[Emacs-diffs] Changes to emacs/lisp/derived.el [lexbind]

[Miles Bader]

Index: emacs/lisp/derived.el
diff -c emacs/lisp/derived.el:1.30.4.1 emacs/lisp/derived.el:removed
*** emacs/lisp/derived.el:1.30.4.1      Fri Apr  4 01:20:01 2003
--- emacs/lisp/derived.el       Tue Oct 14 19:51:42 2003
***************
*** 1,430 ****
- ;;; derived.el --- allow inheritance of major modes
- ;;; (formerly mode-clone.el)
- 
- ;; Copyright (C) 1993, 1994, 1999 Free Software Foundation, Inc.
- 
- ;; Author: David Megginson (address@hidden)
- ;; Maintainer: FSF
- ;; Keywords: extensions
- 
- ;; This file is part of GNU Emacs.
- 
- ;; GNU Emacs is free software; you can redistribute it and/or modify
- ;; it under the terms of the GNU General Public License as published by
- ;; the Free Software Foundation; either version 2, or (at your option)
- ;; any later version.
- 
- ;; GNU Emacs is distributed in the hope that it will be useful,
- ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
- ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- ;; 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, Inc., 59 Temple Place - Suite 330,
- ;; Boston, MA 02111-1307, USA.
- 
- ;;; Commentary:
- 
- ;; GNU Emacs 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.
- ;;
- ;; The only thing missing is a good scheme of inheritance.  It is
- ;; possible to simulate a single level of inheritance with generous
- ;; use of hooks and a bit of work -- sgml-mode, for example, also runs
- ;; the hooks for text-mode, and keymaps can inherit from other keymaps
- ;; -- but generally, each major mode ends up reinventing the wheel.
- ;; Ideally, someone should redesign all of Emacs's major modes to
- ;; follow a more conventional object-oriented system: when defining a
- ;; new major mode, the user should need only to name the existing mode
- ;; it is most similar to, then list the (few) differences.
- ;;
- ;; In the mean time, this package offers most of the advantages of
- ;; full inheritance with the existing major modes.  The macro
- ;; `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-derived-mode hypertext-mode text-mode "Hypertext"
- ;;    "Major mode for hypertext.\n\n\\{hypertext-mode-map}"
- ;;    (setq case-fold-search nil))
- ;;
- ;;  (define-key hypertext-mode-map [down-mouse-3] 'do-hyper-link)
- ;;
- ;; will create a function `hypertext-mode' with its own (sparse)
- ;; keymap `hypertext-mode-map.'  The command M-x hypertext-mode will
- ;; perform the following actions:
- ;;
- ;; - run the command (text-mode) to get its default setup
- ;; - replace the current keymap with 'hypertext-mode-map,' which will
- ;;   inherit from 'text-mode-map'.
- ;; - replace the current syntax table with
- ;;   'hypertext-mode-syntax-table', which will borrow its defaults
- ;;   from the current text-mode-syntax-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.
- ;;
- ;; 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 make
- ;; a derived mode from a derived mode.  The commands
- ;;
- ;;   (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-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).
- 
- ;;; Code:
- 
- (eval-when-compile (require 'cl))
- 
- ;;; 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.
- 
- ;;;###autoload
- (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:
- 
- CHILD:     the name of the command for the derived mode.
- 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.  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:
- 
-   (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 uses `sgml-mode' as
- the parent, and then sets the variable `case-fold-search' to nil:
- 
-   (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."
- 
-   (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 ,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.
-        (delay-mode-hooks
- 
-         (,(or parent 'kill-all-local-variables))
-                                       ; Identify the child mode.
-         (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.
-               (unless (keymap-parent ,map)
-                 (set-keymap-parent ,map (current-local-map)))
-               ,(when declare-syntax
-                  `(let ((parent (char-table-parent ,syntax)))
-                     (unless (and parent
-                                  (not (eq parent (standard-syntax-table))))
-                       (set-char-table-parent ,syntax (syntax-table)))))))
- 
-         (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 hooks, if any.
-        (run-mode-hooks ',hook)))))
- 
- ;; 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 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 "21.4")
- 
- 
- ;;; PRIVATE
- 
- (defun derived-mode-make-docstring (parent child &optional
-                                          docstring syntax abbrev)
-   "Construct a docstring for a new mode if none is provided."
- 
-   (let ((map (derived-mode-map-name child))
-       (hook (derived-mode-hook-name child)))
- 
-     (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:
- 
-   `%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 (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))
- 
- 
- ;;; 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")))
- 
- 
- ;; 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)))))
- 
- ;; 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."
-   (let* ((map-name (derived-mode-map-name mode))
-        (new-map (eval map-name))
-        (old-map (current-local-map)))
-     (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 '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 (derived-mode-setup-function-name mode)))
- ;;;    (if (fboundp fname)
- ;;;   (funcall fname))))
- 
- (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 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."
-   ;; ?? 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."
-   (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 'derived)
- 
- ;;; derived.el ends here
--- 0 ----