[PATCH] Math::BigInt v1.73 final

[p5sagit/p5-mst-13.2.git] / pod / perlre.pod

diff --git a/pod/perlre.pod b/pod/perlre.pod
index a11e3e8..ea88fc0 100644 (file)
--- a/pod/perlre.pod
+++ b/pod/perlre.pod
@@ -394,11 +394,15 @@ the most-recently closed group (submatch). C<$^N> can be used in
 extended patterns (see below), for example to assign a submatch to a
 variable. 
 
-The numbered variables ($1, $2, $3, etc.) and the related punctuation
+The numbered match variables ($1, $2, $3, etc.) and the related punctuation
 set (C<$+>, C<$&>, C<$`>, C<$'>, and C<$^N>) are all dynamically scoped
 until the end of the enclosing block or until the next successful
 match, whichever comes first.  (See L<perlsyn/"Compound Statements">.)
 
+B<NOTE>: failed matches in Perl do not reset the match variables,
+which makes easier to write code that tests for a series of more
+specific cases and remembers the best match.
+
 B<WARNING>: Once Perl sees that you need one of C<$&>, C<$`>, or
 C<$'> anywhere in the program, it has to provide them for every
 pattern match.  This may substantially slow your program.  Perl
@@ -570,6 +574,10 @@ track of the number of nested parentheses. For example:
   /the (\S+)(?{ $color = $^N }) (\S+)(?{ $animal = $^N })/i;
   print "color = $color, animal = $animal\n";
 
+Inside the C<(?{...})> block, C<$_> refers to the string the regular
+expression is matching against. You can also use C<pos()> to know what is
+the current position of matching withing this string.
+
 The C<code> is properly scoped in the following sense: If the assertion
 is backtracked (compare L<"Backtracking">), all changes introduced after
 C<local>ization are undone, so that