and
C<int_p_sign_posn>.
-=head2 Better heuristics on older platforms for determining locale UTF8ness
+=head2 Better heuristics on older platforms for determining locale UTF-8ness
On platforms that implement neither the C99 standard nor the POSIX 2001
-standard, determining if the current locale is UTF8 or not depends on
+standard, determining if the current locale is UTF-8 or not depends on
heuristics. These are improved in this release.
=head2 Aliasing via reference
foreach \%hash (@array_of_hash_refs) { ... }
-This feature is experimental and must be enabled via C<use feature
-'refaliasing'>. It will warn unless the C<experimental::refaliasing>
+This feature is experimental and must be enabled via S<C<use feature
+'refaliasing'>>. It will warn unless the C<experimental::refaliasing>
warnings category is disabled.
See L<perlref/Assigning to References>
Floating point values are able to hold the special values infinity, negative
infinity, and NaN (not-a-number). Now we more robustly recognize and
-propagate the value in computations, and on output normalize them to C<Inf>,
-C<-Inf>, or C<NaN>.
+propagate the value in computations, and on output normalize them to
+an infinite value or not-a-number.
See also the L<POSIX> enhancements.
As a completely new feature, hexadecimal floating point literals
(like C<0x1.23p-4>) are now supported, and they can be output with
-
C<printf "%a">. See L<perldata/Scalar value constructors> for more
+
S<C<printf "%a">>. See L<perldata/Scalar value constructors> for more
details.
=head2 Packing infinity or not-a-number into a character is now fatal
List slices now return an empty list only if the original list was empty
(or if there are no indices). Formerly, a list slice would return an empty
list if all indices fell outside the original list; now it returns a list
-of undef values in that case.
+of C<undef> values in that case.
L<[perl #114498]|https://rt.perl.org/Ticket/Display.html?id=114498>.
=head2 C<\N{}> with a sequence of multiple spaces is now a fatal error
-E.g. C<\N{TOO MANY SPACES}> or C<\N{TRAILING SPACE }>.
+E.g. S<C<\N{TOOE<nbsp>E<nbsp>MANY SPACES}>> or S<C<\N{TRAILING SPACE }>>.
This has been deprecated since v5.18.
=head2 S<C<use UNIVERSAL '...'>> is now a fatal error
In prior releases, failure to do this raised a deprecation warning.
-=head2 Splitting the tokens C<(?> and C<(*> in regular expressions is
-now a fatal compilation error.
+=head2 Splitting the tokens C<(?> and C<(*> in regular expressions is now a fatal compilation error.
These had been deprecated since v5.18.
ASCII or UTF-8. However, it affects all modules globally, leading
to wrong answers and segmentation faults. New scripts should be written
in UTF-8; old scripts should be converted to UTF-8, which is easily done
-with the L<encoding> pragma.
+with the L<piconv> utility.
=head2 Use of non-graphic characters in single-character variable names
is evaluated. This can break the closure behaviour in those cases where
C<$var> is subsequently modified, since the subroutine won't return the
changed value. (Note that this all only applies to anonymous subroutines
-with an empty prototype (C<sub ()>).)
+with an empty prototype (S<C<sub ()>>).)
This usage is now deprecated in those cases where the variable could be
modified elsewhere. Perl detects those cases and emits a deprecation
bracketed character classes (those enclosed in square brackets:
C<[...]>).
-=head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now
-deprecated
+=head2 Using a NO-BREAK space in a character alias for C<\N{...}> is now deprecated
This non-graphic character is essentially indistinguishable from a
regular space, and so should not be allowed. See
=item *
C<join> is now subject to constant folding. So for example
-C<join "-", "a", "b"> is converted at compile-time to C<"a-b">.
+S<C<join "-", "a", "b">> is converted at compile-time to C<"a-b">.
Moreover, C<join> with a scalar or constant for the separator and a
single-item list to join is simplified to a stringification, and the
separator doesn't even get evaluated.
=head1 Modules and Pragmata
-XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
-go here. If Module::CoreList is updated, generate an initial draft of the
-following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
-for important changes should then be added by hand. In an ideal world,
-dual-life modules would have a F<Changes> file that could be cribbed.
+Many of the libraries distributed with perl have been upgraded since v5.20.0.
+For a complete list of changes, run:
-[ Within each section, list entries as a =item entry ]
+ corelist --diff 5.20.0 5.22.0
-=head2 New Modules and Pragmata
+You can substitute your favorite version in place of 5.20.0, too.
-=over 4
-
-=item *
-
-XXX
-
-=back
+=head2 Removed Modules and Pragmata
-=head2 Updated Modules and Pragmata
+The following modules (and associated modules) have been removed from the core
+perl distribution:
=over 4
=item *
-L<ExtUtils::MakeMaker> has been upgraded from version 6.98 to 7.04_01.
-
-Some changes from github have been backported to prevent failures and
-noise on Win32 when C<chcp> is missing or unavailable.
-L<[perl #123998]|https://rt.perl.org/Ticket/Display.html?id=123998>
-
-=back
-
-=head2 Removed Modules and Pragmata
-
-=over 4
+L<CGI>
=item *
-XXX
+L<Module::Build>
=back
=head2 Changes to Existing Documentation
+=head3 L<perlaix>
+
+=over 4
+
+=item *
+
+A note on long doubles has been added.
+
+=back
+
+
=head3 L<perlapi>
=over 4
=item *
-C<sv_usepvn_flags> - fix documentation to mention the use of C<NewX> instead of
+C<sv_usepvn_flags> - fix documentation to mention the use of C<Newx> instead of
C<malloc>.
L<[perl #121869]|https://rt.perl.org/Ticket/Display.html?id=121869>
The syntax of single-character variable names has been brought
up-to-date and more fully explained.
+=item *
+
+Hexadecimal floating point numbers are described, as are infinity and
+NaN.
+
=back
=head3 L<perlebcdic>
=back
+=head3 L<perlfilter>
+
+=over 4
+
+=item *
+
+Added a L<LIMITATIONS|perlfilter/LIMITATIONS> section.
+
+=back
+
+
=head3 L<perlfunc>
=over 4
=back
+=head3 L<perlhack>
+
+=over 4
+
+=item *
+
+A note has been added about running on platforms with non-ASCII
+character sets
+
+=item *
+
+A note has been added about performance testing
+
+=back
+
=head3 L<perlhacktips>
=over 4
L<[perl #121431]|https://rt.perl.org/Ticket/Display.html?id=121431>
+=item *
+
+Information is given about writing test files portably to non-ASCII
+platforms.
+
+=item *
+
+A note has been added about how to get a C language stack backtrace.
+
+=back
+
+=head3 L<perlhpux>
+
+=over 4
+
+=item *
+
+Note that the message "Redeclaration of "sendpath" with a different
+storage class specifier" is harmless.
+
+=back
+
+=head3 L<perllocale>
+
+=over 4
+
+=item *
+
+Updated for the enhancements in v5.22, along with some clarifications.
+
=back
=head3 L<perlmodstyle>
=back
+=head3 L<perlop>
+
+=over 4
+
+=item *
+
+Updated for the enhancements in v5.22, along with some clarifications.
+
+=back
+
+=head3 L<perlpodspec>
+
+=over 4
+
+=item *
+
+The specification of the pod language is changing so that the default
+encoding of pods that aren't in UTF-8 (unless otherwise indicated) is
+CP1252 instead of ISO 8859-1 (Latin1).
+
+=back
+
=head3 L<perlpolicy>
=over 4
The conditions for marking an experimental feature as non-experimental are now
set out.
+=item *
+
+Clarification has been made as to what sorts of changes are permissible in
+maintenance releases.
+
=back
=head3 L<perlport>
=item *
The description of the C</x> modifier has been clarified to note that
-comments cannot be continued onto the next line by escaping them.
+comments cannot be continued onto the next line by escaping them; and
+there is now a list of all the characters that are considered whitespace
+by this modifier.
+
+=item *
+
+The new C</n> modifier is described.
+
+=item *
+
+A note has been added on how to make bracketed character class ranges
+portable to non-ASCII machines.
=back
=back
+=head3 L<perlref>
+
+=over 4
+
+=item *
+
+A new section has been added
+L<Assigning to References|perlref/Assigning to References>
+
+=back
+
=head3 L<perlsec>
=over 4
=item *
This has had extensive revisions to bring it up-to-date with current
-Unicode support and to make it more readable.
+Unicode support and to make it more readable. Notable is that Unicode
+7.0 changed what it should do with non-characters. Perl retains the old
+way of handling for reasons of backward compatibility. See
+L<perlunicode/Noncharacter code points>.
=back
=item *
-Further clarify version number representations and usage.
+C<$]> is no longer listed as being deprecated. Instead, discussion has
+been added on the advantages and disadvantages of using it versus
+C<$^V>.
+
+=item *
+
+C<${^ENCODING}> is now marked as deprecated.
+
+=item *
+
+The entry for C<%^H> has been clarified to indicate it can only handle
+simple values.
=back
(D deprecated) The C<< /\C/ >> character class was deprecated in v5.20, and
now emits a warning. It is intended that it will become an error in v5.24.
This character class matches a single byte even if it appears within a
-multi-byte character, breaks encapsulation, and can corrupt utf8
+multi-byte character, breaks encapsulation, and can corrupt UTF-8
strings.
=item *
(W numeric) You tried to execute the
L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
-C<-Inf>) or C<NaN> times, which doesn't make sense.
+C<-Inf>) or NaN times, which doesn't make sense.
=item *
(W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
one), a multi-byte character was encountered. Perl considers this
-character to be the specified Unicode code point. Combining non-UTF8
+character to be the specified Unicode code point. Combining non-UTF-8
locales and Unicode is dangerous. Almost certainly some characters
will have two different representations. For example, in the ISO 8859-7
(Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
L<Missing or undefined argument to require|perldiag/Missing or undefined argument to require>
-(F) You tried to call require with no argument or with an undefined
-value as an argument. Require expects either a package name or a
+(F) You tried to call C<require> with no argument or with an undefined
+value as an argument. C<require> expects either a package name or a
file-specification as an argument. See L<perlfunc/require>.
-Formerly, C<require> with no argument or undef warned about a Null filename.
+Formerly, C<require> with no argument or C<undef> warned about a Null filename.
=back
=item *
The list form of piped open has been implemented for Win32. Note: unlike
-C< system LIST >> this does not fall back to the shell.
+C<system LIST> this does not fall back to the shell.
L<[perl #121159]|https://rt.perl.org/Ticket/Display.html?id=121159>
=item *
=item *
In the experimental C<:win32> layer, a crash in C<open> was fixed. Also
-opening C</dev/null> (which works under Win32 Perl's default C<:unix>
+opening F</dev/null> (which works under Win32 Perl's default C<:unix>
layer) was implemented for C<:win32>.
L<[perl #122224]|https://rt.perl.org/Ticket/Display.html?id=122224>
=item *
The C<sv_catpvn_flags()> function accepts C<SV_CATBYTES> and C<SV_CATUTF8>
-flags, which specify whether the appended string is bytes or utf8,
+flags, which specify whether the appended string is bytes or UTF-8,
respectively. (These flags have in fact been present since 5.16.0, but
were formerly not regarded as part of the API.)
The defines and labels for the flags in the C<op_private> field of OPs are now
auto-generated from data in F<regen/op_private>. The noticeable effect of this
is that some of the flag output of C<Concise> might differ slightly, and the
-flag output of C<perl -Dx> may differ considerably (they both use the same set
+flag output of S<C<perl -Dx>> may differ considerably (they both use the same set
of labels now). Also, debugging builds now have a new assertion in
C<op_free()> to ensure that the op doesn't have any unrecognized flags set in
C<op_private>.
=item *
-Pad names are now always UTF8. The C<PadnameUTF8> macro always returns
+Pad names are now always UTF
-8. The C<PadnameUTF8> macro always returns
true. Previously, this was effectively the case already, but any support
for two different internal representations of pad names has now been
removed.
=item *
-Perl 5.14.0 introduced a bug whereby C<eval { LABEL: }> would crash. This
+Perl 5.14.0 introduced a bug whereby S<C<eval { LABEL: }>> would crash. This
has been fixed.
L<[perl #123652]|https://rt.perl.org/Ticket/Display.html?id=123652>.
=item *
C<prototype()> with no arguments used to read the previous item on the
-stack, so C<print "foo", prototype()> would print foo's prototype. It has
-been fixed to infer C<$_> instead.
+stack, so S<C<print "foo", prototype()>> would print foo's prototype.
+It has been fixed to infer C<$_> instead.
L<[perl #123514]|https://rt.perl.org/Ticket/Display.html?id=123514>.
=item *
=item *
Fix a couple of string grow size calculation overflows; in particular,
-a repeat expression like C<33 x ~3> could cause a large buffer
+a repeat expression like S<C<33 x ~3>> could cause a large buffer
overflow since the new output buffer size was not correctly handled by
-SvGROW(). An expression like this now properly produces a memory wrap
+C<SvGROW()>. An expression like this now properly produces a memory wrap
panic.
L<[perl #123554]|https://rt.perl.org/Ticket/Display.html?id=123554>.
=item *
-In Perl 5.20.0, C<$^N> accidentally had the internal UTF8 flag turned off
+In Perl 5.20.0, C<$^N> accidentally had the internal UTF-8 flag turned off
if accessed from a code block within a regular expression, effectively
-UTF8-encoding the value. This has been fixed.
+UTF-8-encoding the value. This has been fixed.
L<[perl #123135]|https://rt.perl.org/Ticket/Display.html?id=123135>.
=item *
=item *
On some systems, such as VMS, C<crypt> can return a non-ASCII string. If a
-scalar assigned to had contained a UTF8 string previously, then C<crypt>
-would not turn off the UTF8 flag, thus corrupting the return value. This
-would happen with C<$lexical = crypt ...>.
+scalar assigned to had contained a UTF-8 string previously, then C<crypt>
+would not turn off the UTF-8 flag, thus corrupting the return value. This
+would happen with S<C<$lexical = crypt ...>>.
=item *
=item *
-C<< s///e >> on tainted utf8 strings corrupted C<< pos() >>. This bug,
+C<< s///e >> on tainted UTF-8 strings corrupted C<< pos() >>. This bug,
introduced in 5.20, is now fixed.
L<[perl #122148]|https://rt.perl.org/Ticket/Display.html?id=122148>.
=item *
-Failing to compile C<use Foo> in an eval could leave a spurious
+Failing to compile C<use Foo> in an C<eval> could leave a spurious
C<BEGIN> subroutine definition, which would produce a "Subroutine
BEGIN redefined" warning on the next use of C<use>, or other C<BEGIN>
block.
=item *
-Loading UTF8 tables during a regular expression match could cause assertion
+Loading UTF-8 tables during a regular expression match could cause assertion
failures under debugging builds if the previous match used the very same
regular expression.
L<[perl #122747]|https://rt.perl.org/Ticket/Display.html?id=122747>
=item *
-Aliasing (e.g., via C<*x = *y>) could confuse list assignments that mention the
+Aliasing (e.g., via S<C<*x = *y>>) could confuse list assignments that mention the
two names for the same variable on either side, causing wrong values to be
assigned.
L<[perl #15667]|https://rt.perl.org/Ticket/Display.html?id=15667>
=item *
-An optimization in C<split> to treat C<split /^/> like C<split /^/m> had the
-unfortunate side-effect of also treating C<split /\A/> like C<split /^/m>,
-which it should not. This has been fixed. (Note, however, that C<split /^x/>
-does not behave like C<split /^x/m>, which is also considered to be a bug and
+An optimization in C<split> to treat S<C<split /^/>> like S<C<split /^/m>> had the
+unfortunate side-effect of also treating S<C<split /\A/>> like S<C<split /^/m>>,
+which it should not. This has been fixed. (Note, however, that S<C<split /^x/>>
+does not behave like S<C<split /^x/m>>, which is also considered to be a bug and
will be fixed in a future version.)
L<[perl #122761]|https://rt.perl.org/Ticket/Display.html?id=122761>
=item *
Some patterns including code blocks with syntax errors, such as
-C</ (?{(^{})/>, would hang or fail assertions on debugging builds. Now
+S<C</ (?{(^{})/>>, would hang or fail assertions on debugging builds. Now
they produce errors.
=item *
=item *
-During the optimization phase of a regexp compilation, we no longer
-recurse into C<GOSUB>/C<GOSTART> when the internal C<SCF_DO_SUBSTR> flag
-is false. This prevents the optimizer from running "forever" and
-exhausting all memory.
+The optimization phase of a regexp compilation could run "forever" and
+exhaust all memory under certain circumstances; now fixed.
L<[perl #122283]|https://rt.perl.org/Ticket/Display.html?id=122283>.
=item *
=item *
+C<pack>-ing a NaN on a perl compiled with Visual C 6 does not behave properly,
+leading to a test failure in F<t/op/infnan.t>.
+L<[perl 125203]|https://rt.perl.org/Ticket/Display.html?id=125203>
+
+=item *
+
A goal is for Perl to be able to be recompiled to work reasonably well on any
Unicode version. In Perl 5.22, though, the earliest such version is Unicode
5.1 (current is 7.0).
=head1 Acknowledgements
-XXX Generate this with:
-
- perl Porting/acknowledgements.pl v5.20.0..HEAD
+Perl 5.22.0 represents approximately 12 months of development since Perl 5.20.0
+and contains approximately 590,000 lines of changes across 2,400 files from 94
+authors.
+
+Excluding auto-generated files, documentation and release tools, there were
+approximately 370,000 lines of changes to 1,500 .pm, .t, .c and .h files.
+
+Perl continues to flourish into its third decade thanks to a vibrant community
+of users and developers. The following people are known to have contributed the
+improvements that became Perl 5.22.0:
+
+Aaron Crane, Abhijit Menon-Sen, Abigail, Alberto Simões, Alex Solovey, Alex
+Vandiver, Alexandr Ciornii, Alexandre (Midnite) Jousset, Andreas König,
+Andreas Voegele, Andrew Fresh, Andy Dougherty, Anthony Heading, Aristotle
+Pagaltzis, brian d foy, Brian Fraser, Chad Granum, Chris 'BinGOs' Williams,
+Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, Darin McBride, Dave
+Rolsky, David Golden, David Mitchell, David Wheeler, Dmitri Tikhonov, Doug
+Bell, E. Choroba, Ed J, Eric Herman, Father Chrysostomos, George Greer, Glenn
+D. Golden, Graham Knop, H.Merijn Brand, Herbert Breunung, Hugo van der Sanden,
+James E Keenan, James McCoy, James Raspass, Jan Dubois, Jarkko Hietaniemi,
+Jasmine Ngan, Jerry D. Hedden, Jim Cromie, John Goodyear, kafka, Karen
+Etheridge, Karl Williamson, Kent Fredric, kmx, Lajos Veres, Leon Timmermans,
+Lukas Mai, Mathieu Arnold, Matthew Horsfall, Max Maischein, Michael Bunk,
+Nicholas Clark, Niels Thykier, Niko Tyni, Norman Koch, Olivier Mengué, Peter
+John Acklam, Peter Martini, Petr Písař, Philippe Bruhat (BooK), Pierre
+Bogossian, Rafael Garcia-Suarez, Randy Stauner, Reini Urban, Ricardo Signes,
+Rob Hoelz, Rostislav Skudnov, Sawyer X, Shirakata Kentaro, Shlomi Fish,
+Sisyphus, Slaven Rezic, Smylers, Steffen Müller, Steve Hay, Sullivan Beck,
+syber, Tadeusz Sośnierz, Thomas Sibley, Todd Rinaldo, Tony Cook, Vincent Pit,
+Vladimir Marek, Yaroslav Kuzmin, Yves Orton, Ævar Arnfjörð Bjarmason.
+
+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
https://perl5.git.perl.org / perl5.git / blobdiff