4 This has been completed up to 7cb18e1b02, except for:
5 04777d295957ad270188e4debf51b523e07cc5b0
6 c565ab54dc649bb62cd4d57149d7b2abb21df5f3
7 1c8d11ca3d0ce8bc11562f159b94c2c7e62dea6c
11 [ this is a template for a new perldelta file. Any text flagged as
12 XXX needs to be processed before release. ]
14 perldelta - what is new for perl v5.13.7
18 This document describes differences between the 5.13.6 release and
21 If you are upgrading from an earlier release such as 5.13.5, first read
22 L<perl5136delta>, which describes differences between 5.13.5 and
27 XXX Any important notices here
29 =head1 Core Enhancements
31 XXX New core language features go here. Summarise user-visible core language
32 enhancements. Particularly prominent performance optimisations could go
33 here, but most should go in the L</Performance Enhancements> section.
35 [ List each enhancement as a =head2 entry ]
37 =head2 Single term prototype
39 The C<+> prototype is a special alternative to C<$> that will act like
40 C<\[@%]> when given a literal array or hash variable, but will otherwise
41 force scalar context on the argument. This is useful for functions which
42 should accept either a literal array or an array reference as the argument:
46 die "Not an array or arrayref" unless ref $aref eq 'ARRAY';
50 When using the C<+> prototype, your function must check that the argument
51 is of an acceptable type.
53 =head2 C<use re '/flags';>
55 The C<re> pragma now has the ability to turn on regular expression flags
56 till the end of the lexical scope:
59 "foo" =~ / (.+) /; # /x implied
61 See L<re/'/flags' mode> for details.
63 =head2 Statement labels can appear in more places
65 Statement labels can now occur before any type of statement or declaration,
68 =head2 C<use feature "unicode_strings"> now applies to more regex matching
70 Another chunk of the L<perlunicode/The "Unicode Bug"> is fixed in this
71 release. Now, regular expressions compiled within the scope of the
72 "unicode_strings" feature (or under the "u" regex modifier (specifiable
73 currently only with infix notation C<(?u:...)> or via C<use re '/u'>)
74 will match the same whether or not the target string is encoded in utf8,
75 with regard to C<[[:posix:]]> character classes
77 Work is underway to add the case sensitive matching to the control of
78 this feature, but was not complete in time for this dot release.
80 =head2 Array and hash container functions accept references
82 All built-in functions that operate directly on array or hash
83 containers now also accept hard references to arrays or hashes:
85 |----------------------------+---------------------------|
86 | Traditional syntax | Terse syntax |
87 |----------------------------+---------------------------|
88 | push @$arrayref, @stuff | push $arrayref, @stuff |
89 | unshift @$arrayref, @stuff | unshift $arrayref, @stuff |
90 | pop @$arrayref | pop $arrayref |
91 | shift @$arrayref | shift $arrayref |
92 | splice @$arrayref, 0, 2 | splice $arrayref, 0, 2 |
93 | keys %$hashref | keys $hashref |
94 | keys @$arrayref | keys $arrayref |
95 | values %$hashref | values $hashref |
96 | values @$arrayref | values $arrayref |
97 | ($k,$v) = each %$hashref | ($k,$v) = each $hashref |
98 | ($k,$v) = each @$arrayref | ($k,$v) = each $arrayref |
99 |----------------------------+---------------------------|
101 This allows these built-in functions to act on long dereferencing chains
102 or on the return value of subroutines without needing to wrap them in
105 push @{$obj->tags}, $new_tag; # old way
106 push $obj->tags, $new_tag; # new way
108 for ( keys %{$hoh->{genres}{artists}} ) {...} # old way
109 for ( keys $hoh->{genres}{artists} ) {...} # new way
111 For C<push>, C<unshift> and C<splice>, the reference will auto-vivify
112 if it is not defined, just as if it were wrapped with C<@{}>.
114 Calling C<keys> or C<values> directly on a reference gives a substantial
115 performance improvement over explicit dereferencing.
117 For C<keys>, C<values>, C<each>, when overloaded dereferencing is
118 present, the overloaded dereference is used instead of dereferencing the
119 underlying reftype. Warnings are issued about assumptions made in the
120 following three ambiguous cases:
122 (a) If both %{} and @{} overloading exists, %{} is used
123 (b) If %{} overloading exists on a blessed arrayref, %{} is used
124 (c) If @{} overloading exists on a blessed hashref, @{} is used
128 XXX Any security-related notices go here. In particular, any security
129 vulnerabilities closed should be noted here rather than in the
130 L</Selected Bug Fixes> section.
132 [ List each security issue as a =head2 entry ]
134 =head1 Incompatible Changes
136 XXX For a release on a stable branch, this section aspires to be:
138 There are no changes intentionally incompatible with 5.XXX.XXX. If any
139 exist, they are bugs and reports are welcome.
141 [ List each incompatible change as a =head2 entry ]
143 =head2 Dereferencing typeglobs
145 If you assign a typeglob to a scalar variable:
149 the glob that is copied to C<$glob> is marked with a special flag
150 indicating that the glob is just a copy. This allows subsequent assignments
151 to C<$glob> to overwrite the glob. The original glob, however, is
154 Many Perl operators did not distinguish between these two types of globs.
155 This would result in strange behaviour in edge cases: C<untie $scalar>
156 would do nothing if the last thing assigned to the scalar was a glob
157 (because it treated it as C<untie *$scalar>, which unties a handle).
158 Assignment to a glob slot (e.g., C<(*$glob) = \@some_array>) would simply
159 assign C<\@some_array> to C<$glob>.
161 To fix this, the C<*{}> operator (including the C<*foo> and C<*$foo> forms)
162 has been modified to make a new immutable glob if its operand is a glob
163 copy. Various operators that make a distinction between globs and scalars
164 have been modified to treat only immutable globs as globs.
166 This causes an incompatible change in code that assigns a glob to the
167 return value of C<*{}> when that operator was passed a glob copy. Take the
168 following code, for instance:
173 The C<*$glob> on the second line returns a new immutable glob. That new
174 glob is made an alias to C<*bar>. Then it is discarded.
176 The upside to this incompatible change is that bugs
177 L<[perl #77496]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77496>,
178 L<[perl #77502]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77502>,
179 L<[perl #77508]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77508>,
180 L<[perl #77688]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77688>,
182 L<[perl #77812]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77812>,
183 and maybe others, too, have been fixed.
185 See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for even
190 XXX Any deprecated features, syntax, modules etc. should be listed here.
191 In particular, deprecated modules should be listed here even if they are
192 listed as an updated module in the L</Modules and Pragmata> section.
194 [ List each deprecation as a =head2 entry ]
196 =head1 Performance Enhancements
198 XXX Changes which enhance performance without changing behaviour go here. There
199 may well be none in a stable release.
201 [ List each enhancement as a =item entry ]
211 =head1 Modules and Pragmata
213 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
214 go here. If Module::CoreList is updated, generate an initial draft of the
215 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
216 entries to STDOUT. Results can be pasted in place of the '=head2' entries
217 below. A paragraph summary for important changes should then be added by hand.
218 In an ideal world, dual-life modules would have a F<Changes> file that could be
221 [ Within each section, list entries as a =item entry ]
223 =head2 New Modules and Pragmata
229 C<Unicode::Collate::CJK::JISX0208> module was added by the C<Unicode::Collate>
230 upgrade from 0.63 to 0.64. See below.
234 =head2 Updated Modules and Pragmata
240 C<Archive::Extract> has been upgraded from 0.44 to 0.46
242 Resolves an issue with NetBSD-current and its new unzip
247 C<B> has been upgraded from 1.24 to 1.25.
251 C<B::Deparse> has been upgraded from 0.99 to 1.01.
253 It fixes deparsing of C<our> followed by a variable with funny characters
254 (as permitted under the C<utf8> pragma)
255 L<[perl #33752]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=33752>.
259 C<CPAN> has been upgraded from 1.94_61 to 1.94_62
263 C<CPANPLUS> has been upgraded from 0.9007 to 0.9010
265 Fixes for the SQLite source engine and resolving of issues with the
266 testsuite when run under local::lib and/or cpanminus
270 C<CPANPLUS::Dist::Build> has been upgraded from 0.48 to 0.50
274 C<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
278 C<Fcntl> has been upgraded from 1.09 to 1.10.
282 C<File::Glob> has been upgraded from 1.09 to 1.10.
286 C<GDBM_File> has been upgraded from 1.11 to 1.12.
288 This fixes a memory leak when DBM filters are used.
292 C<Hash::Util> has been upgraded from 0.09 to 0.10.
296 C<Hash::Util::FieldHash> has been upgraded from 1.05 to 1.06.
300 C<I18N::Langinfo> has been upgraded from 0.06 to 0.07.
304 C<Locale::Maketext> has been upgraded from 1.16 to 1.17
308 C<Math::BigInt::FastCalc> has been upgraded from 0.22 to 0.23.
312 C<mro> has been upgraded from 1.04 to 1.05.
316 C<NDBM_File> has been upgraded from 1.09 to 1.10.
318 This fixes a memory leak when DBM filters are used.
322 C<ODBM_File> has been upgraded from 1.08 to 1.09.
324 This fixes a memory leak when DBM filters are used.
328 C<parent> has been upgraded from 0.223 to 0.224
332 C<POSIX> has been upgraded from 1.21 to 1.22.
336 C<re> has been upgraded from 0.13 to 0.14, for the sake of the new
337 C<use re "/flags"> pragma.
341 C<Safe> has been upgraded from 2.28 to 2.29.
343 It adds C<&version::vxs::VCMP> to the default share.
347 C<SDBM_File> has been upgraded from 1.07 to 1.08.
351 C<SelfLoader> has been upgraded from 1.17 to 1.18.
353 It now works in taint mode
354 L<[perl #72062]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=72062>.
358 C<Socket> has been upgraded from 1.90 to 1.91.
362 C<Sys::Hostname> has been upgraded from 1.13 to 1.14.
366 C<Unicode::Collate> has been upgraded from 0.63 to 0.64
368 This release newly adds locale C<ja> and the module
369 C<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
370 (CJK Unified Ideographs) in the JIS X 0208 order.
374 =head2 Removed Modules and Pragmata
386 XXX Changes to files in F<pod/> go here. Consider grouping entries by
387 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
389 =head2 New Documentation
391 XXX Changes which create B<new> files in F<pod/> go here.
395 XXX Description of the purpose of the new file here
397 =head2 Changes to Existing Documentation
399 XXX Changes which significantly change existing files in F<pod/> go here.
400 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
407 Array and hash slices in scalar context are now documented in L<perldata>.
411 L<perlform> and L<perllocale> have been corrected to state that
412 C<use locale> affects formats.
422 XXX Description of the change here
428 The following additions or changes have been made to diagnostic output,
429 including warnings and fatal error messages. For the complete list of
430 diagnostic messages, see L<perldiag>.
432 XXX New or changed warnings emitted by the core's C<C> code go here. Also
433 include any changes in L<perldiag> that reconcile it to the C<C> code.
435 [ Within each section, list entries as a =item entry ]
437 =head2 New Diagnostics
439 XXX Newly added diagnostic messages go here
449 =head2 Changes to Existing Diagnostics
451 XXX Changes (i.e. rewording) of diagnostic messages go here
461 =head1 Utility Changes
463 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
464 here. Most of these are built within the directories F<utils> and F<x2p>.
466 [ List utility changes as a =head3 entry for each utility and =item
467 entries for each change
468 Use L<XXX> with program names to get proper documentation linking. ]
480 =head1 Configuration and Compilation
482 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
483 go here. Any other changes to the Perl build process should be listed here.
484 However, any platform-specific changes should be listed in the
485 L</Platform Support> section, instead.
487 [ List changes as a =item entry ].
499 XXX Any significant changes to the testing of a freshly built perl should be
500 listed here. Changes which create B<new> files in F<t/> go here as do any
501 large changes to the testing harness (e.g. when parallel testing was added).
502 Changes to existing files in F<t/> aren't worth summarising, although the bugs
503 that they represent may be covered elsewhere.
505 [ List each test improvement as a =item entry ]
515 =head1 Platform Support
517 XXX Any changes to platform support should be listed in the sections below.
519 [ Within the sections, list each platform as a =item entry with specific
520 changes as paragraphs below it. ]
524 XXX List any platforms that this version of perl compiles on, that previous
525 versions did not. These will either be enabled by new files in the F<hints/>
526 directories, or new subdirectories and F<README> files at the top level of the
531 =item XXX-some-platform
537 =head2 Discontinued Platforms
539 XXX List any platforms that this version of perl no longer compiles on.
543 =item XXX-some-platform
549 =head2 Platform-Specific Notes
551 XXX List any changes for specific platforms. This could include configuration
552 and compilation changes or changes in portability/compatibility. However,
553 changes within modules for platforms should generally be listed in the
554 L</Modules and Pragmata> section.
560 Directory handles are now properly cloned when threads are created. In perl
561 5.13.6, child threads simply stopped inheriting directory handles. In
562 previous versions, threads would share handles, resulting in crashes.
566 =head1 Internal Changes
568 XXX Changes which affect the interface available to C<XS> code go here.
569 Other significant internal changes for future core maintainers should
572 [ List each test improvement as a =item entry ]
578 C<lex_start> has been added to the API, but is considered experimental.
582 A new C<parse_block> function has been added to the API
583 L<[perl #78222]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78222>.
587 A new, experimental API has been added for accessing the internal
588 structure that Perl uses for C<%^H>. See the functions beginning with
589 C<cophh_> in L<perlapi>.
593 A stash can now have a list of effective names in addition to its usual
594 name. The first effective name can be accessed via the C<HvENAME> macro,
595 which is now the recommended name to use in MRO linearisations (C<HvNAME>
596 being a fallback if there is no C<HvENAME>).
598 These names are added and deleted via C<hv_ename_add> and
599 C<hv_ename_delete>. These two functions are I<not> part of the API.
603 The way the parser handles labels has been cleaned up and refactored. As a
604 result, the C<newFOROP()> constructor function no longer takes a parameter
605 stating what label is to go in the state op.
609 The C<newWHILEOP()> and C<newFOROP()> functions no longer accept a line
610 number as a parameter.
614 A new C<parse_barestmt()> function has been added, for parsing a statement
619 A new C<parse_label()> function has been added, that parses a statement
620 labels, separate from statements.
624 The C<CvSTASH()> macro can now only be used as an rvalue. C<CvSTASH_set()>
625 has been added to replace assignment to C<CvSTASH()>. This is to ensure
626 that backreferences are handled properly. These macros are not part of the
631 The C<op_scope()> and C<op_lvalue()> functions have been added to the API,
632 but are considered experimental.
636 =head1 Selected Bug Fixes
638 XXX Important bug fixes in the core language are summarised here.
639 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
640 L</Modules and Pragmata>.
642 [ List each fix as a =item entry ]
648 The C<parse_stmt> C function added in earlier in the 5.13.x series has been
649 fixed to work with statements ending with C<}>
650 L<[perl #78222]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78222>.
654 The C<parse_fullstmt> C function added in 5.13.5 has been fixed to work
655 when called while an expression is being parsed.
659 Characters in the Latin-1 non-ASCII range (0x80 to 0xFF) used not to match
660 themselves if the string happened to be UTF8-encoded internally, the
661 regular expression was not, and the character in the regular expression was
662 inside a repeated group (e.g.,
663 C<Encode::decode_utf8("\303\200") =~ /(\xc0)+/>)
664 L<[perl #78464]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78464>.
668 The C<(?d)> regular expression construct now overrides a previous C<(?u)>
669 or C<use feature "unicode_string">
670 L<[perl #78508]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78508>.
674 A memory leak in C<do "file">, introduced in perl 5.13.6, has been fixed
675 L<[perl #78488]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78488>.
679 Various bugs related to typeglob dereferencing have been fixed. See
680 L</Dereferencing typeglobs>, above.
684 The C<SvPVbyte> function available to XS modules now calls magic before
685 downgrading the SV, to avoid warnings about wide characters
686 L<[perl #72398]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=72398>.
690 The C<=> operator used to ignore magic (e.g., tie methods) on its
691 right-hand side if the scalar happened to hold a typeglob. This could
692 happen if a typeglob was the last thing returned from or assigned to a tied
694 L<[perl #77498]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77498>.
698 C<sprintf> was ignoring locales when called with constant arguments
699 L<[perl #78632]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78632>.
703 A non-ASCII character in the Latin-1 range could match both a Posix
704 class, such as C<[[:alnum:]]>, and its inverse C<[[:^alnum:]]>. This is
705 now fixed for regular expressions compiled under the C<"u"> modifier.
706 See L</C<use feature "unicode_strings"> now applies to more regex matching>.
707 L<[perl #18281]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=18281>.
711 Concatenating long strings under C<use encoding> no longer causes perl to
713 L<[perl #78674]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78674>.
717 Typeglob assignments would crash if the glob's stash no longer existed, if
718 the glob assigned to was named 'ISA' or the glob on either side of the
719 assignment contained a subroutine.
723 Calling C<< ->import >> on a class lacking an import method could corrupt the stack result in strange behaviour. For instance,
725 push @a, "foo", $b = bar->import;
727 would assign 'foo' to C<$b>
728 L<[perl #63790]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=63790>.
732 Creating an alias to a package when that package had been detached from the
733 symbol table would result in corrupted isa caches
734 L<[perl #77358]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=77358>.
738 C<.=> followed by C<< <> >> or C<readline> would leak memory if C<$/>
739 contained characters beyond the octet range and the scalar assigned to
740 happened to be encoded as UTF8 internally
741 L<[perl #72246]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=72246>.
745 The C<recv> function could crash when called with the MSG_TRUNC flag
746 L<[perl #75082]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75082>.
750 =head1 Known Problems
752 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
753 tests that had to be C<TODO>ed for the release would be noted here, unless
754 they were specific to a particular platform (see below).
756 This is a list of some significant unfixed bugs, which are regressions
757 from either 5.XXX.XXX or 5.XXX.XXX.
759 [ List each fix as a =item entry ]
771 XXX If any significant core contributor has died, we've added a short obituary
774 =head1 Acknowledgements
776 XXX The list of people to thank goes here.
778 =head1 Reporting Bugs
780 If you find what you think is a bug, you might check the articles
781 recently posted to the comp.lang.perl.misc newsgroup and the perl
782 bug database at http://rt.perl.org/perlbug/ . There may also be
783 information at http://www.perl.org/ , the Perl Home Page.
785 If you believe you have an unreported bug, please run the B<perlbug>
786 program included with your release. Be sure to trim your bug down
787 to a tiny but sufficient test case. Your bug report, along with the
788 output of C<perl -V>, will be sent off to perlbug@perl.org to be
789 analysed by the Perl porting team.
791 If the bug you are reporting has security implications, which make it
792 inappropriate to send to a publicly archived mailing list, then please send
793 it to perl5-security-report@perl.org. This points to a closed subscription
794 unarchived mailing list, which includes all the core committers, who be able
795 to help assess the impact of issues, figure out a resolution, and help
796 co-ordinate the release of patches to mitigate or fix the problem across all
797 platforms on which Perl is supported. Please only use this address for
798 security issues in the Perl core, not for modules independently
803 The F<Changes> file for an explanation of how to view exhaustive details
806 The F<INSTALL> file for how to build Perl.
808 The F<README> file for general stuff.
810 The F<Artistic> and F<Copying> files for copyright information.