-;;; derived.el --- allow inheritance of major modes.
+;;; derived.el --- allow inheritance of major modes
;;; (formerly mode-clone.el)
-;; Copyright (C) 1993, 1994 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.
;; - 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,'
;;
;; 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).
-;;
-;; (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:
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').
+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
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\"
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 '(, child))
- (put '(, child) 'derived-mode-parent '(, parent))
- (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 '(, parent) 'special)
- (put '(, child) 'special t))
+ (if (get (quote ,parent) 'special)
+ (put (quote ,child) 'special t))
; Identify the child mode.
- (setq major-mode '(, child))
- (setq mode-name (, name))
+ (setq major-mode (quote ,child))
+ (setq mode-name ,name)
; Set up maps and tables.
- (derived-mode-set-keymap '(, child))
- (derived-mode-set-syntax-table '(, child))
- (derived-mode-set-abbrev-table '(, 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.
-;;; (derived-mode-run-setup-function '(, child))
+ ,@body
+ ;; )
; Run the hooks, if any.
- (derived-mode-run-hooks '(, child))))))
+ (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.
+ "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 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 derived-mode-setup-function-name (mode)
- "Construct a setup-function name based on a mode name."
- (intern (concat (symbol-name mode) "-setup")))
+;;; PRIVATE
-(defsubst derived-mode-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 derived-mode-map-name (mode)
- "Construct a map name based on a mode name."
+ "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."
+ "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."
+ "Construct an abbrev-table name based on a MODE name."
(intern (concat (symbol-name mode) "-abbrev-table")))
+(defun derived-mode-make-docstring (parent child &optional docstring)
+ "Construct a docstring for a new mode if none is provided."
+
+ (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', `%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))
+
+\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.
;;;###autoload
(defun derived-mode-init-mode-variables (mode)
- "Initialise 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))
+ (eval `(defvar ,(derived-mode-map-name mode)
(make-sparse-keymap)
- (, (format "Keymap for %s." 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))
- ;; 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)))))
+ (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)))))))
-
-(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.
+ "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."
+ ;; ?? Can this just use `set-keymap-parent'?
(let ((tail new))
;; Scan the NEW map for prefix keys.
(while (consp 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.
+ "Merge an OLD syntax table into a NEW one.
Where the new table already has an entry, nothing is copied from the old one."
(set-char-table-parent new old))
;; 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)
HCoop / bpt / emacs.git / blobdiff