Add Regexp::Keep \K functionality to regex engine as well as add \v and \V, cleanup and more docs for regatom()

Message-ID: <9b18b3110701101133i46dc5fd0p1476a0f1dd1e9c5a@mail.gmail.com>

(plus POD nits by Merijn and myself)

p4raw-id: //depot/perl@29756

1 files changed, 17 insertions, 2 deletions

diff --git a/pod/perl595delta.pod b/pod/perl595delta.pod
index 0497d55781..47fbaf51a1 100644
--- a/pod/perl595delta.pod
+++ b/pod/perl595delta.pod
@@ -107,9 +107,9 @@ would expect. This is considered a feature. :-) (Yves Orton)
 
 =item Possessive Quantifiers
 
-Perl now supports the "possessive quantifier" syntax of the "atomic match" 
+Perl now supports the "possessive quantifier" syntax of the "atomic match"
 pattern. Basically a possessive quantifier matches as much as it can and never
-gives any back. Thus it can be used to control backtracking. The syntax is 
+gives any back. Thus it can be used to control backtracking. The syntax is
 similar to non-greedy matching, except instead of using a '?' as the modifier
 the '+' is used. Thus C<?+>, C<*+>, C<++>, C<{min,max}+> are now legal
 quantifiers. (Yves Orton)
@@ -129,6 +129,21 @@ that contain backreferences. (Yves Orton)
 
 =back
 
+=item Regexp::Keep internalized
+
+The functionality of Jeff Pinyan's module Regexp::Keep has been added to
+the core. You can now use in regular expressions the special escape C<\K>
+as a way to do something like floating length positive lookbehind. It is
+also useful in substitutions like:
+
+  s/(foo)bar/$1/g
+
+that can now be converted to
+
+  s/foo\Kbar//g
+
+which is much more efficient.
+
 =head2 The C<_> prototype
 
 A new prototype character has been added. C<_> is equivalent to C<$> (it