ((variables-file (or (and (buffer-file-name)
+                                   (not (file-remote-p (buffer-file-name)))
+                                   (dir-locals-find-file (buffer-file-name)))
+                              dir-locals-file))
+          variables)
+
+      ;; Don't create ".dir-locals.el" for the deletion operation.
+      (when (and (eq op 'delete)
+                 (not (file-exists-p variables-file)))
+        (throw 'exit (message "File .dir-locals.el not found")))
+
+      (let ((auto-insert nil))
+        (find-file variables-file))
+      (widen)
+      (goto-char (point-min))
+
+      ;; Read alist of directory-local variables.
+      (ignore-errors
+        (delete-region
+         (prog1 (point)
+           (setq variables (let ((read-circle nil))
+                             (read (current-buffer)))))
+         (point)))
+
+      ;; Add or replace variable in alist of directory-local variables.
+      (let ((mode-assoc (assoc mode variables)))
+        (if mode-assoc
+            (setq variables
+                  (cons (cons mode
+                              (if (eq op 'delete)
+                                  (assq-delete-all variable (cdr mode-assoc))
+                                (cons
+                                 (cons variable value)
+                                 (if (memq variable '(mode eval))
+                                     (cdr mode-assoc)
+                                   (assq-delete-all variable (cdr mode-assoc))))))
+                        (assq-delete-all mode variables)))
+          (setq variables
+                (cons `(,mode . ((,variable . ,value)))
+                      variables))))
+
+      ;; Insert modified alist of directory-local variables.
+      (insert ";;; Directory Local Variables\n")
+      (insert ";;; See Info node `(emacs) Directory Variables' for more information.\n\n")
+      (pp (sort variables
+                (lambda (a b)
+                  (cond
+                   ((null (car a)) t)
+                   ((null (car b)) nil)
+                   ((and (symbolp (car a)) (stringp (car b))) t)
+                   ((and (symbolp (car b)) (stringp (car a))) nil)
+                   (t (string< (car a) (car b))))))
+          (current-buffer)))))
+
+(defun add-dir-local-variable (mode variable value)
+  "Add directory-local VARIABLE with its VALUE and MODE to .dir-locals.el."
+  (interactive
+   (let (variable)
+     (list
+      (read-file-local-variable-mode)
+      (setq variable (read-file-local-variable "Add directory-local variable"))
+      (read-file-local-variable-value variable))))
+  (modify-dir-local-variable mode variable value 'add-or-replace))
+
+(defun delete-dir-local-variable (mode variable)
+  "Delete all MODE settings of file-local VARIABLE from .dir-locals.el."
+  (interactive
+   (list
+    (read-file-local-variable-mode)
+    (read-file-local-variable "Delete directory-local variable")))
+  (modify-dir-local-variable mode variable nil 'delete))
+
+(defun copy-file-locals-to-dir-locals ()
+  "Copy file-local variables to .dir-locals.el."
+  (interactive)
+  (dolist (elt file-local-variables-alist)
+    (unless (assq (car elt) dir-local-variables-alist)
+      (add-dir-local-variable major-mode (car elt) (cdr elt)))))
+
+(defun copy-dir-locals-to-file-locals ()
+  "Copy directory-local variables to the Local Variables list."
+  (interactive)
+  (dolist (elt dir-local-variables-alist)
+    (add-file-local-variable (car elt) (cdr elt))))
+
+(defun copy-dir-locals-to-file-locals-prop-line ()
+  "Copy directory-local variables to the the -*- line."
+  (interactive)
+  (dolist (elt dir-local-variables-alist)
+    (add-file-local-variable-prop-line (car elt) (cdr elt))))
+
+
 (defcustom change-major-mode-with-file-name t
   "Non-nil means \\[write-file] should set the major mode from the file name.
 However, the mode will not be changed if