-;;; derived.el --- allow inheritance of major modes.
+;;; derived.el --- allow inheritance of major modes
+;;; (formerly mode-clone.el)
-;; Copyright (C) 1993, 1994, 1997 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994, 1999, 2003 Free Software Foundation, Inc.
;; Author: David Megginson (dmeggins@aix1.uottawa.ca)
;; Maintainer: XEmacs Development Team
;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
;; 02111-1307, USA.
-;;; Synched up with: FSF 19.34.
+;;; Synched up with: FSF 21.3.
;;; Commentary:
;; This file is dumped with XEmacs.
-;; GNU Emacs is already, in a sense, object oriented -- each object
+;; XEmacs is already, in a sense, object oriented -- each object
;; (buffer) belongs to a class (major mode), and that class defines
;; the relationship between messages (input events) and methods
;; (commands) by means of a keymap.
;; - 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,'
;;
;; (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 `derived-mode-class,' which returns the non-derived
-;; major mode which a derived mode is based on (ie. NOT necessarily the
-;; immediate parent).
+;; will add a new major mode for HTML with very little fuss.
;;
-;; (derived-mode-class 'text-mode) ==> text-mode
-;; (derived-mode-class 'hypertext-mode) ==> text-mode
-;; (derived-mode-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:
+;;; PRIVATE: defsubst must be defined before they are first used
+
+(defsubst derived-mode-hook-name (mode)
+ "Construct the mode hook name based on mode name MODE."
+ (intern (concat (symbol-name mode) "-hook")))
+
+(defsubst derived-mode-map-name (mode)
+ "Construct a map name based on a MODE name."
+ (intern (concat (symbol-name mode) "-map")))
+
+(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 derived-mode-abbrev-table-name (mode)
+ "Construct an abbrev-table name based on a MODE name."
+ (intern (concat (symbol-name mode) "-abbrev-table")))
+
;; PUBLIC: define a new major mode which inherits from an existing one.
;; XEmacs -- no autoload
The arguments to this command are as follow:
CHILD: the name of the command for the derived mode.
-PARENT: the name of the command for the parent mode (ie. text-mode).
-NAME: a string which will appear in the status line (ie. \"Hypertext\")
+PARENT: the name of the command for the parent mode (e.g. `text-mode')
+ or nil if there is no parent.
+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.
+ hooks for the new mode. Do not use `interactive' here.
+
+BODY can start with a bunch of keyword arguments. The following keyword
+ arguments are currently understood:
+:group GROUP
+ Declare the customization group that corresponds to this mode.
+:syntax-table TABLE
+ Use TABLE instead of the default.
+ A nil value means to simply use the same syntax-table as the parent.
+:abbrev-table TABLE
+ Use TABLE instead of the default.
+ A nil value means to simply use the same abbrev-table as the parent.
Here is how you could define LaTeX-Thesis mode as a variant of LaTeX mode:
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 uses sgml-mode as
+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-derived-mode article-mode sgml-mode \"Article\"
(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 (derived-mode-make-docstring parent child)))
-
- (` (progn
- (derived-mode-init-mode-variables (quote (, child)))
- (defun (, child) ()
- (, docstring)
+been generated automatically, with a reference to the keymap.
+
+The new mode runs the hook constructed by the function
+`derived-mode-hook-name'."
+ (declare (debug (&define name symbolp sexp [&optional stringp]
+ [&rest keywordp sexp] def-body)))
+
+ (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))
+
+ (when (eq parent 'fundamental-mode) (setq parent nil))
+
+ (let ((map (derived-mode-map-name child))
+ (syntax (derived-mode-syntax-table-name child))
+ (abbrev (derived-mode-abbrev-table-name child))
+ (declare-abbrev t)
+ (declare-syntax t)
+ (hook (derived-mode-hook-name child))
+ (group nil))
+
+ ;; Process the keyword args.
+ (while (keywordp (car body))
+ (case (pop body)
+ (:group (setq group (pop body)))
+ (:abbrev-table (setq abbrev (pop body)) (setq declare-abbrev nil))
+ (:syntax-table (setq syntax (pop body)) (setq declare-syntax nil))
+ (t (pop body))))
+
+ (setq docstring (derived-mode-make-docstring
+ parent child docstring syntax abbrev))
+
+ `(progn
+ (defvar ,hook nil ,(format "Hook run when entering %s mode." name))
+ (defvar ,map (make-sparse-keymap))
+ ,(if declare-syntax
+ `(defvar ,syntax (make-syntax-table)))
+ ,(if declare-abbrev
+ `(defvar ,abbrev
+ (progn (define-abbrev-table ',abbrev nil) ,abbrev)))
+ (put ',child 'derived-mode-parent ',parent)
+ ,(if group `(put ',child 'custom-mode-group ,group))
+
+ (defun ,child ()
+ ,docstring
(interactive)
; Run the parent.
- ((, parent))
- ; Identify special modes.
- (if (get (quote (, parent)) 'special)
- (put (quote (, child)) 'special t))
- ;; XEmacs addition
- (let ((mode-class (get (quote (, parent)) 'mode-class)))
- (if mode-class
- (put (quote (, child)) 'mode-class mode-class)))
+ (delay-mode-hooks
+
+ (,(or parent 'kill-all-local-variables))
; Identify the child mode.
- (setq major-mode (quote (, child)))
- (setq mode-name (, name))
+ (setq major-mode (quote ,child))
+ (setq mode-name ,name)
+ ; Identify special modes.
+ ,(when parent
+ `(progn
+ (if (get (quote ,parent) 'mode-class)
+ (put (quote ,child) 'mode-class
+ (get (quote ,parent) 'mode-class)))
; Set up maps and tables.
- (derived-mode-set-keymap (quote (, child)))
- (derived-mode-set-syntax-table (quote (, child)))
- (derived-mode-set-abbrev-table (quote (, child)))
+ (unless (keymap-parent ,map)
+ (set-keymap-parents ,map (list (current-local-map))))
+ ,(when declare-syntax
+ ;; XEmacs change: we do not have char-table-parent
+ `(derived-mode-merge-syntax-tables
+ (syntax-table) ,syntax))))
+
+ (use-local-map ,map)
+ ,(when syntax `(set-syntax-table ,syntax))
+ ,(when abbrev `(setq local-abbrev-table ,abbrev))
; Splice in the body (if any).
- (,@ body)
-;;; ; Run the setup function, if
-;;; ; any -- this will soon be
-;;; ; obsolete.
-;;; (derived-mode-run-setup-function (quote (, child)))
- ; Run the hooks, if any.
- (derived-mode-run-hooks (quote (, child)))))))
-
+ ,@body
+ )
+ ;; Run the hooks, if any.
+ ;; Make the generated code work in older Emacs versions
+ ;; that do not yet have run-mode-hooks.
+ (if (fboundp 'run-mode-hooks)
+ (run-mode-hooks ',hook)
+ (run-hooks ',hook))))))
;; PUBLIC: find the ultimate class of a derived mode.
(defun derived-mode-class (mode)
- "Find the class of a major 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."
+Use the `derived-mode-parent' property of the symbol to trace backwards.
+Since major-modes might all derive from `fundamental-mode', this function
+is not very useful."
(while (get mode 'derived-mode-parent)
(setq mode (get mode 'derived-mode-parent)))
mode)
+(make-obsolete 'derived-mode-class 'derived-mode-p)
+
+;; PUBLIC: find if the current mode derives from another.
+;; from GNU Emacs 21 subr.el
+
+(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))
\f
-;; Inline functions to construct various names from a mode name.
+;;; PRIVATE
-(defsubst derived-mode-setup-function-name (mode)
- "Construct a setup-function name based on a mode name."
- (intern (concat (symbol-name mode) "-setup")))
+(defun derived-mode-make-docstring (parent child &optional
+ docstring syntax abbrev)
+ "Construct a docstring for a new mode if none is provided."
-(defsubst derived-mode-hooks-name (mode)
- "Construct a hooks name based on a mode name."
- ;; XEmacs change from -hooks
- (intern (concat (symbol-name mode) "-hook")))
+ (let ((map (derived-mode-map-name child))
+ (hook (derived-mode-hook-name child)))
-(defsubst derived-mode-map-name (mode)
- "Construct a map name based on a mode name."
- (intern (concat (symbol-name mode) "-map")))
+ (unless (stringp docstring)
+ ;; Use a default docstring.
+ (setq docstring
+ (if (null parent)
+ (format "Major-mode.
+Uses keymap `%s', abbrev table `%s' and syntax-table `%s'." map abbrev syntax)
+ (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:
-(defsubst derived-mode-syntax-table-name (mode)
- "Construct a syntax-table name based on a mode name."
- (intern (concat (symbol-name mode) "-syntax-table")))
+ `%s', `%s' and `%s'
-(defsubst derived-mode-abbrev-table-name (mode)
- "Construct an abbrev-table name based on a mode name."
- (intern (concat (symbol-name mode) "-abbrev-table")))
+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 (null parent)
+ "\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))
+
+\f
+;;; OBSOLETE
+;; The functions below are only provided for backward compatibility with
+;; code byte-compiled with versions of derived.el prior to Emacs-21.
+
+(defsubst derived-mode-setup-function-name (mode)
+ "Construct a setup-function name based on a MODE name."
+ (intern (concat (symbol-name mode) "-setup")))
\f
;; Utility functions for defining a derived mode.
;; XEmacs -- don't autoload
(defun derived-mode-init-mode-variables (mode)
- "Initialize variables for a new 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))
- ;; XEmacs change
- (make-sparse-keymap (derived-mode-map-name mode))
- (, (format "Keymap for %s." mode)))))
+ (eval `(defvar ,(derived-mode-map-name mode)
+ ;; XEmacs change
+ (make-sparse-keymap (derived-mode-map-name mode))
+ ,(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))
- ;; XEmacs change
- ;; 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)
- (make-syntax-table)
- (, (format "Syntax table for %s." mode)))))
+ (eval `(defvar ,(derived-mode-syntax-table-name mode)
+ ;; XEmacs change
+ ;; 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)
+ (make-syntax-table)
+ ,(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)))))))
-
-(defun derived-mode-make-docstring (parent child)
- "Construct a docstring for a new mode if none is provided."
-
- (format "This major mode is a variant of `%s', created 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'
-
-which more-or-less shadow
-
- `%s-map' and `%s-syntax-table'
-
-\\{%s-map}" parent child child parent parent child))
-
+ (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 derived mode.
(defun derived-mode-set-keymap (mode)
- "Set the keymap of the new mode, maybe merging with the parent."
+ "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)))
(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."
+(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)))
(set-syntax-table new-table)))
(defun derived-mode-set-abbrev-table (mode)
- "Set the abbrev table if it exists.
+ "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)
;;; (funcall fname))))
(defun derived-mode-run-hooks (mode)
- "Run the hooks if they exist."
-
- (let ((hooks-name (derived-mode-hooks-name 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 derived-mode-merge-keymaps (old new)
- "Merge an old keymap into a new one.
-The old keymap is set to be the parent of the new one, so that there will
+ "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."
- ;; XEmacs change. FSF 19.30 & 19.34 has a whole bunch of weird crap here
+ ;; XEmacs change. FSF 19.30 to 21.3 has a whole bunch of weird crap here
;; for merging prefix keys and such. Hopefully none of this is
;; necessary in XEmacs.
(set-keymap-parents new (list old)))
(defun derived-mode-merge-syntax-tables (old new)
- "Merge an old syntax table into a new one.
+ "Merge an OLD syntax table into a NEW one.
Where the new table already has an entry, nothing is copied from the old one."
- ;; 20.x
- (if (fboundp 'map-char-table)
- ;; we use map-char-table not map-syntax-table so we can explicitly
- ;; check for inheritance.
- (map-char-table
- #'(lambda (key value)
- (if (eq ?@ (char-syntax-from-code value))
- (map-char-table #'(lambda (key1 value1)
- (put-char-table key1 value1 new))
- old
- key)))
- new)
- ;; pre-20.0
- (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))))))
+ ;; XEmacs change: on the other hand, Emacs 21.3 just has
+ ;; (set-char-table-parent new old) here.
+ ;; We use map-char-table, not map-syntax-table, so we can explicitly
+ ;; check for inheritance.
+ (map-char-table
+ #'(lambda (key value)
+ (if (eq ?@ (char-syntax-from-code value))
+ (map-char-table #'(lambda (key1 value1)
+ (put-char-table key1 value1 new))
+ old
+ key)))
+ new))
;; Merge an old abbrev table into a new one.
;; This function requires internal knowledge of how abbrev tables work,
;; as the value of the symbol, and the hook as the function definition.
(defun derived-mode-merge-abbrev-tables (old new)
(if old
- (mapatoms
- (function
- (lambda (symbol)
- (or (intern-soft (symbol-name symbol) new)
- (define-abbrev new (symbol-name symbol)
- (symbol-value symbol) (symbol-function symbol)))))
+ (mapatoms
+ #'(lambda (symbol)
+ (or (intern-soft (symbol-name symbol) new)
+ (define-abbrev new (symbol-name symbol)
+ (symbol-value symbol) (symbol-function symbol))))
old)))
-
+
(provide 'derived)
+;;; arch-tag: 630be248-47d1-4f02-afa0-8207de0ebea0
;;; derived.el ends here