X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/37a4f4b6b6669ddcd8723cc668984b3b6d91a7be..4da61803184cb96c97e0feac8adb99d3ebc2e54d:/lisp/derived.el diff --git a/lisp/derived.el b/lisp/derived.el index a1cfe8485f..b837922865 100644 --- a/lisp/derived.el +++ b/lisp/derived.el @@ -1,10 +1,11 @@ -;;; 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: obsolete ;; This file is part of GNU Emacs. @@ -19,11 +20,19 @@ ;; 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. ;;; Commentary: +;; Obsolete. +;; Use the `derived-major-mode' provided by easy-mmode.el instead. +;; It is only kept for backward compatibility with Emacs-20 byte-compiled +;; files that refer to `derived-mode-init-mode-variables' and other functions. + + + ;; 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 @@ -69,12 +78,6 @@ ;; - 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,' @@ -100,15 +103,17 @@ ;; PUBLIC: define a new major mode which inherits from an existing one. -;;;###autoload +;; ;;;###autoload +;; Don't override the definition provided by easy-mmode.el +(unless (fboundp 'define-derived-mode) (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 (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 @@ -122,7 +127,7 @@ 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 +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\" @@ -141,37 +146,37 @@ been generated automatically, with a reference to the keymap." (setq docstring nil))) (setq docstring (or docstring (derived-mode-make-docstring parent child))) - (` (progn - (derived-mode-init-mode-variables (quote (, child))) - (defun (, child) () - (, docstring) - (interactive) + `(progn + (derived-mode-init-mode-variables (quote ,child)) + (defun ,child () + ,docstring + (interactive) ; Run the parent. - ((, parent)) + (,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. - (derived-mode-set-keymap (quote (, child))) - (derived-mode-set-syntax-table (quote (, child))) - (derived-mode-set-abbrev-table (quote (, child))) + (derived-mode-set-keymap (quote ,child)) + (derived-mode-set-syntax-table (quote ,child)) + (derived-mode-set-abbrev-table (quote ,child)) ; Splice in the body (if any). - (,@ body) + ,@body ;;; ; Run the setup function, if ;;; ; any -- this will soon be ;;; ; obsolete. -;;; (derived-mode-run-setup-function (quote (, child))) +;;; (derived-mode-run-setup-function (quote ,child)) ; Run the hooks, if any. - (derived-mode-run-hooks (quote (, child))))))) + (derived-mode-run-hooks (quote ,child)))))) ;; 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." (while (get mode 'derived-mode-parent) @@ -182,23 +187,23 @@ Use the `derived-mode-parent' property of the symbol to trace backwards." ;; 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." + "Construct a setup-function name based on a MODE name." (intern (concat (symbol-name mode) "-setup"))) -(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"))) @@ -206,31 +211,35 @@ Use the `derived-mode-parent' property of the symbol to trace backwards." ;;;###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-vector 256 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))))))) + (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." @@ -251,17 +260,18 @@ which more-or-less shadow ;; 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))) - (if (get map-name 'derived-mode-unmerged) - (derived-mode-merge-keymaps old-map new-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." +(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))) @@ -271,7 +281,7 @@ which more-or-less shadow (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) @@ -287,18 +297,19 @@ Always merge its parent into it, since the merge is non-destructive." ;;; (funcall fname)))) (defun derived-mode-run-hooks (mode) - "Run the hooks if they exist." + "Run the mode hook for MODE." - (let ((hooks-name (derived-mode-hooks-name 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) @@ -324,14 +335,9 @@ be automatic inheritance." (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." - (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, @@ -339,12 +345,11 @@ Where the new table already has an entry, nothing is copied from the old one." ;; 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)