4 This has been completed up to a75c6ed6bbe.
8 [ this is a template for a new perldelta file. Any text flagged as
9 XXX needs to be processed before release. ]
11 perldelta - what is new for perl v5.15.8
15 This document describes differences between the 5.15.7 release and
18 If you are upgrading from an earlier release such as 5.15.6, first read
19 L<perl5157delta>, which describes differences between 5.15.6 and
24 XXX Any important notices here
26 =head1 Core Enhancements
28 XXX New core language features go here. Summarise user-visible core language
29 enhancements. Particularly prominent performance optimisations could go
30 here, but most should go in the L</Performance Enhancements> section.
32 [ List each enhancement as a =head2 entry ]
34 =head2 Improved ability to mix locales and Unicode, including UTF-8 locales
36 An optional parameter has been added to C<use locale>
38 use locale ':not_characters';
40 which tells Perl to use all but the C<LC_CTYPE> and C<LC_COLLATE>
41 portions of the current locale. Instead, the character set is assumed
42 to be Unicode. This allows locales and Unicode to be seamlessly mixed,
43 including the increasingly frequent UTF-8 locales. When using this
44 hybrid form of locales, the C<:locale> layer to the L<open> pragma can
45 be used to interface with the file system, and there are CPAN modules
46 available for ARGV and environment variable conversions.
48 Full details are in L<perllocale>.
50 =head2 New function C<fc> and corresponding escape sequence C<\F> for Unicode foldcase
52 Unicode foldcase is an extension to lowercase that gives better results
53 when comparing two strings case-insensitively. It has long been used
54 internally in regular expression C</i> matching. Now it is available
55 explicitly through the new C<fc> function call (enabled by
56 S<C<"use feature 'fc'">>, or C<use v5.16>, or explicitly callable via
57 C<CORE::fc>) or through the new C<\F> sequence in double-quotish
60 Full details are in L<perlfunc/fc>.
64 XXX Any security-related notices go here. In particular, any security
65 vulnerabilities closed should be noted here rather than in the
66 L</Selected Bug Fixes> section.
68 [ List each security issue as a =head2 entry ]
70 =head1 Incompatible Changes
72 XXX For a release on a stable branch, this section aspires to be:
74 There are no changes intentionally incompatible with 5.XXX.XXX
75 If any exist, they are bugs, and we request that you submit a
76 report. See L</Reporting Bugs> below.
78 [ List each incompatible change as a =head2 entry ]
80 =head2 Special blocks called in void context
82 Special blocks (C<BEGIN>, C<CHECK>, C<INIT>, C<UNITCHECK>, C<END>) are now
83 called in void context. This avoids wasteful copying of the result of the
84 last statement [perl #108794].
86 =head2 The C<overloading> pragma and regexp objects
88 With C<no overloading>, regular expression objects returned by C<qr//> are
89 now stringified as "Regexp=REGEXP(0xbe600d)" instead of the regular
90 expression itself [perl #108780].
94 XXX Any deprecated features, syntax, modules etc. should be listed here.
95 In particular, deprecated modules should be listed here even if they are
96 listed as an updated module in the L</Modules and Pragmata> section.
98 [ List each deprecation as a =head2 entry ]
100 =head1 Performance Enhancements
102 XXX Changes which enhance performance without changing behaviour go here. There
103 may well be none in a stable release.
105 [ List each enhancement as a =item entry ]
115 =head1 Modules and Pragmata
117 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
118 go here. If Module::CoreList is updated, generate an initial draft of the
119 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
120 entries to STDOUT. Results can be pasted in place of the '=head2' entries
121 below. A paragraph summary for important changes should then be added by hand.
122 In an ideal world, dual-life modules would have a F<Changes> file that could be
125 [ Within each section, list entries as a =item entry ]
127 =head2 New Modules and Pragmata
137 =head2 Updated Modules and Pragmata
143 L<B> has been upgraded from version 1.33 to version 1.34.
145 C<B::COP> now has a C<stashflags> method, corresponding to a new internal
146 field added in 5.15.4 [perl #108860].
150 L<Compress::Raw::Bzip2> has been upgraded from version 2.045 to version 2.048.
154 L<Compress::Raw::Zlib> has been upgraded from version 2.045 to version 2.048.
158 L<Compress::Zlib> has been upgraded from version 2.046 to version 2.048.
162 L<DB_File> has been upgraded from version 1.824 to version 1.826.
166 L<diagnostics> has been upgraded from version 1.27 to version 1.28.
168 When searching for F<perldiag.pod>, it no longer uses paths that were only
169 relevant on Perl 5.004 and earlier.
173 L<IPC::Cmd> has been upgraded from version 0.72 to version 0.76.
177 L<Math::Complex> has been upgraded from version 1.58 to version 1.59.
179 This avoids a new core warning.
183 L<Pod::Parser> has been upgraded from version 1.37 to version 1.51.
187 L<Time::HiRes> has been upgraded from version 1.9724 to version 1.9725.
189 There is an important bugfix for C<Time::HiRes::stat()>.
193 L<Unicode::UCD> has been upgraded from version 0.39 to 0.40.
195 The only change is to fix a formatting error in the Pod.
199 =head2 Removed Modules and Pragmata
211 XXX Changes to files in F<pod/> go here. Consider grouping entries by
212 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
214 =head2 New Documentation
216 XXX Changes which create B<new> files in F<pod/> go here.
220 XXX Description of the purpose of the new file here
222 =head2 Changes to Existing Documentation
224 XXX Changes which significantly change existing files in F<pod/> go here.
225 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
234 XXX Description of the change here
240 The following additions or changes have been made to diagnostic output,
241 including warnings and fatal error messages. For the complete list of
242 diagnostic messages, see L<perldiag>.
244 XXX New or changed warnings emitted by the core's C<C> code go here. Also
245 include any changes in L<perldiag> that reconcile it to the C<C> code.
247 [ Within each section, list entries as a =item entry that links to perldiag,
252 L<Invalid version object|perldiag/"Invalid version object">
255 =head2 New Diagnostics
257 XXX Newly added diagnostic messages go here
265 XXX L<message|perldiag/"message">
275 XXX L<message|perldiag/"message">
279 =head2 Changes to Existing Diagnostics
281 XXX Changes (i.e. rewording) of diagnostic messages go here
287 XXX Describe change here
291 =head1 Utility Changes
293 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
294 here. Most of these are built within the directories F<utils> and F<x2p>.
296 [ List utility changes as a =head3 entry for each utility and =item
297 entries for each change
298 Use L<XXX> with program names to get proper documentation linking. ]
310 =head1 Configuration and Compilation
312 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
313 go here. Any other changes to the Perl build process should be listed here.
314 However, any platform-specific changes should be listed in the
315 L</Platform Support> section, instead.
317 [ List changes as a =item entry ].
329 XXX Any significant changes to the testing of a freshly built perl should be
330 listed here. Changes which create B<new> files in F<t/> go here as do any
331 large changes to the testing harness (e.g. when parallel testing was added).
332 Changes to existing files in F<t/> aren't worth summarising, although the bugs
333 that they represent may be covered elsewhere.
335 [ List each test improvement as a =item entry ]
345 =head1 Platform Support
347 XXX Any changes to platform support should be listed in the sections below.
349 [ Within the sections, list each platform as a =item entry with specific
350 changes as paragraphs below it. ]
354 XXX List any platforms that this version of perl compiles on, that previous
355 versions did not. These will either be enabled by new files in the F<hints/>
356 directories, or new subdirectories and F<README> files at the top level of the
361 =item XXX-some-platform
367 =head2 Discontinued Platforms
369 XXX List any platforms that this version of perl no longer compiles on.
373 =item XXX-some-platform
379 =head2 Platform-Specific Notes
381 XXX List any changes for specific platforms. This could include configuration
382 and compilation changes or changes in portability/compatibility. However,
383 changes within modules for platforms should generally be listed in the
384 L</Modules and Pragmata> section.
388 =item XXX-some-platform
394 =head1 Internal Changes
396 XXX Changes which affect the interface available to C<XS> code go here.
397 Other significant internal changes for future core maintainers should
400 [ List each change as a =item entry ]
410 =head1 Selected Bug Fixes
412 XXX Important bug fixes in the core language are summarised here.
413 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
414 L</Modules and Pragmata>.
416 [ List each fix as a =item entry ]
422 C<~~> now correctly handles the precedence of Any~~Object, and is not tricked
423 by an overloaded object on the left-hand side.
427 C<stat _> no longer warns about unopened filehandles [perl #71002].
431 C<stat> on an unopened filehandle now warns consistently, instead of
432 skipping the warning at times.
436 A change in an earlier 5.15 release caused warning hints to propagate into
437 C<do $file>. This has been fixed [rt.cpan.org #72767].
441 Starting with 5.12.0, Perl used to get its internal bookkeeping muddled up
442 after assigning C<${ qr// }> to a hash element and locking it with
443 L<Hash::Util>. This could result in double frees, crashes or erratic
448 In 5.15.7, some typeglobs in the CORE namespace were made read-only by
449 mistake. This has been fixed [rt.cpan.org #74289].
453 C<-t> now works when stacked with other filetest operators [perl #77388].
457 Stacked filetest operators now only call FETCH once on a tied argument.
461 =head1 Known Problems
463 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
464 tests that had to be C<TODO>ed for the release would be noted here, unless
465 they were specific to a particular platform (see below).
467 This is a list of some significant unfixed bugs, which are regressions
468 from either 5.XXX.XXX or 5.XXX.XXX.
470 [ List each fix as a =item entry ]
482 XXX If any significant core contributor has died, we've added a short obituary
485 =head1 Acknowledgements
487 XXX Generate this with:
489 perl Porting/acknowledgements.pl v5.15.7..HEAD
491 =head1 Reporting Bugs
493 If you find what you think is a bug, you might check the articles
494 recently posted to the comp.lang.perl.misc newsgroup and the perl
495 bug database at http://rt.perl.org/perlbug/ . There may also be
496 information at http://www.perl.org/ , the Perl Home Page.
498 If you believe you have an unreported bug, please run the L<perlbug>
499 program included with your release. Be sure to trim your bug down
500 to a tiny but sufficient test case. Your bug report, along with the
501 output of C<perl -V>, will be sent off to perlbug@perl.org to be
502 analysed by the Perl porting team.
504 If the bug you are reporting has security implications, which make it
505 inappropriate to send to a publicly archived mailing list, then please send
506 it to perl5-security-report@perl.org. This points to a closed subscription
507 unarchived mailing list, which includes
508 all the core committers, who will be able
509 to help assess the impact of issues, figure out a resolution, and help
510 co-ordinate the release of patches to mitigate or fix the problem across all
511 platforms on which Perl is supported. Please only use this address for
512 security issues in the Perl core, not for modules independently
517 The F<Changes> file for an explanation of how to view exhaustive details
520 The F<INSTALL> file for how to build Perl.
522 The F<README> file for general stuff.
524 The F<Artistic> and F<Copying> files for copyright information.