=head1 NAME
-perldelta - what is new for perl 5.10.0
+perl5100delta - what is new for perl 5.10.0
=head1 DESCRIPTION
< # match an opening angle bracket
(?: # match one of:
(?> # don't backtrack over the inside of this group
- [^<>]+ # one or more non angle brackets
+ [^<>]+ # one or more non angle brackets
) # end non backtracking group
| # ... or ...
(?1) # recurse to bracket 1 and try it again
=head2 The C<_> prototype
A new prototype character has been added. C<_> is equivalent to C<$> but
-defaults to C<$_> if the corresponding argument isn't supplied. (both C<$>
-and C<_> denote a scalar). Due to the optional nature of the argument, you
-can only use it at the end of a prototype, or before a semicolon.
+defaults to C<$_> if the corresponding argument isn't supplied (both C<$>
+and C<_> denote a scalar). Due to the optional nature of the argument,
+you can only use it at the end of a prototype, or before a semicolon.
This has a small incompatible consequence: the prototype() function has
been adjusted to return C<_> for some built-ins in appropriate cases (for
use feature 'state';
or by using the C<-E> command-line switch in one-liners.
-See L<perlsub/"Persistent variables via state()">.
+See L<perlsub/"Persistent Private Variables">.
=head2 Stacked filetest operators
matching F<.pm> file. Starting with 5.9.4, they'll be always loaded if
they exist.
+=head2 $^V is now a C<version> object instead of a v-string
+
+$^V can still be used with the C<%vd> format in printf, but any
+character-level operations will now access the string representation
+of the C<version> object and not the ordinals of a v-string.
+Expressions like C<< substr($^V, 0, 2) >> or C<< split //, $^V >>
+no longer work and must be rewritten.
+
=head2 @- and @+ in patterns
The special arrays C<@-> and C<@+> are no longer interpolated in regular
chr() on a negative value now gives C<\x{FFFD}>, the Unicode replacement
character, unless when the C<bytes> pragma is in effect, where the low
-eight bytes of the value are used.
+eight bits of the value are used.
=item PERL5SHELL and tainting
The anonymous hash and array constructors now take 1 op in the optree
instead of 3, now that pp_anonhash and pp_anonlist return a reference to
-an hash/array when the op is flagged with OPf_SPECIAL (Nicholas Clark).
+an hash/array when the op is flagged with OPf_SPECIAL. (Nicholas Clark)
=head1 Known Problems
effect, because they rely on the stat() buffer C<_> being populated, and
filetest bypasses stat().
+=head2 UTF-8 problems
+
+The handling of Unicode still is unclean in several places, where it's
+dependent on whether a string is internally flagged as UTF-8. This will
+be made more consistent in perl 5.12, but that won't be possible without
+a certain amount of backwards incompatibility.
+
+=head1 Platform Specific Problems
+
When compiled with g++ and thread support on Linux, it's reported that the
C<$!> stops working correctly. This is related to the fact that the glibc
provides two strerror_r(3) implementation, and perl selects the wrong
one.
-=head1 Platform Specific Problems
-
=head1 Reporting Bugs
+If you find what you think is a bug, you might check the articles
+recently posted to the comp.lang.perl.misc newsgroup and the perl
+bug database at http://rt.perl.org/rt3/ . There may also be
+information at http://www.perl.org/ , the Perl Home Page.
+
+If you believe you have an unreported bug, please run the B<perlbug>
+program included with your release. Be sure to trim your bug down
+to a tiny but sufficient test case. Your bug report, along with the
+output of C<perl -V>, will be sent off to perlbug@perl.org to be
+analysed by the Perl porting team.
+
=head1 SEE ALSO
The F<Changes> file and the perl590delta to perl595delta man pages for