Lazy highlighting.

man/search.texi

@@ -1,5 +1,5 @@
 @c This is part of the Emacs manual.
-@c Copyright (C) 1985, 86, 87, 93, 94, 95, 1997 Free Software Foundation, Inc.
+@c Copyright (C) 1985, 86, 87, 93-95, 97, 2000 Free Software Foundation, Inc.
 @c See file emacs.texi for copying conditions.
 @node Search, Fixit, Display, Top
 @chapter Searching and Replacement
@@ -165,6 +165,7 @@ search remains case-insensitive.
 
   The character @kbd{M-y} copies text from the kill ring into the search
 string.  It uses the same text that @kbd{C-y} as a command would yank.
+@kbd{mouse-2} in the echo area does the same.
 @xref{Yanking}.
 
   When you exit the incremental search, it sets the mark to where point
@@ -172,6 +173,23 @@ string.  It uses the same text that @kbd{C-y} as a command would yank.
 there.  In Transient Mark mode, incremental search sets the mark without
 activating it, and does so only if the mark is not already active.
 
+@cindex lazy search highlighting
+  By default, Isearch uses @dfn{lazy highlighting}.  All matches for
+the current search string in the buffer after the point where searching
+starts are highlighted.  The extra highlighting makes it easier to
+anticipate where the cursor will end up each time you press @kbd{C-s} or
+@kbd{C-r} to repeat a pending search.  Highlighting of these additional
+matches happens in a deferred fashion so as not to rob Isearch of its
+usual snappy response.
+@vindex isearch-lazy-highlight-cleanup
+By default the highlighting of matches is cleared when you end the
+search.  Customize the variable @code{isearch-lazy-highlight-cleanup} to
+avoid cleaning up automatically.  The command @kbd{M-x
+isearch-lazy-highlight-cleanup} can be used to clean up manually.
+@vindex isearch-lazy-highlight
+Customize the variable @code{isearch-lazy-highlight} to turn off this
+feature.
+
 @vindex isearch-mode-map
   To customize the special characters that incremental search understands,
 alter their bindings in the keymap @code{isearch-mode-map}.  For a list