Reapply "docs: clarify effect of $^H, %^H, ${^WARNING_BITS}"

[perl5.git] / pod / perl5358delta.pod

=encoding utf8

=head1 NAME

perl5358delta - what is new for perl v5.35.8

=head1 DESCRIPTION

This document describes differences between the 5.35.7 release and the 5.35.8
release.

If you are upgrading from an earlier release such as 5.35.6, first read
L<perl5357delta>, which describes differences between 5.35.6 and 5.35.7.

=head1 Core Enhancements

=head2 Try/Catch Syntax Now Recognises C<finally> Blocks

The experimental C<try>/C<catch> syntax has been extended to support an
optional third block introduced by the C<finally> keyword.

    try {
        attempt();
        print "Success\n";
    }
    catch ($e) {
        print "Failure\n";
    }
    finally {
        print "This happens regardless\n";
    }

This provides code which runs at the end of the C<try>/C<catch> construct,
even if aborted by an exception or control-flow keyword. They are similar
to C<defer> blocks.

For more information, see L<perlsyn/"Try Catch Exception Handling">.

=head1 Incompatible Changes

=head2 A physically empty sort is now a compile-time error

    @a = sort @empty; # unaffected
    @a = sort;        # now a compile-time error

A bare sort used to be a weird way to create an empty list; now it croaks
at compile time. This is change is intended to free up some of the syntax
space for possible future enhancements to C<sort>.

=head1 Performance Enhancements

=over 4

=item *

Try / Catch optimization: make sure to rpeep() the body of catch {} blocks

=back

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Module::CoreList> has been upgraded from version 5.20211220 to 5.20220120.

=item *

L<bignum> has been upgraded from version 0.63 to 0.64.

=item *

L<Data::Dumper> has been upgraded from version 2.183 to 2.184.

Fixes for EBCDIC.

=item *

L<File::Fetch> has been upgraded from version 1.00 to 1.04.

=item *

L<File::Find> has been upgraded from version 1.39_01 to 1.40.

Replace bareword filehandle with a lexical scalar.

=item *

L<Locale::Maketext> has been upgraded from version 1.29 to 1.30.

Provide inclusive names allowlist and denylist

=item *

L<Math::BigInt> has been upgraded from version 1.999828 to 1.999829.

=item *

L<NEXT> has been upgraded from version 0.68 to 0.69.

=item *

L<POSIX> has been upgraded from version 2.02 to 2.03.

FLT_ROUNDS now emulates (more) standard behavior that reflects
the current rounding mode set by fesetround.

=item *

L<Win32> has been upgraded from version 0.57 to 0.58.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

We have attempted to update the documentation to reflect the changes
listed in this document.  If you find any we have missed, open an issue
at L<https://github.com/Perl/perl5/issues>.

Additionally, the following selected changes have been made:

=head3 L<perlrun>

=over 4

=item *

B<-?> is now a synonym for B<-h>

=back

=head1 Testing

Tests were added and changed to reflect the other additions and changes
in this release.

Tests were added and changed to reflect the other additions and
changes in this release.  Furthermore, these significant changes were
made:

=over 4

=item *

ExtUtils-ParseXS test suite improvement

=item *

Hash::Util::FieldHash test suite improvement

=item *

Pod::Html test suite improvement

=item *

Tie::SubstrHash test suite improvement

=item *

Time-HiRes test suite improvement

=item *

Fix several test failures on CygWin and MSWin32.

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item z/OS

=over 4

=item *

Update z/OS (previously called OS/390) README to describe ASCII and EBCDIC builds 
z/OS ASCII Enablement: Manage untagged header errno.h by copy & tag

=back

=back

=over 4

=item Windows

=over 4

=item *

Support for compiling perl on Windows using Microsoft Visual Studio 2022
(containing Visual C++ 14.3) has been added.

=back

=back

=head1 Internal Changes

=over 4

=item *

Add missing aliases for \p{Present_In}

=item *

Change C<pack> U behavior for EBCDIC

=item *

sv_upgrade: use c99 compound literals to initialize xpvav/xpvhv

=back

=head1 Acknowledgements

Perl 5.35.8 represents approximately 4 weeks of development since Perl
5.35.7 and contains approximately 29,000 lines of changes across 190 files
from 19 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 23,000 lines of changes to 120 .pm, .t, .c and .h files.

Perl continues to flourish into its fourth decade thanks to a vibrant
community of users and developers. The following people are known to have
contributed the improvements that became Perl 5.35.8:

Chris 'BinGOs' Williams, Craig A. Berry, David Mitchell, E. Choroba,
François Perrad, Graham Knop, Ivan Panchenko, James E Keenan, Karl
Williamson, Michiel Beijen, Mike Fulton, Neil Bowers, Nicholas Clark,
Nicolas R., Paul Evans, Richard Leach, Sawyer X, TAKAI Kousuke, Tomasz
Konojacki.

The list above is almost certainly incomplete as it is automatically
generated from version control history. In particular, it does not include
the names of the (very much appreciated) contributors who reported issues to
the Perl bug tracker.

Many of the changes included in this version originated in the CPAN modules
included in Perl's core. We're grateful to the entire CPAN community for
helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please
see the F<AUTHORS> file in the Perl source distribution.

=head1 Reporting Bugs

If you find what you think is a bug, you might check the perl bug database
at L<https://github.com/Perl/perl5/issues>.  There may also be information at
L<http://www.perl.org/>, the Perl Home Page.

If you believe you have an unreported bug, please open an issue at
L<https://github.com/Perl/perl5/issues>.  Be sure to trim your bug down to a
tiny but sufficient test case.

If the bug you are reporting has security implications which make it
inappropriate to send to a public issue tracker, then see
L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
for details of how to report the issue.

=head1 Give Thanks

If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
you can do so by running the C<perlthanks> program:

    perlthanks

This will send an email to the Perl 5 Porters list with your show of thanks.

=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