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authorChong Yidong <cyd@stupidchicken.com>2009-04-15 21:54:15 +0000
committerChong Yidong <cyd@stupidchicken.com>2009-04-15 21:54:15 +0000
commit80d7cdca53f26dfd282c654eadeda63e0ca09715 (patch)
treed8bc8690b0aecd9aa4a28b2ea59ea682dbb49684 /doc/lispref
parentb0f439fc190963f329b221678c8c495011df834b (diff)
downloademacs-80d7cdca53f26dfd282c654eadeda63e0ca09715.tar.gz
* searching.texi (Regexp Backslash): Also refer to shy groups as
non-capturing or unnumbered groups. (Regexp Functions): Add cross-reference to Regexp Backslash.
Diffstat (limited to 'doc/lispref')
-rw-r--r--doc/lispref/ChangeLog4
-rw-r--r--doc/lispref/searching.texi17
2 files changed, 15 insertions, 6 deletions
diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index 073bdc41842..8cb1e0206b3 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,5 +1,9 @@
2009-04-15 Chong Yidong <cyd@stupidchicken.com>
+ * searching.texi (Regexp Backslash): Also refer to shy groups as
+ non-capturing or unnumbered groups.
+ (Regexp Functions): Add cross-reference to Regexp Backslash.
+
* display.texi (Truncation): Overlays can use line-prefix and
wrap-prefix too.
(Overlay Properties): Document wrap-prefix and line-prefix.
diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index bc223f8ac3f..9c9b60fb201 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -654,14 +654,19 @@ occasionally there is a conflict, and that led to the introduction of
shy groups.
@item \(?: @dots{} \)
+@cindex shy groups
+@cindex non-capturing group
+@cindex unnumbered group
is the @dfn{shy group} construct. A shy group serves the first two
purposes of an ordinary group (controlling the nesting of other
operators), but it does not get a number, so you cannot refer back to
-its value with @samp{\@var{digit}}.
+its value with @samp{\@var{digit}}. Shy groups are particularly
+useful for mechanically-constructed regular expressions, because they
+can be added automatically without altering the numbering of ordinary,
+non-shy groups.
-Shy groups are particularly useful for mechanically-constructed regular
-expressions because they can be added automatically without altering the
-numbering of any ordinary, non-shy groups.
+Shy groups are also called @dfn{non-capturing} or @dfn{unnumbered
+groups}.
@item \(?@var{num}: @dots{} \)
is the @dfn{explicitly numbered group} construct. Normal groups get
@@ -939,8 +944,8 @@ regular expression which is equivalent to the actual value
@defun regexp-opt-depth regexp
This function returns the total number of grouping constructs
-(parenthesized expressions) in @var{regexp}. (This does not include
-shy groups.)
+(parenthesized expressions) in @var{regexp}. This does not include
+shy groups (@pxref{Regexp Backslash}).
@end defun
@node Regexp Search