This is similar to C<$&> (C<$POSTMATCH>) except that it does not incur the
performance penalty associated with that variable, and is only guaranteed
to return a defined value when the pattern was compiled or executed with
-the C</k> modifier.
+the C</p> modifier.
=item $PREMATCH
This is similar to C<$`> ($PREMATCH) except that it does not incur the
performance penalty associated with that variable, and is only guaranteed
to return a defined value when the pattern was compiled or executed with
-the C</k> modifier.
+the C</p> modifier.
=item $POSTMATCH
This is similar to C<$'> (C<$POSTMATCH>) except that it does not incur the
performance penalty associated with that variable, and is only guaranteed
to return a defined value when the pattern was compiled or executed with
-the C</k> modifier.
+the C</p> modifier.
=item $LAST_PAREN_MATCH
buffers, should they exist, in the last successful match in the
currently active dynamic scope.
-C<$+{foo}> is equivalent to C<$1> after the following match:
+For example, C<$+{foo}> is equivalent to C<$1> after the following match:
- 'foo'=~/(?<foo>foo)/;
+ 'foo' =~ /(?<foo>foo)/;
-The underlying behaviour of %+ is provided by the L<re::Tie::Hash::NamedCapture>
-module.
+The keys of the C<%+> hash list only the names of buffers that have
+captured (and that are thus associated to defined values).
-B<Note:> As C<%-> and C<%+> are tied views into a common internal hash
+The underlying behaviour of C<%+> is provided by the
+L<Tie::Hash::NamedCapture> module.
+
+B<Note:> C<%-> and C<%+> are tied views into a common internal hash
associated with the last successful regular expression. Therefore mixing
iterative access to them via C<each> may have unpredictable results.
-Likewise, if the last successful match changes then the results may be
+Likewise, if the last successful match changes, then the results may be
surprising.
=item HANDLE->input_line_number(EXPR)
=item %-
X<%->
-Similar to %+, this variable allows access to the named capture
-buffers that were defined in the last successful match. It returns
-a reference to an array containing one value per buffer of a given
-name in the pattern.
+Similar to C<%+>, this variable allows access to the named capture buffers
+in the last successful match in the currently active dynamic scope. To
+each capture buffer name found in the regular expression, it associates a
+reference to an array containing the list of values captured by all
+buffers with that name (should there be several of them), in the order
+where they appear.
+
+Here's an example:
- if ('1234'=~/(?<A>1)(?<B>2)(?<A>3)(?<B>4)/) {
- foreach my $name (sort keys(%-)) {
- my $ary = $-{$name};
+ if ('1234' =~ /(?<A>1)(?<B>2)(?<A>3)(?<B>4)/) {
+ foreach my $bufname (sort keys %-) {
+ my $ary = $-{$bufname};
foreach my $idx (0..$#$ary) {
- print "\$-{$name}[$idx] : ",
+ print "\$-{$bufname}[$idx] : ",
(defined($ary->[$idx]) ? "'$ary->[$idx]'" : "undef"),
"\n";
}
$-{B}[0] : '2'
$-{B}[1] : '4'
-The behaviour of %- is implemented via the L<re::Tie::Hash::NamedCapture> module.
+The keys of the C<%-> hash correspond to all buffer names found in
+the regular expression.
+
+The behaviour of C<%-> is implemented via the
+L<Tie::Hash::NamedCapture> module.
-Note that C<%-> and C<%+> are tied views into a common internal hash
+B<Note:> C<%-> and C<%+> are tied views into a common internal hash
associated with the last successful regular expression. Therefore mixing
iterative access to them via C<each> may have unpredictable results.
-Likewise, if the last successful match changes then the results may be
+Likewise, if the last successful match changes, then the results may be
surprising.
=item HANDLE->format_name(EXPR)
The current value of the flag associated with the B<-c> switch.
Mainly of use with B<-MO=...> to allow code to alter its behavior
when being compiled, such as for example to AUTOLOAD at compile
-time rather than normal, deferred loading. See L<perlcc>. Setting
+time rather than normal, deferred loading. Setting
C<$^C = 1> is similar to calling C<B::minus_c>.
=item $DEBUGGING
as a string composed of characters with those ordinals. Thus in Perl v5.6.0
it equals C<chr(5) . chr(6) . chr(0)> and will return true for
C<$^V eq v5.6.0>. Note that the characters in this string value can
-potentially be in Unicode range.
+potentially be greater than 255.
This variable first appeared in perl 5.6.0; earlier versions of perl will
see an undefined value.