Subject: [PATCH] Delete fast-lock.el and lazy-lock.el

From: Stefan Kangas <[email-masked]>
Date: Thu, 14 Jul 2022 11:45:47 -0700

Severity: wishlist

I guess it's high time to retire lazy-lock.el and fast-lock.el, obsolete
since Emacs 22.1.

The last time we discussed this, I proposed to obsolete the variable
'font-lock-support-mode'.  It turns out that it is still useful for
debugging, so the discussion got side-tracked and nothing came of it.

In a new attempt, I submit here a new patch where this variable is
turned into a defvar instead, so that it can still be used for
debugging.  Hopefully, this should be more palatable.
From 6e73afed3478b018f57f85681d7a137738532712 Mon Sep 17 00:00:00 2001
From: Stefan Kangas <[email-masked]>
Date: Thu, 14 Jul 2022 20:27:03 +0200
Subject: [PATCH] Delete fast-lock.el and lazy-lock.el

The 'font-lock-support-mode' is occasionally useful for debugging
purposes, so it remains as a defvar.
Ref: https://lists.gnu.org/r/emacs-devel/2020-08/msg00125.html

* lisp/obsolete/fast-lock.el:
* lisp/obsolete/lazy-lock.el: Delete libraries obsolete since 22.1.

* lisp/font-lock.el (font-lock-support-mode): Make into a defvar and
delete any mention of 'lazy-lock-mode' and 'fast-lock-mode'.
(font-lock-turn-on-thing-lock, font-lock-turn-off-thing-lock):
Drop support for obsolete modes lazy-lock and fast-lock.
(font-lock-after-fontify-buffer)
(font-lock-after-unfontify-buffer): Make into obsolete function
aliases for 'ignore'.  Adjust callers.
(font-lock-keywords, font-lock-inhibit-thing-lock): Adjust
documentation to not mention lazy-lock and fast-lock.
* lisp/font-core.el (font-lock-defaults): Adjust documentation to
not mention 'font-lock-inhibit-thing-lock'.
* lisp/mail/rmail.el (rmail-variables): Don't inhibit obsolete
lazy-lock-mode and fast-lock-mode.
---
 etc/NEWS                   |    8 +
 lisp/font-core.el          |    2 +-
 lisp/font-lock.el          |  103 +---
 lisp/mail/rmail.el         |    3 +-
 lisp/obsolete/fast-lock.el |  730 -------------------------
 lisp/obsolete/lazy-lock.el | 1025 ------------------------------------
 6 files changed, 22 insertions(+), 1849 deletions(-)
 delete mode 100644 lisp/obsolete/fast-lock.el
 delete mode 100644 lisp/obsolete/lazy-lock.el

diff --git a/etc/NEWS b/etc/NEWS
index 57845df979..ebea9ef248 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -325,6 +325,14 @@ startup.  Previously, these functions ignored
 ** The rlogin.el library and 'rsh' command are now obsolete.
 Use something like 'M-x shell RET ssh <host> RET' instead.
 
+---
+** The fast-lock.el and lazy-lock.el library have been removed.
+They have been obsolete since Emacs 22.1.
+
+The variable 'font-lock-support-mode' is occasionally useful for
+debugging purposes.  It is now a regular variable (instead of a user
+option) and can be set to nil to disable Just-in-time Lock mode.
+
 
 * Changes in Emacs 29.1
 
diff --git a/lisp/font-core.el b/lisp/font-core.el
index f92d1e3830..f70c42bb03 100644
--- a/lisp/font-core.el
+++ b/lisp/font-core.el
@@ -65,7 +65,7 @@ font-lock-defaults
 `font-lock-syntactic-keywords' and those for buffer-specialized fontification
 functions, `font-lock-fontify-buffer-function',
 `font-lock-unfontify-buffer-function', `font-lock-fontify-region-function',
-`font-lock-unfontify-region-function', and `font-lock-inhibit-thing-lock'.")
+`font-lock-unfontify-region-function'.")
 ;; Autoload if this file no longer dumped.
 ;;;###autoload
 (put 'font-lock-defaults 'risky-local-variable t)
diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index 181a7dc90e..09e46ef424 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -490,8 +490,7 @@ font-lock-keywords
 These regular expressions can match text which spans lines,
 although it is better to avoid it if possible since updating them
 while editing text is slower, and it is not guaranteed to be
-always correct when using support modes like jit-lock or
-lazy-lock.
+always correct.
 
 This variable is set by major modes via the variable
 `font-lock-defaults'.  Be careful when composing regexps for this
@@ -623,11 +622,8 @@ font-lock-unfontify-region-function
 It should take two args, the beginning and end of the region.
 This is normally set via `font-lock-defaults'.")
 
-(defvar font-lock-inhibit-thing-lock nil
-  "List of Font Lock mode related modes that should not be turned on.
-Currently, valid mode names are `fast-lock-mode', `jit-lock-mode' and
-`lazy-lock-mode'.  This is normally set via `font-lock-defaults'.")
-(make-obsolete-variable 'font-lock-inhibit-thing-lock nil "25.1")
+(defvar font-lock-inhibit-thing-lock nil)
+(make-obsolete-variable 'font-lock-inhibit-thing-lock "it does nothing." "25.1")
 
 (defvar-local font-lock-multiline nil
   "Whether font-lock should cater to multiline keywords.
@@ -642,7 +638,6 @@ font-lock-fontified
 
 (eval-when-compile
   ;;
-  ;; Borrowed from lazy-lock.el.
   ;; We use this to preserve or protect things when modifying text properties.
   (defmacro save-buffer-state (&rest body)
     "Bind variables according to VARLIST and eval BODY restoring buffer state."
@@ -881,65 +876,17 @@ font-lock-remove-keywords
 
 ;;; Font Lock Support mode.
 
-;; This is the code used to interface font-lock.el with any of its add-on
-;; packages, and provide the user interface.  Packages that have their own
-;; local buffer fontification functions (see below) may have to call
-;; `font-lock-after-fontify-buffer' and/or `font-lock-after-unfontify-buffer'
-;; themselves.
-
-(defcustom font-lock-support-mode 'jit-lock-mode
+(defvar font-lock-support-mode #'jit-lock-mode
   "Support mode for Font Lock mode.
-Support modes speed up Font Lock mode by being choosy about when fontification
-occurs.  The default support mode, Just-in-time Lock mode (symbol
-`jit-lock-mode'), is recommended.
-
-Other, older support modes are Fast Lock mode (symbol `fast-lock-mode') and
-Lazy Lock mode (symbol `lazy-lock-mode').  See those modes for more info.
-However, they are no longer recommended, as Just-in-time Lock mode is better.
-
 If nil, means support for Font Lock mode is never performed.
-If a symbol, use that support mode.
-If a list, each element should be of the form (MAJOR-MODE . SUPPORT-MODE),
-where MAJOR-MODE is a symbol or t (meaning the default).  For example:
- ((c-mode . fast-lock-mode) (c++-mode . fast-lock-mode) (t . lazy-lock-mode))
-means that Fast Lock mode is used to support Font Lock mode for buffers in C or
-C++ modes, and Lazy Lock mode is used to support Font Lock mode otherwise.
-
-The value of this variable is used when Font Lock mode is turned on."
-  :type '(choice (const :tag "none" nil)
-		 (const :tag "fast lock" fast-lock-mode)
-		 (const :tag "lazy lock" lazy-lock-mode)
-		 (const :tag "jit lock" jit-lock-mode)
-		 (repeat :menu-tag "mode specific" :tag "mode specific"
-			 :value ((t . jit-lock-mode))
-			 (cons :tag "Instance"
-			       (radio :tag "Mode"
-				      (const :tag "all" t)
-				      (symbol :tag "name"))
-			       (radio :tag "Support"
-				      (const :tag "none" nil)
-				      (const :tag "fast lock" fast-lock-mode)
-				      (const :tag "lazy lock" lazy-lock-mode)
-				      (const :tag "JIT lock" jit-lock-mode)))
-			 ))
-  :version "21.1"
-  :group 'font-lock)
+This can be useful for debugging.
 
-(defvar fast-lock-mode)
-(defvar lazy-lock-mode)
-(defvar jit-lock-mode)
+The value of this variable is used when Font Lock mode is turned on.")
 
-(declare-function fast-lock-after-fontify-buffer "fast-lock")
-(declare-function fast-lock-after-unfontify-buffer "fast-lock")
-(declare-function fast-lock-mode "fast-lock")
-(declare-function lazy-lock-after-fontify-buffer "lazy-lock")
-(declare-function lazy-lock-after-unfontify-buffer "lazy-lock")
-(declare-function lazy-lock-mode "lazy-lock")
+(defvar jit-lock-mode)
 
 (defun font-lock-turn-on-thing-lock ()
   (pcase (font-lock-value-in-major-mode font-lock-support-mode)
-    ('fast-lock-mode (fast-lock-mode t))
-    ('lazy-lock-mode (lazy-lock-mode t))
     ('jit-lock-mode
      ;; Prepare for jit-lock
      (remove-hook 'after-change-functions
@@ -962,37 +909,13 @@ font-lock-turn-on-thing-lock
                nil t))))
 
 (defun font-lock-turn-off-thing-lock ()
-  (cond ((bound-and-true-p fast-lock-mode)
-	 (fast-lock-mode -1))
-	((bound-and-true-p jit-lock-mode)
+  (cond ((bound-and-true-p jit-lock-mode)
 	 (jit-lock-unregister 'font-lock-fontify-region)
 	 ;; Reset local vars to the non-jit-lock case.
-	 (kill-local-variable 'font-lock-fontify-buffer-function))
-	((bound-and-true-p lazy-lock-mode)
-	 (lazy-lock-mode -1))))
-
-(defun font-lock-after-fontify-buffer ()
-  (cond ((bound-and-true-p fast-lock-mode)
-	 (fast-lock-after-fontify-buffer))
-	;; Useless now that jit-lock intercepts font-lock-fontify-buffer.  -sm
-	;; (jit-lock-mode
-	;;  (jit-lock-after-fontify-buffer))
-	((bound-and-true-p lazy-lock-mode)
-	 (lazy-lock-after-fontify-buffer))))
-
-(defun font-lock-after-unfontify-buffer ()
-  (cond ((bound-and-true-p fast-lock-mode)
-	 (fast-lock-after-unfontify-buffer))
-	;; Useless as well.  It's only called when:
-	;; - turning off font-lock: it does not matter if we leave spurious
-	;;   `fontified' text props around since jit-lock-mode is also off.
-	;; - font-lock-default-fontify-buffer fails: this is not run
-	;;   any more anyway.   -sm
-	;;
-	;; (jit-lock-mode
-	;;  (jit-lock-after-unfontify-buffer))
-	((bound-and-true-p lazy-lock-mode)
-	 (lazy-lock-after-unfontify-buffer))))
+         (kill-local-variable 'font-lock-fontify-buffer-function))))
+
+(define-obsolete-function-alias 'font-lock-after-fontify-buffer #'ignore "29.1")
+(define-obsolete-function-alias 'font-lock-after-unfontify-buffer #'ignore "29.1")
 
 ;; End of Font Lock Support mode.
 
@@ -1160,7 +1083,6 @@ font-lock-default-fontify-buffer
 	    (save-excursion
 	      (save-match-data
 		(font-lock-fontify-region (point-min) (point-max) verbose)
-		(font-lock-after-fontify-buffer)
 		(setq font-lock-fontified t)))
 	  ;; We don't restore the old fontification, so it's best to unfontify.
 	  (quit (font-lock-unfontify-buffer)))))))
@@ -1171,7 +1093,6 @@ font-lock-default-unfontify-buffer
   (save-restriction
     (widen)
     (font-lock-unfontify-region (point-min) (point-max))
-    (font-lock-after-unfontify-buffer)
     (setq font-lock-fontified nil)))
 
 (defvar font-lock-dont-widen nil
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 71eda7cd2b..4bfec22b3a 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -1451,8 +1451,7 @@ rmail-variables
   (setq-local font-lock-defaults
               '(rmail-font-lock-keywords
                 t t nil nil
-                (font-lock-dont-widen . t)
-                (font-lock-inhibit-thing-lock . (lazy-lock-mode fast-lock-mode))))
+                (font-lock-dont-widen . t)))
   (setq-local require-final-newline nil)
   (setq-local version-control 'never)
   (add-hook 'kill-buffer-hook #'rmail-mode-kill-summary nil t)
diff --git a/lisp/obsolete/fast-lock.el b/lisp/obsolete/fast-lock.el
deleted file mode 100644
index 1614935f03..0000000000
--- a/lisp/obsolete/fast-lock.el
+++ /dev/null
@@ -1,730 +0,0 @@
-;;; fast-lock.el --- automagic text properties caching for fast Font Lock mode  -*- lexical-binding: t; -*-
-
-;; Copyright (C) 1994-1998, 2001-2022 Free Software Foundation, Inc.
-
-;; Author: Simon Marshall <[email-masked]>
-;; Maintainer: [email-masked]
-;; Keywords: faces files
-;; Version: 3.14
-;; Obsolete-since: 22.1
-
-;; 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 3 of the License, 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.  If not, see <https://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;; Fast Lock mode is a Font Lock support mode.
-;; It makes visiting a file in Font Lock mode faster by restoring its face text
-;; properties from automatically saved associated Font Lock cache files.
-;;
-;; See caveats and feedback below.
-;; See also the lazy-lock package.  (But don't use the two at the same time!)
-
-;; Installation:
-;;
-;; Put in your ~/.emacs:
-;;
-;; (setq font-lock-support-mode 'fast-lock-mode)
-;;
-;; Start up a new Emacs and use font-lock as usual (except that you can use the
-;; so-called "gaudier" fontification regexps on big files without frustration).
-;;
-;; When you visit a file (which has `font-lock-mode' enabled) that has a
-;; corresponding Font Lock cache file associated with it, the Font Lock cache
-;; will be loaded from that file instead of being generated by Font Lock code.
-
-;; Caveats:
-;;
-;; A cache will be saved when visiting a compressed file using crypt++, but not
-;; be read.  This is a "feature"/"consequence"/"bug" of crypt++.
-;;
-;; Version control packages are likely to stamp all over file modification
-;; times.  Therefore the act of checking out may invalidate a cache.
-
-;; History:
-;;
-;; 0.02--1.00:
-;; - Changed name from turbo-prop to fast-lock.  Automagic for font-lock only
-;; - Made `fast-lock-mode' a minor mode, like G. Dinesh Dutt's fss-mode
-;; 1.00--1.01:
-;; - Turn on `fast-lock-mode' only if `buffer-file-name' or `interactive-p'
-;; - Made `fast-lock-file-name' use `buffer-name' if `buffer-file-name' is nil
-;; - Moved save-all conditions to `fast-lock-save-cache'
-;; - Added `fast-lock-save-text-properties' to `kill-buffer-hook'
-;; 1.01--2.00: complete rewrite---not worth the space to document
-;; - Changed structure of text properties cache and threw out file mod checks
-;; 2.00--2.01:
-;; - Made `condition-case' forms understand `quit'.
-;; - Made `fast-lock' require `font-lock'
-;; - Made `fast-lock-cache-name' chase links (from Ben Liblit)
-;; 2.01--3.00:
-;; - Changed structure of cache to include `font-lock-keywords' (from rms)
-;; - Changed `fast-lock-cache-mechanisms' to `fast-lock-cache-directories'
-;; - Removed `fast-lock-read-others'
-;; - Made `fast-lock-read-cache' ignore cache owner
-;; - Made `fast-lock-save-cache-external' create cache directory
-;; - Made `fast-lock-save-cache-external' save `font-lock-keywords'
-;; - Made `fast-lock-cache-data' check `font-lock-keywords'
-;; 3.00--3.01: incorporated port of 2.00 to Lucid, made by Barry Warsaw
-;; - Package now provides itself
-;; - Lucid: Use `font-lock-any-extents-p' for `font-lock-any-properties-p'
-;; - Lucid: Use `list-faces' for `face-list'
-;; - Lucid: Added `set-text-properties'
-;; - Lucid: Made `turn-on-fast-lock' pass 1 not t to `fast-lock-mode'
-;; - Removed test for `fast-lock-mode' from `fast-lock-read-cache'
-;; - Lucid: Added Lucid-specific `fast-lock-get-face-properties'
-;; 3.01--3.02: now works with Lucid Emacs, thanks to Barry Warsaw
-;; - Made `fast-lock-cache-name' map ":" to ";" for OS/2 (from Serganova Vera)
-;; - Made `fast-lock-cache-name' use abbreviated file name (from Barry Warsaw)
-;; - Lucid: Separated handlers for `error' and `quit' for `condition-case'
-;; 3.02--3.03:
-;; - Changed `fast-lock-save-cache-external' to `fast-lock-save-cache-data'
-;; - Lucid: Added Lucid-specific `fast-lock-set-face-properties'
-;; 3.03--3.04:
-;; - Corrected `subrp' test of Lucid code
-;; - Replaced `font-lock-any-properties-p' with `text-property-not-all'
-;; - Lucid: Made `fast-lock-set-face-properties' put `text-prop' on extents
-;; - Made `fast-lock-cache-directories' a regexp alist (from Colin Rafferty)
-;; - Made `fast-lock-cache-directory' to return a usable cache file directory
-;; 3.04--3.05:
-;; - Lucid: Fix for XEmacs 19.11 `text-property-not-all'
-;; - Replaced `subrp' test of Lucid code with `emacs-version' `string-match'
-;; - Made `byte-compile-warnings' omit `unresolved' on compilation
-;; - Made `fast-lock-save-cache-data' use a buffer (from Rick Sladkey)
-;; - Reverted to old `fast-lock-get-face-properties' (from Rick Sladkey)
-;; 3.05--3.06: incorporated hack of 3.03, made by Jonathan Stigelman (Stig)
-;; - Reverted to 3.04 version of `fast-lock-get-face-properties'
-;; - XEmacs: Removed `list-faces' `defalias'
-;; - Made `fast-lock-mode' and `turn-on-fast-lock' succeed `autoload' cookies
-;; - Added `fast-lock-submit-bug-report'
-;; - Renamed `fast-lock-save-size' to `fast-lock-minimum-size'
-;; - Made `fast-lock-save-cache' output a message if no save ever attempted
-;; - Made `fast-lock-save-cache-data' output a message if save attempted
-;; - Made `fast-lock-cache-data' output a message if load attempted
-;; - Made `fast-lock-save-cache-data' do `condition-case' not `unwind-protect'
-;; - Made `fast-lock-save-cache' and `fast-lock-read-cache' return nothing
-;; - Made `fast-lock-save-cache' check `buffer-modified-p' (Stig)
-;; - Added `fast-lock-save-events'
-;; - Added `fast-lock-after-save-hook' to `after-save-hook' (Stig)
-;; - Added `fast-lock-kill-buffer-hook' to `kill-buffer-hook'
-;; - Changed `fast-lock-save-caches' to `fast-lock-kill-emacs-hook'
-;; - Added `fast-lock-kill-emacs-hook' to `kill-emacs-hook'
-;; - Made `fast-lock-save-cache' check `verify-visited-file-modtime' (Stig)
-;; - Made `visited-file-modtime' be the basis of the timestamp (Stig)
-;; - Made `fast-lock-save-cache-1' and `fast-lock-cache-data' use/reformat it
-;; - Added `fast-lock-cache-filename' to keep track of the cache file name
-;; - Added `fast-lock-after-fontify-buffer'
-;; - Added `fast-lock-save-faces' list of faces to save (idea from Stig/Tibor)
-;; - Made `fast-lock-get-face-properties' functions use it
-;; - XEmacs: Made `fast-lock-set-face-properties' do extents the Font Lock way
-;; - XEmacs: Removed fix for `text-property-not-all' (19.11 support dropped)
-;; - Made `fast-lock-mode' ensure `font-lock-mode' is on
-;; - Made `fast-lock-save-cache' do `cdr-safe' not `cdr' (from Dave Foster)
-;; - Made `fast-lock-save-cache' do `set-buffer' first (from Dave Foster)
-;; - Made `fast-lock-save-cache' loop until saved or quit (from Georg Nikodym)
-;; - Made `fast-lock-cache-data' check `buffer-modified-p'
-;; - Made `fast-lock-cache-data' do `font-lock-compile-keywords' if necessary
-;; - XEmacs: Made `font-lock-compile-keywords' `defalias'
-;; 3.06--3.07:
-;; - XEmacs: Add `fast-lock-after-fontify-buffer' to the Font Lock hook
-;; - Made `fast-lock-cache-name' explain the use of `directory-abbrev-alist'
-;; - Made `fast-lock-mode' use `buffer-file-truename' not `buffer-file-name'
-;; 3.07--3.08:
-;; - Made `fast-lock-read-cache' set `fast-lock-cache-filename'
-;; 3.08--3.09:
-;; - Made `fast-lock-save-cache' cope if `fast-lock-minimum-size' is a list
-;; - Made `fast-lock-mode' respect the value of `font-lock-inhibit-thing-lock'
-;; - Added `fast-lock-after-unfontify-buffer'
-;; 3.09--3.10:
-;; - Rewrite for Common Lisp macros
-;; - Made fast-lock.el barf on a crap 8+3 pseudo-OS (Eli Zaretskii help)
-;; - XEmacs: Made `add-minor-mode' succeed `autoload' cookie
-;; - XEmacs: Made `fast-lock-save-faces' default to `font-lock-face-list'
-;; - Made `fast-lock-save-cache' use `font-lock-value-in-major-mode'
-;; - Wrap with `save-buffer-state' (Ray Van Tassle report)
-;; - Made `fast-lock-mode' wrap `font-lock-support-mode'
-;; 3.10--3.11:
-;; - Made `fast-lock-get-face-properties' cope with face lists
-;; - Added `fast-lock-verbose'
-;; - XEmacs: Add `font-lock-value-in-major-mode' if necessary
-;; - Removed `fast-lock-submit-bug-report' and bade farewell
-;; 3.11--3.12:
-;; - Added Custom support (Hrvoje Nikšić help)
-;; - Made `save-buffer-state' wrap `inhibit-point-motion-hooks'
-;; - Made `fast-lock-cache-data' simplify calls of `font-lock-compile-keywords'
-;; 3.12--3.13:
-;; - Removed `byte-*' variables from `eval-when-compile' (Erik Naggum hint)
-;; - Changed structure of cache to include `font-lock-syntactic-keywords'
-;; - Made `fast-lock-save-cache-1' save syntactic fontification data
-;; - Made `fast-lock-cache-data' take syntactic fontification data
-;; - Added `fast-lock-get-syntactic-properties'
-;; - Renamed `fast-lock-set-face-properties' to `fast-lock-add-properties'
-;; - Made `fast-lock-add-properties' add syntactic and face fontification data
-;; 3.13--3.14:
-;; - Made `fast-lock-cache-name' cope with `windowsnt' (Geoff Voelker fix)
-;; - Made `fast-lock-verbose' use `other' widget (Andreas Schwab fix)
-;; - Used `with-temp-message' where possible to make messages temporary.
-
-;;; Code:
-
-(require 'font-lock)
-
-(declare-function msdos-long-file-names "msdos.c")
-
-;; Make sure fast-lock.el is supported.
-(if (and (eq system-type 'ms-dos) (not (msdos-long-file-names)))
-    (error "`fast-lock' was written for long file name systems"))
-
-(defvar font-lock-face-list)
-
-(eval-when-compile
- ;;
- ;; We use this to verify that a face should be saved.
- (defmacro fast-lock-save-facep (face)
-   "Return non-nil if FACE is one of `fast-lock-save-faces'."
-   `(or (null fast-lock-save-faces)
-     (if (symbolp ,face)
-         (memq ,face fast-lock-save-faces)
-         (let ((faces ,face))
-           (while (unless (memq (car faces) fast-lock-save-faces)
-                    (setq faces (cdr faces))))
-           faces)))))
-
-(defgroup fast-lock nil
-  "Font Lock support mode to cache fontification."
-  :load 'fast-lock
-  :group 'font-lock)
-
-(defvar fast-lock-mode nil)		; Whether we are turned on.
-(defvar fast-lock-cache-timestamp nil)	; For saving/reading.
-(defvar fast-lock-cache-filename nil)	; For deleting.
-
-;; User Variables:
-
-(defcustom fast-lock-minimum-size 25600
-  "Minimum size of a buffer for cached fontification.
-Only buffers more than this can have associated Font Lock cache files saved.
-If nil, means cache files are never created.
-If a list, each element should be a cons pair of the form (MAJOR-MODE . SIZE),
-where MAJOR-MODE is a symbol or t (meaning the default).  For example:
- ((c-mode . 25600) (c++-mode . 25600) (rmail-mode . 1048576))
-means that the minimum size is 25K for buffers in C or C++ modes, one megabyte
-for buffers in Rmail mode, and size is irrelevant otherwise."
-  :type '(choice (const :tag "none" nil)
-		 (integer :tag "size")
-		 (repeat :menu-tag "mode specific" :tag "mode specific"
-			 :value ((t . nil))
-			 (cons :tag "Instance"
-			       (radio :tag "Mode"
-				      (const :tag "all" t)
-				      (symbol :tag "name"))
-			       (radio :tag "Size"
-				      (const :tag "none" nil)
-				      (integer :tag "size"))))))
-
-(defcustom fast-lock-cache-directories '("~/.emacs-flc")
-; - `internal', keep each file's Font Lock cache file in the same file.
-; - `external', keep each file's Font Lock cache file in the same directory.
-  "Directories in which Font Lock cache files are saved and read.
-Each item should be either DIR or a cons pair of the form (REGEXP . DIR) where
-DIR is a directory name (relative or absolute) and REGEXP is a regexp.
-
-An attempt will be made to save or read Font Lock cache files using these items
-until one succeeds (i.e., until a readable or writable one is found).  If an
-item contains REGEXP, DIR is used only if the buffer file name matches REGEXP.
-For example:
-
- (let ((home (expand-file-name (abbreviate-file-name (file-truename \"~/\")))))
-   (list (cons (concat \"^\" (regexp-quote home)) \".\") \"~/.emacs-flc\"))
-    =>
- ((\"^/your/true/home/directory/\" . \".\") \"~/.emacs-flc\")
-
-would cause a file's current directory to be used if the file is under your
-home directory hierarchy, or otherwise the absolute directory `~/.emacs-flc'.
-For security reasons, it is not advisable to use the file's current directory
-to avoid the possibility of using the cache of another user."
-  :type '(repeat (radio (directory :tag "directory")
-			(cons :tag "Matching"
-			      (regexp :tag "regexp")
-			      (directory :tag "directory")))))
-(put 'fast-lock-cache-directories 'risky-local-variable t)
-
-(defcustom fast-lock-save-events '(kill-buffer kill-emacs)
-  "Events under which caches will be saved.
-Valid events are `save-buffer', `kill-buffer' and `kill-emacs'.
-If concurrent editing sessions use the same associated cache file for a file's
-buffer, then you should add `save-buffer' to this list."
-  :type '(set (const :tag "buffer saving" save-buffer)
-	      (const :tag "buffer killing" kill-buffer)
-	      (const :tag "emacs killing" kill-emacs)))
-
-(defcustom fast-lock-save-others t
-  "If non-nil, save Font Lock cache files irrespective of file owner.
-If nil, means only buffer files known to be owned by you can have associated
-Font Lock cache files saved.  Ownership may be unknown for networked files."
-  :type 'boolean)
-
-(defcustom fast-lock-verbose font-lock-verbose
-  "If non-nil, means show status messages for cache processing.
-If a number, only buffers greater than this size have processing messages."
-  :type '(choice (const :tag "never" nil)
-		 (other :tag "always" t)
-		 (integer :tag "size")))
-
-(defvar fast-lock-save-faces nil
-  "Faces that will be saved in a Font Lock cache file.
-If nil, means information for all faces will be saved.")
-
-;; User Functions:
-
-;;;###autoload
-(defun fast-lock-mode (&optional arg)
-  "Toggle Fast Lock mode.
-With arg, turn Fast Lock mode on if and only if arg is positive and the buffer
-is associated with a file.  Enable it automatically in your `~/.emacs' by:
-
- (setq font-lock-support-mode \\='fast-lock-mode)
-
-If Fast Lock mode is enabled, and the current buffer does not contain any text
-properties, any associated Font Lock cache is used if its timestamp matches the
-buffer's file, and its `font-lock-keywords' match those that you are using.
-
-Font Lock caches may be saved:
-- When you save the file's buffer.
-- When you kill an unmodified file's buffer.
-- When you exit Emacs, for all unmodified or saved buffers.
-Depending on the value of `fast-lock-save-events'.
-See also the commands `fast-lock-read-cache' and `fast-lock-save-cache'.
-
-Use \\[font-lock-fontify-buffer] to fontify the buffer if the cache is bad.
-
-Various methods of control are provided for the Font Lock cache.  In general,
-see variable `fast-lock-cache-directories' and function `fast-lock-cache-name'.
-For saving, see variables `fast-lock-minimum-size', `fast-lock-save-events',
-`fast-lock-save-others' and `fast-lock-save-faces'."
-  (interactive "P")
-  ;; Only turn on if we are visiting a file.  We could use `buffer-file-name',
-  ;; but many packages temporarily wrap that to nil when doing their own thing.
-  (set (make-local-variable 'fast-lock-mode)
-       (and buffer-file-truename
-	    (not (memq 'fast-lock-mode font-lock-inhibit-thing-lock))
-	    (if arg (> (prefix-numeric-value arg) 0) (not fast-lock-mode))))
-  (if (and fast-lock-mode (not font-lock-mode))
-      ;; Turned on `fast-lock-mode' rather than `font-lock-mode'.
-      (progn
-        (message "Use font-lock-support-mode rather than calling fast-lock-mode")
-        (sit-for 2))
-    ;; Let's get down to business.
-    (set (make-local-variable 'fast-lock-cache-timestamp) nil)
-    (set (make-local-variable 'fast-lock-cache-filename) nil)
-    (when (and fast-lock-mode (not font-lock-fontified))
-      (fast-lock-read-cache))))
-
-(defun fast-lock-read-cache ()
-  "Read the Font Lock cache for the current buffer.
-
-The following criteria must be met for a Font Lock cache file to be read:
-- Fast Lock mode must be turned on in the buffer.
-- The buffer must not be modified.
-- The buffer's `font-lock-keywords' must match the cache's.
-- The buffer file's timestamp must match the cache's.
-- Criteria imposed by `fast-lock-cache-directories'.
-
-See `fast-lock-mode'."
-  (interactive)
-  (let ((directories fast-lock-cache-directories)
-	(modified (buffer-modified-p)) (inhibit-read-only t)
-	(fontified font-lock-fontified))
-    (set (make-local-variable 'font-lock-fontified) nil)
-    ;; Keep trying directories until fontification is turned off.
-    (while (and directories (not font-lock-fontified))
-      (let ((directory (fast-lock-cache-directory (car directories) nil)))
-	(condition-case nil
-	    (when directory
-	      (setq fast-lock-cache-filename (fast-lock-cache-name directory))
-	      (when (file-readable-p fast-lock-cache-filename)
-		(load fast-lock-cache-filename t t t)))
-	  (error nil) (quit nil))
-	(setq directories (cdr directories))))
-    ;; Unset `fast-lock-cache-filename', and restore `font-lock-fontified', if
-    ;; we don't use a cache.  (Note that `fast-lock-cache-data' sets the value
-    ;; of `fast-lock-cache-timestamp'.)
-    (set-buffer-modified-p modified)
-    (unless font-lock-fontified
-      (setq fast-lock-cache-filename nil font-lock-fontified fontified))))
-
-(defun fast-lock-save-cache (&optional buffer)
-  "Save the Font Lock cache of BUFFER or the current buffer.
-
-The following criteria must be met for a Font Lock cache file to be saved:
-- Fast Lock mode must be turned on in the buffer.
-- The event must be one of `fast-lock-save-events'.
-- The buffer must be at least `fast-lock-minimum-size' bytes long.
-- The buffer file must be owned by you, or `fast-lock-save-others' must be t.
-- The buffer must contain at least one `face' text property.
-- The buffer must not be modified.
-- The buffer file's timestamp must be the same as the file's on disk.
-- The on disk file's timestamp must be different than the buffer's cache.
-- Criteria imposed by `fast-lock-cache-directories'.
-
-See `fast-lock-mode'."
-  (interactive)
-  (save-excursion
-    (when buffer
-      (set-buffer buffer))
-    (let ((min-size (font-lock-value-in-major-mode fast-lock-minimum-size))
-	  (file-timestamp (visited-file-modtime)) (saved nil))
-      (when (and fast-lock-mode
-	     ;;
-	     ;; "Only save if the buffer matches the file, the file has
-	     ;; changed, and it was changed by the current emacs session."
-	     ;;
-	     ;; Only save if the buffer is not modified,
-	     ;; (i.e., so we don't save for something not on disk)
-	     (not (buffer-modified-p))
-	     ;; and the file's timestamp is the same as the buffer's,
-	     ;; (i.e., someone else hasn't written the file in the meantime)
-	     (verify-visited-file-modtime (current-buffer))
-	     ;; and the file's timestamp is different from the cache's.
-	     ;; (i.e., a save has occurred since the cache was read)
-	     (not (equal fast-lock-cache-timestamp file-timestamp))
-	     ;;
-	     ;; Only save if user's restrictions are satisfied.
-	     (and min-size (>= (buffer-size) min-size))
-	     (or fast-lock-save-others
-		 (eq (user-uid) (file-attribute-user-id
-				 (file-attributes buffer-file-name))))
-	     ;;
-	     ;; Only save if there are `face' properties to save.
-	     (text-property-not-all (point-min) (point-max) 'face nil))
-	;;
-	;; Try each directory until we manage to save or the user quits.
-	(let ((directories fast-lock-cache-directories))
-	  (while (and directories (memq saved '(nil error)))
-	    (let* ((dir (fast-lock-cache-directory (car directories) t))
-		   (file (and dir (fast-lock-cache-name dir))))
-	      (when (and file (file-writable-p file))
-		(setq saved (fast-lock-save-cache-1 file file-timestamp)))
-	      (setq directories (cdr directories)))))))))
-
-;;;###autoload
-(defun turn-on-fast-lock ()
-  "Unconditionally turn on Fast Lock mode."
-  (fast-lock-mode t))
-
-;;; API Functions:
-
-(defun fast-lock-after-fontify-buffer ()
-  ;; Delete the Font Lock cache file used to restore fontification, if any.
-  (when fast-lock-cache-filename
-    (if (file-writable-p fast-lock-cache-filename)
-	(delete-file fast-lock-cache-filename)
-      (message "File %s font lock cache cannot be deleted" (buffer-name))))
-  ;; Flag so that a cache will be saved later even if the file is never saved.
-  (setq fast-lock-cache-timestamp nil))
-
-(defalias 'fast-lock-after-unfontify-buffer #'ignore)
-
-;; Miscellaneous Functions:
-
-(defun fast-lock-save-cache-after-save-file ()
-  ;; Do `fast-lock-save-cache' if `save-buffer' is on `fast-lock-save-events'.
-  (when (memq 'save-buffer fast-lock-save-events)
-    (fast-lock-save-cache)))
-
-(defun fast-lock-save-cache-before-kill-buffer ()
-  ;; Do `fast-lock-save-cache' if `kill-buffer' is on `fast-lock-save-events'.
-  (when (memq 'kill-buffer fast-lock-save-events)
-    (fast-lock-save-cache)))
-
-(defun fast-lock-save-caches-before-kill-emacs ()
-  ;; Do `fast-lock-save-cache's if `kill-emacs' is on `fast-lock-save-events'.
-  (when (memq 'kill-emacs fast-lock-save-events)
-    (mapcar #'fast-lock-save-cache (buffer-list))))
-
-(defun fast-lock-cache-directory (directory create)
-  "Return usable directory based on DIRECTORY.
-Returns nil if the directory does not exist, or, if CREATE non-nil, cannot be
-created.  DIRECTORY may be a string or a cons pair of the form (REGEXP . DIR).
-See `fast-lock-cache-directories'."
-  (let ((dir
-	 (cond ((not buffer-file-name)
-		;; Should never be nil, but `crypt++' screws it up.
-		nil)
-	       ((stringp directory)
-		;; Just a directory.
-		directory)
-	       (t
-		;; A directory if the file name matches the regexp.
-		(let ((bufile (expand-file-name buffer-file-truename))
-		      (case-fold-search nil))
-		  (when (save-match-data (string-match (car directory) bufile))
-		    (cdr directory)))))))
-    (cond ((not dir)
-	   nil)
-	  ((file-accessible-directory-p dir)
-	   dir)
-	  (create
-	   (condition-case nil
-	       (progn (make-directory dir t) dir)
-	     (error nil))))))
-
-;; If you are wondering why we only hash if the directory is not ".", rather
-;; than if `file-name-absolute-p', it is because if we just appended ".flc" for
-;; relative cache directories (that are not ".") then it is possible that more
-;; than one file would have the same cache name in that directory, if the luser
-;; made a link from one relative cache directory to another.  (Phew!)
-(defun fast-lock-cache-name (directory)
-  "Return full cache file name using caching DIRECTORY.
-If DIRECTORY is `.', the file name is the buffer file name appended with `.flc'.
-Otherwise, the file name is constructed from DIRECTORY and the buffer's true
-abbreviated file name, with all `/' characters in the name replaced with `#'
-characters, and appended with `.flc'.
-
-If the same file has different cache file names when edited on different
-machines, e.g., on one machine the cache file name has the prefix `#home',
-perhaps due to automount, try putting in your `~/.emacs' something like:
-
- (setq directory-abbrev-alist (cons \\='(\"^/home/\" . \"/\") directory-abbrev-alist))
-
-Emacs automagically removes the common `/tmp_mnt' automount prefix by default.
-
-See `fast-lock-cache-directory'."
-  (if (string-equal directory ".")
-      (concat buffer-file-name ".flc")
-    (let* ((bufile (expand-file-name buffer-file-truename))
-	   (chars-alist
-	    (if (memq system-type '(windows-nt cygwin))
-		'((?/ . (?#)) (?# . (?# ?#)) (?: . (?\;)) (?\; . (?\; ?\;)))
-	      '((?/ . (?#)) (?# . (?# ?#)))))
-	   (mapchars
-	    (function (lambda (c) (or (cdr (assq c chars-alist)) (list c))))))
-      (concat
-       (file-name-as-directory (expand-file-name directory))
-       (mapconcat #'char-to-string (apply #'append (mapcar mapchars bufile)) "")
-       ".flc"))))
-
-;; Font Lock Cache Processing Functions:
-
-;; The version 3 format of the cache is:
-;;
-;; (fast-lock-cache-data VERSION TIMESTAMP
-;;  font-lock-syntactic-keywords SYNTACTIC-PROPERTIES
-;;  font-lock-keywords FACE-PROPERTIES)
-
-(defun fast-lock-save-cache-1 (file timestamp)
-  ;; Save the FILE with the TIMESTAMP plus fontification data.
-  ;; Returns non-nil if a save was attempted to a writable cache file.
-  (let ((tpbuf (generate-new-buffer " *fast-lock*"))
-	(verbose (if (numberp fast-lock-verbose)
-		     (> (buffer-size) fast-lock-verbose)
-		   fast-lock-verbose))
-	(saved t))
-    (with-temp-message
-	(when verbose
-	  (format "Saving %s font lock cache..." (buffer-name)))
-      (condition-case nil
-	  (save-excursion
-	    (print (list 'fast-lock-cache-data 3
-			 (list 'quote timestamp)
-			 (list 'quote font-lock-syntactic-keywords)
-			 (list 'quote (fast-lock-get-syntactic-properties))
-			 (list 'quote font-lock-keywords)
-			 (list 'quote (fast-lock-get-face-properties)))
-		   tpbuf)
-	    (set-buffer tpbuf)
-	    (write-region (point-min) (point-max) file nil 'quietly)
-	    (setq fast-lock-cache-timestamp timestamp
-		  fast-lock-cache-filename file))
-	(error (setq saved 'error)) (quit (setq saved 'quit)))
-      (kill-buffer tpbuf))
-    (cond ((eq saved 'quit)
-	   (message "Saving %s font lock cache...quit" (buffer-name)))
-	  ((eq saved 'error)
-	   (message "Saving %s font lock cache...failed" (buffer-name))))
-    ;; We return non-nil regardless of whether a failure occurred.
-    saved))
-
-(defun fast-lock-cache-data (version timestamp
-			     syntactic-keywords syntactic-properties
-			     keywords face-properties
-			     &rest _ignored)
-  ;; Find value of syntactic keywords in case it is a symbol.
-  (setq font-lock-syntactic-keywords (font-lock-eval-keywords
-				      font-lock-syntactic-keywords))
-  ;; Compile all keywords in case some are and some aren't.
-  (when font-lock-syntactic-keywords
-    (setq font-lock-syntactic-keywords (font-lock-compile-keywords
-					font-lock-syntactic-keywords t)))
-  (when syntactic-keywords
-    (setq syntactic-keywords (font-lock-compile-keywords syntactic-keywords t)))
-  (setq font-lock-keywords (font-lock-compile-keywords font-lock-keywords)
-	keywords (font-lock-compile-keywords keywords))
-  ;; Use the Font Lock cache SYNTACTIC-PROPERTIES and FACE-PROPERTIES if we're
-  ;; using cache VERSION format 3, the current buffer's file timestamp matches
-  ;; the TIMESTAMP, the current buffer's `font-lock-syntactic-keywords' are the
-  ;; same as SYNTACTIC-KEYWORDS, and the current buffer's `font-lock-keywords'
-  ;; are the same as KEYWORDS.
-  (let ((buf-timestamp (visited-file-modtime))
-	(verbose (if (numberp fast-lock-verbose)
-		     (> (buffer-size) fast-lock-verbose)
-		   fast-lock-verbose))
-	(loaded t))
-    (if (or (/= version 3)
-	    (buffer-modified-p)
-	    (not (equal timestamp buf-timestamp))
-	    (not (equal syntactic-keywords font-lock-syntactic-keywords))
-	    (not (equal keywords font-lock-keywords)))
-	(setq loaded nil)
-      (with-temp-message
-	  (when verbose
-	    (format "Loading %s font lock cache..." (buffer-name)))
-	(condition-case nil
-	    (fast-lock-add-properties syntactic-properties face-properties)
-	  (error (setq loaded 'error)) (quit (setq loaded 'quit))))
-      (cond ((eq loaded 'quit)
-	     (message "Loading %s font lock cache...quit" (buffer-name)))
-	    ((eq loaded 'error)
-	     (message "Loading %s font lock cache...failed" (buffer-name)))))
-    (setq font-lock-fontified (eq loaded t)
-	  fast-lock-cache-timestamp (and (eq loaded t) timestamp))))
-
-;; Text Properties Processing Functions:
-
-;; This is fast, but fails if adjacent characters have different `face' text
-;; properties.  Maybe that's why I dropped it in the first place?
-;(defun fast-lock-get-face-properties ()
-;  "Return a list of `face' text properties in the current buffer.
-;Each element of the list is of the form (VALUE START1 END1 START2 END2 ...)
-;where VALUE is a `face' property value and STARTx and ENDx are positions."
-;  (save-restriction
-;    (widen)
-;    (let ((start (text-property-not-all (point-min) (point-max) 'face nil))
-;	  (limit (point-max)) end properties value cell)
-;      (while start
-;	(setq end (next-single-property-change start 'face nil limit)
-;	      value (get-text-property start 'face))
-;	;; Make, or add to existing, list of regions with same `face'.
-;	(if (setq cell (assq value properties))
-;	    (setcdr cell (cons start (cons end (cdr cell))))
-;	  (setq properties (cons (list value start end) properties)))
-;	(setq start (next-single-property-change end 'face)))
-;      properties)))
-
-;; This is slow, but copes if adjacent characters have different `face' text
-;; properties, but fails if they are lists.
-;(defun fast-lock-get-face-properties ()
-;  "Return a list of `face' text properties in the current buffer.
-;Each element of the list is of the form (VALUE START1 END1 START2 END2 ...)
-;where VALUE is a `face' property value and STARTx and ENDx are positions.
-;Only those `face' VALUEs in `fast-lock-save-faces' are returned."
-;  (save-restriction
-;    (widen)
-;    (let ((faces (or fast-lock-save-faces (face-list))) (limit (point-max))
-;	  properties regions face start end)
-;      (while faces
-;	(setq face (car faces) faces (cdr faces) regions () end (point-min))
-;	;; Make a list of start/end regions with `face' property face.
-;	(while (setq start (text-property-any end limit 'face face))
-;	  (setq end (or (text-property-not-all start limit 'face face) limit)
-;		regions (cons start (cons end regions))))
-;	;; Add `face' face's regions, if any, to properties.
-;	(when regions
-;	  (push (cons face regions) properties)))
-;      properties)))
-
-(defun fast-lock-get-face-properties ()
-  "Return a list of `face' text properties in the current buffer.
-Each element of the list is of the form (VALUE START1 END1 START2 END2 ...)
-where VALUE is a `face' property value and STARTx and ENDx are positions."
-  (save-restriction
-    (widen)
-    (let ((start (text-property-not-all (point-min) (point-max) 'face nil))
-	  end properties value cell)
-      (while start
-	(setq end (next-single-property-change start 'face nil (point-max))
-	      value (get-text-property start 'face))
-	;; Make, or add to existing, list of regions with same `face'.
-	(cond ((setq cell (assoc value properties))
-	       (setcdr cell (cons start (cons end (cdr cell)))))
-	      ((fast-lock-save-facep value)
-	       (push (list value start end) properties)))
-	(setq start (text-property-not-all end (point-max) 'face nil)))
-      properties)))
-
-(defun fast-lock-get-syntactic-properties ()
-  "Return a list of `syntax-table' text properties in the current buffer.
-See `fast-lock-get-face-properties'."
-  (save-restriction
-    (widen)
-    (let ((start (text-property-not-all (point-min) (point-max) 'syntax-table
-					nil))
-	  end properties value cell)
-      (while start
-	(setq end (next-single-property-change start 'syntax-table nil
-					       (point-max))
-	      value (get-text-property start 'syntax-table))
-	;; Make, or add to existing, list of regions with same `syntax-table'.
-	(if (setq cell (assoc value properties))
-	    (setcdr cell (cons start (cons end (cdr cell))))
-	  (push (list value start end) properties))
-	(setq start (text-property-not-all end (point-max) 'syntax-table nil)))
-      properties)))
-
-(defun fast-lock-add-properties (syntactic-properties face-properties)
-  "Add `syntax-table' and `face' text properties to the current buffer.
-Any existing `syntax-table' and `face' text properties are removed first.
-See `fast-lock-get-face-properties'."
-  (with-silent-modifications
-    (let ((inhibit-point-motion-hooks t))
-      (save-restriction
-        (widen)
-        (font-lock-unfontify-region (point-min) (point-max))
-        ;;
-        ;; Set the `syntax-table' property for each start/end region.
-        (pcase-dolist (`(,plist . ,regions) syntactic-properties)
-	  (while regions
-	    (add-text-properties (nth 0 regions) (nth 1 regions) plist)
-	    (setq regions (nthcdr 2 regions))))
-	;;
-	;; Set the `face' property for each start/end region.
-        (pcase-dolist (`(,plist . ,regions) face-properties)
-	  (while regions
-	    (add-text-properties (nth 0 regions) (nth 1 regions) plist)
-	    (setq regions (nthcdr 2 regions))))))))
-
-
-;; Install ourselves:
-
-(add-hook 'after-save-hook #'fast-lock-save-cache-after-save-file)
-(add-hook 'kill-buffer-hook #'fast-lock-save-cache-before-kill-buffer)
-(unless noninteractive
-  (add-hook 'kill-emacs-hook #'fast-lock-save-caches-before-kill-emacs))
-
-;;;###autoload
-(when (fboundp 'add-minor-mode)
-  (defvar fast-lock-mode nil)
-  (add-minor-mode 'fast-lock-mode nil))
-;;;###dont-autoload
-(unless (assq 'fast-lock-mode minor-mode-alist)
-  (setq minor-mode-alist (append minor-mode-alist '((fast-lock-mode nil)))))
-
-(provide 'fast-lock)
-
-;;; fast-lock.el ends here
-
-;; Local Variables:
-;; byte-compile-warnings: (not obsolete)
-;; End:
diff --git a/lisp/obsolete/lazy-lock.el b/lisp/obsolete/lazy-lock.el
deleted file mode 100644
index 5c35cb3212..0000000000
--- a/lisp/obsolete/lazy-lock.el
+++ /dev/null
@@ -1,1025 +0,0 @@
-;;; lazy-lock.el --- lazy demand-driven fontification for fast Font Lock mode  -*- lexical-binding: t; -*-
-
-;; Copyright (C) 1994-1998, 2001-2022 Free Software Foundation, Inc.
-
-;; Author: Simon Marshall <[email-masked]>
-;; Maintainer: [email-masked]
-;; Keywords: faces files
-;; Version: 2.11
-;; Obsolete-since: 22.1
-
-;; 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 3 of the License, 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.  If not, see <https://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;; Purpose:
-;;
-;; Lazy Lock mode is a Font Lock support mode.
-;; It makes visiting buffers in Font Lock mode faster by making fontification
-;; be demand-driven, deferred and stealthy, so that fontification only occurs
-;; when, and where, necessary.
-;;
-;; See caveats and feedback below.
-;; See also the fast-lock package.  (But don't use them at the same time!)
-
-;; Installation:
-;;
-;; Put in your ~/.emacs:
-;;
-;; (setq font-lock-support-mode 'lazy-lock-mode)
-;;
-;; Start up a new Emacs and use font-lock as usual (except that you can use the
-;; so-called "gaudier" fontification regexps on big files without frustration).
-;;
-;; In a buffer (which has `font-lock-mode' enabled) which is at least
-;; `lazy-lock-minimum-size' characters long, buffer fontification will not
-;; occur and only the visible portion of the buffer will be fontified.  Motion
-;; around the buffer will fontify those visible portions not previously
-;; fontified.  If stealth fontification is enabled, buffer fontification will
-;; occur in invisible parts of the buffer after `lazy-lock-stealth-time'
-;; seconds of idle time.  If on-the-fly fontification is deferred, on-the-fly
-;; fontification will occur after `lazy-lock-defer-time' seconds of idle time.
-
-;; User-visible differences with version 1:
-;;
-;; - Version 2 can defer on-the-fly fontification.  Therefore you need not, and
-;; should not, use defer-lock.el with this version of lazy-lock.el.
-;;
-;; A number of variables have changed meaning:
-;;
-;; - A value of nil for the variable `lazy-lock-minimum-size' means never turn
-;; on demand-driven fontification.  In version 1 this meant always turn on
-;; demand-driven fontification.  If you really want demand-driven fontification
-;; regardless of buffer size, set this variable to 0.
-;;
-;; - The variable `lazy-lock-stealth-lines' cannot have a nil value.  In
-;; version 1 this meant use `window-height' as the maximum number of lines to
-;; fontify as a stealth chunk.  This makes no sense; stealth fontification is
-;; of a buffer, not a window.
-
-;; Implementation differences with version 1:
-;;
-;; - Version 1 of lazy-lock.el is a bit of a hack.  Version 1 demand-driven
-;; fontification, the core feature of lazy-lock.el, is implemented by placing a
-;; function on `post-command-hook'.  This function fontifies where necessary,
-;; i.e., where a window scroll has occurred.  However, there are a number of
-;; problems with using `post-command-hook':
-;;
-;; (a) As the name suggests, `post-command-hook' is run after every command,
-;;     i.e., frequently and regardless of whether scrolling has occurred.
-;; (b) Scrolling can occur during a command, when `post-command-hook' is not
-;;     run, i.e., it is not necessarily run after scrolling has occurred.
-;; (c) When `post-command-hook' is run, there is nothing to suggest where
-;;     scrolling might have occurred, i.e., which windows have scrolled.
-;;
-;; Thus lazy-lock.el's function is called almost as often as possible, usually
-;; when it need not be called, yet it is not always called when it is needed.
-;; Also, lazy-lock.el's function must check each window to see if a scroll has
-;; occurred there.  Worse still, lazy-lock.el's function must fontify a region
-;; twice as large as necessary to make sure the window is completely fontified.
-;; Basically, `post-command-hook' is completely inappropriate for lazy-lock.el.
-;;
-;; Ideally, we want to attach lazy-lock.el's function to a hook that is run
-;; only when scrolling occurs, e.g., `window-start' has changed, and tells us
-;; as much information as we need, i.e., the window and its new buffer region.
-;; Richard Stallman implemented a `window-scroll-functions' for Emacs 19.30.
-;; Functions on it are run when `window-start' has changed, and are supplied
-;; with the window and the window's new `window-start' position.  (It would be
-;; better if it also supplied the window's new `window-end' position, but that
-;; is calculated as part of the redisplay process, and the functions on
-;; `window-scroll-functions' are run before redisplay has finished.)  Thus, the
-;; hook deals with the above problems (a), (b) and (c).
-;;
-;; If only life was that easy.  Version 2 demand-driven fontification is mostly
-;; implemented by placing a function on `window-scroll-functions'.  However,
-;; not all scrolling occurs when `window-start' has changed.  A change in
-;; window size, e.g., via C-x 1, or a significant deletion, e.g., of a number
-;; of lines, causes text previously invisible (i.e., after `window-end') to
-;; become visible without changing `window-start'.  Arguably, these events are
-;; not scrolling events, but fontification must occur for lazy-lock.el to work.
-;; Hooks `window-size-change-functions' and `redisplay-end-trigger-functions'
-;; were added for these circumstances.
-;;
-;; (Ben Wing thinks these hooks are "horribly horribly kludgy", and implemented
-;; a `pre-idle-hook', a `mother-of-all-post-command-hooks', for XEmacs 19.14.
-;; He then hacked up a version 1 lazy-lock.el to use `pre-idle-hook' rather
-;; than `post-command-hook'.  Whereas functions on `post-command-hook' are
-;; called almost as often as possible, functions on `pre-idle-hook' really are
-;; called as often as possible, even when the mouse moves and, on some systems,
-;; while XEmacs is idle.  Thus, the hook deals with the above problem (b), but
-;; unfortunately it makes (a) worse and does not address (c) at all.
-;;
-;; I freely admit that `redisplay-end-trigger-functions' and, to a much lesser
-;; extent, `window-size-change-functions' are not pretty.  However, I feel that
-;; a `window-scroll-functions' feature is cleaner than a `pre-idle-hook', and
-;; the result is faster and smaller, less intrusive and more targeted, code.
-;; Since `pre-idle-hook' is pretty much like `post-command-hook', there is no
-;; point in making this version of lazy-lock.el work with it.  Anyway, that's
-;; Lit 30 of my humble opinion.
-;;
-;; - Version 1 stealth fontification is also implemented by placing a function
-;; on `post-command-hook'.  This function waits for a given amount of time,
-;; and, if Emacs remains idle, fontifies where necessary.  Again, there are a
-;; number of problems with using `post-command-hook':
-;;
-;; (a) Functions on `post-command-hook' are run sequentially, so this function
-;;     can interfere with other functions on the hook, and vice versa.
-;; (b) This function waits for a given amount of time, so it can interfere with
-;;     various features that are dealt with by Emacs after a command, e.g.,
-;;     region highlighting, asynchronous updating and keystroke echoing.
-;; (c) Fontification may be required during a command, when `post-command-hook'
-;;     is not run.  (Version 2 deferred fontification only.)
-;;
-;; Again, `post-command-hook' is completely inappropriate for lazy-lock.el.
-;; Richard Stallman and Morten Welinder implemented internal Timers and Idle
-;; Timers for Emacs 19.31.  Functions can be run independently at given times
-;; or after given amounts of idle time.  Thus, the feature deals with the above
-;; problems (a), (b) and (c).  Version 2 deferral and stealth are implemented
-;; by functions on Idle Timers.  (A function on XEmacs' `pre-idle-hook' is
-;; similar to an Emacs Idle Timer function with a fixed zero second timeout.)
-
-;; - Version 1 has the following problems (relative to version 2):
-;;
-;; (a) It is slow when it does its job.
-;; (b) It does not always do its job when it should.
-;; (c) It slows all interaction (when it doesn't need to do its job).
-;; (d) It interferes with other package functions on `post-command-hook'.
-;; (e) It interferes with Emacs things within the read-eval loop.
-;;
-;; Ben's hacked-up lazy-lock.el 1.14 almost solved (b) but made (c) worse.
-;;
-;; - Version 2 has the following additional features (relative to version 1):
-;;
-;; (a) It can defer fontification (both on-the-fly and on-scrolling).
-;; (b) It can fontify contextually (syntactically true on-the-fly).
-
-;; Caveats:
-;;
-;; Lazy Lock mode does not work efficiently with Outline mode.
-;; This is because when in Outline mode, although text may be not visible to
-;; you in the window, the text is visible to Emacs Lisp code (not surprisingly)
-;; and Lazy Lock fontifies it mercilessly.  Maybe it will be fixed one day.
-;;
-;; Because buffer text is not necessarily fontified, other packages that expect
-;; buffer text to be fontified in Font Lock mode either might not work as
-;; expected, or might not display buffer text as expected.  An example of the
-;; latter is `occur', which copies lines of buffer text into another buffer.
-;;
-;; In Emacs 19.30, Lazy Lock mode does not ensure that an existing buffer is
-;; fontified if it is made visible via a minibuffer-less command that replaces
-;; an existing window's buffer (e.g., via the Buffers menu).  Upgrade!
-;;
-;; In Emacs 19.30, Lazy Lock mode does not work well with Transient Mark mode
-;; or modes based on Comint mode (e.g., Shell mode), and also interferes with
-;; the echoing of keystrokes in the minibuffer.  This is because of the way
-;; deferral and stealth have to be implemented for Emacs 19.30.  Upgrade!
-;;
-;; Currently XEmacs does not have the features to support this version of
-;; lazy-lock.el.  Maybe it will one day.
-
-;; History:
-;;
-;; 1.15--2.00:
-;; - Rewrite for Emacs 19.30 and the features rms added to support lazy-lock.el
-;;   so that it could work correctly and efficiently.
-;; - Many thanks to those who reported bugs, fixed bugs, made suggestions or
-;;   otherwise contributed in the version 1 cycle; Jari Aalto, Kevin Broadey,
-;;   Ulrik Dickow, Bill Dubuque, Bob Glickstein, Boris Goldowsky,
-;;   Jonas Jarnestrom, David Karr, Michael Kifer, Erik Naggum, Rick Sladkey,
-;;   Jim Thompson, Ben Wing, Ilya Zakharevich, and Richard Stallman.
-;; 2.00--2.01:
-;; - Made `lazy-lock-fontify-after-command' always `sit-for' and so redisplay
-;; - Use `buffer-name' not `buffer-live-p' (Bill Dubuque hint)
-;; - Made `lazy-lock-install' do `add-to-list' not `setq' of `current-buffer'
-;; - Made `lazy-lock-fontify-after-install' loop over buffer list
-;; - Made `lazy-lock-arrange-before-change' to arrange `window-end' triggering
-;; - Made `lazy-lock-let-buffer-state' wrap both `befter-change-functions'
-;; - Made `lazy-lock-fontify-region' do `condition-case' (Hyman Rosen report)
-;; 2.01--2.02:
-;; - Use `buffer-live-p' as `buffer-name' can barf (Richard Stanton report)
-;; - Made `lazy-lock-install' set `font-lock-fontified' (Kevin Davidson report)
-;; - Made `lazy-lock-install' add hooks only if needed
-;; - Made `lazy-lock-unstall' add `font-lock-after-change-function' if needed
-;; 2.02--2.03:
-;; - Made `lazy-lock-fontify-region' do `condition-case' for `quit' too
-;; - Made `lazy-lock-mode' respect the value of `font-lock-inhibit-thing-lock'
-;; - Added `lazy-lock-after-unfontify-buffer'
-;; - Removed `lazy-lock-fontify-after-install' hack
-;; - Made `lazy-lock-fontify-after-scroll' not `set-buffer' to `window-buffer'
-;; - Made `lazy-lock-fontify-after-trigger' not `set-buffer' to `window-buffer'
-;; - Made `lazy-lock-fontify-after-idle' be interruptible (Scott Burson hint)
-;; 2.03--2.04:
-;; - Rewrite for Emacs 19.31 idle timers
-;; - Renamed `buffer-windows' to `get-buffer-window-list'
-;; - Removed `buffer-live-p'
-;; - Made `lazy-lock-defer-after-change' always save `current-buffer'
-;; - Made `lazy-lock-fontify-after-defer' just process buffers
-;; - Made `lazy-lock-install-hooks' add hooks correctly (Kevin Broadey report)
-;; - Made `lazy-lock-install' cope if `lazy-lock-defer-time' is a list
-;; 2.04--2.05:
-;; - Rewrite for Common Lisp macros
-;; - Added `do-while' macro
-;; - Renamed `lazy-lock-let-buffer-state' macro to `save-buffer-state'
-;; - Returned `lazy-lock-fontify-after-install' hack (Darren Hall hint)
-;; - Added `lazy-lock-defer-on-scrolling' functionality (Scott Byer hint)
-;; - Made `lazy-lock-mode' wrap `font-lock-support-mode'
-;; 2.05--2.06:
-;; - Made `lazy-lock-fontify-after-defer' swap correctly (Scott Byer report)
-;; 2.06--2.07:
-;; - Added `lazy-lock-stealth-load' functionality (Rob Hooft hint)
-;; - Made `lazy-lock-unstall' call `lazy-lock-fontify-region' if needed
-;; - Made `lazy-lock-mode' call `lazy-lock-unstall' only if needed
-;; - Made `lazy-lock-defer-after-scroll' do `set-window-redisplay-end-trigger'
-;; - Added `lazy-lock-defer-contextually' functionality
-;; - Added `lazy-lock-defer-on-the-fly' from `lazy-lock-defer-time'
-;; - Renamed `lazy-lock-defer-driven' to `lazy-lock-defer-on-scrolling'
-;; - Removed `lazy-lock-submit-bug-report' and bade farewell
-;; 2.07--2.08:
-;; - Made `lazy-lock-fontify-conservatively' fontify around `window-point'
-;; - Made `save-buffer-state' wrap `inhibit-point-motion-hooks'
-;; - Added Custom support
-;; 2.08--2.09:
-;; - Removed `byte-*' variables from `eval-when-compile' (Erik Naggum hint)
-;; - Made various wrapping `inhibit-point-motion-hooks' (Vinicius Latorre hint)
-;; - Made `lazy-lock-fontify-after-idle' wrap `minibuffer-auto-raise'
-;; - Made `lazy-lock-fontify-after-defer' paranoid about deferred buffers
-;; 2.09--2.10:
-;; - Use `window-end' UPDATE arg for Emacs 20.4 and later.
-;; - Made deferral `widen' before unfontifying (Dan Nicolaescu report)
-;; - Use `lazy-lock-fontify-after-visage' for hideshow.el (Dan Nicolaescu hint)
-;; - Use `other' widget where possible (Andreas Schwab fix)
-;; 2.10--2.11:
-;; - Used `with-temp-message' where possible to make messages temporary.
-
-;;; Code:
-
-(require 'font-lock)
-(eval-when-compile (require 'cl-lib))
-
-(eval-when-compile
- ;;
- ;; We use this for clarity and speed.  Naughty but nice.
- (defmacro do-while (test &rest body)
-   "(do-while TEST BODY...): eval BODY... and repeat if TEST yields non-nil.
-The order of execution is thus BODY, TEST, BODY, TEST and so on
-until TEST returns nil."
-   (declare (indent 1) (debug t))
-   `(while (progn ,@body ,test))))
-
-(defgroup lazy-lock nil
-  "Font Lock support mode to fontify lazily."
-  :group 'font-lock)
-
-(defvar lazy-lock-mode nil)			; Whether we are turned on.
-(defvar lazy-lock-buffers nil)			; For deferral.
-(defvar lazy-lock-timers (cons nil nil))	; For deferral and stealth.
-
-;; User Variables:
-
-(defcustom lazy-lock-minimum-size 25600
-  "Minimum size of a buffer for demand-driven fontification.
-On-demand fontification occurs if the buffer size is greater than this value.
-If nil, means demand-driven fontification is never performed.
-If a list, each element should be a cons pair of the form (MAJOR-MODE . SIZE),
-where MAJOR-MODE is a symbol or t (meaning the default).  For example:
- ((c-mode . 25600) (c++-mode . 25600) (rmail-mode . 1048576))
-means that the minimum size is 25K for buffers in C or C++ modes, one megabyte
-for buffers in Rmail mode, and size is irrelevant otherwise.
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "none" nil)
-		 (integer :tag "size")
-		 (repeat :menu-tag "mode specific" :tag "mode specific"
-			 :value ((t . nil))
-			 (cons :tag "Instance"
-			       (radio :tag "Mode"
-				      (const :tag "all" t)
-				      (symbol :tag "name"))
-			       (radio :tag "Size"
-				      (const :tag "none" nil)
-				      (integer :tag "size"))))))
-
-(defcustom lazy-lock-defer-on-the-fly t
-  "If non-nil, means fontification after a change should be deferred.
-If nil, means on-the-fly fontification is performed.  This means when changes
-occur in the buffer, those areas are immediately fontified.
-If a list, it should be a list of `major-mode' symbol names for which deferred
-fontification should occur.  The sense of the list is negated if it begins with
-`not'.  For example:
- (c-mode c++-mode)
-means that on-the-fly fontification is deferred for buffers in C and C++ modes
-only, and deferral does not occur otherwise.
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "never" nil)
-		 (const :tag "always" t)
-		 (set :menu-tag "mode specific" :tag "modes"
-		      :value (not)
-		      (const :tag "Except" not)
-		      (repeat :inline t (symbol :tag "mode")))))
-
-(defcustom lazy-lock-defer-on-scrolling nil
-  "If non-nil, means fontification after a scroll should be deferred.
-If nil, means demand-driven fontification is performed.  This means when
-scrolling into unfontified areas of the buffer, those areas are immediately
-fontified.  Thus scrolling never presents unfontified areas.  However, since
-fontification occurs during scrolling, scrolling may be slow.
-If t, means defer-driven fontification is performed.  This means fontification
-of those areas is deferred.  Thus scrolling may present momentarily unfontified
-areas.  However, since fontification does not occur during scrolling, scrolling
-will be faster than demand-driven fontification.
-If any other value, e.g., `eventually', means demand-driven fontification is
-performed until the buffer is fontified, then buffer fontification becomes
-defer-driven.  Thus scrolling never presents unfontified areas until the buffer
-is first fontified, after which subsequent scrolling may present future buffer
-insertions momentarily unfontified.  However, since fontification does not
-occur during scrolling after the buffer is first fontified, scrolling will
-become faster.  (But, since contextual changes continually occur, such a value
-makes little sense if `lazy-lock-defer-contextually' is non-nil.)
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "never" nil)
-		 (const :tag "always" t)
-		 (other :tag "eventually" eventually)))
-
-(defcustom lazy-lock-defer-contextually 'syntax-driven
-  "If non-nil, means deferred fontification should be syntactically true.
-If nil, means deferred fontification occurs only on those lines modified.  This
-means where modification on a line causes syntactic change on subsequent lines,
-those subsequent lines are not refontified to reflect their new context.
-If t, means deferred fontification occurs on those lines modified and all
-subsequent lines.  This means those subsequent lines are refontified to reflect
-their new syntactic context, either immediately or when scrolling into them.
-If any other value, e.g., `syntax-driven', means deferred syntactically true
-fontification occurs only if syntactic fontification is performed using the
-buffer mode's syntax table, i.e., only if `font-lock-keywords-only' is nil.
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "never" nil)
-		 (const :tag "always" t)
-		 (other :tag "syntax-driven" syntax-driven)))
-
-(defcustom lazy-lock-defer-time 0.25
-  "Time in seconds to delay before beginning deferred fontification.
-Deferred fontification occurs if there is no input within this time.
-If nil, means fontification is never deferred, regardless of the values of the
-variables `lazy-lock-defer-on-the-fly', `lazy-lock-defer-on-scrolling' and
-`lazy-lock-defer-contextually'.
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "never" nil)
-		 (number :tag "seconds")))
-
-(defcustom lazy-lock-stealth-time 30
-  "Time in seconds to delay before beginning stealth fontification.
-Stealth fontification occurs if there is no input within this time.
-If nil, means stealth fontification is never performed.
-
-The value of this variable is used when Lazy Lock mode is turned on."
-  :type '(choice (const :tag "never" nil)
-		 (number :tag "seconds")))
-
-(defcustom lazy-lock-stealth-lines (if font-lock-maximum-decoration 100 250)
-  "Maximum size of a chunk of stealth fontification.
-Each iteration of stealth fontification can fontify this number of lines.
-To speed up input response during stealth fontification, at the cost of stealth
-taking longer to fontify, you could reduce the value of this variable."
-  :type '(integer :tag "lines"))
-
-(defcustom lazy-lock-stealth-load
-  (if (condition-case nil (load-average) (error)) 200)
-  "Load in percentage above which stealth fontification is suspended.
-Stealth fontification pauses when the system short-term load average (as
-returned by the function `load-average' if supported) goes above this level,
-thus reducing the demand that stealth fontification makes on the system.
-If nil, means stealth fontification is never suspended.
-To reduce machine load during stealth fontification, at the cost of stealth
-taking longer to fontify, you could reduce the value of this variable.
-See also `lazy-lock-stealth-nice'."
-  :type (if (condition-case nil (load-average) (error))
-	    '(choice (const :tag "never" nil)
-		     (integer :tag "load"))
-	  '(const :format "%t: unsupported\n" nil)))
-
-(defcustom lazy-lock-stealth-nice 0.125
-  "Time in seconds to pause between chunks of stealth fontification.
-Each iteration of stealth fontification is separated by this amount of time,
-thus reducing the demand that stealth fontification makes on the system.
-If nil, means stealth fontification is never paused.
-To reduce machine load during stealth fontification, at the cost of stealth
-taking longer to fontify, you could increase the value of this variable.
-See also `lazy-lock-stealth-load'."
-  :type '(choice (const :tag "never" nil)
-		 (number :tag "seconds")))
-
-(defcustom lazy-lock-stealth-verbose
-  (and (not lazy-lock-defer-contextually) (not (null font-lock-verbose)))
-  "If non-nil, means stealth fontification should show status messages."
-  :type 'boolean)
-
-;; User Functions:
-
-;;;###autoload
-(defun lazy-lock-mode (&optional arg)
-  "Toggle Lazy Lock mode.
-With arg, turn Lazy Lock mode on if and only if arg is positive.  Enable it
-automatically in your `~/.emacs' by:
-
- (setq font-lock-support-mode \\='lazy-lock-mode)
-
-For a newer font-lock support mode with similar functionality, see
-`jit-lock-mode'.  Eventually, Lazy Lock mode will be deprecated in
-JIT Lock's favor.
-
-When Lazy Lock mode is enabled, fontification can be lazy in a number of ways:
-
-- Demand-driven buffer fontification if `lazy-lock-minimum-size' is non-nil.
-  This means initial fontification does not occur if the buffer is greater than
-  `lazy-lock-minimum-size' characters in length.  Instead, fontification occurs
-  when necessary, such as when scrolling through the buffer would otherwise
-  reveal unfontified areas.  This is useful if buffer fontification is too slow
-  for large buffers.
-
-- Deferred scroll fontification if `lazy-lock-defer-on-scrolling' is non-nil.
-  This means demand-driven fontification does not occur as you scroll.
-  Instead, fontification is deferred until after `lazy-lock-defer-time' seconds
-  of Emacs idle time, while Emacs remains idle.  This is useful if
-  fontification is too slow to keep up with scrolling.
-
-- Deferred on-the-fly fontification if `lazy-lock-defer-on-the-fly' is non-nil.
-  This means on-the-fly fontification does not occur as you type.  Instead,
-  fontification is deferred until after `lazy-lock-defer-time' seconds of Emacs
-  idle time, while Emacs remains idle.  This is useful if fontification is too
-  slow to keep up with your typing.
-
-- Deferred context fontification if `lazy-lock-defer-contextually' is non-nil.
-  This means fontification updates the buffer corresponding to true syntactic
-  context, after `lazy-lock-defer-time' seconds of Emacs idle time, while Emacs
-  remains idle.  Otherwise, fontification occurs on modified lines only, and
-  subsequent lines can remain fontified corresponding to previous syntactic
-  contexts.  This is useful where strings or comments span lines.
-
-- Stealthy buffer fontification if `lazy-lock-stealth-time' is non-nil.
-  This means remaining unfontified areas of buffers are fontified if Emacs has
-  been idle for `lazy-lock-stealth-time' seconds, while Emacs remains idle.
-  This is useful if any buffer has any deferred fontification.
-
-Basic Font Lock mode on-the-fly fontification behavior fontifies modified
-lines only.  Thus, if `lazy-lock-defer-contextually' is non-nil, Lazy Lock mode
-on-the-fly fontification may fontify differently, albeit correctly.  In any
-event, to refontify some lines you can use \\[font-lock-fontify-block].
-
-Stealth fontification only occurs while the system remains unloaded.
-If the system load rises above `lazy-lock-stealth-load' percent, stealth
-fontification is suspended.  Stealth fontification intensity is controlled via
-the variable `lazy-lock-stealth-nice' and `lazy-lock-stealth-lines', and
-verbosity is controlled via the variable `lazy-lock-stealth-verbose'."
-  (interactive "P")
-  (let* ((was-on lazy-lock-mode)
-	 (now-on (unless (memq 'lazy-lock-mode font-lock-inhibit-thing-lock)
-		   (if arg (> (prefix-numeric-value arg) 0) (not was-on)))))
-    (cond ((and now-on (not font-lock-mode))
-	   ;; Turned on `lazy-lock-mode' rather than `font-lock-mode'.
-           (message "Use font-lock-support-mode rather than calling lazy-lock-mode")
-           (sit-for 2))
-	  (now-on
-	   ;; Turn ourselves on.
-	   (set (make-local-variable 'lazy-lock-mode) t)
-	   (lazy-lock-install))
-	  (was-on
-	   ;; Turn ourselves off.
-	   (set (make-local-variable 'lazy-lock-mode) nil)
-	   (lazy-lock-unstall)))))
-
-;;;###autoload
-(defun turn-on-lazy-lock ()
-  "Unconditionally turn on Lazy Lock mode."
-  (lazy-lock-mode t))
-
-(defun lazy-lock-install ()
-  (let ((min-size (font-lock-value-in-major-mode lazy-lock-minimum-size))
-	(defer-change (and lazy-lock-defer-time lazy-lock-defer-on-the-fly))
-	(defer-scroll (and lazy-lock-defer-time lazy-lock-defer-on-scrolling))
-	(defer-context (and lazy-lock-defer-time lazy-lock-defer-contextually
-			    (or (eq lazy-lock-defer-contextually t)
-				(null font-lock-keywords-only)))))
-    ;;
-    ;; Tell Font Lock whether Lazy Lock will do fontification.
-    (make-local-variable 'font-lock-fontified)
-    (setq font-lock-fontified (and min-size (>= (buffer-size) min-size)))
-    ;;
-    ;; Add the text properties and fontify.
-    (if (not font-lock-fontified)
-	(lazy-lock-after-fontify-buffer)
-      ;; Make sure we fontify in any existing windows showing the buffer.
-      (let ((windows (get-buffer-window-list (current-buffer) 'nomini t)))
-	(lazy-lock-after-unfontify-buffer)
-	(while windows
-	  (lazy-lock-fontify-conservatively (car windows))
-	  (setq windows (cdr windows)))))
-    ;;
-    ;; Add the fontification hooks.
-    (lazy-lock-install-hooks
-     font-lock-fontified
-     (cond ((eq (car-safe defer-change) 'not)
-	    (not (memq major-mode (cdr defer-change))))
-	   ((listp defer-change)
-	    (memq major-mode defer-change))
-	   (t
-	    defer-change))
-     (eq defer-scroll t)
-     defer-context)
-    ;;
-    ;; Add the fontification timers.
-    (lazy-lock-install-timers
-     (if (or defer-change defer-scroll defer-context) lazy-lock-defer-time)
-     lazy-lock-stealth-time)))
-
-(defun lazy-lock-install-hooks (fontifying
-				defer-change defer-scroll defer-context)
-  ;;
-  ;; Add hook if lazy-lock.el is fontifying on scrolling or is deferring.
-  (when (or fontifying defer-change defer-scroll defer-context)
-    (add-hook 'window-scroll-functions (if defer-scroll
-					   #'lazy-lock-defer-after-scroll
-					 #'lazy-lock-fontify-after-scroll)
-	      nil t))
-  ;;
-  ;; Add hook if lazy-lock.el is fontifying and is not deferring changes.
-  (when (and fontifying (not defer-change) (not defer-context))
-    (add-hook 'before-change-functions #'lazy-lock-arrange-before-change nil t))
-  ;;
-  ;; Replace Font Lock mode hook.
-  (remove-hook 'after-change-functions #'font-lock-after-change-function t)
-  (add-hook 'after-change-functions
-	    (cond ((and defer-change defer-context)
-		   #'lazy-lock-defer-rest-after-change)
-		  (defer-change
-		   #'lazy-lock-defer-line-after-change)
-		  (defer-context
-		   #'lazy-lock-fontify-rest-after-change)
-		  (t
-		   #'lazy-lock-fontify-line-after-change))
-	    nil t)
-  ;;
-  ;; Add package-specific hook.
-  (add-hook 'outline-view-change-hook #'lazy-lock-fontify-after-visage nil t)
-  (add-hook 'hs-hide-hook #'lazy-lock-fontify-after-visage nil t))
-
-(defun lazy-lock-install-timers (dtime stime)
-  ;; Schedule or re-schedule the deferral and stealth timers.
-  ;; The layout of `lazy-lock-timers' is:
-  ;;  ((DEFER-TIME . DEFER-TIMER) (STEALTH-TIME . STEALTH-TIMER)
-  ;; If an idle timeout has changed, cancel the existing idle timer (if there
-  ;; is one) and schedule a new one (if the new idle timeout is non-nil).
-  (unless (eq dtime (car (car lazy-lock-timers)))
-    (let ((defer (car lazy-lock-timers)))
-      (when (cdr defer)
-	(cancel-timer (cdr defer)))
-      (setcar lazy-lock-timers (cons dtime (and dtime
-	      (run-with-idle-timer dtime t #'lazy-lock-fontify-after-defer))))))
-  (unless (eq stime (car (cdr lazy-lock-timers)))
-    (let ((stealth (cdr lazy-lock-timers)))
-      (when (cdr stealth)
-	(cancel-timer (cdr stealth)))
-      (setcdr lazy-lock-timers (cons stime (and stime
-	      (run-with-idle-timer stime t #'lazy-lock-fontify-after-idle)))))))
-
-(defun lazy-lock-unstall ()
-  ;;
-  ;; If Font Lock mode is still enabled, make sure that the buffer is
-  ;; fontified, and reinstall its hook.  We must do this first.
-  (when font-lock-mode
-    (when (lazy-lock-unfontified-p)
-      (let ((verbose (if (numberp font-lock-verbose)
-			 (> (buffer-size) font-lock-verbose)
-		       font-lock-verbose)))
-	(with-temp-message
-	    (when verbose
-	      (format "Fontifying %s..." (buffer-name)))
-	  ;; Make sure we fontify etc. in the whole buffer.
-	  (save-restriction
-	    (widen)
-	    (lazy-lock-fontify-region (point-min) (point-max))))))
-    (add-hook 'after-change-functions #'font-lock-after-change-function nil t))
-  ;;
-  ;; Remove the text properties.
-  (lazy-lock-after-unfontify-buffer)
-  ;;
-  ;; Remove the fontification hooks.
-  (remove-hook 'window-scroll-functions #'lazy-lock-fontify-after-scroll t)
-  (remove-hook 'window-scroll-functions #'lazy-lock-defer-after-scroll t)
-  (remove-hook 'before-change-functions #'lazy-lock-arrange-before-change t)
-  (remove-hook 'after-change-functions #'lazy-lock-fontify-line-after-change t)
-  (remove-hook 'after-change-functions #'lazy-lock-fontify-rest-after-change t)
-  (remove-hook 'after-change-functions #'lazy-lock-defer-line-after-change t)
-  (remove-hook 'after-change-functions #'lazy-lock-defer-rest-after-change t)
-  (remove-hook 'outline-view-change-hook #'lazy-lock-fontify-after-visage t)
-  (remove-hook 'hs-hide-hook #'lazy-lock-fontify-after-visage t))
-
-;; Hook functions.
-
-;; Lazy Lock mode intervenes when (1) a previously invisible buffer region
-;; becomes visible, i.e., for demand- or defer-driven on-the-scroll
-;; fontification, (2) a buffer modification occurs, i.e., for defer-driven
-;; on-the-fly fontification, (3) Emacs becomes idle, i.e., for fontification of
-;; deferred fontification and stealth fontification, and (4) other special
-;; occasions.
-
-;; 1.  There are three ways whereby this can happen.
-;;
-;; (a) Scrolling the window, either explicitly (e.g., `scroll-up') or
-;;     implicitly (e.g., `search-forward').  Here, `window-start' changes.
-;;     Fontification occurs by adding `lazy-lock-fontify-after-scroll' (for
-;;     demand-driven fontification) or `lazy-lock-defer-after-scroll' (for
-;;     defer-driven fontification) to the hook `window-scroll-functions'.
-
-(defun lazy-lock-fontify-after-scroll (window window-start)
-  ;; Called from `window-scroll-functions'.
-  ;; Fontify WINDOW from WINDOW-START following the scroll.
-  (let ((inhibit-point-motion-hooks t))
-    (lazy-lock-fontify-region window-start (window-end window t)))
-  ;; A prior deletion that did not cause scrolling, followed by a scroll, would
-  ;; result in an unnecessary trigger after this if we did not cancel it now.
-  (set-window-redisplay-end-trigger window nil))
-
-(defun lazy-lock-defer-after-scroll (window _window-start)
-  ;; Called from `window-scroll-functions'.
-  ;; Defer fontification following the scroll.  Save the current buffer so that
-  ;; we subsequently fontify in all windows showing the buffer.
-  (unless (memq (current-buffer) lazy-lock-buffers)
-    (push (current-buffer) lazy-lock-buffers))
-  ;; A prior deletion that did not cause scrolling, followed by a scroll, would
-  ;; result in an unnecessary trigger after this if we did not cancel it now.
-  (set-window-redisplay-end-trigger window nil))
-
-;; (b) Resizing the window, either explicitly (e.g., `enlarge-window') or
-;;     implicitly (e.g., `delete-other-windows').  Here, `window-end' changes.
-;;     Fontification occurs by adding `lazy-lock-fontify-after-resize' to the
-;;     hook `window-size-change-functions'.
-
-(defun lazy-lock-fontify-after-resize (frame)
-  ;; Called from `window-size-change-functions'.
-  ;; Fontify windows in FRAME following the resize.  We cannot use
-  ;; `window-start' or `window-end' so we fontify conservatively.
-  (save-excursion
-    (save-selected-window
-      (select-frame frame)
-      (walk-windows (function (lambda (window)
-		       (set-buffer (window-buffer window))
-		       (when lazy-lock-mode
-			 (lazy-lock-fontify-conservatively window))
-		       (set-window-redisplay-end-trigger window nil)))
-		    'nomini frame))))
-
-;; (c) Deletion in the buffer.  Here, a `window-end' marker can become visible.
-;;     Fontification occurs by adding `lazy-lock-arrange-before-change' to
-;;     `before-change-functions' and `lazy-lock-fontify-after-trigger' to the
-;;     hook `redisplay-end-trigger-functions'.  Before every deletion, the
-;;     marker `window-redisplay-end-trigger' position is set to the soon-to-be
-;;     changed `window-end' position.  If the marker becomes visible,
-;;     `lazy-lock-fontify-after-trigger' gets called.  Ouch.  Note that we only
-;;     have to deal with this eventuality if there is no on-the-fly deferral.
-
-(defun lazy-lock-arrange-before-change (beg end)
-  ;; Called from `before-change-functions'.
-  ;; Arrange that if text becomes visible it will be fontified (if a deletion
-  ;; is pending, text might become visible at the bottom).
-  (unless (eq beg end)
-    (let ((windows (get-buffer-window-list (current-buffer) 'nomini t)) window)
-      (while windows
-	(setq window (car windows))
-	(unless (markerp (window-redisplay-end-trigger window))
-	  (set-window-redisplay-end-trigger window (make-marker)))
-	(set-marker (window-redisplay-end-trigger window) (window-end window))
-	(setq windows (cdr windows))))))
-
-(defun lazy-lock-fontify-after-trigger (window trigger-point)
-  ;; Called from `redisplay-end-trigger-functions'.
-  ;; Fontify WINDOW from TRIGGER-POINT following the redisplay.
-  ;; We could probably just use `lazy-lock-fontify-after-scroll' without loss:
-  ;;  (inline (lazy-lock-fontify-after-scroll window (window-start window)))
-  (let ((inhibit-point-motion-hooks t))
-    (lazy-lock-fontify-region trigger-point (window-end window t))))
-
-;; 2.  Modified text must be marked as unfontified so it can be identified and
-;;     fontified later when Emacs is idle.  Deferral occurs by adding one of
-;;     `lazy-lock-fontify-*-after-change' (for on-the-fly fontification) or
-;;     `lazy-lock-defer-*-after-change' (for deferred fontification) to the
-;;     hook `after-change-functions'.
-
-(defalias 'lazy-lock-fontify-line-after-change
-  ;; Called from `after-change-functions'.
-  ;; Fontify the current change.
-  #'font-lock-after-change-function)
-
-(defun lazy-lock-fontify-rest-after-change (beg end old-len)
-  ;; Called from `after-change-functions'.
-  ;; Fontify the current change and defer fontification of the rest of the
-  ;; buffer.  Save the current buffer so that we subsequently fontify in all
-  ;; windows showing the buffer.
-  (lazy-lock-fontify-line-after-change beg end old-len)
-  (with-silent-modifications
-    (unless (memq (current-buffer) lazy-lock-buffers)
-      (push (current-buffer) lazy-lock-buffers))
-    (save-restriction
-      (widen)
-      (remove-text-properties end (point-max) '(lazy-lock nil)))))
-
-(defun lazy-lock-defer-line-after-change (beg end _old-len)
-  ;; Called from `after-change-functions'.
-  ;; Defer fontification of the current change.  Save the current buffer so
-  ;; that we subsequently fontify in all windows showing the buffer.
-  (with-silent-modifications
-    (unless (memq (current-buffer) lazy-lock-buffers)
-      (push (current-buffer) lazy-lock-buffers))
-    (remove-text-properties (max (1- beg) (point-min))
-			    (min (1+ end) (point-max))
-			    '(lazy-lock nil))))
-
-(defun lazy-lock-defer-rest-after-change (beg _end _old-len)
-  ;; Called from `after-change-functions'.
-  ;; Defer fontification of the rest of the buffer.  Save the current buffer so
-  ;; that we subsequently fontify in all windows showing the buffer.
-  (with-silent-modifications
-    (unless (memq (current-buffer) lazy-lock-buffers)
-      (push (current-buffer) lazy-lock-buffers))
-    (save-restriction
-      (widen)
-      (remove-text-properties (max (1- beg) (point-min))
-			      (point-max)
-			      '(lazy-lock nil)))))
-
-;; 3.  Deferred fontification and stealth fontification are done from these two
-;;     functions.  They are set up as Idle Timers.
-
-(defun lazy-lock-fontify-after-defer ()
-  ;; Called from `timer-idle-list'.
-  ;; Fontify all windows where deferral has occurred for its buffer.
-  (save-excursion
-    (while (and lazy-lock-buffers (not (input-pending-p)))
-      (let ((buffer (car lazy-lock-buffers)) windows)
-	;; Paranoia: check that the buffer is still live and Lazy Lock mode on.
-	(when (buffer-live-p buffer)
-	  (set-buffer buffer)
-	  (when lazy-lock-mode
-	    (setq windows (get-buffer-window-list buffer 'nomini t))
-	    (while windows
-	      (lazy-lock-fontify-window (car windows))
-	      (setq windows (cdr windows)))))
-	(setq lazy-lock-buffers (cdr lazy-lock-buffers)))))
-  ;; Add hook if fontification should now be defer-driven in this buffer.
-  (when (and lazy-lock-mode lazy-lock-defer-on-scrolling
-	     (memq #'lazy-lock-fontify-after-scroll window-scroll-functions)
-	     (not (or (input-pending-p) (lazy-lock-unfontified-p))))
-    (remove-hook 'window-scroll-functions #'lazy-lock-fontify-after-scroll t)
-    (add-hook 'window-scroll-functions #'lazy-lock-defer-after-scroll nil t)))
-
-(defun lazy-lock-fontify-after-idle ()
-  ;; Called from `timer-idle-list'.
-  ;; Fontify all buffers that need it, stealthily while idle.
-  (unless (or executing-kbd-macro (window-minibuffer-p (selected-window)))
-    ;; Loop over all buffers, fontify stealthily for each if necessary.
-    (let ((buffers (buffer-list)) (continue t)
-	  message message-log-max minibuffer-auto-raise)
-      (save-excursion
-	(do-while (and buffers continue)
-	  (set-buffer (car buffers))
-	  (if (not (and lazy-lock-mode (lazy-lock-unfontified-p)))
-	      (setq continue (not (input-pending-p)))
-	    ;; Fontify regions in this buffer while there is no input.
-	    (with-temp-message
-		(when lazy-lock-stealth-verbose
-		  "Fontifying stealthily...")
-	      (do-while (and (lazy-lock-unfontified-p) continue)
-		(if (and lazy-lock-stealth-load
-			 (> (car (load-average)) lazy-lock-stealth-load))
-		    ;; Wait a while before continuing with the loop.
-		    (progn
-		      (when message
-			(message "Fontifying stealthily...suspended")
-			(setq message nil))
-		      (setq continue (sit-for (or lazy-lock-stealth-time 30))))
-		  ;; Fontify a chunk.
-		  (when lazy-lock-stealth-verbose
-		    (if message
-			(message "Fontifying stealthily... %2d%% of %s"
-				 (lazy-lock-percent-fontified) (buffer-name))
-		      (message "Fontifying stealthily...")
-		      (setq message t)))
-		  ;; Current buffer may have changed during `sit-for'.
-		  (set-buffer (car buffers))
-		  (lazy-lock-fontify-chunk)
-		  (setq continue (sit-for (or lazy-lock-stealth-nice 0)))))))
-	  (setq buffers (cdr buffers)))))))
-
-;; 4.  Special circumstances.
-
-(defun lazy-lock-fontify-after-visage ()
-  ;; Called from `outline-view-change-hook' and `hs-hide-hook'.
-  ;; Fontify windows showing the current buffer, as its visibility has changed.
-  ;; This is a conspiracy hack between lazy-lock.el, outline.el and
-  ;; hideshow.el.
-  (let ((windows (get-buffer-window-list (current-buffer) 'nomini t)))
-    (while windows
-      (lazy-lock-fontify-conservatively (car windows))
-      (setq windows (cdr windows)))))
-
-(defun lazy-lock-after-fontify-buffer ()
-  ;; Called from `font-lock-after-fontify-buffer'.
-  ;; Mark the current buffer as fontified.
-  ;; This is a conspiracy hack between lazy-lock.el and font-lock.el.
-  (with-silent-modifications
-    (add-text-properties (point-min) (point-max) '(lazy-lock t))))
-
-(defun lazy-lock-after-unfontify-buffer ()
-  ;; Called from `font-lock-after-unfontify-buffer'.
-  ;; Mark the current buffer as unfontified.
-  ;; This is a conspiracy hack between lazy-lock.el and font-lock.el.
-  (with-silent-modifications
-    (remove-text-properties (point-min) (point-max) '(lazy-lock nil))))
-
-;; Fontification functions.
-
-;; If packages want to ensure that some region of the buffer is fontified, they
-;; should use this function.  For an example, see ps-print.el.
-(defun lazy-lock-fontify-region (beg end)
-  ;; Fontify between BEG and END, where necessary, in the current buffer.
-  (save-restriction
-    (widen)
-    (when (setq beg (text-property-any beg end 'lazy-lock nil))
-      (save-excursion
-	(with-silent-modifications
-	  (let ((inhibit-point-motion-hooks t))
-	    ;; Find successive unfontified regions between BEG and END.
-	    (condition-case data
-		(do-while beg
-		  (let ((next (or (text-property-any beg end 'lazy-lock t)
-		                  end)))
-		    ;; Make sure the region end points are at beginning of line.
-		    (goto-char beg)
-		    (unless (bolp)
-		      (beginning-of-line)
-		      (setq beg (point)))
-		    (goto-char next)
-		    (unless (bolp)
-		      (forward-line)
-		      (setq next (point)))
-		    ;; Fontify the region, then flag it as fontified.
-		    (font-lock-fontify-region beg next)
-		    (add-text-properties beg next '(lazy-lock t))
-		    (setq beg (text-property-any next end 'lazy-lock nil))))
-	      ((error quit) (message "Fontifying region...%s" data)))))))))
-
-(defun lazy-lock-fontify-chunk ()
-  ;; Fontify the nearest chunk, for stealth, in the current buffer.
-  (let ((inhibit-point-motion-hooks t))
-    (save-excursion
-      (save-restriction
-	(widen)
-	;; Move to end of line in case the character at point is not fontified.
-	(end-of-line)
-	;; Find where the previous (next) unfontified regions end (begin).
-	(let ((prev (previous-single-property-change (point) 'lazy-lock))
-	      (next (text-property-any (point) (point-max) 'lazy-lock nil)))
-	  ;; Fontify from the nearest unfontified position.
-	  (if (or (null prev) (and next (< (- next (point)) (- (point) prev))))
-	      ;; The next, or neither, region is the nearest not fontified.
-	      (lazy-lock-fontify-region
-	       (progn (goto-char (or next (point-min)))
-		      (beginning-of-line)
-		      (point))
-	       (progn (goto-char (or next (point-min)))
-		      (forward-line lazy-lock-stealth-lines)
-		      (point)))
-	    ;; The previous region is the nearest not fontified.
-	    (lazy-lock-fontify-region
-	     (progn (goto-char prev)
-		    (forward-line (- lazy-lock-stealth-lines))
-		    (point))
-	     (progn (goto-char prev)
-		    (forward-line)
-		    (point)))))))))
-
-(defun lazy-lock-fontify-window (window)
-  ;; Fontify in WINDOW between `window-start' and `window-end'.
-  ;; We can only do this when we can use `window-start' and `window-end'.
-  (with-current-buffer (window-buffer window)
-    (lazy-lock-fontify-region (window-start window) (window-end window))))
-
-(defun lazy-lock-fontify-conservatively (window)
-  ;; Fontify in WINDOW conservatively around point.
-  ;; Where we cannot use `window-start' and `window-end' we do `window-height'
-  ;; lines around point.  That way we guarantee to have done enough.
-  (with-current-buffer (window-buffer window)
-    (let ((inhibit-point-motion-hooks t))
-      (lazy-lock-fontify-region
-       (save-excursion
-	 (goto-char (window-point window))
-	 (vertical-motion (- (window-height window)) window) (point))
-       (save-excursion
-	 (goto-char (window-point window))
-	 (vertical-motion (window-height window) window) (point))))))
-
-(defun lazy-lock-unfontified-p ()
-  ;; Return non-nil if there is anywhere still to be fontified.
-  (save-restriction
-    (widen)
-    (text-property-any (point-min) (point-max) 'lazy-lock nil)))
-
-(defun lazy-lock-percent-fontified ()
-  ;; Return the percentage (of characters) of the buffer that are fontified.
-  (save-restriction
-    (widen)
-    (let ((beg (point-min)) (size 0) next)
-      ;; Find where the next fontified region begins.
-      (while (setq beg (text-property-any beg (point-max) 'lazy-lock t))
-	(setq next (or (text-property-any beg (point-max) 'lazy-lock nil)
-		       (point-max)))
-	(cl-incf size (- next beg))
-	(setq beg next))
-      ;; Float because using integer multiplication will frequently overflow.
-      (truncate (* (/ (float size) (point-max)) 100)))))
-
-;; Version dependent workarounds and fixes.
-
-(when (consp lazy-lock-defer-time)
-  ;;
-  ;; In 2.06.04 and below, `lazy-lock-defer-time' could specify modes and time.
-  (with-output-to-temp-buffer "*Help*"
-    (princ "The value of the variable `lazy-lock-defer-time' was\n ")
-    (princ lazy-lock-defer-time)
-    (princ "\n")
-    (princ "This variable cannot now be a list of modes and time,\n")
-    (princ "so instead use ")
-    (princ (substitute-command-keys "\\[customize-option]"))
-    (princ " to modify the variables, or put the forms:\n")
-    (princ " (setq lazy-lock-defer-time ")
-    (princ (cdr lazy-lock-defer-time))
-    (princ ")\n")
-    (princ " (setq lazy-lock-defer-on-the-fly '")
-    (princ (car lazy-lock-defer-time))
-    (princ ")\n")
-    (princ "in your ~/.emacs.  ")
-    (princ "The above forms have been evaluated for this editor session,\n")
-    (princ "but you should use ")
-    (princ (substitute-command-keys "\\[customize-option]"))
-    (princ " or change your ~/.emacs now."))
-  (setq lazy-lock-defer-on-the-fly (car lazy-lock-defer-time)
-	lazy-lock-defer-time (cdr lazy-lock-defer-time)))
-
-(when (boundp 'lazy-lock-defer-driven)
-  ;;
-  ;; In 2.06.04 and below, `lazy-lock-defer-driven' was the variable name.
-  (with-output-to-temp-buffer "*Help*"
-    (princ "The value of the variable `lazy-lock-defer-driven' is set to ")
-    (if (memq lazy-lock-defer-driven '(nil t))
-	(princ lazy-lock-defer-driven)
-      (princ "`")
-      (princ lazy-lock-defer-driven)
-      (princ "'"))
-    (princ ".\n")
-    (princ "This variable is now called `lazy-lock-defer-on-scrolling',\n")
-    (princ "so instead use ")
-    (princ (substitute-command-keys "\\[customize-option]"))
-    (princ " to modify the variable, or put the form:\n")
-    (princ " (setq lazy-lock-defer-on-scrolling ")
-    (unless (memq lazy-lock-defer-driven '(nil t))
-      (princ "'"))
-    (princ lazy-lock-defer-driven)
-    (princ ")\n")
-    (princ "in your ~/.emacs.  ")
-    (princ "The above form has been evaluated for this editor session,\n")
-    (princ "but you should use ")
-    (princ (substitute-command-keys "\\[customize-option]"))
-    (princ " or change your ~/.emacs now."))
-  (setq lazy-lock-defer-on-scrolling lazy-lock-defer-driven))
-
-;; Install ourselves:
-
-(add-hook 'window-size-change-functions #'lazy-lock-fontify-after-resize)
-(add-hook 'redisplay-end-trigger-functions #'lazy-lock-fontify-after-trigger)
-
-(unless (assq 'lazy-lock-mode minor-mode-alist)
-  (setq minor-mode-alist (append minor-mode-alist '((lazy-lock-mode nil)))))
-
-(provide 'lazy-lock)
-
-;; Local Variables:
-;; byte-compile-warnings: (not obsolete)
-;; End:
-
-;;; lazy-lock.el ends here
-- 
2.30.2