Integrate from maint-5.8 : changes 18290-1, 18293-5, 18297

[p5sagit/p5-mst-13.2.git] / pod / perldelta.pod

=head1 NAME

perldelta - what is new for perl v5.9.0

=head1 DESCRIPTION

This document describes differences between the 5.8.0 release and
the 5.9.0 release.

=head1 Incompatible Changes

=head1 Core Enhancements

=head2 Tied Arrays with Negative Array Indices

Formerly, the indices passed to C<FETCH>, C<STORE>, C<EXISTS>, and
C<DELETE> methods in tied array class were always non-negative.  If
the actual argument was negative, Perl would call FETCHSIZE implicitly
and add the result to the index before passing the result to the tied
array method.  This behavior is now optional.  If the tied array class
contains a package variable named C<$NEGATIVE_INDICES> which is set to
a true value, negative values will be passed to C<FETCH>, C<STORE>,
C<EXISTS>, and C<DELETE> unchanged.

=head2 Fewer parentheses needed with C<? :>

The grammar of the conditional operator (C<$x ? $y : $z>) has been
broadened so that any operator may appear between the C<?> and the
C<:> without parentheses.  Previously, the comma operator and the
low-precedence logical operators had required parentheses in this
context.  For instance, you may now write

     $x ? $a and $b : $c

as a shorter version of the more explicit

     $x ? ($a and $b) : $c

Perl is now compatible with C in this regard. However, writing the
parentheses is still recommended as a matter of style.

=head1 Modules and Pragmata

=head1 Utility Changes

=head1 New Documentation

=head1 Performance Enhancements

=head1 Installation and Configuration Improvements

=head1 Selected Bug Fixes

=head1 New or Changed Diagnostics

=head1 Changed Internals

=head1 New Tests

=head1 Known Problems

=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://bugs.perl.org/ .  There may also be
information at http://www.perl.com/ , 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 for 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