5 perl5110delta - what is new for perl v5.11.0
9 This document describes differences between the 5.10.0 release and
10 the 5.11.0 development release.
12 =head1 Incompatible Changes
14 =head2 Unicode interpretation of \w, \d, \s, and the POSIX character classes redefined.
16 Previous versions of Perl tried to map POSIX style character class definitions onto
17 Unicode property names so that patterns would "dwim" when matches were made against latin-1 or
18 unicode strings. This proved to be a mistake, breaking character class negation, causing
19 forward compatibility problems (as Unicode keeps updating their property definitions and adding
20 new characters), and other problems.
22 Therefore we have now defined a new set of artificial "unicode" property names which will be
23 used to do unicode matching of patterns using POSIX style character classes and perl short-form
24 escape character classes like \w and \d.
26 The key change here is that \d will no longer match every digit in the unicode standard
27 (there are thousands) nor will \w match every word character in the standard, instead they
28 will match precisely their POSIX or Perl definition.
30 Those needing to match based on Unicode properties can continue to do so by using the \p{} syntax
31 to match whichever property they like, including the new artificial definitions.
33 B<NOTE:> This is a backwards incompatible no-warning change in behaviour. If you are upgrading
34 and you process large volumes of text look for POSIX and Perl style character classes and
35 change them to the relevent property name (by removing the word 'Posix' from the current name).
37 The following table maps the POSIX character class names, the escapes and the old and new
38 Unicode property mappings:
40 POSIX Esc Class New-Property ! Old-Property
41 ----------------------------------------------+-------------
42 alnum [0-9A-Za-z] IsPosixAlnum ! IsAlnum
43 alpha [A-Za-z] IsPosixAlpha ! IsAlpha
44 ascii [\000-\177] IsASCII = IsASCII
45 blank [\011 ] IsPosixBlank !
46 cntrl [\0-\37\177] IsPosixCntrl ! IsCntrl
47 digit \d [0-9] IsPosixDigit ! IsDigit
48 graph [!-~] IsPosixGraph ! IsGraph
49 lower [a-z] IsPosixLower ! IsLower
50 print [ -~] IsPosixPrint ! IsPrint
51 punct [!-/:-@[-`{-~] IsPosixPunct ! IsPunct
52 space [\11-\15 ] IsPosixSpace ! IsSpace
53 \s [\11\12\14\15 ] IsPerlSpace ! IsSpacePerl
54 upper [A-Z] IsPosixUpper ! IsUpper
55 word \w [0-9A-Z_a-z] IsPerlWord ! IsWord
56 xdigit [0-9A-Fa-f] IsXDigit = IsXDigit
58 If you wish to build perl with the old mapping you may do so by setting
60 #define PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS 1
62 in regcomp.h, and then setting
64 PERL_TEST_LEGACY_POSIX_CC
66 to true your enviornment when testing.
69 =head2 In @INC, move ARCHLIB and PRIVLIB after the current version's site_perl and vendor_perl.
71 =head2 Switch statement changes
73 The handling of complex expressions by the C<given>/C<when> switch
74 statement has been enhanced. These enhancements are also available in
75 5.10.1 and subsequent 5.10 releases. There are two new cases where C<when> now
76 interprets its argument as a boolean, instead of an expression to be used
81 =item flip-flop operators
83 The C<..> and C<...> flip-flop operators are now evaluated in boolean
84 context, following their usual semantics; see L<perlop/"Range Operators">.
86 Note that, as in perl 5.10.0, C<when (1..10)> will not work to test
87 whether a given value is an integer between 1 and 10; you should use
88 C<when ([1..10])> instead (note the array reference).
90 However, contrary to 5.10.0, evaluating the flip-flop operators in boolean
91 context ensures it can now be useful in a C<when()>, notably for
92 implementing bistable conditions, like in:
94 when (/^=begin/ .. /^=end/) {
98 =item defined-or operator
100 A compound expression involving the defined-or operator, as in
101 C<when (expr1 // expr2)>, will be treated as boolean if the first
102 expression is boolean. (This just extends the existing rule that applies
103 to the regular or operator, as in C<when (expr1 || expr2)>.)
107 The next section details more changes brought to the semantics to
108 the smart match operator, that naturally also modify the behaviour
109 of the switch statements where smart matching is implicitly used.
110 These changers were also made for the 5.10.1 release, and will remain in
111 subsequent 5.10 releases.
113 =head2 Smart match changes
115 =head3 Changes to type-based dispatch
117 The smart match operator C<~~> is no longer commutative. The behaviour of
118 a smart match now depends primarily on the type of its right hand
119 argument. Moreover, its semantics have been adjusted for greater
120 consistency or usefulness in several cases. While the general backwards
121 compatibility is maintained, several changes must be noted:
127 Code references with an empty prototype are no longer treated specially.
128 They are passed an argument like the other code references (even if they
129 choose to ignore it).
133 C<%hash ~~ sub {}> and C<@array ~~ sub {}> now test that the subroutine
134 returns a true value for each key of the hash (or element of the
135 array), instead of passing the whole hash or array as a reference to
140 Due to the commutativity breakage, code references are no longer
141 treated specially when appearing on the left of the C<~~> operator,
142 but like any vulgar scalar.
146 C<undef ~~ %hash> is always false (since C<undef> can't be a key in a
147 hash). No implicit conversion to C<""> is done (as was the case in perl
152 C<$scalar ~~ @array> now always distributes the smart match across the
153 elements of the array. It's true if one element in @array verifies
154 C<$scalar ~~ $element>. This is a generalization of the old behaviour
155 that tested whether the array contained the scalar.
159 The full dispatch table for the smart match operator is given in
160 L<perlsyn/"Smart matching in detail">.
162 =head3 Smart match and overloading
164 According to the rule of dispatch based on the rightmost argument type,
165 when an object overloading C<~~> appears on the right side of the
166 operator, the overload routine will always be called (with a 3rd argument
167 set to a true value, see L<overload>.) However, when the object will
168 appear on the left, the overload routine will be called only when the
169 rightmost argument is a simple scalar. This way distributivity of smart match
170 across arrays is not broken, as well as the other behaviours with complex
171 types (coderefs, hashes, regexes). Thus, writers of overloading routines
172 for smart match mostly need to worry only with comparing against a scalar,
173 and possibly with stringification overloading; the other common cases
174 will be automatically handled consistently.
176 C<~~> will now refuse to work on objects that do not overload it (in order
177 to avoid relying on the object's underlying structure). (However, if the
178 object overloads the stringification or the numification operators, and
179 if overload fallback is active, it will be used instead, as usual.)
181 =head2 Labels can't be keywords
183 Labels used as targets for the C<goto>, C<last>, C<next> or C<redo>
184 statements cannot be keywords anymore. This restriction will prevent
185 potential confusion between the C<goto LABEL> and C<goto EXPR> syntaxes:
186 for example, a statement like C<goto print> would jump to a label whose
187 name would be the return value of C<print()>, (usually 1), instead of a
188 label named C<print>. Moreover, the other control flow statements
189 would just ignore any keyword passed to them as a label name. Since
190 such labels cannot be defined anymore, this kind of error will be
193 =head2 Other incompatible changes
199 The semantics of C<use feature :5.10*> have changed slightly.
200 See L<"Modules and Pragmata"> for more information.
204 It is now a run-time error to use the smart match operator C<~~>
205 with an object that has no overload defined for it. (This way
206 C<~~> will not break encapsulation by matching against the
207 object's internal representation as a reference.)
211 The version control system used for the development of the perl
212 interpreter has been switched from Perforce to git. This is mainly an
213 internal issue that only affects people actively working on the perl core;
214 but it may have minor external visibility, for example in some of details
215 of the output of C<perl -V>. See L<perlrepository> for more information.
219 The internal structure of the C<ext/> directory in the perl source has
220 been reorganised. In general, a module C<Foo::Bar> whose source was
221 stored under F<ext/Foo/Bar/> is now located under F<ext/Foo-Bar/>. Also,
222 nearly all dual-life modules have been moved from F<lib/> to F<ext/>. This
223 is purely a source tarball change, and should make no difference to the
224 compilation or installation of perl, unless you have a very customised build
225 process that explicitly relies on this structure, or which hard-codes the
226 C<nonxs_ext> F<Configure> parameter. Specifically, this change does not by
227 default alter the location of any files in the final installation.
231 As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental
232 C<Test::Harness::Straps> module has been removed.
233 See L</"Updated Modules"> for more details.
237 As part of the C<ExtUtils::MakeMaker> upgrade, the
238 C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> modules
239 have been removed from this distribution.
243 C<Module::CoreList> no longer contains the C<%:patchlevel> hash.
247 This one is actually a change introduced in 5.10.0, but it was missed
248 from that release's perldelta, so it is mentioned here instead.
250 A bugfix related to the handling of the C</m> modifier and C<qr> resulted
251 in a change of behaviour between 5.8.x and 5.10.0:
253 # matches in 5.8.x, doesn't match in 5.10.0
254 $re = qr/^bar/; "foo\nbar" =~ /$re/m;
258 C<length undef> now returns undef.
262 Unsupported private C API functions are now declared "static" to prevent
263 leakage to Perl's public API
267 F<miniperl> no longer builds with UTF-8 support in the regexp engine to support the bootstrapping process
269 This allows a build to complete with PERL_UNICODE set and a UTF-8 locale.
270 Without this there's a bootstrapping problem, as miniperl can't load the UTF-8
271 components of the regexp engine, because they're not yet built.
275 F<miniperl>'s @INC is now restricted to just -I..., the split of $ENV{PERL5LIB}, and "."
279 A space or a newline is now required after a C<"#line XXX"> directive.
283 Tied filehandles now have an additional method EOF which provides the EOF type
287 To better match all other flow control statements, C<foreach> may no longer be used as an attribute.
291 =head1 Core Enhancements
293 =head2 Unicode Character Database 5.1.0
295 The copy of the Unicode Character Database included in Perl 5.11.0 has
296 been updated to 5.1.0 from 5.0.0. See
297 L<http://www.unicode.org/versions/Unicode5.1.0/#Notable_Changes> for the
300 =head2 A proper interface for pluggable Method Resolution Orders
302 As of Perl 5.11.0 there is a new interface for plugging and using method
303 resolution orders other than the default (linear depth first search).
304 The C3 method resolution order added in 5.10.0 has been re-implemented as
305 a plugin, without changing its Perl-space interface. See L<perlmroapi> for
308 =head2 The C<overloading> pragma
310 This pragma allows you to lexically disable or enable overloading
311 for some or all operations. (Yuval Kogman)
313 =head2 C<\N> regex escape
315 A new regex escape has been added, C<\N>. It will match any character that
316 is not a newline, independently from the presence or absence of the single
317 line match modifier C</s>. (If C<\N> is followed by an opening brace and
318 by a letter, perl will still assume that a Unicode character name is
319 coming, so compatibility is preserved.) (Rafael Garcia-Suarez)
321 =head2 Implicit strictures
323 Using the C<use VERSION> syntax with a version number greater or equal
324 to 5.11.0 will also lexically enable strictures just like C<use strict>
325 would do (in addition to enabling features.) So, the following:
334 =head2 Parallel tests
336 The core distribution can now run its regression tests in parallel on
337 Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
338 your environment to the number of tests to run in parallel, and run
339 C<make test_harness>. On a Bourne-like shell, this can be done as
341 TEST_JOBS=3 make test_harness # Run 3 tests in parallel
343 An environment variable is used, rather than parallel make itself, because
344 L<TAP::Harness> needs to be able to schedule individual non-conflicting test
345 scripts itself, and there is no standard interface to C<make> utilities to
346 interact with their job schedulers.
348 Note that currently some test scripts may fail when run in parallel (most
349 notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts
350 again sequentially and see if the failures go away.
352 =head2 The C<...> operator
354 A new operator, C<...>, nicknamed the Yada Yada operator, has been added.
355 It is intended to mark placeholder code, that is not yet implemented.
356 See L<perlop/"Yada Yada Operator">. (chromatic)
358 =head2 DTrace support
360 Some support for DTrace has been added. See "DTrace support" in F<INSTALL>.
362 =head2 Support for C<configure_requires> in CPAN module metadata
364 Both C<CPAN> and C<CPANPLUS> now support the C<configure_requires> keyword
365 in the F<META.yml> metadata file included in most recent CPAN distributions.
366 This allows distribution authors to specify configuration prerequisites that
367 must be installed before running F<Makefile.PL> or F<Build.PL>.
369 See the documentation for C<ExtUtils::MakeMaker> or C<Module::Build> for more
370 on how to specify C<configure_requires> when creating a distribution for CPAN.
372 =head2 The C<each> function can now operate on arrays
374 =head2 Perl's core time-related functions are now Y2038 compliand
376 =head2 The variable C<$,> may now be tied
378 =head2 // now behaves like || in when clauses
380 =head2 You can now set C<-W> from the C<PERL5OPT> environment variable
382 =head2 Add support for Abstract namespace sockets
384 Abstract namespace sockets are Linux-specific socket type that live in
385 AF_UNIX family, slightly abusing it to be able to use arbitrary
386 character arrays as addresses: They start with nul byte and are not
387 terminated by nul byte, but with the length passed to the socket()
391 =head2 C<delete local> now allows you to lexically delete a hash entry.
393 =head1 Modules and Pragmata
395 =head2 Dual-lifed modules moved
397 Dual-lifed modules maintained primarily in the Perl core now live in dist/.
398 Dual-lifed modules maintained primarily on CPAN now live in cpan/
400 =head2 New Modules and Pragmata
406 This is a new lexically-scoped alternative for the C<Fatal> module.
407 The bundled version is 2.06_01. Note that in this release, using a string
408 eval when C<autodie> is in effect can cause the autodie behaviour to leak
409 into the surrounding scope. See L<autodie/"BUGS"> for more details.
411 =item C<Compress::Raw::Bzip2>
413 This has been added to the core (version 2.020).
417 This pragma establishes an ISA relationship with base classes at compile
418 time. It provides the key feature of C<base> without the feature creep.
420 =item C<Parse::CPAN::Meta>
422 This has been added to the core (version 1.39).
426 =head2 Pragmata Changes
432 See L</"The C<overloading> pragma"> above.
436 Upgraded from version 0.08 to 0.09.
440 The C<attrs> pragma has been removed. It had been marked as deprecated since
445 Upgraded from version 2.13 to 2.14. See L<parent> for a replacement.
449 Upgraded from version 0.22 to 0.23.
453 Upgraded from version 0.22 to 0.23.
457 Upgraded from version 0.22 to 0.23.
461 Upgraded from version 1.06 to 1.07.
463 The Unicode F<NameAliases.txt> database file has been added. This has the
464 effect of adding some extra C<\N> character names that formerly wouldn't
465 have been recognised; for example, C<"\N{LATIN CAPITAL LETTER GHA}">.
469 Upgraded from version 1.13 to 1.19. Some code has been shifted from run time to
470 compile time, and the amount of MRO cache flushing has been minimised.
474 The meaning of the C<:5.10> and C<:5.10.X> feature bundles has
475 changed slightly. The last component, if any (i.e. C<X>) is simply ignored.
476 This is predicated on the assumption that new features will not, in
477 general, be added to maintenance releases. So C<:5.10> and C<:5.10.X>
478 have identical effect. This is a change to the behaviour documented for
483 Upgraded from version 2.13 to 2.14 (this was just a version bump; there
484 were no functional changes).
488 Upgraded from version 0.5565 to 0.62.
492 Upgraded from version 1.06 to 1.07.
496 Upgraded from version 1.06 to 1.07.
500 See L</"The C<overloading> pragma"> above.
504 Upgraded from version 1.00 to 1.01. Performance for single inheritance is 40%
505 faster - see L</"Performance Enhancements"> below.
507 C<mro> is now implemented as an XS extension. The documented interface has not
508 changed. Code relying on the implementation detail that some C<mro::>
509 methods happened to be available at all times gets to "keep both pieces".
513 Upgraded from version 0.74 to 0.77.
517 =head2 Updated Modules
521 =item C<Archive::Extract>
523 Upgraded from version 0.24 to 0.34.
525 =item C<Archive::Tar>
527 Upgraded from version 1.38 to 1.52.
529 =item C<Attribute::Handlers>
531 Upgraded from version 0.79 to 0.85.
535 Upgraded from version 5.63 to 5.68.
539 Upgraded from version 1.05 to 1.06.
543 Upgraded from version 1.17 to 1.22.
547 Upgraded from version 1.05 to 1.11.
551 Upgraded from version 0.83 to 0.89.
555 Upgraded from version 1.09 to 1.11.
559 Upgraded from version 1.01 to 1.02.
563 Upgraded from version 1.10 to 1.11.
567 Upgraded from version 1.08 to 1.11.
569 L<Carp> now includes all the necessary code to function. Previously, it
570 used to be a lightweight placeholder that loaded the actual code from
571 C<Carp::Heavy> on demand. C<Carp::Heavy> is now a simple, empty module
572 kept for backwards compatibility for programs that used to pre-load it.
576 Upgraded from version 3.29 to 3.43.
577 (also includes the "default_value for popup_menu()" fix from 3.45).
579 =item C<Compress::Zlib>
581 Upgraded from version 2.008 to 2.020.
585 Upgraded from version 1.9205 to 1.9402. C<CPAN::FTP> has a local fix to
586 stop it being too verbose on download failure.
590 Upgraded from version 0.84 to 0.88.
592 =item C<CPANPLUS::Dist::Build>
594 Upgraded from version 0.06_02 to 0.36.
598 Upgraded from version 3.25_01 to 3.30.
600 =item C<Data::Dumper>
602 Upgraded from version 2.121_14 to 2.124.
606 Upgraded from version 1.01 to 1.02.
610 Upgraded from version 1.816_1 to 1.820.
612 =item C<Devel::PPPort>
614 Upgraded from version 3.13 to 3.19.
618 Upgraded from version 2.36_01 to 2.39.
622 Upgraded from version 5.45 to 5.47.
626 Upgraded from version 1.01 to 1.03.
630 Upgraded from version 1.12 to 1.13.
634 Upgraded from version 1.08 to 1.10.
638 Upgraded from version 2.23 to 2.35.
642 Upgraded from version 1.10 to 1.11.
646 Upgraded from version 5.62 to 5.63.
648 =item C<ExtUtils::CBuilder>
650 Upgraded from version 0.21 to 0.2602.
652 =item C<ExtUtils::Command>
654 Upgraded from version 1.13 to 1.16.
656 =item C<ExtUtils::Constant>
658 Upgraded from 0.20 to 0.22. (Note that neither of these versions are
661 =item C<ExtUtils::Embed>
663 Upgraded from version 1.27 to 1.28.
665 =item C<ExtUtils::Install>
667 Upgraded from version 1.44 to 1.54.
669 =item C<ExtUtils::MakeMaker>
671 Upgraded from version 6.42 to 6.55_02.
673 Note that C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish>
674 have been removed from this distribution.
676 =item C<ExtUtils::Manifest>
678 Upgraded from version 1.51_01 to 1.56.
680 =item C<ExtUtils::ParseXS>
682 Upgraded from version 2.18_02 to 2.2002.
686 Upgraded from version 1.05 to 2.06_01. See also the new pragma C<autodie>.
688 =item C<File::Basename>
690 Upgraded from version 2.76 to 2.77.
692 =item C<File::Compare>
694 Upgraded from version 1.1005 to 1.1006.
698 Upgraded from version 2.11 to 2.16.
700 File::Copy now always return 0 (not "") on failure.
702 FIXME - describe C<cp>
706 Upgraded from version 0.14 to 0.20.
710 Upgraded from version 1.12 to 1.14.
714 Upgraded from version 2.04 to 2.07_03.
718 Upgraded from version 3.2501 to 3.30.
722 Upgraded from version 1.00 to 1.01.
724 Added -X overloading, -M, -C and -A.
728 Upgraded from version 0.18 to 0.22.
732 Upgraded from version 1.07 to 1.08.
736 Upgraded from version 2.01 to 2.02.
738 =item C<Filter::Simple>
740 Upgraded from version 0.82 to 0.84.
742 =item C<Filter::Util::Call>
744 Upgraded from version 1.07 to 1.08.
748 Upgraded from version 1.49 to 1.50.
752 Upgraded from version 1.08 to 1.09.
754 =item C<Getopt::Long>
756 Upgraded from version 2.37 to 2.38.
758 =item C<Hash::Util::FieldHash>
760 Upgraded from version 1.03 to 1.04. This fixes a memory leak.
762 =item C<I18N::Collate>
764 Upgraded from version 1.00 to 1.01.
768 Upgraded from version 1.23_01 to 1.25.
770 This makes non-blocking mode work on Windows in C<IO::Socket::INET>
773 =item C<IO::Compress::*>
775 Upgraded from version 2.008 to 2.020.
779 Upgraded from version 1.06 to 1.07.
783 Upgraded from version 1.27 to 1.28.
787 Upgraded from version 1.30_01 to 1.31.
791 Upgraded from version 1.07 to 1.09.
795 Upgraded from version 0.40_1 to 0.46.
799 Upgraded from version 1.02 to 1.04.
803 Upgraded from version 1.05 to 2.01.
807 Upgraded from version 0.5565 to 0.62.
811 Upgraded from version 1.19 to 1.21.
813 =item C<Locale::MakeText>
815 Upgraded from version 1.12 to 1.13.
817 =item C<Log::Message>
819 Upgraded from version 0.01 to 0.02.
821 =item C<Math::BigFloat>
823 Upgraded from version 1.59 to 1.60.
825 =item C<Math::BigInt>
827 Upgraded from version 1.88 to 1.89.
829 =item C<Math::BigInt::FastCalc>
831 Upgraded from version 0.16 to 0.19.
833 =item C<Math::BigRat>
835 Upgraded from version 0.21 to 0.22.
837 =item C<Math::Complex>
839 Upgraded from version 1.37 to 1.56.
843 Upgraded from version 1.04 to 1.20.
847 Upgraded from version 1.01_02 to 1.01_03 (just a minor documentation
850 =item C<Module::Build>
852 Upgraded from version 0.2808_01 to 0.34_02.
854 =item C<Module::CoreList>
856 Upgraded from version 2.13 to 2.18. This release no longer contains the
857 C<%Module::CoreList::patchlevel> hash.
859 =item C<Module::Load>
861 Upgraded from version 0.12 to 0.16.
863 =item C<Module::Load::Conditional>
865 Upgraded from version 0.22 to 0.30.
867 =item C<Module::Loaded>
869 Upgraded from version 0.01 to 0.02.
871 =item C<Module::Pluggable>
873 Upgraded from version 3.6 to 3.9.
877 Upgraded from version 1.07 to 1.08.
881 Upgraded from version 2.33 to 2.36.
885 Upgraded from version 0.60_01 to 0.64.
887 =item C<Object::Accessor>
889 Upgraded from version 0.32 to 0.34.
893 Upgraded from version 1.03 to 1.04.
895 =item C<Package::Constants>
897 Upgraded from version 0.01 to 0.02.
901 Upgraded from version 1.04 to 1.06.
905 Upgraded from version 0.04 to 0.07.
909 Upgraded from version 2.16 to 2.22.
913 Upgraded from version 1.35 to 1.37.
915 =item C<Pod::Plainer>
917 Upgraded from version 0.01 to 1.00.
919 There are no code changes - the version bump is because C<Pod::Plainer> has
920 been released to CPAN as a stand alone distribution, and will be removed from
921 the core distribution in 5.14.
925 Upgrade from version 3.14_02 to 3.15.
929 Upgraded from version 3.05 to 3.07.
933 Upgraded from version 3.08 to 3.13.
937 Upgraded from version 1.13 to 1.17.
941 Upgraded from 2.12 to 2.18.
943 =item C<Scalar::Util>
945 Upgraded from version 1.19 to 1.21.
949 Upgraded from 1.01 to 1.02.
953 Upgraded from 1.11 to 1.17.
957 Upgraded from 1.80 to 1.84.
959 As of 1.84, C<Socket> can now handle abstract namespace sockets on Linux.
964 Upgraded from 2.18 to 2.20.
968 Upgraded from version 2.13 to 2.14. Please see L</Deprecations>.
972 Upgraded from version 1.06 to 1.07.
976 Upgraded from version 0.22 to 0.27.
978 =item C<Term::ANSIColor>
980 Upgraded from version 1.12 to 2.01.
982 =item C<Term::ReadLine>
984 Upgraded from version 1.03 to 1.04.
988 Upgraded from version 0.18 to 0.20.
990 =item C<Test::Harness>
992 Upgraded from version 2.64 to 3.17.
994 Note that one side-effect of the 2.x to 3.x upgrade is that the
995 experimental C<Test::Harness::Straps> module (and its supporting
996 C<Assert>, C<Iterator>, C<Point> and C<Results> modules) have been
997 removed. If you still need this, then they are available in the
998 (unmaintained) C<Test-Harness-Straps> distribution on CPAN.
1000 =item C<Test::Simple>
1002 Upgraded from version 0.72 to 0.92.
1004 =item C<Text::ParseWords>
1006 Upgraded from version 3.26 to 3.27.
1010 Upgraded from version 2007.1117 to 2009.0305.
1014 Upgraded from version 2006.1117 to 2009.0305.
1016 =item C<Thread::Queue>
1018 Upgraded from version 2.00 to 2.11.
1020 =item C<Thread::Semaphore>
1022 Upgraded from version 2.01 to 2.09.
1026 Upgraded from version 1.67 to 1.73.
1028 =item C<threads::shared>
1030 Upgraded from version 1.14 to 1.29.
1032 =item C<Tie::RefHash>
1034 Upgraded from version 1.37 to 1.38.
1036 =item C<Tie::StdHandle>
1038 This has documentation changes, and has been assigned a version for the
1039 first time: version 4.2.
1041 =item C<Time::HiRes>
1043 Upgraded from version 1.9711 to 1.9719.
1045 =item C<Time::Local>
1047 Upgraded from version 1.18 to 1.1901.
1049 =item C<Time::Piece>
1051 Upgraded from version 1.12 to 1.15.
1053 =item C<Unicode::Normalize>
1055 Upgraded from version 1.02 to 1.03.
1057 =item C<Unicode::UCD>
1059 Upgraded from version 0.25 to 0.27.
1061 C<charinfo()> now works on Unified CJK code points added to later versions
1064 C<casefold()> has new fields returned to provide both a simpler interface
1065 and previously missing information. The old fields are retained for
1066 backwards compatibility. Information about Turkic-specific code points is
1069 The documentation has been corrected and expanded.
1073 Upgraded from version 1.04 to 1.05.
1075 C<< UNIVERSAL->import() >> is now deprecated.
1079 Upgraded from version 0.34 to 0.39.
1081 =item C<Win32API::File>
1083 Upgraded from version 0.1001_01 to 0.1101.
1087 Upgraded from version 0.08 to 0.10.
1089 =item Upgrade to Class::ISA 0.34
1091 =item Upgrade to Attribute::Handlers 0.87
1093 =item Upgrade to AutoLoader 5.70
1095 =item Upgrade to IO::Zlib 1.10
1097 =item Update parent to CPAN version 0.223
1099 =item Update Log::Message::Simple to CPAN version 0.06
1101 =item Updated Math::BigRat to CPAN version 0.24
1103 =item Update Archive::Tar to CPAN version 1.54
1105 =item Update IPC::Cmd to CPAN version 0.50
1107 =item Updated CPANPLUS::Dist::Build to CPAN version 0.40
1109 =item Updated Module::Loaded to CPAN version 0.06
1111 =item Upgrade Term::ANSIColor to 2.02
1113 =item Update Text::Balanced to 2.02
1115 =item Update Module::Build to 0.35
1117 =item constant has been upgraded to 1.19.
1119 =item upgrade CGI from 3.43 to 3.45
1121 =item bump Safe version to 2.18
1123 =item Upgrade to threads::shared 1.31
1125 =item Update threads to 1.74
1127 =item autodie 2.06_01
1129 =item Synchronize with CPAN's Attribute::Handlers 0.86
1131 =item Synchronize AutoLoader with CPAN's 5.69
1133 =item ExtUtils::MakeMaker 6.55_02
1135 =item Final release of version-0.77 for inclusion in 5.10.1
1137 =item Upgrade to Encode 2.37
1139 =item Upgrade to Class::ISA 0.36 (Fixes installation directories only)
1141 =item Upgrade to PathTools 3.30_02 (with only core reorganization fixes)
1145 =head1 Utility Changes
1151 Now looks in C<include-fixed> too, which is a recent addition to gcc's
1156 No longer incorrectly treats enum values like macros (Daniel Burr).
1158 Now handles C++ style constants (C<//>) properly in enums. (A patch from
1159 Rainer Weikusat was used; Daniel Burr also proposed a similar fix).
1163 C<LVALUE> subroutines now work under the debugger.
1165 The debugger now correctly handles proxy constant subroutines, and
1170 F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out upstream bug
1173 Where the user names a module that their bug report is about, and we know the
1174 URL for its upstream bug tracker, provide a message to the user explaining
1175 that the core copies the CPAN version directly, and provide the URL for
1176 reporting the bug directly to upstream.
1180 Perl 5.11.0 added a new utility F<perlthanks>, which is a variant of
1181 F<perlbug>, but for sending non-bug-reports to the authors and maintainers
1182 of Perl. Getting nothing but bug reports can become a bit demoralising:
1183 we'll see if this changes things.
1187 =head1 New Documentation
1193 This contains instructions on how to build perl for the Haiku platform.
1197 This describes the new interface for pluggable Method Resolution Orders.
1201 This document, by Richard Foley, provides an introduction to the use of
1202 performance and optimization techniques which can be used with particular
1203 reference to perl programs.
1205 =item L<perlrepository>
1207 This describes how to access the perl source using the I<git> version
1212 This describes the new F<perlthanks> utility.
1216 =head1 Changes to Existing Documentation
1218 The various large F<Changes*> files (which listed every change made to perl
1219 over the last 18 years) have been removed, and replaced by a small file,
1220 also called F<Changes>, which just explains how that same information may
1221 be extracted from the git version control system.
1223 The file F<Porting/patching.pod> has been deleted, as it mainly described
1224 interacting with the old Perforce-based repository, which is now obsolete.
1225 Information still relevant has been moved to L<perlrepository>.
1227 L<perlapi>, L<perlintern>, L<perlmodlib> and L<perltoc> are now all
1228 generated at build time, rather than being shipped as part of the release.
1230 =head2 Documented -X overloading.
1232 =head2 Documented that C<when()> treats specially most of the filetest operators
1234 =head2 Documented when as a syntax modifier
1236 =head2 Eliminated "Old Perl threads tutorial", which describes 5005 threads.
1238 pod/perlthrtut.pod is the same material reworked for ithreads.
1240 =head2 Correct previous documentation: v-strings are not deprecated
1242 With version objects, we need them to use MODULE VERSION syntax. This
1243 patch removes the deprecation note.
1245 =head2 Added security contact information to L<perlsec>
1247 =head1 Performance Enhancements
1253 A new internal cache means that C<isa()> will often be faster.
1257 The implementation of C<C3> Method Resolution Order has been optimised -
1258 linearisation for classes with single inheritance is 40% faster. Performance
1259 for multiple inheritance is unchanged.
1263 Under C<use locale>, the locale-relevant information is now cached on
1264 read-only values, such as the list returned by C<keys %hash>. This makes
1265 operations such as C<sort keys %hash> in the scope of C<use locale> much
1270 Empty C<DESTROY> methods are no longer called.
1274 Faster C<Perl_sv_utf8_upgrade()>
1278 Speed up C<keys> on empty hash
1282 =head1 Installation and Configuration Improvements
1284 =head2 F<ext/> reorganisation
1286 The layout of directories in F<ext> has been revised. Specifically, all
1287 extensions are now flat, and at the top level, with C</> in pathnames
1288 replaced by C<->, so that F<ext/Data/Dumper/> is now F<ext/Data-Dumper/>,
1289 etc. The names of the extensions as specified to F<Configure>, and as
1290 reported by C<%Config::Config> under the keys C<dynamic_ext>,
1291 C<known_extensions>, C<nonxs_ext> and C<static_ext> have not changed, and
1292 still use C</>. Hence this change will not have any affect once perl is
1293 installed. C<Safe> has been split out from being part of C<Opcode>, and
1294 C<mro> is now an extension in its own right.
1296 Nearly all dual-life modules have been moved from F<lib> to F<ext>, and will
1297 now appear as known C<nonxs_ext>. This will made no difference to the
1298 structure of an installed perl, nor will the modules installed differ,
1299 unless you run F<Configure> with options to specify an exact list of
1300 extensions to build. In this case, you will rapidly become aware that you
1301 need to add to your list, because various modules needed to complete the
1302 build, such as C<ExtUtils::ParseXS>, have now become extensions, and
1303 without them the build will fail well before it attempts to run the
1306 =head2 Configuration improvements
1308 If C<vendorlib> and C<vendorarch> are the same, then they are only added to
1311 C<$Config{usedevel}> and the C-level C<PERL_USE_DEVEL> are now defined if
1312 perl is built with C<-Dusedevel>.
1314 F<Configure> will enable use of C<-fstack-protector>, to provide protection
1315 against stack-smashing attacks, if the compiler supports it.
1317 F<Configure> will now determine the correct prototypes for re-entrant
1318 functions, and for C<gconvert>, if you are using a C++ compiler rather
1321 On Unix, if you build from a tree containing a git repository, the
1322 configuration process will note the commit hash you have checked out, for
1323 display in the output of C<perl -v> and C<perl -V>. Unpushed local commits
1324 are automatically added to the list of local patches displayed by
1327 =head2 Compilation improvements
1329 As part of the flattening of F<ext>, all extensions on all platforms are
1330 built by F<make_ext.pl>. This replaces the Unix-specific
1331 F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific
1332 F<win32/buildext.pl>.
1334 =head2 Platform Specific Changes
1340 Removed F<libbsd> for AIX 5L and 6.1. Only C<flock()> was used from F<libbsd>.
1342 Removed F<libgdbm> for AIX 5L and 6.1. The F<libgdbm> is delivered as an
1343 optional package with the AIX Toolbox. Unfortunately the 64 bit version
1346 Hints changes mean that AIX 4.2 should work again.
1350 On Cygwin we now strip the last number from the DLL. This has been the
1351 behaviour in the cygwin.com build for years. The hints files have been
1356 Support for Apollo DomainOS was removed in Perl 5.11.0
1360 The hints files now identify the correct threading libraries on FreeBSD 7
1365 We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
1366 C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't.
1370 Patches from the Haiku maintainers have been merged in. Perl should now
1375 Support for Atari MiNT was removed in Perl 5.11.0.
1379 Perl should now build on MirOS BSD.
1383 Hints now supports versions 5.*.
1387 Various changes from Stratus have been merged in.
1391 There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
1395 Improved message window handling means that C<alarm> and C<kill> messages
1396 will no longer be dropped under race conditions.
1400 Reads from the in-memory temporary files of C<PerlIO::scalar> used to fail
1401 if C<$/> was set to a numeric reference (to indicate record-style reads).
1404 VMS now supports C<getgrgid>.
1406 Many improvements and cleanups have been made to the VMS file name handling
1407 and conversion code.
1409 Enabling the C<PERL_VMS_POSIX_EXIT> logical name now encodes a POSIX exit
1410 status in a VMS condition value for better interaction with GNV's bash
1411 shell and other utilities that depend on POSIX exit values. See
1412 L<perlvms/"$?"> for details.
1414 C<File::Copy> now detects Unix compatibility mode on VMS.
1418 =head1 Selected Bug Fixes
1424 C<-I> on shebang line now adds directories in front of @INC
1425 as documented, and as does C<-I> when specified on the command-line.
1429 C<kill> is now fatal when called on non-numeric process identifiers.
1430 Previously, an 'undef' process identifier would be interpreted as a request to
1431 kill process "0", which would terminate the current process group on POSIX
1432 systems. Since process identifiers are always integers, killing a non-numeric
1433 process is now fatal.
1437 5.10.0 inadvertently disabled an optimisation, which caused a measurable
1438 performance drop in list assignment, such as is often used to assign
1439 function parameters from C<@_>. The optimisation has been re-instated, and
1440 the performance regression fixed.
1444 Fixed memory leak on C<while (1) { map 1, 1 }> [RT #53038].
1448 Some potential coredumps in PerlIO fixed [RT #57322,54828].
1452 The debugger now works with lvalue subroutines.
1456 The debugger's C<m> command was broken on modules that defined constants
1461 C<crypt> and string complement could return tainted values for untainted
1462 arguments [RT #59998].
1466 The C<-i>I<.suffix> command-line switch now recreates the file using
1467 restricted permissions, before changing its mode to match the original
1468 file. This eliminates a potential race condition [RT #60904].
1472 On some UNIX systems, the value in C<$?> would not have the top bit set
1473 (C<$? & 128>) even if the child core dumped.
1477 Under some circumstances, C<$^R> could incorrectly become undefined
1482 In the XS API, various hash functions, when passed a pre-computed hash where
1483 the key is UTF-8, might result in an incorrect lookup.
1487 XS code including F<XSUB.h> before F<perl.h> gave a compile-time error
1492 C<< $object->isa('Foo') >> would report false if the package C<Foo> didn't
1493 exist, even if the object's C<@ISA> contained C<Foo>.
1497 Various bugs in the new-to 5.10.0 mro code, triggered by manipulating
1498 C<@ISA>, have been found and fixed.
1502 Bitwise operations on references could crash the interpreter, e.g.
1503 C<$x=\$y; $x |= "foo"> [RT #54956].
1507 Patterns including alternation might be sensitive to the internal UTF-8
1508 representation, e.g.
1510 my $byte = chr(192);
1511 my $utf8 = chr(192); utf8::upgrade($utf8);
1512 $utf8 =~ /$byte|X}/i; # failed in 5.10.0
1516 Within UTF8-encoded Perl source files (i.e. where C<use utf8> is in
1517 effect), double-quoted literal strings could be corrupted where a C<\xNN>,
1518 C<\0NNN> or C<\N{}> is followed by a literal character with ordinal value
1519 greater than 255 [RT #59908].
1523 C<B::Deparse> failed to correctly deparse various constructs:
1524 C<readpipe STRING> [RT #62428], C<CORE::require(STRING)> [RT #62488],
1525 C<sub foo(_)> [RT #62484].
1529 Using C<setpgrp> with no arguments could corrupt the perl stack.
1533 The block form of C<eval> is now specifically trappable by C<Safe> and
1534 C<ops>. Previously it was erroneously treated like string C<eval>.
1538 In 5.10.0, the two characters C<[~> were sometimes parsed as the smart
1539 match operator (C<~~>) [RT #63854].
1543 In 5.10.0, the C<*> quantifier in patterns was sometimes treated as
1544 C<{0,32767}> [RT #60034, #60464]. For example, this match would fail:
1546 ("ab" x 32768) =~ /^(ab)*$/
1550 C<shmget> was limited to a 32 bit segment size on a 64 bit OS [RT #63924].
1554 Using C<next> or C<last> to exit a C<given> block no longer produces a
1555 spurious warning like the following:
1557 Exiting given via last at foo.pl line 123
1561 On Windows, C<'.\foo'> and C<'..\foo'> were treated differently than
1562 C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492].
1566 Assigning a format to a glob could corrupt the format; e.g.:
1568 *bar=*foo{FORMAT}; # foo format now bad
1572 Attempting to coerce a typeglob to a string or number could cause an
1573 assertion failure. The correct error message is now generated,
1574 C<Can't coerce GLOB to I<$type>>.
1578 Under C<use filetest 'access'>, C<-x> was using the wrong access mode. This
1579 has been fixed [RT #49003].
1583 C<length> on a tied scalar that returned a Unicode value would not be
1584 correct the first time. This has been fixed.
1588 Using an array C<tie> inside in array C<tie> could SEGV. This has been
1593 A race condition inside C<PerlIOStdio_close()> has been identified and
1594 fixed. This used to cause various threading issues, including SEGVs.
1598 In C<unpack>, the use of C<()> groups in scalar context was internally
1599 placing a list on the interpreter's stack, which manifested in various
1600 ways, including SEGVs. This is now fixed [RT #50256].
1604 Magic was called twice in C<substr>, C<\&$x>, C<tie $x, $m> and C<chop>.
1605 These have all been fixed.
1609 A 5.10.0 optimisation to clear the temporary stack within the implicit
1610 loop of C<s///ge> has been reverted, as it turned out to be the cause of
1611 obscure bugs in seemingly unrelated parts of the interpreter [commit
1616 The line numbers for warnings inside C<elsif> are now correct.
1620 The C<..> operator now works correctly with ranges whose ends are at or
1621 close to the values of the smallest and largest integers.
1625 C<binmode STDIN, ':raw'> could lead to segmentation faults on some platforms.
1626 This has been fixed [RT #54828].
1630 An off-by-one error meant that C<index $str, ...> was effectively being
1631 executed as C<index "$str\0", ...>. This has been fixed [RT #53746].
1635 Various leaks associated with named captures in regexes have been fixed
1640 A weak reference to a hash would leak. This was affecting C<DBI>
1645 Using (?|) in a regex could cause a segfault [RT #59734].
1649 Use of a UTF-8 C<tr//> within a closure could cause a segfault [RT #61520].
1653 Calling C<Perl_sv_chop()> or otherwise upgrading an SV could result in an
1654 unaligned 64-bit access on the SPARC architecture [RT #60574].
1658 In the 5.10.0 release, C<inc_version_list> would incorrectly list
1659 C<5.10.*> after C<5.8.*>; this affected the C<@INC> search order
1664 In 5.10.0, C<pack "a*", $tainted_value> returned a non-tainted value
1669 In 5.10.0, C<printf> and C<sprintf> could produce the fatal error
1670 C<panic: utf8_mg_pos_cache_update> when printing UTF-8 strings
1675 In the 5.10.0 release, a dynamically created C<AUTOLOAD> method might be
1676 missed (method cache issue) [RT #60220,60232].
1680 In the 5.10.0 release, a combination of C<use feature> and C<//ee> could
1681 cause a memory leak [RT #63110].
1685 C<-C> on the shebang (C<#!>) line is once more permitted if it is also
1686 specified on the command line. C<-C> on the shebang line used to be a
1687 silent no-op I<if> it was not also on the command line, so perl 5.10.0
1688 disallowed it, which broke some scripts. Now perl checks whether it is
1689 also on the command line and only dies if it is not [RT #67880].
1693 In 5.10.0, certain types of re-entrant regular expression could crash,
1694 or cause the following assertion failure [RT #60508]:
1696 Assertion rx->sublen >= (s - rx->subbeg) + i failed
1700 Previously missing files from Unicode 5.1 Character Database are now included.
1704 C<TMPDIR> is now honored when opening an anonymous temporary file
1708 =head1 New or Changed Diagnostics
1712 =item C<panic: sv_chop %s>
1714 This new fatal error occurs when the C routine C<Perl_sv_chop()> was
1715 passed a position that is not within the scalar's string buffer. This
1716 could be caused by buggy XS code, and at this point recovery is not
1719 =item C<Can't locate package %s for the parents of %s>
1721 This warning has been removed. In general, it only got produced in
1722 conjunction with other warnings, and removing it allowed an ISA lookup
1723 optimisation to be added.
1725 =item C<v-string in use/require is non-portable>
1727 This warning has been removed.
1729 =item C<Deep recursion on subroutine "%s">
1731 It is now possible to change the depth threshold for this warning from the
1732 default of 100, by recompiling the F<perl> binary, setting the C
1733 pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1737 =head1 Changed Internals
1743 The J.R.R. Tolkien quotes at the head of C source file have been checked and
1744 proper citations added, thanks to a patch from Tom Christiansen.
1748 C<Perl_vcroak()> now accepts a null first argument. In addition, a full audit
1749 was made of the "not NULL" compiler annotations, and those for several
1750 other internal functions were corrected.
1754 New macros C<dSAVEDERRNO>, C<dSAVE_ERRNO>, C<SAVE_ERRNO>, C<RESTORE_ERRNO>
1755 have been added to formalise the temporary saving of the C<errno>
1760 The function C<Perl_sv_insert_flags> has been added to augment
1765 The function C<Perl_newSV_type(type)> has been added, equivalent to
1766 C<Perl_newSV()> followed by C<Perl_sv_upgrade(type)>.
1770 The function C<Perl_newSVpvn_flags()> has been added, equivalent to
1771 C<Perl_newSVpvn()> and then performing the action relevant to the flag.
1773 Two flag bits are currently supported.
1779 This will call C<SvUTF8_on()> for you. (Note that this does not convert an
1780 sequence of ISO 8859-1 characters to UTF-8). A wrapper, C<newSVpvn_utf8()>
1781 is available for this.
1785 Call C<Perl_sv_2mortal()> on the new SV.
1789 There is also a wrapper that takes constant strings, C<newSVpvs_flags()>.
1793 The function C<Perl_croak_xs_usage> has been added as a wrapper to
1798 The functions C<PerlIO_find_layer> and C<PerlIO_list_alloc> are now
1803 C<PL_na> has been exterminated from the core code, replaced by local STRLEN
1804 temporaries, or C<*_nolen()> calls. Either approach is faster than C<PL_na>,
1805 which is a pointer deference into the interpreter structure under ithreads,
1806 and a global variable otherwise.
1810 C<Perl_mg_free()> used to leave freed memory accessible via C<SvMAGIC()> on
1811 the scalar. It now updates the linked list to remove each piece of magic
1816 Under ithreads, the regex in C<PL_reg_curpm> is now reference counted. This
1817 eliminates a lot of hackish workarounds to cope with it not being reference
1822 C<Perl_mg_magical()> would sometimes incorrectly turn on C<SvRMAGICAL()>.
1823 This has been fixed.
1827 The I<public> IV and NV flags are now not set if the string value has
1828 trailing "garbage". This behaviour is consistent with not setting the
1829 public IV or NV flags if the value is out of range for the type.
1833 SV allocation tracing has been added to the diagnostics enabled by C<-Dm>.
1834 The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if
1835 that was enabled when the F<perl> binary was compiled.
1839 Smartmatch resolution tracing has been added as a new diagnostic. Use C<-DM> to
1845 A new debugging flag C<-DB> now dumps subroutine definitions, leaving
1846 C<-Dx> for its original purpose of dumping syntax trees.
1850 Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have been
1851 replaced by C<NULL> in the core code, and non-dual-life modules, as C<NULL>
1852 is clearer to those unfamiliar with the core code.
1856 A macro C<MUTABLE_PTR(p)> has been added, which on (non-pedantic) gcc will
1857 not cast away C<const>, returning a C<void *>. Macros C<MUTABLE_SV(av)>,
1858 C<MUTABLE_SV(cv)> etc build on this, casting to C<AV *> etc without
1859 casting away C<const>. This allows proper compile-time auditing of
1860 C<const> correctness in the core, and helped picked up some errors (now
1865 Macros C<mPUSHs()> and C<mXPUSHs()> have been added, for pushing SVs on the
1866 stack and mortalizing them.
1870 Use of the private structure C<mro_meta> has changed slightly. Nothing
1871 outside the core should be accessing this directly anyway.
1875 A new tool, F<Porting/expand-macro.pl> has been added, that allows you
1876 to view how a C preprocessor macro would be expanded when compiled.
1877 This is handy when trying to decode the macro hell that is the perl
1884 Many modules updated from CPAN incorporate new tests.
1886 Several tests that have the potential to hang forever if they fail now
1887 incorporate a "watchdog" functionality that will kill them after a timeout,
1888 which helps ensure that C<make test> and C<make test_harness> run to
1889 completion automatically. (Jerry Hedden).
1891 Some core-specific tests have been added:
1895 =item t/comp/retainedlines.t
1897 Check that the debugger can retain source lines from C<eval>.
1899 =item t/io/perlio_fail.t
1901 Check that bad layers fail.
1903 =item t/io/perlio_leaks.t
1905 Check that PerlIO layers are not leaking.
1907 =item t/io/perlio_open.t
1909 Check that certain special forms of open work.
1913 General PerlIO tests.
1917 Check that there is no unexpected interaction between the internal types
1918 C<PVBM> and C<PVGV>.
1920 =item t/mro/package_aliases.t
1922 Check that mro works properly in the presence of aliased packages.
1926 Tests for C<dbmopen> and C<dbmclose>.
1928 =item t/op/index_thr.t
1930 Tests for the interaction of C<index> and threads.
1932 =item t/op/pat_thr.t
1934 Tests for the interaction of esoteric patterns and threads.
1938 Test that C<qr> doesn't leak.
1940 =item t/op/reg_email_thr.t
1942 Tests for the interaction of regex recursion and threads.
1944 =item t/op/regexp_qr_embed_thr.t
1946 Tests for the interaction of patterns with embedded C<qr//> and threads.
1948 =item t/op/regexp_unicode_prop.t
1950 Tests for Unicode properties in regular expressions.
1952 =item t/op/regexp_unicode_prop_thr.t
1954 Tests for the interaction of Unicode properties and threads.
1956 =item t/op/reg_nc_tie.t
1958 Test the tied methods of C<Tie::Hash::NamedCapture>.
1960 =item t/op/reg_posixcc.t
1962 Check that POSIX character classes behave consistently.
1966 Check that exportable C<re> functions in F<universal.c> work.
1968 =item t/op/setpgrpstack.t
1970 Check that C<setpgrp> works.
1972 =item t/op/substr_thr.t
1974 Tests for the interaction of C<substr> and threads.
1976 =item t/op/upgrade.t
1978 Check that upgrading and assigning scalars works.
1980 =item t/uni/lex_utf8.t
1982 Check that Unicode in the lexer works.
1986 Check that Unicode and C<tie> work.
1990 =head1 Known Problems
1992 This is a list of some significant unfixed bugs, which are regressions
1993 from either 5.10.0 or 5.8.x.
1999 C<List::Util::first> misbehaves in the presence of a lexical C<$_>
2000 (typically introduced by C<my $_> or implicitly by C<given>). The variable
2001 which gets set for each iteration is the package variable C<$_>, not the
2002 lexical C<$_> [RT #67694].
2004 A similar issue may occur in other modules that provide functions which
2005 take a block as their first argument, like
2007 foo { ... $_ ...} list
2011 The C<charnames> pragma may generate a run-time error when a regex is
2012 interpolated [RT #56444]:
2014 use charnames ':full';
2015 my $r1 = qr/\N{THAI CHARACTER SARA I}/;
2016 "foo" =~ $r1; # okay
2017 "foo" =~ /$r1+/; # runtime error
2019 A workaround is to generate the character outside of the regex:
2021 my $a = "\N{THAI CHARACTER SARA I}";
2026 Some regexes may run much more slowly when run in a child thread compared
2027 with the thread the pattern was compiled into [RT #55600].
2033 The following items are now deprecated.
2039 C<Switch> is buggy and should be avoided. From perl 5.11.0 onwards, it is
2040 intended that any use of the core version of this module will emit a
2041 warning, and that the module will eventually be removed from the core
2042 (probably in perl 5.14.0). See L<perlsyn/"Switch statements"> for its
2047 The following modules will be removed from the core distribution in a future
2048 release, and should be installed from CPAN instead. Distributions on CPAN
2049 which require these should add them to their prerequisites. The core versions
2050 of these modules warnings will issue a deprecation warning.
2062 C<suidperl> has been removed. It used to provide a mechanism to
2063 emulate setuid permission bits on systems that don't support it properly.
2067 Deprecate assignment to $[
2071 Remove attrs, which has been deprecated since 1999/10/02.
2075 Deprecate use of the attribute :locked on subroutines.
2079 Deprecate using "locked" with the attributes pragma.
2083 Deprecate using "unique" with the attributes pragma.
2087 warn if ++ or -- are unable to change the value because it's beyond the limit of representation
2089 This uses a new warnings category: "imprecision".
2093 Make lc/uc/lcfirst/ucfirst warn when passed undef.
2097 Show constant in "Useless use of a constant in void context"
2101 Make the new warning report undef constants as undef
2105 Add a new warning, "Prototype after '%s'"
2109 Tweak the "Illegal character in prototype" warning so it's more precise when reporting illegal characters after _
2113 Unintented interpolation of $\ in regex
2117 Make overflow warnings in gmtime/localtime only occur when warnings are on
2121 Improve mro merging error messages.
2123 They are now very similar to those produced by Algorithm::C3.
2127 Amelioration of the error message "Unrecognized character %s in column %d"
2129 Changes the error message to "Unrecognized character %s; marked by <--
2130 HERE after %s<-- HERE near column %d". This should make it a little
2131 simpler to spot and correct the suspicious character.
2135 Explicitely point to $. when it causes an uninitialized warning for ranges in scalar context
2139 Removed vestigal support for Tenon Intersystems MachTen Unix layer for MacOS Classic.
2143 Removed the port to Atari MiNT. It's a dead platform that hasn't had any love since 5.005.
2148 Deprecated numerous Perl 4-era libraries:
2150 F<termcap.pl>, F<tainted.pl>, F<stat.pl>, F<shellwords.pl>, F<pwd.pl>,
2151 F<open3.pl>, F<open2.pl>, F<newgetopt.pl>, F<look.pl>, F<find.pl>,
2152 F<finddepth.pl>, F<importenv.pl>, F<hostname.pl>, F<getopts.pl>,
2153 F<getopt.pl>, F<getcwd.pl>, F<flush.pl>, F<fastcwd.pl>, F<exceptions.pl>,
2154 F<ctime.pl>, F<complete.pl>, F<cacheout.pl>, F<bigrat.pl>, F<bigint.pl>,
2155 F<bigfloat.pl>, F<assert.pl>, F<abbrev.pl>, F<dotsh.pl>, and
2156 F<timelocal.pl> are all now deprecated. Using them will incur a warning.
2160 =head1 Acknowledgements
2162 Some of the work in this release was funded by a TPF grant funded by
2163 Dijkmat BV, The Netherlands.
2165 Steffen Mueller and David Golden in particular helped getting CPAN modules
2166 polished and synchronised with their in-core equivalents.
2168 Craig Berry was tireless in getting maint to run under VMS, no matter how
2169 many times we broke it for him.
2171 The other core committers contributed most of the changes, and applied most
2172 of the patches sent in by the hundreds of contributors listed in F<AUTHORS>.
2174 Much of the work of categorizing changes in this perldelta file was contributed
2175 by the following porters using changelogger.bestpractical.com:
2177 Nicholas Clark, leon, shawn, alexm, rjbs, rafl, Pedro Melo, brunorc,
2178 anonymous, ☄, Tom Hukins, anonymous, Jesse, dagolden, Moritz Onken,
2179 Mark Fowler, chorny, anonymous, tmtm
2181 Finally, thanks to Larry Wall, without whom none of this would be
2184 =head1 Reporting Bugs
2186 If you find what you think is a bug, you might check the articles
2187 recently posted to the comp.lang.perl.misc newsgroup and the perl
2188 bug database at http://rt.perl.org/perlbug/ . There may also be
2189 information at http://www.perl.org/ , the Perl Home Page.
2191 If you believe you have an unreported bug, please run the B<perlbug>
2192 program included with your release. Be sure to trim your bug down
2193 to a tiny but sufficient test case. Your bug report, along with the
2194 output of C<perl -V>, will be sent off to perlbug@perl.org to be
2195 analysed by the Perl porting team.
2197 If the bug you are reporting has security implications, which make it
2198 inappropriate to send to a publicly archived mailing list, then please send
2199 it to perl5-security-report@perl.org. This points to a closed subscription
2200 unarchived mailing list, which includes all the core committers, who be able
2201 to help assess the impact of issues, figure out a resolution, and help
2202 co-ordinate the release of patches to mitigate or fix the problem across all
2203 platforms on which Perl is supported. Please only use this address for
2204 security issues in the Perl core, not for modules independently
2205 distributed on CPAN.
2209 The F<Changes> file for an explanation of how to view exhaustive details
2212 The F<INSTALL> file for how to build Perl.
2214 The F<README> file for general stuff.
2216 The F<Artistic> and F<Copying> files for copyright information.