path: root/pod/perl5113delta.pod

=head1 NAME

[ this is a template for a new perldelta file. Any text flagged as
XXX needs to be processed before release. ]

perldelta - what is new for perl v5.11.3

=head1 DESCRIPTION

This document describes differences between the 5.11.3 release and
the 5.11.3 release.

If you are upgrading from an earlier release such as 5.11.3, first read
the L<perl5XXXdelta>, which describes differences between 5.11.3 and
5.10.0

=head1 Notice

XXX Any important notices here

=head1 Incompatible Changes

XXX For a release on a stable branch, this section aspires to be:

    There are no changes intentionally incompatible with 5.11.3. If any
    exist, they are bugs and reports are welcome.


=head1 Core Enhancements

XXX New core language features go here. Summarise user-visible core language
enhancements. Particularly prominent performance optimisations could go
here, but most should go in the L</Performance Enhancements> section.

=head2 Unicode version

Perl is shipped with the latest Unicode version, 5.2, October 2009.  See
L<http://www.unicode.org/versions/Unicode5.2.0> for details about this release
of Unicode.

=head2 Unicode properties

Perl can now handle every Unicode character property.  A new pod,
L<perluniprops>, lists all available non-Unihan character properties.  By
default the Unihan properties and certain others (deprecated and Unicode
internal-only ones) are not exposed.  See below for more details on
these; there is also a section in the pod listing them, and why they are
not exposed.

Perl now fully supports the Unicode compound-style of using C<=> and C<:>
in writing regular expressions: C<\p{property=value}> and
C<\p{property:value}> (both of which mean the same thing).

Perl now supports fully the Unicode loose matching rules for text
between the braces in C<\p{...}> constructs.  In addition, Perl also allows
underscores between digits of numbers.

All the Unicode-defined synonyms for properties and property values are
now accepted.

C<\p{...}> matches using the Canonical_Combining_Class property were
completely broken in previous Perls.  This is now fixed.

In previous Perls, the Unicode Decomposition_Type=Compat property and a
Perl extension had the same name, which led to neither matching all the
correct values (with more than 100 mistakes in one, and several thousand
in the other).  The Perl extension has now been renamed to be
Decomposition_Type=Noncanonical (short: dt=noncanon).  It has the same
meaning as was previously intended, namely the union of all the
non-canonical Decomposition types, with Unicode Compat being just one of
those.

C<\p{Uppercase}> and C<\p{Lowercase}> have been brought into line with the
Unicode definitions.  This means they each match a few more characters
than previously.

C<\p{Cntrl}> now matches the same characters as C<\p{Control}>.  This means it
no longer will match Private Use (gc=co), Surrogates (gc=cs), nor Format
(gc=cf) code points.  The Format code points represent the biggest
possible problem.  All but 36 of them are either officially deprecated
or strongly discouraged from being used.  Of those 36, likely the most
widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ, WJ, and
similar, plus Bi-directional controls.

C<\p{Alpha}> now matches the same characters as C<\p{Alphabetic}>.  The Perl
definition included a number of things that aren't really alpha (all
marks), while omitting many that were.  The Unicode definition is
clearly better, so we are switching to it.  As a direct consequence, the
definitions of C<\p{Alnum}> and C<\p{Word}> which depend on Alpha also change.

C<\p{Word}> also now doesn't match certain characters it wasn't supposed
to, such as fractions.

C<\p{Print}> no longer matches the line control characters: tab, lf, cr,
ff, vt, and nel.  This brings it in line with the documentation.

\p{Decomposition_Type=Canonical} now includes the Hangul syllables

The Numeric type property has been extended to include the Unihan
characters.

There is a new Perl extension, the 'Present_In', or simply 'In'
property.  This is an extension of the Unicode Age property, but
C<\p{In=5.0}> matches any code point whose usage has been determined as of
Unicode version 5.0.  The C<\p{Age=5.0}> only matches code points added in 5.0.

A number of properties did not have the correct values for unassigned
code points.  This is now fixed.  The affected properties are
Bidi_Class, East_Asian_Width, Joining_Type, Decomposition_Type,
Hangul_Syllable_Type, Numeric_Type, and Line_Break.

The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties
have been updated to their current definitions.

Certain properties that are supposed to be Unicode internal-only were
erroneously exposed by previous Perls.  Use of these in regular
expressions will now generate a deprecated warning message, if those
warnings are enabled.  The properties are: Other_Alphabetic,
Other_Default_Ignorable_Code_Point, Other_Grapheme_Extend,
Other_ID_Continue, Other_ID_Start, Other_Lowercase, Other_Math, and
Other_Uppercase.

An installation can now fairly easily change Perl to operate on any
Unicode release.  Perl is shipped with the latest official release, but
an installation can now download any prior release, and Perl will work
with that.  Instructions are in L<perlunicode>.

An installation can now fairly easily change which Unicode properties
Perl understands.  As mentioned above, certain properties are by default
turned off.  These include all the Unihan properties (which should be
accessible via the CPAN module Unicode::Unihan) and any deprecated or
Unicode internal-only property that Perl has never exposed.

The files in the To directory are now more clearly marked as being
stable, directly usable by applications.  New hash entries in them give
the format of the normal entries which allows for easier machine
parsing.  Perl can generate files in this directory for any property,
though most are suppressed.  An installation can choose to change which
get written.   Instructions are in L<perluniprops>.

=head1 New Platforms

XXX List any platforms that this version of perl compiles on, that previous
versions did not. These will either be enabled by new files in the F<hints/>
directories, or new subdirectories and F<README> files at the top level of the
source tree.

=head1 Modules and Pragmata

XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
go here, in a list ordered by distribution name. Minimally it should be the
module version, but it's more useful to the end user to give a paragraph's
summary of the module's changes. In an ideal world, dual-life modules would
have a F<Changes> file that could be cribbed.

=head2 New Modules and Pragmata

=over 4

=item C<XXX>

XXX

=back

=head2 Pragmata Changes

=over 4

=item C<XXX>

XXX

=back

=head2 Updated Modules

=over 4

=item C<XXX>

XXX

=back

=head1 Utility Changes

XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
here. Most of these are built within the directories F<utils> and F<x2p>.

=over 4

=item F<XXX>

XXX

=back

=head1 New Documentation

XXX Changes which create B<new> files in F<pod/> go here.

=over 4

=item L<XXX>

XXX

=back

=head1 Changes to Existing Documentation

XXX Changes which significantly change existing files in F<pod/> go here.
Any changes to F<pod/perldiag.pod> should go in L</New or Changed Diagnostics>.


=head1 Performance Enhancements

XXX Changes which enhance performance without changing behaviour go here. There
may well be none in a stable release.

=over 4

=item *

XXX

=back

=head1 Installation and Configuration Improvements

XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
go here.

=head2 Configuration improvements

XXX

=head2 Compilation improvements

XXX

=head2 Platform Specific Changes

=over 4

=item XXX-some-platform

XXX

=back

=head1 Selected Bug Fixes

XXX Important bug fixes in the core language are summarised here.
Bug fixes in files in F<ext/> and F<lib/> are best summarised in
L</Modules and Pragmata>.

=over 4

=item *

XXX

=back

=head1 New or Changed Diagnostics

XXX New or changed warnings emitted by the core's C<C> code go here.

=over 4

=item C<XXX>

XXX

=back

=head1 Changed Internals

XXX Changes which affect the interface available to C<XS> code go here.

=over 4

=item *

XXX

=back

=head1 New Tests

XXX Changes which create B<new> files in F<t/> go here. Changes to
existing files in F<t/> aren't worth summarising, although the bugs that
they represent may be.

=over 4

=item F<XXX>

XXX

=back

=head1 Known Problems

XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
tests that had to be C<TODO>ed for the release would be noted here, unless
they were specific to a particular platform (see below).

This is a list of some significant unfixed bugs, which are regressions
from either 5.11.3 or 5.11.3.

=over 4

=item *

XXX

=back

=head1 Deprecations

XXX Add any new known deprecations here.

The following items are now deprecated.

=over 4

=item Use of "goto" to jump into a construct is deprecated

Using C<goto> to jump from an outer scope into an inner
scope is now deprecated. This rare use case was causing
problems in the implementation of scopes.

=back

=head1 Platform Specific Notes

XXX Any changes specific to a particular platform. VMS and Win32 are the usual
stars here. It's probably best to group changes under the same section layout
as the main perldelta

=head1 Obituary

XXX If any significant core contributor has died, we've added a short obituary
here.

=head1 Acknowledgements

XXX The list of people to thank goes here.


=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/perlbug/ .  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.

If the bug you are reporting has security implications, which make it
inappropriate to send to a publicly archived mailing list, then please send
it to perl5-security-report@perl.org. This points to a closed subscription
unarchived mailing list, which includes all the core committers, who be able
to help assess the impact of issues, figure out a resolution, and help
co-ordinate the release of patches to mitigate or fix the problem across all
platforms on which Perl is supported. Please only use this address for
security issues in the Perl core, not for modules independently
distributed on CPAN.

=head1 SEE ALSO

The F<Changes> file for an explanation of how to view exhaustive details
on what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut