[ 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 v5.35.6
+perldelta - what is new for perl v5.35.9
=head1 DESCRIPTION
-This document describes differences between the 5.35.5 release and the 5.35.6
+This document describes differences between the 5.35.8 release and the 5.35.9
release.
-If you are upgrading from an earlier release such as 5.35.4, first read
-L<perl5355delta>, which describes differences between 5.35.4 and 5.35.5.
+If you are upgrading from an earlier release such as 5.35.7, first read
+L<perl5358delta>, which describes differences between 5.35.7 and 5.35.8.
=head1 Notice
[ List each enhancement as a =head2 entry ]
-=head2 C<use v5.36> now disables bareword_filehandles, indirect, and multidimensional
+=head2 @_ is now experimental within signatured subs
-The C<:5.36> bundle, loaded by C<use v5.36>, no longer includes
-C<bareword_filehandles>, C<indirect>, or C<multidimensional> meaning that these
-discouraged forms of syntax will not be allowed within the scope of that
-version declaration.
+Even though subroutine signatures currently remain experimental, use of the
+default arguments array (C<@_>) with a subroutine that has a signature is
+specifically also experimental, with its own warning category. Silencing the
+C<experimental::signatures> warning category is not sufficient to dismiss
+this. The new warning is emitted with the category name
+C<experimental::args_array_with_signatures>.
-This will also affect C<use v5.35.x>, even on subversions of v5.35 prior to
-this one.
+Any subroutine that has a signature and tries to make use of the defaults
+argument array or an element thereof (C<@_> or C<$_[INDEX]>), either
+explicitly or implicitly (such as C<shift> or C<pop> with no argument) will
+provoke a warning at compile-time:
+
+ use experimental 'signatures';
+
+ sub f ($x, $y = 123) {
+ say "The first argument is $_[0]";
+ }
+
+Z<>
+
+ Use of @_ in array element with signatured subroutine is experimental
+ at file.pl line 4.
+
+The behaviour of code which attempts to do this is no longer specified, and
+may be subject to change in a future version.
+
+=head2 The C<isa> operator is no longer experimental
+
+Introduced in Perl version 5.32.0, this operator has remained unchanged
+since then. The operator is now considered a stable languauge feature.
+
+For more detail see L<perlop/Class Instance Operator>.
=head1 Security
XXX Any deprecated features, syntax, modules etc. should be listed here.
+=head2 Downgrading a C<use VERSION> statement to below v5.11
+
+Attempting to issue a second C<use VERSION> statement that requests a version
+lower than C<v5.11> when an earlier statement that requested a version at
+least C<v5.11> has already been seen, will now print a deprecation warning.
+
+For example:
+
+ use v5.14;
+ say "The say statement is permitted";
+ use v5.8; # This will print a warning
+ print "We must use print\n";
+
+This is because of an intended related change to the interaction between
+C<use VERSION> and C<use strict>. If you specify a version >= 5.11, strict is
+enabled implicitly. If you request a version < 5.11, strict will become
+disabled I<even if you had previously written> C<use strict>. This was not
+the previous behaviour of C<use VERSION>, which at present will track
+explicitly-enabled strictness flags independently.
+
+Code which wishes to mix versions in this manner should use lexical scoping
+with block syntax to ensure that the differently versioned regions remain
+lexically isolated.
+
+ {
+ use v5.14;
+ say "The say statement is permitted";
+ }
+ {
+ use v5.8; # No warning is emitted
+ print "We must use print\n";
+ }
+
=head2 Module removals
XXX Remove this section if not applicable.
=item *
-XXX Describe change here
+L<Subroutine %s redefined|perldiag/"Subroutine %s redefined">
+
+Localized subroutine redefinitions no longer trigger this warning.
=back
=over 4
-=item DOS/DJGPP
-
-DJGPP is a port of the GNU toolchain to 32-bit x86 systems running
-DOS. The last known attempt to build Perl on it was on 5.20, which
-only got as far as building miniperl.
-
-=item AT&T UWIN
+=item XXX-some-platform
-UWIN is a UNIX compatibility layer for Windows. It was last released
-in 2012 and has been superseded by Cygwin these days.
+XXX
=back
=item *
-XXX
+New equality-test functions C<sv_numeq> and C<sv_streq> have been added, along
+with C<..._flags>-suffixed variants. These expose a simple and consistent API
+to perform numerical or string comparison which is aware of operator
+overloading.
=back
=item *
-Setting a breakpoint on a BEGIN or equivalently a C<use> statement
-could cause a memory write to a freed C<dbstate> op. [github #19198]
+XXX
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.35.5..HEAD
+ perl Porting/acknowledgements.pl v5.35.8..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff