Add more isearch submatch faces

* doc/emacs/search.texi (Search Customizations): Adjust
documentation.
* lisp/isearch.el (search-highlight-submatches): Be a boolean.
(isearch-group-{6-9}): New faces.
(isearch-highlight): Use the variable as a boolean.

1 files changed, 7 insertions, 9 deletions

diff --git a/doc/emacs/search.texi b/doc/emacs/search.texi
index 508debd13c8..d44d7bee2ac 100644
--- a/doc/emacs/search.texi
+++ b/doc/emacs/search.texi
@@ -1981,15 +1981,13 @@ setting the variable @code{search-highlight} to @code{nil}.
   When searching for regular expressions (with @kbd{C-M-s}, for
 instance), subexpressions receive special highlighting depending on
 the @code{search-highlight-submatches} variable.  If this variable's
-value is zero, no special highlighting is done, but if the value is a
-positive integer @var{n}, the strings matching the first @var{n}
-@samp{\( @dots{} \)} constructs (a.k.a.@: ``subexpressions'') in the
-regular expression will be highlighted with distinct faces, named
-@code{isearch-group-@var{n}}.  For instance, when searching for
-@samp{foo-\([0-9]+\)}, the part matched by @samp{[0-9]+} will be
-highlighted with the @code{isearch-group-1} face if
-@code{search-highlight-submatches} is greater or equal to 1.  The
-default value of @code{search-highlight-submatches} is 5.
+value is @code{nil}, no special highlighting is done, but if the value
+is non-@code{nil}, text that matches @samp{\( @dots{} \)} constructs
+(a.k.a.@: ``subexpressions'') in the regular expression will be
+highlighted with distinct faces, named @code{isearch-group-@var{n}}.
+For instance, when searching for @samp{foo-\([0-9]+\)}, the part
+matched by @samp{[0-9]+} will be highlighted with the
+@code{isearch-group-1} face.
 
 @cindex lazy highlighting customizations
 @vindex isearch-lazy-highlight