;; also the variable `font-lock-maximum-size'. Support modes for Font Lock
;; mode can be used to speed up Font Lock mode. See `font-lock-support-mode'.
\f
+;;; How Font Lock mode fontifies:
+
+;; When Font Lock mode is turned on in a buffer, it (a) fontifies the entire
+;; buffer and (b) installs one of its fontification functions on one of the
+;; hook variables that are run by Emacs after every buffer change (i.e., an
+;; insertion or deletion). Fontification means the replacement of `face' text
+;; properties in a given region; Emacs displays text with these `face' text
+;; properties appropriately.
+;;
+;; Fontification normally involves syntactic (i.e., strings and comments) and
+;; regexp (i.e., keywords and everything else) passes. The syntactic pass
+;; involves a syntax table and a syntax parsing function to determine the
+;; context of different parts of a region of text. It is necessary because
+;; generally strings and/or comments can span lines, and so the context of a
+;; given region is not necessarily apparent from the content of that region.
+;; Because the regexp pass only works within a given region, it is not
+;; generally appropriate for syntactic fontification. The regexp pass involves
+;; searching for given regexps (or calling given functions) within the given
+;; region. For each match of the regexp (or non-nil value of the called
+;; function), `face' text properties are added appropriately.
+
;;; How Font Lock mode supports modes or is supported by modes:
;; Modes that support Font Lock mode do so by defining one or more variables
;; (a); (b) is used where it is not clear which package library should contain
;; the pattern definitions.) Font Lock mode chooses which variable to use for
;; fontification based on `font-lock-maximum-decoration'.
+;;
+;; Font Lock mode fontification behaviour can be modified in a number of ways.
+;; See the below comments and the comments distributed throughout this file.
;;; Constructing patterns:
;; Nasty regexps of the form "bar\\(\\|lo\\)\\|f\\(oo\\|u\\(\\|bar\\)\\)\\|lo"
;; are made thusly: (make-regexp '("foo" "fu" "fubar" "bar" "barlo" "lo")) for
;; efficiency. See /pub/gnu/emacs/elisp-archive/functions/make-regexp.el.Z on
-;; archive.cis.ohio-state.edu for this and other functions not just by simon.
+;; archive.cis.ohio-state.edu for this and other functions not just by sm.
;;; Adding patterns for modes that already support Font Lock:
(MATCHER PRE-MATCH-FORM POST-MATCH-FORM MATCH-HIGHLIGHT ...)
-Where MATCHER is as for MATCH-HIGHLIGHT with one exception. The limit of the
-search is currently guaranteed to be (no greater than) the end of the line.
+Where MATCHER is as for MATCH-HIGHLIGHT with one exception; see below.
PRE-MATCH-FORM and POST-MATCH-FORM are evaluated before the first, and after
the last, instance MATCH-ANCHORED's MATCHER is used. Therefore they can be
used to initialise before, and cleanup after, MATCHER is used. Typically,
searching for subsequent instance of \"anchor\" resumes from where searching
for \"item\" concluded.)
+The above-mentioned exception is as follows. The limit of the MATCHER search
+defaults to the end of the line after PRE-MATCH-FORM is evaluated.
+However, if PRE-MATCH-FORM returns a position greater than the position after
+PRE-MATCH-FORM is evaluated, that position is used as the limit of the search.
+It is generally a bad idea to return a position greater than the end of the
+line, i.e., cause the MATCHER search to span lines.
+
Note that the MATCH-ANCHORED feature is experimental; in the future, we may
replace it with other ways of providing this functionality.
;; We don't do this at the top-level as we only use non-autoloaded macros.
(require 'cl)
;;
- ;; Shut the byte-compiler up.
- (require 'fast-lock)
- (require 'lazy-lock)
- ;;
;; Borrowed from lazy-lock.el.
;; We use this to preserve or protect things when modifying text properties.
(defmacro save-buffer-state (varlist &rest body)
(setq font-lock-support-mode 'lazy-lock-mode)
(setq font-lock-maximum-decoration t)
+To add your own highlighting for some major mode, and modify the highlighting
+selected automatically via the variable `font-lock-maximum-decoration', you can
+use `font-lock-add-keywords'.
+
To fontify a buffer, without turning on Font Lock mode and regardless of buffer
size, you can use \\[font-lock-fontify-buffer].
lines around point), perhaps because modification on the current line caused
syntactic change on other lines, you can use \\[font-lock-fontify-block].
-The default Font Lock mode highlighting are normally selected via the variable
-`font-lock-maximum-decoration'. You can add your own highlighting for some
-mode, by calling `font-lock-add-keywords'.
-
The default Font Lock mode faces and their attributes are defined in the
variable `font-lock-face-attributes', and Font Lock mode default settings in
the variable `font-lock-defaults-alist'. You can set your own default settings
(defun turn-on-font-lock ()
"Turn on Font Lock mode conditionally.
Turn on only if the terminal can display it."
- (when window-system
- (font-lock-mode t)))
+ (when (and (not font-lock-mode) window-system)
+ (font-lock-mode)))
;;;###autoload
(defun font-lock-add-keywords (major-mode keywords &optional append)
(defun font-lock-change-major-mode ()
;; Turn off Font Lock mode if it's on.
(when font-lock-mode
- (font-lock-mode nil))
+ (font-lock-mode))
;; Gross hack warning: Delicate readers should avert eyes now.
;; Something is running `kill-all-local-variables', which generally means the
;; major mode is being changed. Run `turn-on-font-lock-if-enabled' after the
\f
;; Fontification functions.
+;; Rather than the function, e.g., `font-lock-fontify-region' containing the
+;; code to fontify a region, the function runs the function whose name is the
+;; value of the variable, e.g., `font-lock-fontify-region-function'. Normally,
+;; the value of this variable is, e.g., `font-lock-default-fontify-region'
+;; which does contain the code to fontify a region. However, the value of the
+;; variable could be anything and thus, e.g., `font-lock-fontify-region' could
+;; do anything. The indirection of the fontification functions gives major
+;; modes the capability of modifying the way font-lock.el fontifies. Major
+;; modes can modify the values of, e.g., `font-lock-fontify-region-function',
+;; via the variable `font-lock-defaults'.
+;;
+;; For example, Rmail mode sets the variable `font-lock-defaults' so that
+;; font-lock.el uses its own function for buffer fontification. This function
+;; makes fontification be on a message-by-message basis and so visiting an
+;; RMAIL file is much faster. A clever implementation of the function might
+;; fontify the headers differently than the message body. (It should, and
+;; correspondingly for Mail mode, but I can't be bothered to do the work. Can
+;; you?) This hints at a more interesting use...
+;;
+;; Languages that contain text normally contained in different major modes
+;; could define their own fontification functions that treat text differently
+;; depending on its context. For example, Perl mode could arrange that here
+;; docs are fontified differently than Perl code. Or Yacc mode could fontify
+;; rules one way and C code another. Neat!
+;;
+;; A further reason to use the fontification indirection feature is when the
+;; default syntactual fontification, or the default fontification in general,
+;; is not flexible enough for a particular major mode. For example, perhaps
+;; comments are just too hairy for `font-lock-fontify-syntactically-region' and
+;; `font-lock-comment-start-regexp' to cope with. You need to write your own
+;; version of that function, e.g., `hairy-fontify-syntactically-region', and
+;; make your own version of `hairy-fontify-region' call it before calling
+;; `font-lock-fontify-keywords-region' for the normal regexp fontification
+;; pass. And Hairy mode would set `font-lock-defaults' so that font-lock.el
+;; would call your region fontification function instead of its own. For
+;; example, TeX modes could fontify {\foo ...} and \bar{...} etc. multi-line
+;; directives correctly and cleanly. (It is the same problem as fontifying
+;; multi-line strings and comments; regexps are not appropriate for the job.)
+
;;;###autoload
(defun font-lock-fontify-buffer ()
"Fontify the current buffer the way `font-lock-mode' would."
(let ((verbose (if (numberp font-lock-verbose)
(> (buffer-size) font-lock-verbose)
font-lock-verbose)))
- (if verbose (message "Fontifying %s..." (buffer-name)))
+ (when verbose
+ (message "Fontifying %s..." (buffer-name)))
;; Make sure we have the right `font-lock-keywords' etc.
- (if (not font-lock-mode) (font-lock-set-defaults))
+ (unless font-lock-mode
+ (font-lock-set-defaults))
;; Make sure we fontify etc. in the whole buffer.
(save-restriction
(widen)
(setq font-lock-fontified t)))
;; We don't restore the old fontification, so it's best to unfontify.
(quit (font-lock-unfontify-buffer))))
+ ;; Make sure we undo `font-lock-keywords' etc.
+ (unless font-lock-mode
+ (font-lock-unset-defaults))
(if verbose (message "Fontifying %s...%s" (buffer-name)
(if font-lock-fontified "done" "quit")))))
(defun font-lock-default-unfontify-buffer ()
+ ;; Make sure we unfontify etc. in the whole buffer.
(save-restriction
(widen)
(font-lock-unfontify-region (point-min) (point-max))
(defsubst font-lock-fontify-anchored-keywords (keywords limit)
"Fontify according to KEYWORDS until LIMIT.
-KEYWORDS should be of the form MATCH-ANCHORED, see `font-lock-keywords'."
- (let ((matcher (nth 0 keywords)) (lowdarks (nthcdr 3 keywords)) highlights)
- ;; Until we come up with a cleaner solution, we make LIMIT the end of line.
- (save-excursion (end-of-line) (setq limit (min limit (point))))
- ;; Evaluate PRE-MATCH-FORM.
- (eval (nth 1 keywords))
+KEYWORDS should be of the form MATCH-ANCHORED, see `font-lock-keywords',
+LIMIT can be modified by the value of its PRE-MATCH-FORM."
+ (let ((matcher (nth 0 keywords)) (lowdarks (nthcdr 3 keywords)) highlights
+ ;; Evaluate PRE-MATCH-FORM.
+ (pre-match-value (eval (nth 1 keywords))))
+ ;; Set LIMIT to value of PRE-MATCH-FORM or the end of line.
+ (if (and (numberp pre-match-value) (> pre-match-value (point)))
+ (setq limit pre-match-value)
+ (save-excursion (end-of-line) (setq limit (point))))
(save-match-data
;; Find an occurrence of `matcher' before `limit'.
(while (if (stringp matcher)
(set-face-underline-p face (nth 5 face-attributes)))
(set face face)))
\f
+;;; Menu support.
+
+;; This section of code is commented out because Emacs does not have real menu
+;; buttons. (We can mimic them by putting "( ) " or "(X) " at the beginning of
+;; the menu entry text, but with Xt it looks both ugly and embarrassingly
+;; amateur.) If/When Emacs gets real menus buttons, put in menu-bar.el after
+;; the entry for "Text Properties" something like:
+;;
+;; (define-key menu-bar-edit-menu [font-lock]
+;; '("Syntax Highlighting" . font-lock-menu))
+;;
+;; and remove a single ";" from the beginning of each line in the rest of this
+;; section. Probably the mechanism for telling the menu code what are menu
+;; buttons and when they are on or off needs tweaking. I have assumed that the
+;; mechanism is via `menu-toggle' and `menu-selected' symbol properties. sm.
+
+;;;;###autoload
+;(progn
+; ;; Make the Font Lock menu.
+; (defvar font-lock-menu (make-sparse-keymap "Syntax Highlighting"))
+; ;; Add the menu items in reverse order.
+; (define-key font-lock-menu [fontify-less]
+; '("Less In Current Buffer" . font-lock-fontify-less))
+; (define-key font-lock-menu [fontify-more]
+; '("More In Current Buffer" . font-lock-fontify-more))
+; (define-key font-lock-menu [font-lock-sep]
+; '("--"))
+; (define-key font-lock-menu [font-lock-mode]
+; '("In Current Buffer" . font-lock-mode))
+; (define-key font-lock-menu [global-font-lock-mode]
+; '("In All Buffers" . global-font-lock-mode)))
+;
+;;;;###autoload
+;(progn
+; ;; We put the appropriate `menu-enable' etc. symbol property values on when
+; ;; font-lock.el is loaded, so we don't need to autoload the three variables.
+; (put 'global-font-lock-mode 'menu-toggle t)
+; (put 'font-lock-mode 'menu-toggle t)
+; (put 'font-lock-fontify-more 'menu-enable '(identity))
+; (put 'font-lock-fontify-less 'menu-enable '(identity)))
+;
+;;; Put the appropriate symbol property values on now. See above.
+;(put 'global-font-lock-mode 'menu-selected 'global-font-lock-mode))
+;(put 'font-lock-mode 'menu-selected 'font-lock-mode)
+;(put 'font-lock-fontify-more 'menu-enable '(nth 2 font-lock-fontify-level))
+;(put 'font-lock-fontify-less 'menu-enable '(nth 1 font-lock-fontify-level))
+;
+;(defvar font-lock-fontify-level nil) ; For less/more fontification.
+;
+;(defun font-lock-fontify-level (level)
+; (let ((font-lock-maximum-decoration level))
+; (when font-lock-mode
+; (font-lock-mode))
+; (font-lock-mode)
+; (when font-lock-verbose
+; (message "Fontifying %s... level %d" (buffer-name) level))))
+;
+;(defun font-lock-fontify-less ()
+; "Fontify the current buffer with less decoration.
+;See `font-lock-maximum-decoration'."
+; (interactive)
+; ;; Check in case we get called interactively.
+; (if (nth 1 font-lock-fontify-level)
+; (font-lock-fontify-level (1- (car font-lock-fontify-level)))
+; (error "No less decoration")))
+;
+;(defun font-lock-fontify-more ()
+; "Fontify the current buffer with more decoration.
+;See `font-lock-maximum-decoration'."
+; (interactive)
+; ;; Check in case we get called interactively.
+; (if (nth 2 font-lock-fontify-level)
+; (font-lock-fontify-level (1+ (car font-lock-fontify-level)))
+; (error "No more decoration")))
+;
+;;; This should be called by `font-lock-set-defaults'.
+;(defun font-lock-set-menu ()
+; ;; Activate less/more fontification entries if there are multiple levels for
+; ;; the current buffer. Sets `font-lock-fontify-level' to be of the form
+; ;; (CURRENT-LEVEL IS-LOWER-LEVEL-P IS-HIGHER-LEVEL-P) for menu activation.
+; (let ((keywords (or (nth 0 font-lock-defaults)
+; (nth 1 (assq major-mode font-lock-defaults-alist))))
+; (level (font-lock-value-in-major-mode font-lock-maximum-decoration)))
+; (make-local-variable 'font-lock-fontify-level)
+; (if (or (symbolp keywords) (= (length keywords) 1))
+; (font-lock-unset-menu)
+; (cond ((eq level t)
+; (setq level (1- (length keywords))))
+; ((or (null level) (zerop level))
+; ;; The default level is usually, but not necessarily, level 1.
+; (setq level (- (length keywords)
+; (length (member (eval (car keywords))
+; (mapcar 'eval (cdr keywords))))))))
+; (setq font-lock-fontify-level (list level (> level 1)
+; (< level (1- (length keywords))))))))
+;
+;;; This should be called by `font-lock-unset-defaults'.
+;(defun font-lock-unset-menu ()
+; ;; Deactivate less/more fontification entries.
+; (setq font-lock-fontify-level nil))
+\f
;;; Various regexp information shared by several modes.
;;; Information specific to a single mode should go in its load library.
;; Font Lock support for C, C++, Objective-C and Java modes will one day be in
-;; cc-font.el (and required by cc-mode.el). However, the below function should
-;; stay in font-lock.el, since it is used by other libraries. sm.
+;; some cc-font.el (and required by cc-mode.el). However, the below function
+;; should stay in font-lock.el, since it is used by other libraries. sm.
(defun font-lock-match-c-style-declaration-item-and-skip-to-next (limit)
"Match, and move over, any declaration/definition item after point.
;; about five times slower.
(list (concat "^(\\(def\\("
;; Variable declarations.
- "\\(const\\|custom\\|var\\)\\|"
+ "\\(const\\|custom\\|face\\|var\\)\\|"
;; Structure declarations.
- "\\(class\\|struct\\|type\\)\\|"
+ "\\(class\\|group\\|struct\\|type\\)\\|"
;; Everything else is a function declaration.
"\\sw+"
"\\)\\)\\>"
(t font-lock-function-name-face))
nil t))
))
- "Subdued level highlighting for Lisp modes.")
+ "Subdued level highlighting for Lisp modes.")
(defconst lisp-font-lock-keywords-2
(append lisp-font-lock-keywords-1
(concat "\\<\\(" c-keywords "\\)\\>")
;;
;; Fontify case/goto keywords and targets, and case default/goto tags.
- '("\\<\\(case\\|goto\\)\\>[ \t]*\\(\\sw+\\)?"
+ '("\\<\\(case\\|goto\\)\\>[ \t]*\\(-?\\sw+\\)?"
(1 font-lock-keyword-face) (2 font-lock-reference-face nil t))
;; Anders Lindgren <andersl@csd.uu.se> points out that it is quicker to use
;; MATCH-ANCHORED to effectively anchor the regexp on the left.
'(2 font-lock-builtin-face nil t))
;;
;; Fontify case/goto keywords and targets, and case default/goto tags.
- '("\\<\\(case\\|goto\\)\\>[ \t]*\\(\\sw+\\)?"
+ '("\\<\\(case\\|goto\\)\\>[ \t]*\\(-?\\sw+\\)?"
(1 font-lock-keyword-face) (2 font-lock-reference-face nil t))
'(":" ("^[ \t]*\\(\\sw+\\)[ \t]*:\\($\\|[^:]\\)"
(beginning-of-line) (end-of-line)
(concat "\\<\\(" objc-keywords "\\)\\>")
;;
;; Fontify case/goto keywords and targets, and case default/goto tags.
- '("\\<\\(case\\|goto\\)\\>[ \t]*\\(\\sw+\\)?"
+ '("\\<\\(case\\|goto\\)\\>[ \t]*\\(-?\\sw+\\)?"
(1 font-lock-keyword-face) (2 font-lock-reference-face nil t))
;; Fontify tags iff sole statement on line, otherwise we detect selectors.
'(":" ("^[ \t]*\\(\\sw+\\)[ \t]*:[ \t]*$"
(concat "\\<\\(" java-keywords "\\)\\>")
;;
;; Fontify keywords and targets, and case default/goto tags.
- (list "\\<\\(break\\|case\\|continue\\|goto\\)\\>[ \t]*\\(\\sw+\\)?"
+ (list "\\<\\(break\\|case\\|continue\\|goto\\)\\>[ \t]*\\(-?\\sw+\\)?"
'(1 font-lock-keyword-face) '(2 font-lock-reference-face nil t))
'(":" ("^[ \t]*\\(\\sw+\\)[ \t]*:"
(beginning-of-line) (end-of-line)
projects / emacs.git / commitdiff