-;;; mode-clone.el (alpha version) -- allow inheritance of major modes.
+;;; derived.el --- allow inheritance of major modes
+;;; (formerly mode-clone.el)
-;; Copyright (C) 1993 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994, 1999 Free Software Foundation, Inc.
;; Author: David Megginson (dmeggins@aix1.uottawa.ca)
+;; Maintainer: FSF
+;; Keywords: extensions
;; This file is part of GNU Emacs.
;; 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.
\f
;;; Commentary:
;;
;; In the mean time, this package offers most of the advantages of
;; full inheritance with the existing major modes. The macro
-;; `define-mode-clone' allows the user to make a clone of an existing
+;; `define-derived-mode' allows the user to make a variant of an existing
;; major mode, with its own keymap. The new mode will inherit the key
;; bindings of its parent, and will, in fact, run its parent first
;; every time it is called. For example, the commands
;;
-;; (define-mode-clone hypertext-mode text-mode "Hypertext"
+;; (define-derived-mode hypertext-mode text-mode "Hypertext"
;; "Major mode for hypertext.\n\n\\{hypertext-mode-map}"
;; (setq case-fold-search nil))
;;
;; - replace the current syntax table with
;; 'hypertext-mode-syntax-table', which will borrow its defaults
;; from the current text-mode-syntax-table.
-;; - if 'hypertext-mode-abbrev-table' exists, it will become the
-;; current abbrev table.
+;; - replace the current abbrev table with
+;; 'hypertext-mode-abbrev-table', which will borrow its defaults
+;; from the current text-mode-abbrev table
;; - change the mode line to read "Hypertext"
;; - assign the value 'hypertext-mode' to the 'major-mode' variable
;; - run the body of commands provided in the macro -- in this case,
;; set the local variable `case-fold-search' to nil.
-;; - **run the command (hypertext-mode-setup), which is empty by
-;; default, but may be redefined by the user to contain special
-;; commands (ie. setting local variables like 'outline-regexp')
-;; **NOTE: do not use this option -- it will soon be obsolete.
-;; - run anything assigned to 'hypertext-mode-hooks' (obsolete, but
-;; supported for the sake of compatibility).
;;
;; The advantages of this system are threefold. First, text mode is
;; untouched -- if you had added the new keystroke to `text-mode-map,'
;; possibly using hooks, you would have added it to all text buffers
;; -- here, it appears only in hypertext buffers, where it makes
-;; sense. Second, it is possible to build even further, and clone the
-;; clone. The commands
+;; sense. Second, it is possible to build even further, and make
+;; a derived mode from a derived mode. The commands
;;
-;; (define-mode-clone html-mode hypertext-mode "HTML")
+;; (define-derived-mode html-mode hypertext-mode "HTML")
;; [various key definitions]
;;
;; will add a new major mode for HTML with very little fuss.
;;
-;; Note also the function `clone-class,' which returns the non-clone
-;; major mode which a clone is based on (ie. NOT necessarily the
-;; immediate parent).
-;;
-;; (clone-class 'text-mode) ==> text-mode
-;; (clone-class 'hypertext-mode) ==> text-mode
-;; (clone-class 'html-mode) ==> text-mode
+;; Note also the function `derived-mode-p' which can tell if the current
+;; mode derives from another. In a hypertext-mode, buffer, for example,
+;; (derived-mode-p 'text-mode) would return non-nil. This should always
+;; be used in place of (eq major-mode 'text-mode).
\f
;;; Code:
;; PUBLIC: define a new major mode which inherits from an existing one.
;;;###autoload
-(defmacro define-mode-clone (child parent name &optional docstring &rest body)
- "Create a new mode which is similar to an old one.
+(defmacro define-derived-mode (child parent name &optional docstring &rest body)
+ "Create a new mode as a variant of an existing mode.
The arguments to this command are as follow:
-PARENT: the name of the command for the parent mode (ie. text-mode).
-CHILD: the name of the command for the clone mode.
-NAME: a string which will appear in the status line (ie. \"Hypertext\")
+CHILD: the name of the command for the derived mode.
+PARENT: the name of the command for the parent mode (e.g. `text-mode').
+NAME: a string which will appear in the status line (e.g. \"Hypertext\")
DOCSTRING: an optional documentation string--if you do not supply one,
the function will attempt to invent something useful.
BODY: forms to execute just before running the
hooks for the new mode.
-The following simple command would clone LaTeX mode into
-LaTeX-Thesis mode:
+Here is how you could define LaTeX-Thesis mode as a variant of LaTeX mode:
- (define-mode-clone LaTeX-thesis-mode LaTeX-mode \"LaTeX-Thesis\")
+ (define-derived-mode LaTeX-thesis-mode LaTeX-mode \"LaTeX-Thesis\")
You could then make new key bindings for `LaTeX-thesis-mode-map'
without changing regular LaTeX mode. In this example, BODY is empty,
and DOCSTRING is generated by default.
-On a more complicated level, the following command would clone
-sgml-mode and change the variable `case-fold-search' to nil:
+On a more complicated level, the following command uses `sgml-mode' as
+the parent, and then sets the variable `case-fold-search' to nil:
- (define-mode-clone article-mode sgml-mode \"Article\"
+ (define-derived-mode article-mode sgml-mode \"Article\"
\"Major mode for editing technical articles.\"
(setq case-fold-search nil))
Note that if the documentation string had been left out, it would have
been generated automatically, with a reference to the keymap."
- ; Some trickiness, since what
- ; appears to be the docstring
- ; may really be the first
- ; element of the body.
- (if (and docstring (not (stringp docstring)))
- (progn (setq body (cons docstring body))
- (setq docstring nil)))
- (setq docstring (or docstring (clone-make-docstring parent child)))
-
- (` (progn
- (clone-init-mode-variables (quote (, child)))
- (defun (, child) ()
- (, docstring)
+ (when (and docstring (not (stringp docstring)))
+ ;; Some trickiness, since what appears to be the docstring may really be
+ ;; the first element of the body.
+ (push docstring body)
+ (setq docstring nil))
+
+ (unless parent (setq parent 'fundamental-mode))
+
+ (let ((map (derived-mode-map-name child))
+ (syntax (derived-mode-syntax-table-name child))
+ (abbrev (derived-mode-abbrev-table-name child))
+ (hook (derived-mode-hook-name child))
+ (docstring (derived-mode-make-docstring parent child docstring)))
+
+ `(progn
+ (defvar ,map (make-sparse-keymap))
+ (defvar ,syntax (make-char-table 'syntax-table nil))
+ (defvar ,abbrev)
+ (define-abbrev-table ',abbrev nil)
+ (put ',child 'derived-mode-parent ',parent)
+
+ (defun ,child ()
+ ,docstring
(interactive)
; Run the parent.
- ((, parent))
+ ;; (combine-run-hooks
+
+ (,parent)
; Identify special modes.
- (if (get (quote (, parent)) 'special)
- (put (quote (, child)) 'special t))
+ (if (get (quote ,parent) 'special)
+ (put (quote ,child) 'special t))
; Identify the child mode.
- (setq major-mode (quote (, child)))
- (setq mode-name (, name))
+ (setq major-mode (quote ,child))
+ (setq mode-name ,name)
; Set up maps and tables.
- (clone-set-keymap (quote (, child)))
- (clone-set-syntax-table (quote (, child)))
- (clone-set-abbrev-table (quote (, child)))
+ (unless (keymap-parent ,map)
+ (set-keymap-parent ,map (current-local-map)))
+ (let ((parent (char-table-parent ,syntax)))
+ (unless (and parent (not (eq parent (standard-syntax-table))))
+ (set-char-table-parent ,syntax (syntax-table))))
+ (when local-abbrev-table
+ (mapatoms
+ (lambda (symbol)
+ (or (intern-soft (symbol-name symbol) ,abbrev)
+ (define-abbrev ,abbrev (symbol-name symbol)
+ (symbol-value symbol) (symbol-function symbol))))
+ local-abbrev-table))
+
+ (use-local-map ,map)
+ (set-syntax-table ,syntax)
+ (setq local-abbrev-table ,abbrev)
; Splice in the body (if any).
- (,@ body)
-;;; ; Run the setup function, if
-;;; ; any -- this will soon be
-;;; ; obsolete.
-;;; (clone-run-setup-function (quote (, child)))
+ ,@body
+ ;; )
; Run the hooks, if any.
- (clone-run-hooks (quote (, child)))))))
-
-
-;; PUBLIC: find the ultimate class of a clone mode.
-
-(defun clone-class (mode)
- "Find the class of a major mode.
-A mode's class is the first ancestor which is NOT a clone.
-Use the `clone-parent' property of the symbol to trace backwards."
- (while (get mode 'clone-parent)
- (setq mode (get mode 'clone-parent)))
+ (run-hooks ',hook)))))
+
+;; PUBLIC: find if the current mode derives from another.
+
+(defun derived-mode-p (&rest modes)
+ "Non-nil if the current major mode is derived from one of MODES.
+Uses the `derived-mode-parent' property of the symbol to trace backwards."
+ (let ((parent major-mode))
+ (while (and (not (memq parent modes))
+ (setq parent (get parent 'derived-mode-parent))))
+ parent))
+
+;; PUBLIC: find the ultimate class of a derived mode.
+
+(defun derived-mode-class (mode)
+ "Find the class of a major MODE.
+A mode's class is the first ancestor which is NOT a derived mode.
+Use the `derived-mode-parent' property of the symbol to trace backwards.
+Since major-modes might derive from each other and from `fundamental-mode',
+this function is not very useful. Use `derived-mode-p' instead."
+ (while (get mode 'derived-mode-parent)
+ (setq mode (get mode 'derived-mode-parent)))
mode)
\f
-;; Inline functions to construct various names from a mode name.
-
-(defsubst clone-setup-function-name (mode)
- "Construct a setup-function name based on a mode name."
- (intern (concat (symbol-name mode) "-setup")))
+;;; PRIVATE
-(defsubst clone-hooks-name (mode)
- "Construct a hooks name based on a mode name."
- (intern (concat (symbol-name mode) "-hooks")))
+(defsubst derived-mode-hook-name (mode)
+ "Construct the mode hook name based on mode name MODE."
+ (intern (concat (symbol-name mode) "-hook")))
-(defsubst clone-map-name (mode)
- "Construct a map name based on a mode name."
+(defsubst derived-mode-map-name (mode)
+ "Construct a map name based on a MODE name."
(intern (concat (symbol-name mode) "-map")))
-(defsubst clone-syntax-table-name (mode)
- "Construct a syntax-table name based on a mode name."
+(defsubst derived-mode-syntax-table-name (mode)
+ "Construct a syntax-table name based on a MODE name."
(intern (concat (symbol-name mode) "-syntax-table")))
-(defsubst clone-abbrev-table-name (mode)
- "Construct an abbrev-table name based on a mode name."
+(defsubst derived-mode-abbrev-table-name (mode)
+ "Construct an abbrev-table name based on a MODE name."
(intern (concat (symbol-name mode) "-abbrev-table")))
-\f
-;; Utility functions for defining a clone mode.
-
-(defun clone-init-mode-variables (mode)
- "Initialise variables for a new mode.
-Right now, just set up a blank keymap and an empty syntax table."
-
- (eval (` (defvar (, (clone-map-name mode))
- (make-sparse-keymap)
- (, (format "Keymap for %s." mode)))))
- (put (clone-map-name mode) 'clone-merged nil)
-
- (eval (` (defvar (, (clone-syntax-table-name mode))
- (make-vector 256 nil)
- (, (format "Syntax table for %s." mode)))))
- (put (clone-syntax-table-name mode) 'clone-merged nil)
-
- (eval (` (defvar (, (clone-abbrev-table-name mode))
- nil
- (, (format "Abbrev table for %s." mode)))))
- (define-abbrev-table (clone-abbrev-table-name mode) ()))
-
-(defun clone-make-docstring (parent child)
+(defun derived-mode-make-docstring (parent child &optional docstring)
"Construct a docstring for a new mode if none is provided."
- (format "This major mode is a clone of `%s', created by `define-mode-clone'.
+ (let ((map (derived-mode-map-name child))
+ (syntax (derived-mode-syntax-table-name child))
+ (abbrev (derived-mode-abbrev-table-name child))
+ (hook (derived-mode-hook-name child)))
+
+ (unless (stringp docstring)
+ ;; Use a default docstring.
+ (setq docstring
+ (format "Major mode derived from `%s' by `define-derived-mode'.
It inherits all of the parent's attributes, but has its own keymap,
abbrev table and syntax table:
- `%s-map' and `%s-syntax-table'
+ `%s', `%s' and `%s'
+
+which more-or-less shadow %s's corresponding tables."
+ parent map abbrev syntax parent)))
+
+ (unless (string-match (regexp-quote (symbol-name hook)) docstring)
+ ;; Make sure the docstring mentions the mode's hook
+ (setq docstring
+ (concat docstring
+ (if (eq parent 'fundamental-mode)
+ "\n\nThis mode "
+ (concat
+ "\n\nIn addition to any hooks its parent mode "
+ (if (string-match (regexp-quote (format "`%s'" parent))
+ docstring) nil
+ (format "`%s' " parent))
+ "might have run,\nthis mode "))
+ (format "runs the hook `%s'" hook)
+ ", as the final step\nduring initialization.")))
+
+ (unless (string-match "\\\\[{[]" docstring)
+ ;; And don't forget to put the mode's keymap
+ (setq docstring (concat docstring "\n\n\\{" (symbol-name map) "}")))
+
+ docstring))
-which more-or-less shadow
+\f
+;;; OBSOLETE
+;; The functions below are only provided for backward compatibility with
+;; code byte-compiled with versions of derived.el prior to Emacs-21.
- `%s-map' and `%s-syntax-table'
+(defsubst derived-mode-setup-function-name (mode)
+ "Construct a setup-function name based on a MODE name."
+ (intern (concat (symbol-name mode) "-setup")))
-\\{%s-map}" parent child child parent parent child))
+\f
+;; Utility functions for defining a derived mode.
+;;;###autoload
+(defun derived-mode-init-mode-variables (mode)
+ "Initialise variables for a new MODE.
+Right now, if they don't already exist, set up a blank keymap, an
+empty syntax table, and an empty abbrev table -- these will be merged
+the first time the mode is used."
+
+ (if (boundp (derived-mode-map-name mode))
+ t
+ (eval `(defvar ,(derived-mode-map-name mode)
+ (make-sparse-keymap)
+ ,(format "Keymap for %s." mode)))
+ (put (derived-mode-map-name mode) 'derived-mode-unmerged t))
+
+ (if (boundp (derived-mode-syntax-table-name mode))
+ t
+ (eval `(defvar ,(derived-mode-syntax-table-name mode)
+ ;; Make a syntax table which doesn't specify anything
+ ;; for any char. Valid data will be merged in by
+ ;; derived-mode-merge-syntax-tables.
+ (make-char-table 'syntax-table nil)
+ ,(format "Syntax table for %s." mode)))
+ (put (derived-mode-syntax-table-name mode) 'derived-mode-unmerged t))
+
+ (if (boundp (derived-mode-abbrev-table-name mode))
+ t
+ (eval `(defvar ,(derived-mode-abbrev-table-name mode)
+ (progn
+ (define-abbrev-table (derived-mode-abbrev-table-name mode) nil)
+ (make-abbrev-table))
+ ,(format "Abbrev table for %s." mode)))))
\f
-;; Utility functions for running a clone mode.
+;; Utility functions for running a derived mode.
-(defun clone-set-keymap (mode)
- "Set the keymap of the new mode, maybe merging with the parent."
- (let* ((map-name (clone-map-name mode))
+(defun derived-mode-set-keymap (mode)
+ "Set the keymap of the new MODE, maybe merging with the parent."
+ (let* ((map-name (derived-mode-map-name mode))
(new-map (eval map-name))
(old-map (current-local-map)))
- (if (get map-name 'clone-merged)
- (use-local-map new-map)
- (put map-name 'clone-merged t)
- (use-local-map (set map-name (clone-merge-keymaps old-map new-map))))))
-
-(defun clone-set-syntax-table (mode)
- "Set the syntax table of the new mode, maybe merging with the parent."
- (let* ((table-name (clone-syntax-table-name mode))
+ (and old-map
+ (get map-name 'derived-mode-unmerged)
+ (derived-mode-merge-keymaps old-map new-map))
+ (put map-name 'derived-mode-unmerged nil)
+ (use-local-map new-map)))
+
+(defun derived-mode-set-syntax-table (mode)
+ "Set the syntax table of the new MODE, maybe merging with the parent."
+ (let* ((table-name (derived-mode-syntax-table-name mode))
(old-table (syntax-table))
(new-table (eval table-name)))
- (if (get table-name 'clone-merged)
- t
- (clone-merge-syntax-tables old-table new-table))
- (set-syntax-table new-table)
- (put table-name 'clone-merged t)))
-
-(defun clone-set-abbrev-table (mode)
- "Set the abbrev table if it exists."
- (let* ((table-name (clone-abbrev-table-name mode))
- (table (and (boundp table-name) (eval table-name))))
- (if table
- (setq local-abbrev-table table))))
-
-;;;(defun clone-run-setup-function (mode)
+ (if (get table-name 'derived-mode-unmerged)
+ (derived-mode-merge-syntax-tables old-table new-table))
+ (put table-name 'derived-mode-unmerged nil)
+ (set-syntax-table new-table)))
+
+(defun derived-mode-set-abbrev-table (mode)
+ "Set the abbrev table for MODE if it exists.
+Always merge its parent into it, since the merge is non-destructive."
+ (let* ((table-name (derived-mode-abbrev-table-name mode))
+ (old-table local-abbrev-table)
+ (new-table (eval table-name)))
+ (derived-mode-merge-abbrev-tables old-table new-table)
+ (setq local-abbrev-table new-table)))
+
+;;;(defun derived-mode-run-setup-function (mode)
;;; "Run the setup function if it exists."
-;;; (let ((fname (clone-setup-function-name mode)))
+;;; (let ((fname (derived-mode-setup-function-name mode)))
;;; (if (fboundp fname)
;;; (funcall fname))))
-(defun clone-run-hooks (mode)
- "Run the hooks if they exist."
-
- (let ((hooks-name (clone-hooks-name mode)))
+(defun derived-mode-run-hooks (mode)
+ "Run the mode hook for MODE."
+ (let ((hooks-name (derived-mode-hook-name mode)))
(if (boundp hooks-name)
(run-hooks hooks-name))))
;; Functions to merge maps and tables.
-(defun clone-merge-keymaps (old new)
- "Merge a new keymap into an old one.
-The old keymap is set to be the cdr of the new one, so that there will
+(defun derived-mode-merge-keymaps (old new)
+ "Merge an OLD keymap into a NEW one.
+The old keymap is set to be the last cdr of the new one, so that there will
be automatic inheritance."
- (append new old))
-
-(defun clone-merge-syntax-tables (old new)
- "Merge a new syntax table into an old one.
+ ;; ?? Can this just use `set-keymap-parent'?
+ (let ((tail new))
+ ;; Scan the NEW map for prefix keys.
+ (while (consp tail)
+ (and (consp (car tail))
+ (let* ((key (vector (car (car tail))))
+ (subnew (lookup-key new key))
+ (subold (lookup-key old key)))
+ ;; If KEY is a prefix key in both OLD and NEW, merge them.
+ (and (keymapp subnew) (keymapp subold)
+ (derived-mode-merge-keymaps subold subnew))))
+ (and (vectorp (car tail))
+ ;; Search a vector of ASCII char bindings for prefix keys.
+ (let ((i (1- (length (car tail)))))
+ (while (>= i 0)
+ (let* ((key (vector i))
+ (subnew (lookup-key new key))
+ (subold (lookup-key old key)))
+ ;; If KEY is a prefix key in both OLD and NEW, merge them.
+ (and (keymapp subnew) (keymapp subold)
+ (derived-mode-merge-keymaps subold subnew)))
+ (setq i (1- i)))))
+ (setq tail (cdr tail))))
+ (setcdr (nthcdr (1- (length new)) new) old))
+
+(defun derived-mode-merge-syntax-tables (old new)
+ "Merge an OLD syntax table into a NEW one.
Where the new table already has an entry, nothing is copied from the old one."
- (let ((idx 0)
- (end (min (length new) (length old))))
- (while (< idx end)
- (if (not (aref new idx))
- (aset new idx (aref old idx)))
- (setq idx (1+ idx)))))
+ (set-char-table-parent new old))
+
+;; Merge an old abbrev table into a new one.
+;; This function requires internal knowledge of how abbrev tables work,
+;; presuming that they are obarrays with the abbrev as the symbol, the expansion
+;; as the value of the symbol, and the hook as the function definition.
+(defun derived-mode-merge-abbrev-tables (old new)
+ (if old
+ (mapatoms
+ (lambda (symbol)
+ (or (intern-soft (symbol-name symbol) new)
+ (define-abbrev new (symbol-name symbol)
+ (symbol-value symbol) (symbol-function symbol))))
+ old)))
-(provide 'mode-clone)
+(provide 'derived)
-;;; mode-clone.el ends here
+;;; derived.el ends here
HCoop / bpt / emacs.git / blobdiff