perl5120delta - what is new for perl v5.12.0
-=head1 XXX - THIS DOCUMENT IS ONLY CURRENT THROUGH PERL5115
-
-FIX ME BEFORE RELEASE
-
-OTHER ISSUES:
-
-UPDATED MODULE LIST NEEDS TO BE GENERATED
-ORDERING NEEDS CHECKING
-HEAVY COPYEDITING IS NEEDED
-
-
=head1 DESCRIPTION
This document describes differences between the 5.10.0 release and
You can see the list of those changes in the 5.10.1 release notes (L<perl5101delta>).
-=head1 New features and New syntax
+=head1 Core Enhancements
=head2 New C<package NAME VERSION> syntax
=item *
C<$VERSION> is a version object that provides proper overloading of
-comparision operators so comparing C<$VERSION> to decimal (1.23) or
+comparison operators so comparing C<$VERSION> to decimal (1.23) or
dotted-decimal (v1.2.3) version numbers works correctly.
=item *
literal, it can be statically parsed by toolchain modules
without C<eval> the way MM-E<gt>parse_version does for C<$VERSION = ...>
-=item *
+=back
It does not break old code with only C<package NAME>, but code that uses
C<package NAME VERSION> will need to be restricted to perl 5.12.0 or newer
Users requiring the latest Perl will benefit, and perhaps after several
years, it will become a standard practice.
-=back
However, C<package NAME VERSION> requires a new, 'strict' version
number format. See L<"Version number formats"> for details.
A new operator, C<...>, nicknamed the Yada Yada operator, has been added.
It is intended to mark placeholder code that is not yet implemented.
-See L<perlop/"Yada Yada Operator">. (chromatic)
+See L<perlop/"Yada Yada Operator">.
=head2 Implicit strictures
use strict;
use feature ':5.12';
+=head2 Unicode improvements
-=head1 Core Enhancements
+Perl 5.12 comes with Unicode 5.2, the latest version available to
+us at the time of release. This version of Unicode was released in
+October 2009. See L<http://www.unicode.org/versions/Unicode5.2.0> for
+further details about what's changed in this version of the standard.
+See L<perlunicode> for instructions on installing and using other versions
+of Unicode.
+
+Additionally, Perl's developers have significantly improved Perl's Unicode
+implementation. For full details, see L</Unicode overhaul> below.
+
+=head2 Y2038 compliance
+
+Perl's core time-related functions are now Y2038 compliant. (It may not mean much to you, but your kids will love it!)
=head2 qr overloading
mechanism, so extensions could only properly influence subroutine names
that appeared with an C<&> sigil.)
-=head2 Unicode version 5.2
-
-Perl 5.12 comes with Unicode 5.2, the latest version available to
-us at the time of release. This version of Unicode was released in
-October 2009. See L<http://www.unicode.org/versions/Unicode5.2.0> for
-further details about what's changed in this version of the standard.
-See L<perlunicode> for instructions on installing and using other versions
-of Unicode.
-
-=head2 Overhaul of Unicode property support
-
-Perl's developers have made a concerted effort to update Perl to be in
-sync with the latest Unicode standard. Changes for this include:
-
-Perl can now handle every Unicode character property. New documentation,
-L<perluniprops>, lists all available non-Unihan character properties. By
-default, perl does not expose Unihan, deprecated or Unicode-internal
-properties. See below for more details on these; there is also a section
-in the pod listing them, and explaining why they are not exposed.
-
-Perl now fully supports the Unicode compound-style of using C<=> and C<:>
-in writing regular expressions: C<\p{property=value}> and
-C<\p{property:value}> (both of which mean the same thing).
-
-Perl now fully supports the Unicode loose matching rules for text
-between the braces in C<\p{...}> constructs. In addition, Perl allows
-underscores between digits of numbers.
-
-Perl now accepts all the Unicode-defined synonyms for properties and property values.
-
-C<qr/\X/>, which matches a Unicode logical character, has been expanded to work
-better with various Asian languages. It now is defined as an I<extended
-grapheme cluster>. (See L<http://www.unicode.org/reports/tr29/>).
-Anything matched previously and that made sense will continue to be
-accepted. Additionally:
-
-=over
-
-=item *
-
-C<\X> will not break apart a C<S<CR LF>> sequence.
-
-=item *
-
-C<\X> will now match a sequence which includes the C<ZWJ> and C<ZWNJ> characters.
-
-=item *
-
-C<\X> will now always match at least one character, including an initial mark.
-Marks generally come after a base character, but it is possible in Unicode to
-have them in isolation, and C<\X> will now handle that case, for example at the
-beginning of a line, or after a C<ZWSP>. And this is the part where C<\X>
-doesn't match the things that it used to that don't make sense. Formerly, for
-example, you could have the nonsensical case of an accented LF.
-
-=item *
-
-C<\X> will now match a (Korean) Hangul syllable sequence, and the Thai and Lao
-exception cases.
-
-=back
-
-Otherwise, this change should be transparent for the non-affected languages.
-
-C<\p{...}> matches using the Canonical_Combining_Class property were
-completely broken in previous releases of Perl. They should now work correctly.
-
-Before Perl 5.12, the Unicode C<Decomposition_Type=Compat> property and a
-Perl extension had the same name, which led to neither matching all the
-correct values (with more than 100 mistakes in one, and several thousand
-in the other). The Perl extension has now been renamed to be
-C<Decomposition_Type=Noncanonical> (short: C<dt=noncanon>). It has the same
-meaning as was previously intended, namely the union of all the
-non-canonical Decomposition types, with Unicode C<Compat> being just one of
-those.
-
-C<\p{Decomposition_Type=Canonical}> now includes the Hangul syllables.
-
-C<\p{Uppercase}> and C<\p{Lowercase}> now work as the Unicode standard says they should.
-This means they each match a few more characters than they used to.
-
-C<\p{Cntrl}> now matches the same characters as C<\p{Control}>. This means it
-no longer will match Private Use (gc=co), Surrogates (gc=cs), nor Format
-(gc=cf) code points. The Format code points represent the biggest
-possible problem. All but 36 of them are either officially deprecated
-or strongly discouraged from being used. Of those 36, likely the most
-widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ, WJ, and
-similar characters, plus bidirectional controls.
-
-C<\p{Alpha}> now matches the same characters as C<\p{Alphabetic}>. Before 5.12, Perl's definition
-definition included a number of things that aren't really alpha (all
-marks) while omitting many that were. The
-definitions of C<\p{Alnum}> and C<\p{Word}> depend on Alpha's definition and have changed accordingly.
-
-C<\p{Word}> no longer incorrectly matches non-word characters such as fractions.
-
-C<\p{Print}> no longer matches the line control characters: Tab, LF, CR,
-FF, VT, and NEL. This brings it in line with standards and the documentation.
-
-C<\p{XDigit}> now matches the same characters as C<\p{Hex_Digit}>. This
-means that in addition to the characters it currently matches,
-C<[A-Fa-f0-9]>, it will also match the 22 fullwidth equivalents, for
-example U+FF10: FULLWIDTH DIGIT ZERO.
-
-The Numeric type property has been extended to include the Unihan
-characters.
-
-There is a new Perl extension, the 'Present_In', or simply 'In',
-property. This is an extension of the Unicode Age property, but
-C<\p{In=5.0}> matches any code point whose usage has been determined
-I<as of> Unicode version 5.0. The C<\p{Age=5.0}> only matches code points
-added in I<precisely> version 5.0.
-
-A number of properties now have the correct values for unassigned
-code points. The affected properties are
-Bidi_Class, East_Asian_Width, Joining_Type, Decomposition_Type,
-Hangul_Syllable_Type, Numeric_Type, and Line_Break.
-
-The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties
-are now up to date with current Unicode definitions.
-
-Earlier versions of Perl erroneously exposed certain properties that are supposed to be Unicode internal-only.
-Use of these in regular expressions will now generate, if enabled, a deprecation warning message.
-The properties are: Other_Alphabetic, Other_Default_Ignorable_Code_Point,
-Other_Grapheme_Extend, Other_ID_Continue, Other_ID_Start, Other_Lowercase,
-Other_Math, and Other_Uppercase.
-
-It is now possible to change which Unicode properties Perl understands
-on a per-installation basis. As mentioned above, certain properties
-are turned off by default. These include all the Unihan properties
-(which should be accessible via the CPAN module Unicode::Unihan) and any
-deprecated or Unicode internal-only property that Perl has never exposed.
-
-The generated files in the C<lib/unicore/To> directory are now more
-clearly marked as being stable, directly usable by applications.
-New hash entries in them give the format of the normal entries,
-which allows for easier machine parsing. Perl can generate files
-in this directory for any property, though most are suppressed.
-You can find instructions for changing which are written in L<perluniprops>.
-
-=head2 Regular Expressions
-
-U+0FFFF is now a legal character in regular expressions.
-
=head2 A proper interface for pluggable Method Resolution Orders
As of Perl 5.12.0 there is a new interface for plugging and using method
a plugin, without changing its Perl-space interface. See L<perlmroapi> for
more information.
-=head2 The C<overloading> pragma
-
-This pragma allows you to lexically disable or enable overloading
-for some or all operations. (Yuval Kogman)
-
-=head2 \N{...} now compiles better, always forces UTF-8 internal representation.
-
-There were several problems that have been fixed with recognizing C<\N{...}>
-constructs. As part of this, any scalar or regex that has either a
-C<\N{I<name>}> or C<\N{U+I<wide hex char>}> in its definition will be stored in
-UTF-8 format. (This was true previously for all occurences of C<\N{I<name>}>
-that did not use a custom translator, but now it's always true.)
=head2 C<\N> experimental regex escape
The C<each> function can now operate on arrays.
-=head2 Y2038 compliance
+=head2 C<when> as a statement modifier
-Perl's core time-related functions are now Y2038 compliant. (It may not mean much to you, but your kids will love it!)
+C<when> is now allowed to be used as a statement modifier.
=head2 C<$,> flexibility
The variable C<$,> may now be tied.
-=head2 // in where clauses
+=head2 // in when clauses
// now behaves like || in when clauses
of the system's signed and unsigned integers is now available for the C<pos>
and C<len> arguments.
-=head1 Incompatible Changes
+=head1 Potentially Incompatible Changes
=head2 Deprecations warn by default
To disable this feature in a given lexical scope, you should use C<no
warnings 'deprecated';> For information about which language features
are deprecated and explanations of various deprecation warnings, please
-see L<perldiag.pod>
+see L<perldiag.pod>. See L</Deprecations> below for the list of features
+and modules Perl's developers have deprecated as part of this release.
=head2 Version number formats
=head2 @INC reorganization
-In @INC, ARCHLIB and PRIVLIB now occur after after the current version's
-site_perl and vendor_perl.
+In C<@INC>, C<ARCHLIB> and C<PRIVLIB> now occur after after the current
+version's C<site_perl> and C<vendor_perl>. Modules installed into
+C<site_perl> and C<vendor_perl> will now be loaded in preference to
+those installed in C<ARCHLIB> and C<PRIVLIB>.
=head2 Switch statement changes
-The handling of complex expressions by the C<given>/C<when> switch
-statement has been enhanced. These enhancements are also available in
-5.10.1 and subsequent 5.10 releases. There are two new cases where
+The C<given>/C<when> switch statement handles complex statements better
+than Perl 5.10.0 did (These enhancements are also available in
+5.10.1 and subsequent 5.10 releases.) There are two new cases where
C<when> now interprets its argument as a boolean, instead of an
expression to be used in a smart match:
-=head2 flip-flop operators
+=over
+
+=item flip-flop operators
The C<..> and C<...> flip-flop operators are now evaluated in boolean
context, following their usual semantics; see L<perlop/"Range Operators">.
# do something
}
-=head2 defined-or operator
+=item defined-or operator
A compound expression involving the defined-or operator, as in
C<when (expr1 // expr2)>, will be treated as boolean if the first
expression is boolean. (This just extends the existing rule that applies
to the regular or operator, as in C<when (expr1 || expr2)>.)
+=back
+
=head2 Smart match changes
-This section details more changes brought to the semantics to
-the smart match operator, that naturally also modify the behaviour
+Since Perl 5.10.0, Perl's developers have made a number of changes to
+the smart match operator. These, of course, also alter the behaviour
of the switch statements where smart matching is implicitly used.
These changes were also made for the 5.10.1 release, and will remain in
subsequent 5.10 releases.
object overloads the stringification or the numification operators, and
if overload fallback is active, it will be used instead, as usual.)
-=head2 Labels can't be keywords
-
-Labels used as targets for the C<goto>, C<last>, C<next> or C<redo>
-statements cannot be keywords anymore. This restriction will prevent
-potential confusion between the C<goto LABEL> and C<goto EXPR> syntaxes:
-for example, a statement like C<goto print> would jump to a label whose
-name would be the return value of C<print()>, (usually 1), instead of a
-label named C<print>. Moreover, the other control flow statements
-would just ignore any keyword passed to them as a label name. Since
-such labels cannot be defined anymore, this kind of error will be
-avoided.
-
-=head2 Other incompatible changes
+=head2 Other potentially incompatible changes
=over 4
The definitions of a number of Unicode properties have changed to match
those of the current Unicode standard. These are listed above under
-L</Overhaul of Unicode property support>. This could break code that
-is expecting the old definitions.
+L</Unicode overhaul>. This change may break code that expects the old definitions.
=item *
-The boolkeys op moved to the group of hash ops. This breaks binary
+The boolkeys op has moved to the group of hash ops. This breaks binary
compatibility.
=item *
=item *
-The version control system used for the development of the perl
-interpreter has been switched from Perforce to git. This is mainly an
-internal issue that only affects people actively working on the perl core;
-but it may have minor external visibility, for example in some of details
-of the output of C<perl -V>. See L<perlrepository> for more information.
-
-=item *
-
-The internal structure of the C<ext/> directory in the perl source has
-been reorganised. In general, a module C<Foo::Bar> whose source was
-stored under F<ext/Foo/Bar/> is now located under F<ext/Foo-Bar/>. Also,
-nearly all dual-life modules have been moved from F<lib/> to F<ext/>. This
-is purely a source tarball change, and should make no difference to the
-compilation or installation of perl, unless you have a very customised build
-process that explicitly relies on this structure, or which hard-codes the
-C<nonxs_ext> F<Configure> parameter. Specifically, this change does not by
-default alter the location of any files in the final installation.
+Perl's developers now use git, rather than Perforce. This should be
+a purely internal change only relevant to people actively working on
+the core. However, you may see minor difference in perl as a consequence
+of the change. For example in some of details of the output of C<perl
+-V>. See L<perlrepository> for more information.
=item *
As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental
C<Test::Harness::Straps> module has been removed.
-See L</"Updated Modules"> for more details.
+See L</"Modules and Pragmata"> for more details.
=item *
C<Module::CoreList> no longer contains the C<%:patchlevel> hash.
-=item *
-
-This one is actually a change introduced in 5.10.0, but it was missed
-from that release's perldelta, so it is mentioned here instead.
-
-A bugfix related to the handling of the C</m> modifier and C<qr> resulted
-in a change of behaviour between 5.8.x and 5.10.0:
-
- # matches in 5.8.x, doesn't match in 5.10.0
- $re = qr/^bar/; "foo\nbar" =~ /$re/m;
=item *
=back
+
=head1 Deprecations
From time to time, Perl's developers find it necessary to deprecate
disrupting our ability to maintain and extend Perl, we'll try to leave
it in place as long as possible.
-The following items are now deprecated.
+The following items are now deprecated:
+
+=over
+
+=item suidperl
+
+C<suidperl> is no longer part of Perl. It used to provide a mechanism to
+emulate setuid permission bits on systems that don't support it properly.
-=over 4
-=item Use of C<:=> to mean an empty attribute list is now deprecated.
+=item Use of C<:=> to mean an empty attribute list
An accident of Perl's parser meant that these constructions were all
equivalent:
pass import arguments to a C<use UNIVERSAL> statement will result in a
deprecation warning.
-=item Use of "goto" to jump into a construct is deprecated
+
+=item Use of "goto" to jump into a construct
Using C<goto> to jump from an outer scope into an inner scope is now
deprecated. This rare use case was causing problems in the
implementation of scopes.
-=item Custom character names in \N{name} should look like names
+=item Custom character names in \N{name} that don't look like names
In C<\N{I<name>}>, I<name> can be just about anything. The standard Unicode
names have a very limited domain, but a custom name translator could create
=item L<Switch>
-Switch is buggy and should be avoided. See L<perlsyn/"Switch
-statements"> for its replacement.
+Switch is buggy and should be avoided. You may find Perl's new
+C<given>/C<when> feature a suitable replacement. See L<perlsyn/"Switch
+statements"> for more information.
=back
-=item suidperl
-
-C<suidperl> has been removed. It used to provide a mechanism to
-emulate setuid permission bits on systems that don't support it properly.
-
=item Assignment to $[
-=item attrs
+=item Use of the attribute :locked on subroutines
-Remove attrs, which has been deprecated since 1999-10-02.
+=item Use of "locked" with the attributes pragma
-=item Use of the attribute :locked on subroutines.
+=item Use of "unique" with the attributes pragma
-=item Use of "locked" with the attributes pragma.
+=item Perl_pmflag
-=item Use of "unique" with the attributes pragma.
+C<Perl_pmflag> is no longer part of Perl's public API. Calling it now
+generates a deprecation warning, and it will be removed in a future
+release. Although listed as part of the API, it was never documented,
+and only ever used in F<toke.c>, and prior to 5.10, F<regcomp.c>. In
+core, it has been replaced by a static function.
-=item Numerous Perl 4-era libraries:
+=item Numerous Perl 4-era libraries
F<termcap.pl>, F<tainted.pl>, F<stat.pl>, F<shellwords.pl>, F<pwd.pl>,
F<open3.pl>, F<open2.pl>, F<newgetopt.pl>, F<look.pl>, F<find.pl>,
F<bigfloat.pl>, F<assert.pl>, F<abbrev.pl>, F<dotsh.pl>, and
F<timelocal.pl> are all now deprecated. Using them will incur a warning.
-=back
-=head1 Modules and Pragmata
+=back
-=head2 Dual-lifed modules moved
+=head1 Unicode overhaul
-Dual-lifed modules maintained primarily in the Perl core now live in dist/.
-Dual-lifed modules maintained primarily on CPAN now live in cpan/
+Perl's developers have made a concerted effort to update Perl to be in
+sync with the latest Unicode standard. Changes for this include:
-In previous releases of Perl, it was customary to enumerate all module
-changes in this section of the C<perldelta> file. From 5.11.0 forward
-only notable updates (such as new or deprecated modules ) will be listed
-in this section. For a complete reference to the versions of modules
-shipped in a given release of perl, please see L<Module::CoreList>.
+Perl can now handle every Unicode character property. New documentation,
+L<perluniprops>, lists all available non-Unihan character properties. By
+default, perl does not expose Unihan, deprecated or Unicode-internal
+properties. See below for more details on these; there is also a section
+in the pod listing them, and explaining why they are not exposed.
-=head2 New Modules and Pragmata
+Perl now fully supports the Unicode compound-style of using C<=> and C<:>
+in writing regular expressions: C<\p{property=value}> and
+C<\p{property:value}> (both of which mean the same thing).
-=over 4
+Perl now fully supports the Unicode loose matching rules for text
+between the braces in C<\p{...}> constructs. In addition, Perl allows
+underscores between digits of numbers.
-=item *
+Perl now accepts all the Unicode-defined synonyms for properties and property values.
-C<autodie>
+C<qr/\X/>, which matches a Unicode logical character, has been expanded to work
+better with various Asian languages. It now is defined as an I<extended
+grapheme cluster>. (See L<http://www.unicode.org/reports/tr29/>).
+Anything matched previously and that made sense will continue to be
+accepted. Additionally:
-This is a new lexically-scoped alternative for the C<Fatal> module.
-The bundled version is 2.06_01. Note that in this release, using a string
-eval when C<autodie> is in effect can cause the autodie behaviour to leak
-into the surrounding scope. See L<autodie/"BUGS"> for more details.
+=over
=item *
-C<Compress::Raw::Bzip2>
-
-This has been added to the core (version 2.020).
+C<\X> will not break apart a C<S<CR LF>> sequence.
=item *
-C<parent>
-
-This pragma establishes an ISA relationship with base classes at compile
-time. It provides the key feature of C<base> without further unwanted
-behaviors.
+C<\X> will now match a sequence which includes the C<ZWJ> and C<ZWNJ> characters.
=item *
-C<Parse::CPAN::Meta>
+C<\X> will now always match at least one character, including an initial mark.
+Marks generally come after a base character, but it is possible in Unicode to
+have them in isolation, and C<\X> will now handle that case, for example at the
+beginning of a line, or after a C<ZWSP>. And this is the part where C<\X>
+doesn't match the things that it used to that don't make sense. Formerly, for
+example, you could have the nonsensical case of an accented LF.
+
+=item *
-This has been added to the core (version 1.39).
+C<\X> will now match a (Korean) Hangul syllable sequence, and the Thai and Lao
+exception cases.
=back
-=head2 Pragmata Changes
+Otherwise, this change should be transparent for the non-affected
+languages.
-=over 4
+C<\p{...}> matches using the Canonical_Combining_Class property were
+completely broken in previous releases of Perl. They should now work
+correctly.
+
+Before Perl 5.12, the Unicode C<Decomposition_Type=Compat> property
+and a Perl extension had the same name, which led to neither matching
+all the correct values (with more than 100 mistakes in one, and several
+thousand in the other). The Perl extension has now been renamed to be
+C<Decomposition_Type=Noncanonical> (short: C<dt=noncanon>). It has the
+same meaning as was previously intended, namely the union of all the
+non-canonical Decomposition types, with Unicode C<Compat> being just
+one of those.
-=item *
+C<\p{Decomposition_Type=Canonical}> now includes the Hangul syllables.
-C<overloading>
+C<\p{Uppercase}> and C<\p{Lowercase}> now work as the Unicode standard
+says they should. This means they each match a few more characters than
+they used to.
-See L</"The C<overloading> pragma"> above.
+C<\p{Cntrl}> now matches the same characters as C<\p{Control}>. This
+means it no longer will match Private Use (gc=co), Surrogates (gc=cs),
+nor Format (gc=cf) code points. The Format code points represent the
+biggest possible problem. All but 36 of them are either officially
+deprecated or strongly discouraged from being used. Of those 36, likely
+the most widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ,
+WJ, and similar characters, plus bidirectional controls.
-=item *
+C<\p{Alpha}> now matches the same characters as C<\p{Alphabetic}>. Before
+5.12, Perl's definition definition included a number of things that aren't
+really alpha (all marks) while omitting many that were. The definitions
+of C<\p{Alnum}> and C<\p{Word}> depend on Alpha's definition and have
+changed accordingly.
-C<attrs>
+C<\p{Word}> no longer incorrectly matches non-word characters such
+as fractions.
-The C<attrs> pragma has been removed. It had been marked as deprecated since
-5.6.0.
+C<\p{Print}> no longer matches the line control characters: Tab, LF,
+CR, FF, VT, and NEL. This brings it in line with standards and the
+documentation.
-=item *
+C<\p{XDigit}> now matches the same characters as C<\p{Hex_Digit}>. This
+means that in addition to the characters it currently matches,
+C<[A-Fa-f0-9]>, it will also match the 22 fullwidth equivalents, for
+example U+FF10: FULLWIDTH DIGIT ZERO.
-C<charnames>
+The Numeric type property has been extended to include the Unihan
+characters.
-The Unicode F<NameAliases.txt> database file has been added. This has the
-effect of adding some extra C<\N> character names that formerly wouldn't
-have been recognised; for example, C<"\N{LATIN CAPITAL LETTER GHA}">.
+There is a new Perl extension, the 'Present_In', or simply 'In',
+property. This is an extension of the Unicode Age property, but
+C<\p{In=5.0}> matches any code point whose usage has been determined
+I<as of> Unicode version 5.0. The C<\p{Age=5.0}> only matches code points
+added in I<precisely> version 5.0.
-=item *
+A number of properties now have the correct values for unassigned
+code points. The affected properties are Bidi_Class, East_Asian_Width,
+Joining_Type, Decomposition_Type, Hangul_Syllable_Type, Numeric_Type,
+and Line_Break.
-C<feature>
+The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties
+are now up to date with current Unicode definitions.
-The meaning of the C<:5.10> and C<:5.10.X> feature bundles has
-changed slightly. The last component, if any (i.e. C<X>) is simply ignored.
-This is predicated on the assumption that new features will not, in
-general, be added to maintenance releases. So C<:5.10> and C<:5.10.X>
-have identical effect. This is a change to the behaviour documented for
-5.10.0.
+Earlier versions of Perl erroneously exposed certain properties that
+are supposed to be Unicode internal-only. Use of these in regular
+expressions will now generate, if enabled, a deprecation warning message.
+The properties are: Other_Alphabetic, Other_Default_Ignorable_Code_Point,
+Other_Grapheme_Extend, Other_ID_Continue, Other_ID_Start, Other_Lowercase,
+Other_Math, and Other_Uppercase.
-=item *
+It is now possible to change which Unicode properties Perl understands
+on a per-installation basis. As mentioned above, certain properties
+are turned off by default. These include all the Unihan properties
+(which should be accessible via the CPAN module Unicode::Unihan) and any
+deprecated or Unicode internal-only property that Perl has never exposed.
-C<mro>
+The generated files in the C<lib/unicore/To> directory are now more
+clearly marked as being stable, directly usable by applications. New hash
+entries in them give the format of the normal entries, which allows for
+easier machine parsing. Perl can generate files in this directory for
+any property, though most are suppressed. You can find instructions
+for changing which are written in L<perluniprops>.
-Upgraded from version 1.00 to 1.01. Performance for single inheritance is 40%
-faster - see L</"Performance Enhancements"> below.
-C<mro> is now implemented as an XS extension. The documented interface has not
-changed. Code relying on the implementation detail that some C<mro::>
-methods happened to be available at all times gets to "keep both pieces".
-=item *
+=head1 Modules and Pragmata
-C<diagnostics>
+=head2 New Modules and Pragmata
-Supports %.0f formatting internally.
+=over 4
-=item *
+=item C<autodie>
+
+C<autodie> is a new lexically-scoped alternative for the C<Fatal> module.
+The bundled version is 2.06_01. Note that in this release, using a string
+eval when C<autodie> is in effect can cause the autodie behaviour to leak
+into the surrounding scope. See L<autodie/"BUGS"> for more details.
-C<overload>
+Version 2.06_01 has been added to the Perl core.
-Allow overloading of 'qr'.
+=item C<Compress::Raw::Bzip2>
-=item *
+Version 2.024 has been added to the Perl core.
-C<constant>
+=item C<overloading>
-Upgraded from version 1.19 to 1.20.
+C<overloading> allows you to lexically disable or enable overloading
+for some or all operations.
-=item *
+Version 0.001 has been added to the Perl core.
+
+=item C<parent>
+
+C<parent> establishes an ISA relationship with base classes at compile
+time. It provides the key feature of C<base> without further unwanted
+behaviors.
+
+Version 0.223 has been added to the Perl core.
+
+=item C<Parse::CPAN::Meta>
+
+Version 1.40 has been added to the Perl core.
+
+=item C<VMS::DCLsym>
+
+Version 1.03 has been added to the Perl core.
+
+=item C<VMS::Stdio>
+
+Version 2.4 has been added to the Perl core.
+
+=item C<XS::APItest::KeywordRPN>
+
+Version 0.003 has been added to the Perl core.
+
+=back
+
+=head2 Updated Pragmata
+
+=over 4
+
+=item C<base>
+
+Upgraded from version 2.13 to 2.15.
+
+=item C<bignum>
+
+Upgraded from version 0.22 to 0.23.
+
+=item C<charnames>
-C<diagnostics>
+C<charnames> now contains the Unicode F<NameAliases.txt> database file.
+This has the effect of adding some extra C<\N> character names that
+formerly wouldn't have been recognised; for example, C<"\N{LATIN CAPITAL
+LETTER GHA}">.
-This pragma no longer suppresses C<Use of uninitialized value in range
+Upgraded from version 1.06 to 1.07.
+
+=item C<constant>
+
+Upgraded from version 1.13 to 1.20.
+
+=item C<diagnostics>
+
+C<diagnostics> now supports %.0f formatting internally.
+
+C<diagnostics> no longer suppresses C<Use of uninitialized value in range
(or flip)> warnings. [perl #71204]
-=item *
+Upgraded from version 1.17 to 1.19.
-C<feature>
+=item C<feature>
+
+In C<feature>, the meaning of the C<:5.10> and C<:5.10.X> feature bundles has
+changed slightly. The last component, if any (i.e. C<X>) is simply ignored.
+This is predicated on the assumption that new features will not, in
+general, be added to maintenance releases. So C<:5.10> and C<:5.10.X>
+have identical effect. This is a change to the behaviour documented for
+5.10.0.
-Upgraded from 1.13 to 1.14. Added the C<unicode_strings> feature:
+C<feature> now includes the C<unicode_strings> feature:
use feature "unicode_strings";
internal UTF-8 flag set, but that contain single-byte characters between
128 and 255.
-=item *
+Upgraded from version 1.11 to 1.16.
-C<threads>
+=item C<less>
-Upgraded from version 1.74 to 1.75.
+C<less> now includes the C<stash_name> method to allow subclasses of
+C<less> to pick where in %^H to store their stash.
-=item *
+Upgraded from version 0.02 to 0.03.
-C<less>
+=item C<lib>
-Upgraded from version 0.02 to 0.03.
+Upgraded from version 0.5565 to 0.62.
-This version introduces the C<stash_name> method to allow subclasses of
-C<less> to pick where in %^H to store their stash.
+=item C<mro>
-=item *
+C<mro> is now implemented as an XS extension. The documented interface has not
+changed. Code relying on the implementation detail that some C<mro::>
+methods happened to be available at all times gets to "keep both pieces".
-C<version>
+Upgraded from version 1.00 to 1.02.
-Upgraded from version 0.77 to 0.81.
+=item C<overload>
-This version adds support for L</Version number formats> as described earlier
-in this document and in its own documentation.
+C<overload> now allow overloading of 'qr'.
-=item *
+Upgraded from version 1.06 to 1.10.
+
+=item C<threads>
+
+Upgraded from version 1.67 to 1.75.
+
+=item C<threads::shared>
+
+Upgraded from version 1.14 to 1.32.
+
+=item C<version>
+
+C<version> now has support for L</Version number formats> as described earlier
+in this document and in its own documentation.
-C<warnings>
+Upgraded from version 0.74 to 0.82.
-Upgraded from 1.07 to 1.09.
+=item C<warnings>
-Added new C<warnings::fatal_enabled()> function.
-This version adds the C<illegalproto> warning category. See also L</New or
+C<warnings> has a new C<warnings::fatal_enabled()> function. It also
+includes a new C<illegalproto> warning category. See also L</New or
Changed Diagnostics> for this change.
-=back
+Upgraded from version 1.06 to 1.09.
+=back
=head2 Updated Modules
=over 4
-=item XXX TODO RECALCULATE THIS VS 5.10.0
+=item C<Archive::Extract>
+
+Upgraded from version 0.24 to 0.38.
+
+=item C<Archive::Tar>
+
+Upgraded from version 1.38 to 1.54.
+
+=item C<Attribute::Handlers>
+
+Upgraded from version 0.79 to 0.87.
+
+=item C<AutoLoader>
+
+Upgraded from version 5.63 to 5.70.
+
+=item C<B::Concise>
+
+Upgraded from version 0.74 to 0.78.
+
+=item C<B::Debug>
+
+Upgraded from version 1.05 to 1.12.
+
+=item C<B::Deparse>
+
+Upgraded from version 0.83 to 0.94.
+
+=item C<B::Lint>
+
+Upgraded from version 1.09 to 1.11_01.
+
+=item C<CGI>
+
+Upgraded from version 3.29 to 3.48.
+
+=item C<Class::ISA>
+
+Upgraded from version 0.33 to 0.36.
+
+NOTE: C<Class::ISA> is deprecated and may be removed from a future version of Perl.
+
+=item C<Compress::Raw::Zlib>
+
+Upgraded from version 2.008 to 2.024.
+
+=item C<CPAN>
+
+Upgraded from version 1.9205 to 1.94_56.
+
+=item C<CPANPLUS>
+
+Upgraded from version 0.84 to 0.90.
+
+=item C<CPANPLUS::Dist::Build>
+
+Upgraded from version 0.06_02 to 0.46.
+
+=item C<Data::Dumper>
+
+Upgraded from version 2.121_14 to 2.125.
+
+=item C<DB_File>
+
+Upgraded from version 1.816_1 to 1.820.
+
+=item C<Devel::PPPort>
+
+Upgraded from version 3.13 to 3.19.
+
+=item C<Digest>
+
+Upgraded from version 1.15 to 1.16.
+
+=item C<Digest::MD5>
+
+Upgraded from version 2.36_01 to 2.39.
+
+=item C<Digest::SHA>
+
+Upgraded from version 5.45 to 5.47.
+
+=item C<Encode>
+
+Upgraded from version 2.23 to 2.39.
+
+=item C<Exporter>
+
+Upgraded from version 5.62 to 5.64_01.
+
+=item C<ExtUtils::CBuilder>
+
+Upgraded from version 0.21 to 0.27.
+
+=item C<ExtUtils::Command>
+
+Upgraded from version 1.13 to 1.16.
+
+=item C<ExtUtils::Constant>
+
+Upgraded from version 0.2 to 0.22.
+
+=item C<ExtUtils::Install>
+
+Upgraded from version 1.44 to 1.55.
+
+=item C<ExtUtils::MakeMaker>
+
+Upgraded from version 6.42 to 6.56.
+
+=item C<ExtUtils::Manifest>
+
+Upgraded from version 1.51_01 to 1.57.
+
+=item C<ExtUtils::ParseXS>
+
+Upgraded from version 2.18_02 to 2.21.
+
+=item C<File::Fetch>
+
+Upgraded from version 0.14 to 0.24.
+
+=item C<File::Path>
+
+Upgraded from version 2.04 to 2.08_01.
+
+=item C<File::Temp>
+
+Upgraded from version 0.18 to 0.22.
+
+=item C<Filter::Simple>
+
+Upgraded from version 0.82 to 0.84.
+
+=item C<Filter::Util::Call>
+
+Upgraded from version 1.07 to 1.08.
+
+=item C<Getopt::Long>
+
+Upgraded from version 2.37 to 2.38.
+
+=item C<IO>
+
+Upgraded from version 1.23_01 to 1.25_02.
+
+=item C<IO::Zlib>
+
+Upgraded from version 1.07 to 1.10.
+
+=item C<IPC::Cmd>
+
+Upgraded from version 0.40_1 to 0.54.
+
+=item C<IPC::SysV>
+
+Upgraded from version 1.05 to 2.01.
+
+=item C<Locale::Maketext>
+
+Upgraded from version 1.12 to 1.14.
+
+=item C<Locale::Maketext::Simple>
+
+Upgraded from version 0.18 to 0.21.
+
+=item C<Log::Message>
+
+Upgraded from version 0.01 to 0.02.
+
+=item C<Log::Message::Simple>
+
+Upgraded from version 0.04 to 0.06.
+
+=item C<Math::BigInt>
+
+Upgraded from version 1.88 to 1.89_01.
+
+=item C<Math::BigInt::FastCalc>
+
+Upgraded from version 0.16 to 0.19.
+
+=item C<Math::BigRat>
+
+Upgraded from version 0.21 to 0.24.
+
+=item C<Math::Complex>
+
+Upgraded from version 1.37 to 1.56.
+
+=item C<Memoize>
+
+Upgraded from version 1.01_02 to 1.01_03.
+
+=item C<MIME::Base64>
+
+Upgraded from version 3.07_01 to 3.08.
+
+=item C<Module::Build>
+
+Upgraded from version 0.2808_01 to 0.3603.
+
+=item C<Module::CoreList>
+
+Upgraded from version 2.12 to 2.27.
+
+=item C<Module::Load>
+
+Upgraded from version 0.12 to 0.16.
+
+=item C<Module::Load::Conditional>
+
+Upgraded from version 0.22 to 0.34.
+
+=item C<Module::Loaded>
+
+Upgraded from version 0.01 to 0.06.
+
+=item C<Module::Pluggable>
+
+Upgraded from version 3.6 to 3.9.
+
+=item C<Net::Ping>
+
+Upgraded from version 2.33 to 2.36.
+
+=item C<NEXT>
+
+Upgraded from version 0.60_01 to 0.64.
+
+=item C<Object::Accessor>
+
+Upgraded from version 0.32 to 0.36.
+
+=item C<Package::Constants>
+
+Upgraded from version 0.01 to 0.02.
+
+=item C<PerlIO>
+
+Upgraded from version 1.04 to 1.06.
+
+=item C<Pod::Parser>
+
+Upgraded from version 1.35 to 1.37.
+
+=item C<Pod::Perldoc>
+
+Upgraded from version 3.14_02 to 3.15_02.
+
+=item C<Pod::Plainer>
+
+Upgraded from version 0.01 to 1.02.
+
+NOTE: C<Pod::Plainer> is deprecated and may be removed from a future version of Perl.
+
+=item C<Pod::Simple>
+
+Upgraded from version 3.05 to 3.13.
+
+=item C<Safe>
+
+Upgraded from version 2.12 to 2.22.
+
+=item C<SelfLoader>
+
+Upgraded from version 1.11 to 1.17.
+
+=item C<Storable>
+
+Upgraded from version 2.18 to 2.22.
+
+=item C<Switch>
+
+Upgraded from version 2.13 to 2.16.
+
+NOTE: C<Switch> is deprecated and may be removed from a future version of Perl.
+
+=item C<Sys::Syslog>
+
+Upgraded from version 0.22 to 0.27.
+
+=item C<Term::ANSIColor>
+
+Upgraded from version 1.12 to 2.02.
+
+=item C<Term::UI>
+
+Upgraded from version 0.18 to 0.20.
+
+=item C<Test>
+
+Upgraded from version 1.25 to 1.25_02.
+
+=item C<Test::Harness>
+
+Upgraded from version 2.64 to 3.17.
+
+=item C<Test::Simple>
+
+Upgraded from version 0.72 to 0.94.
+
+=item C<Text::Balanced>
+
+Upgraded from version 2.0.0 to 2.02.
+
+=item C<Text::ParseWords>
+
+Upgraded from version 3.26 to 3.27.
+
+=item C<Text::Soundex>
+
+Upgraded from version 3.03 to 3.03_01.
+
+=item C<Thread::Queue>
+
+Upgraded from version 2.00 to 2.11.
+
+=item C<Thread::Semaphore>
+
+Upgraded from version 2.01 to 2.09.
+
+=item C<Tie::RefHash>
+
+Upgraded from version 1.37 to 1.38.
+
+=item C<Time::HiRes>
+
+Upgraded from version 1.9711 to 1.9719.
+
+=item C<Time::Local>
+
+Upgraded from version 1.18 to 1.1901_01.
+
+=item C<Time::Piece>
+
+Upgraded from version 1.12 to 1.15.
+
+=item C<Unicode::Collate>
+
+Upgraded from version 0.52 to 0.52_01.
+
+=item C<Unicode::Normalize>
+
+Upgraded from version 1.02 to 1.03.
+
+=item C<Win32>
+
+Upgraded from version 0.34 to 0.39.
+
+=item C<Win32API::File>
+
+Upgraded from version 0.1001_01 to 0.1101.
+
+=item C<XSLoader>
+
+Upgraded from version 0.08 to 0.10.
=back
=over 4
-=item *
+=item C<attrs>
+
+Removed from the Perl core. Prior version was 1.02.
+
+=item C<CPAN::API::HOWTO>
-C<Devel::DProf::V>
+Removed from the Perl core. Prior version was 'undef'.
-Removed from the Perl core. Prior version was 'undef'.
+=item C<CPAN::DeferedCode>
+
+Removed from the Perl core. Prior version was 5.50.
+
+=item C<CPANPLUS::inc>
+
+Removed from the Perl core. Prior version was 'undef'.
+
+=item C<DCLsym>
+
+Removed from the Perl core. Prior version was 1.03.
+
+=item C<ExtUtils::MakeMaker::bytes>
+
+Removed from the Perl core. Prior version was 6.42.
+
+=item C<ExtUtils::MakeMaker::vmsish>
+
+Removed from the Perl core. Prior version was 6.42.
+
+=item C<Stdio>
+
+Removed from the Perl core. Prior version was 2.3.
+
+=item C<Test::Harness::Assert>
+
+Removed from the Perl core. Prior version was 0.02.
+
+=item C<Test::Harness::Iterator>
+
+Removed from the Perl core. Prior version was 0.02.
+
+=item C<Test::Harness::Point>
+
+Removed from the Perl core. Prior version was 0.01.
+
+=item C<Test::Harness::Results>
+
+Removed from the Perl core. Prior version was 0.01.
+
+=item C<Test::Harness::Straps>
+
+Removed from the Perl core. Prior version was 0.26_01.
+
+=item C<Test::Harness::Util>
+
+Removed from the Perl core. Prior version was 0.01.
+
+=item C<XSSymSet>
+
+Removed from the Perl core. Prior version was 1.1.
=back
+=head2 Deprecated Modules and Pragmata
+
+See L</Deprecated Modules> above.
+
+
=head1 Documentation
=head2 New Documentation
=item *
-L<perlhaiku>
-
-This contains instructions on how to build perl for the Haiku platform.
+L<perlhaiku> contains instructions on how to build perl for the Haiku platform.
=item *
-L<perlmroapi>
-
-This describes the new interface for pluggable Method Resolution Orders.
+L<perlmroapi> describes the new interface for pluggable Method Resolution Orders.
=item *
-L<perlperf>
-
-This document, by Richard Foley, provides an introduction to the use of
+L<perlperf>, by Richard Foley, provides an introduction to the use of
performance and optimization techniques which can be used with particular
reference to perl programs.
=item *
-L<perlrepository>
-
-This describes how to access the perl source using the I<git> version
+L<perlrepository> describes how to access the perl source using the I<git> version
control system.
=item *
=head2 Changes to Existing Documentation
+
=over
=item *
-The file F<Porting/patching.pod> has been deleted, as it mainly described
+F<Porting/patching.pod> has been deleted, as it mainly described
interacting with the old Perforce-based repository, which is now obsolete.
Information still relevant has been moved to L<perlrepository>.
=item *
-Documented C<when> as a syntax modifier
+Documented C<when> as a syntax modifier.
=item *
=item *
-Added security contact information to L<perlsec>
+Security contact information is now part of L<perlsec>.
+
+=item *
A significant fraction of the core documentation has been updated to clarify
the behavior of Perl's Unicode handling.
for clarity, consistent use of language, and to fix the spelling of Tom
Christiansen's name.
+=item *
+
The Pod specification (L<perlpodspec>) has been updated to bring the
specification in line with modern usage already supported by most Pod
systems. A parameter string may now follow the format name in a
allowed. The usage of C<LE<lt>"section"E<gt>> has been marked as
deprecated.
+=item *
+
L<if.pm|if> has been documented in L<perlfunc/use> as a means to get
conditional loading of modules despite the implicit BEGIN block around
C<use>.
=back
-=head1 Performance Enhancements
+=head1 Selected Performance Enhancements
=over 4
=item *
-Faster C<Perl_sv_utf8_upgrade()>
+C<Perl_sv_utf8_upgrade()> is now faster.
=item *
-Speed up C<keys> on empty hash
+C<keys> on empty hash is now faster.
=item *
-C<if (%foo)> has been optimized to be faster than C<if (keys %foo)>
+C<if (%foo)> has been optimized to be faster than C<if (keys %foo)>.
+
+=item *
+
+The string repetition operator (C<$str x $num>) is now several times faster
+when C<$str> has length one or C<$num> is large.
=item *
=head1 Installation and Configuration Improvements
-=head2 F<ext/> reorganisation
-
-The layout of directories in F<ext> has been revised. Specifically, all
-extensions are now flat, and at the top level, with C</> in pathnames
-replaced by C<->, so that F<ext/Data/Dumper/> is now F<ext/Data-Dumper/>,
-etc. The names of the extensions as specified to F<Configure>, and as
-reported by C<%Config::Config> under the keys C<dynamic_ext>,
-C<known_extensions>, C<nonxs_ext> and C<static_ext> have not changed, and
-still use C</>. Hence this change will not have any affect once perl is
-installed. C<Safe> has been split out from being part of C<Opcode>, and
-C<mro> is now an extension in its own right.
-
-Nearly all dual-life modules have been moved from F<lib> to F<ext>, and will
-now appear as known C<nonxs_ext>. This will made no difference to the
-structure of an installed perl, nor will the modules installed differ,
-unless you run F<Configure> with options to specify an exact list of
-extensions to build. In this case, you will rapidly become aware that you
-need to add to your list, because various modules needed to complete the
-build, such as C<ExtUtils::ParseXS>, have now become extensions, and
-without them the build will fail well before it attempts to run the
-regression tests.
-
-=head2 Other Installation and Configuration Improvements
-
=over 4
=item *
=item *
-USE_ATTRIBUTES_FOR_PERLIO is now reported in the compile-time options
-listed by the C<-V> switch.
-
-=item *
-
-Support for SystemTap's C<dtrace> compatibility layer has been added and an
+Perl now supports SystemTap's C<dtrace> compatibility layer and an
issue with linking C<miniperl> has been fixed in the process.
=item *
-C<less -R> is now used instead of C<less> for C<groff>'s new usage of ANSI
-escape codes by setting C<$Config{less}> (and thereby C<$Config{pager}>,
-which fixes RT #72156.
+perldoc now uses C<less -R> instead of C<less> for improved behaviour
+in the face of C<groff>'s new usage of ANSI escape codes.
=item *
-USE_PERL_ATOF is now reported in the compile-time options listed by the C<-V>
-switch.
-
-=back
+C<perl -V> now reports use of the compile-time options C<USE_PERL_ATOF> and
+C<USE_ATTRIBUTES_FOR_PERLIO>.
-=head2 Compilation improvements
+=item *
As part of the flattening of F<ext>, all extensions on all platforms are
built by F<make_ext.pl>. This replaces the Unix-specific
F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific
F<win32/buildext.pl>.
-=head1 Changed Internals
+=back
+
+=head1 Internal Changes
-=over 4
+Each release of Perl sees numerous internal changes which shouldn't
+affect day to day usage but may still be notable for developers working
+with Perl's source code.
+
+=over
=item *
-C<Perl_pmflag> has been removed from the public API. Calling it now
-generates a deprecation warning, and it will be removed in a future
-release. Although listed as part of the API, it was never documented,
-and only ever used in F<toke.c>, and prior to 5.10, F<regcomp.c>. In
-core, it has been replaced by a static function.
+The J.R.R. Tolkien quotes at the head of C source file have been checked and
+proper citations added, thanks to a patch from Tom Christiansen.
=item *
-Perl_magic_setmglob now knows about globs, fixing RT #71254.
+The internal structure of the dual-life modules traditionally found in
+the F<lib/> and F<ext/> directories y in the perl source has changed
+significantly. Where possible, dual-lifed modules have been extracted
+from F<lib/> and F<ext/>.
+
+Dual-lifed modules maintained by Perl's developers as part of the Perl
+core now live in F<dist/>. Dual-lifed modules maintained primarily on
+CPAN now live in F<cpan/>. When reporting a bug in a module located
+under F<cpan/>, please send your bug report directly to the module's
+bug tracker or author, rather than Perl's bug tracker.
=item *
-TODO: C<SVt_RV> is gone. RVs are now stored in IVs
+C<\N{...}> now compiles better, always forces UTF-8 internal representation
+
+Perl's developers have fixed several problems with the recognition of C<\N{...}>
+constructs. As part of this, perl will store any scalar or regex containing
+C<\N{I<name>}> or C<\N{U+I<wide hex char>}> in its definition in
+UTF-8 format. (This was true previously for all occurences of C<\N{I<name>}>
+that did not use a custom translator, but now it's always true.)
=item *
-TODO: REGEXPs are first class
+Perl_magic_setmglob now knows about globs, fixing RT #71254.
=item *
-TODO: OOK is reworked, such that an OOKed scalar is PV not PVIV
+C<SVt_RV> no longer exists. RVs are now stored in IVs.
=item *
-The J.R.R. Tolkien quotes at the head of C source file have been checked and
-proper citations added, thanks to a patch from Tom Christiansen.
+REGEXPs are now first class.
=item *
=item *
-C<SVf_UTF8>
-
-This will call C<SvUTF8_on()> for you. (Note that this does not convert an
+C<SVf_UTF8> will call C<SvUTF8_on()> for you. (Note that this does not convert an
sequence of ISO 8859-1 characters to UTF-8). A wrapper, C<newSVpvn_utf8()>
is available for this.
=item *
-C<SVs_TEMP>
-
-Call C<Perl_sv_2mortal()> on the new SV.
+C<SVs_TEMP> now calls C<Perl_sv_2mortal()> on the new SV.
=back
=item *
-The functions C<PerlIO_find_layer> and C<PerlIO_list_alloc> are now
-exported.
+Perl now exports the functions C<PerlIO_find_layer> and C<PerlIO_list_alloc>.
=item *
=item *
-SV allocation tracing has been added to the diagnostics enabled by C<-Dm>.
-The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if
-that was enabled when the F<perl> binary was compiled.
-
-=item *
-
-Smartmatch resolution tracing has been added as a new diagnostic. Use C<-DM> to
-enable it.
-
-=item *
-
-A new debugging flag C<-DB> now dumps subroutine definitions, leaving
-C<-Dx> for its original purpose of dumping syntax trees.
-
-=item *
-
Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have been
replaced by C<NULL> in the core code, and non-dual-life modules, as C<NULL>
is clearer to those unfamiliar with the core code.
=head1 Testing
-=head2 New Tests
+=head2 Testing improvements
+
+=over 4
+
+=item Parallel tests
+
+The core distribution can now run its regression tests in parallel on
+Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
+your environment to the number of tests to run in parallel, and run
+C<make test_harness>. On a Bourne-like shell, this can be done as
+
+ TEST_JOBS=3 make test_harness # Run 3 tests in parallel
+
+An environment variable is used, rather than parallel make itself, because
+L<TAP::Harness> needs to be able to schedule individual non-conflicting test
+scripts itself, and there is no standard interface to C<make> utilities to
+interact with their job schedulers.
+
+Note that currently some test scripts may fail when run in parallel (most
+notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts
+again sequentially and see if the failures go away.
+
+=item Test harness flexibility
+
+It's now possible to override C<PERL5OPT> and friends in F<t/TEST>
+
+=item Test watchdog
-Many modules updated from CPAN incorporate new tests.
Several tests that have the potential to hang forever if they fail now
incorporate a "watchdog" functionality that will kill them after a timeout,
which helps ensure that C<make test> and C<make test_harness> run to
-completion automatically. (Jerry Hedden).
+completion automatically.
+
-Some core-specific tests have been added:
+=back
+
+=head2 New Tests
+
+Perl's developers have added a number of new tests to the core.
+In addition to the items listed below, many modules updated from CPAN
+incorporate new tests.
=over 4
=item *
-F<t/op/while_readdir.t>
-
-Test that a bare readdir in while loop sets $_.
+F<t/op/while_readdir.t> tests that a bare readdir in while loop sets $_.
=item *
-F<t/comp/retainedlines.t>
-
-Check that the debugger can retain source lines from C<eval>.
+F<t/comp/retainedlines.t> checks that the debugger can retain source lines from C<eval>.
=item *
-F<t/io/perlio_fail.t>
-
-Check that bad layers fail.
+F<t/io/perlio_fail.t> checks that bad layers fail.
=item *
-F<t/io/perlio_leaks.t>
-
-Check that PerlIO layers are not leaking.
+F<t/io/perlio_leaks.t> checks that PerlIO layers are not leaking.
=item *
-F<t/io/perlio_open.t>
-
-Check that certain special forms of open work.
+F<t/io/perlio_open.t> checks that certain special forms of open work.
=item *
-F<t/io/perlio.t>
-
-General PerlIO tests.
+F<t/io/perlio.t> includes general PerlIO tests.
=item *
-F<t/io/pvbm.t>
-
-Check that there is no unexpected interaction between the internal types
+F<t/io/pvbm.t> checks that there is no unexpected interaction between the internal types
C<PVBM> and C<PVGV>.
=item *
-F<t/mro/package_aliases.t>
-
-Check that mro works properly in the presence of aliased packages.
+F<t/mro/package_aliases.t> checks that mro works properly in the presence of aliased packages.
=item *
-F<t/op/dbm.t>
-
-Tests for C<dbmopen> and C<dbmclose>.
+F<t/op/dbm.t> tests C<dbmopen> and C<dbmclose>.
=item *
-F<t/op/index_thr.t>
-
-Tests for the interaction of C<index> and threads.
+F<t/op/index_thr.t> tests the interaction of C<index> and threads.
=item *
-F<t/op/pat_thr.t>
-
-Tests for the interaction of esoteric patterns and threads.
+F<t/op/pat_thr.t> tests the interaction of esoteric patterns and threads.
=item *
-F<t/op/qr_gc.t>
-
-Test that C<qr> doesn't leak.
+F<t/op/qr_gc.t> tests that C<qr> doesn't leak.
=item *
-F<t/op/reg_email_thr.t>
+F<t/op/reg_email_thr.t> tests the interaction of regex recursion and threads.
+
+=item *
-Tests for the interaction of regex recursion and threads.
+F<t/op/regexp_qr_embed_thr.t> tests the interaction of patterns with embedded C<qr//> and threads.
=item *
-F<t/op/regexp_qr_embed_thr.t>
+F<t/op/regexp_unicode_prop.t> tests Unicode properties in regular expressions.
+
+=item *
-Tests for the interaction of patterns with embedded C<qr//> and threads.
+F<t/op/regexp_unicode_prop_thr.t> tests the interaction of Unicode properties and threads.
=item *
-F<t/op/regexp_unicode_prop.t>
+F<t/op/reg_nc_tie.t> tests the tied methods of C<Tie::Hash::NamedCapture>.
+
+=item *
-Tests for Unicode properties in regular expressions.
+F<t/op/reg_posixcc.t> checks that POSIX character classes behave consistently.
=item *
-F<t/op/regexp_unicode_prop_thr.t>
+F<t/op/re.t>
-Tests for the interaction of Unicode properties and threads.
+checks that exportable C<re> functions in F<universal.c> work.
=item *
-F<t/op/reg_nc_tie.t>
-
-Test the tied methods of C<Tie::Hash::NamedCapture>.
+F<t/op/setpgrpstack.t> checks that C<setpgrp> works.
=item *
-F<t/op/reg_posixcc.t>
+F<t/op/substr_thr.t> tests the interaction of C<substr> and threads.
-Check that POSIX character classes behave consistently.
+=item *
+
+F<t/op/upgrade.t> checks that upgrading and assigning scalars works.
=item *
-F<t/op/re.t>
+F<t/uni/lex_utf8.t> checks that Unicode in the lexer works.
+
+=item *
-Check that exportable C<re> functions in F<universal.c> work.
+F<t/uni/tie.t> checks that Unicode and C<tie> work.
=item *
-F<t/op/setpgrpstack.t>
+F<t/comp/final_line_num.t> tests whether line numbers are correct at EOF
-Check that C<setpgrp> works.
+=item *
+
+F<t/comp/form_scope.t> tests format scoping.
=item *
-F<t/op/substr_thr.t>
+F<t/comp/line_debug.t> tests whether C<< @{"_<$file"} >> works.
+
+=item *
-Tests for the interaction of C<substr> and threads.
+F<t/op/filetest_t.t> tests if -t file test works.
=item *
-F<t/op/upgrade.t>
+F<t/op/qr.t> tests C<qr>.
-Check that upgrading and assigning scalars works.
+=item *
+
+F<t/op/utf8cache.t> tests malfunctions of the utf8 cache.
=item *
-F<t/uni/lex_utf8.t>
+F<t/re/uniprops.t> test unicodes C<\p{}> regex constructs.
+
+=item *
-Check that Unicode in the lexer works.
+F<t/op/filehandle.t> tests some suitably portable filetest operators
+to check that they work as expected, particularly in the light of some
+internal changes made in how filehandles are blessed.
=item *
-F<t/uni/tie.t>
+F<t/op/time_loop.t> tests that unix times greater than C<2**63>, which
+can now be handed to C<gmtime> and C<localtime>, do not cause an internal
+overflow or an excessively long loop.
-Check that Unicode and C<tie> work.
+=back
-=item *
-F<t/comp/final_line_num.t>
+=head1 New or Changed Diagnostics
-See if line numbers are correct at EOF
+=head2 New Diagnostics
-=item *
+=over
-F<t/comp/form_scope.t>
+=item *
-See if format scoping works
+SV allocation tracing has been added to the diagnostics enabled by C<-Dm>.
+The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if
+that was enabled when the F<perl> binary was compiled.
=item *
-F<t/comp/line_debug.t>
+Smartmatch resolution tracing has been added as a new diagnostic. Use C<-DM> to
+enable it.
-See if C<< @{"_<$file"} >> works
+=item *
+
+A new debugging flag C<-DB> now dumps subroutine definitions, leaving
+C<-Dx> for its original purpose of dumping syntax trees.
=item *
-F<t/op/filetest_t.t>
+Perl 5.12 provides a number of new diagnostic messages to help you write
+better code. See L<perldiag> for details of these new messages.
-See if -t file test works
+=over 4
=item *
-F<t/op/qr.t>
-
-See if qr works
+C<Bad plugin affecting keyword '%s'>
=item *
-F<t/op/utf8cache.t>
+C<gmtime(%.0f) too large>
+
+=item *
-Tests malfunctions of utf8 cache
+C<Lexing code attempted to stuff non-Latin-1 character into Latin-1 input>
=item *
-F<t/re/uniprops.t>
+C<Lexing code internal error (%s)>
+
+=item *
-Test unicode \p{} regex constructs
+C<localtime(%.0f) too large>
=item *
-F<t/op/filehandle.t>
+C<Overloaded dereference did not return a reference>
+
+=item *
-Tests some suitably portable filetest operators to check that they work as
-expected, particularly in the light of some internal changes made in how
-filehandles are blessed.
+C<Overloaded qr did not return a REGEXP>
=item *
-F<t/op/time_loop.t>
+C<Perl_pmflag() is deprecated, and will be removed from the XS API>
-Tests that times greater than C<2**63>, which can now be handed to C<gmtime>
-and C<localtime>, do not cause an internal overflow or an excessively long
-loop.
+=item *
-=back
+C<lvalue attribute ignored after the subroutine has been defined>
-=head2 Testing improvements
+This new warning is issued when one attempts to mark a subroutine as
+lvalue after it has been defined.
-=over 4
+=item *
-=item Parallel tests
+Perl now warns you if C<++> or C<--> are unable to change the value because it's
+beyond the limit of representation.
-The core distribution can now run its regression tests in parallel on
-Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
-your environment to the number of tests to run in parallel, and run
-C<make test_harness>. On a Bourne-like shell, this can be done as
+This uses a new warnings category: "imprecision".
- TEST_JOBS=3 make test_harness # Run 3 tests in parallel
+=item *
-An environment variable is used, rather than parallel make itself, because
-L<TAP::Harness> needs to be able to schedule individual non-conflicting test
-scripts itself, and there is no standard interface to C<make> utilities to
-interact with their job schedulers.
+C<lc>, C<uc>, C<lcfirst>, and C<ucfirst> warn when passed undef.
-Note that currently some test scripts may fail when run in parallel (most
-notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts
-again sequentially and see if the failures go away.
+=item *
-=item Test harness flexibility
+C<Show constant in "Useless use of a constant in void context">
-It's now possible to override C<PERL5OPT> and friends in F<t/TEST>
+=item *
-=back
+C<Prototype after '%s'>
+=item *
-=head1 New or Changed Diagnostics
+C<panic: sv_chop %s>
-Several new diagnostics, see L<perldiag> for details.
+This new fatal error occurs when the C routine C<Perl_sv_chop()> was
+passed a position that is not within the scalar's string buffer. This
+could be caused by buggy XS code, and at this point recovery is not
+possible.
-=over 4
=item *
-C<Bad plugin affecting keyword '%s'>
+The fatal error C<Malformed UTF-8 returned by \N> is now produced if the
+C<charnames> handler returns malformed UTF-8.
=item *
-C<gmtime(%.0f) too large>
+If an unresolved named character or sequence was encountered when compiling a
+regex pattern then the fatal error C<\N{NAME} must be resolved by the lexer>
+is now produced. This can happen, for example, when using a single-quotish
+context like C<$re = '\N{SPACE}'; /$re/;>. See L<perldiag> for more examples of
+how the lexer can get bypassed.
=item *
-C<Lexing code attempted to stuff non-Latin-1 character into Latin-1 input>
+C<Invalid hexadecimal number in \N{U+...}> is a new fatal error triggered when
+the character constant represented by C<...> is not a valid hexadecimal
+number.
=item *
-C<Lexing code internal error (%s)>
+The new meaning of C<\N> as C<[^\n]> is not valid in a bracketed character
+class, just like C<.> in a character class loses its special meaning, and will
+cause the fatal error C<\N in a character class must be a named character: \N{...}>.
=item *
-C<localtime(%.0f) too large>
+The rules on what is legal for the C<...> in C<\N{...}> have been tightened
+up so that unless the C<...> begins with an alphabetic character and continues
+with a combination of alphanumerics, dashes, spaces, parentheses or colons
+then the warning C<Deprecated character(s) in \N{...} starting at '%s'> is
+now issued.
=item *
-C<Overloaded dereference did not return a reference>
+The warning C<Using just the first characters returned by \N{}> will be
+issued if the C<charnames> handler returns a sequence of characters which
+exceeds the limit of the number of characters that can be used. The message
+will indicate which characters were used and which were discarded.
-=item *
+=back
-C<Overloaded qr did not return a REGEXP>
+=back
+
+=head2 Changed Diagnostics
+
+A number of existing diagnostic messages have been improved or corrected:
+
+=over
=item *
-C<Perl_pmflag() is deprecated, and will be removed from the XS API>
+A new warning category C<illegalproto> allows finer-grained control of
+warnings around function prototypes.
-=item *
+The two warnings:
+
+=over
-New warning category C<illegalproto>
+=item C<Illegal character in prototype for %s : %s>
-The two warnings :
+=item C<Prototype after '%c' for %s : %s>
- Illegal character in prototype for %s : %s
- Prototype after '%c' for %s : %s
+=back
have been moved from the C<syntax> top-level warnings category into a new
first-level category, C<illegalproto>. These two warnings are currently the
to suppress only those, but not other syntax-related warnings. Warnings where
prototypes are changed, ignored, or not met are still in the C<prototype>
-category as before. (Matt S. Trout)
-
-=item *
-
-lvalue attribute ignored after the subroutine has been defined
-
-This new warning is issued when one attempts to mark a subroutine as
-lvalue after it has been defined.
-
-=item *
-
-warn if C<++> or C<--> are unable to change the value because it's
-beyond the limit of representation
-
-This uses a new warnings category: "imprecision".
-
-=item *
-
-C<lc>, C<uc>, C<lcfirst>, and C<ucfirst> warn when passed undef.
-
-=item *
-
-Show constant in "Useless use of a constant in void context"
+category as before.
=item *
-Make the new warning report undef constants as undef
-
-=item *
+C<Deep recursion on subroutine "%s">
-Add a new warning, "Prototype after '%s'"
+It is now possible to change the depth threshold for this warning from the
+default of 100, by recompiling the F<perl> binary, setting the C
+pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
=item *
-Tweak the "Illegal character in prototype" warning so it's more precise
+C<Illegal character in prototype> warning is now more precise
when reporting illegal characters after _
=item *
-Correct the unintended interpolation of C<$\> in regex
-
-=item *
-
-Make overflow warnings in C<gmtime> and C<localtime> only occur when
-warnings are enabled
-
-=item *
-
-Improve mro merging error messages.
-
-They are now very similar to those produced by Algorithm::C3.
+mro merging error messages are now very similar to those produced by L<Algorithm::C3>.
=item *
=item *
-Explicitely point to C<$.> when it causes an uninitialized warning for
-ranges in scalar context
+Perl now explicitly points to C<$.> when it causes an uninitialized warning for
+ranges in scalar context.
=item *
-C<split> now warns when called in void context
+C<split> now warns when called in void context.
=item *
=item *
-C<panic: sv_chop %s>
-
-This new fatal error occurs when the C routine C<Perl_sv_chop()> was
-passed a position that is not within the scalar's string buffer. This
-could be caused by buggy XS code, and at this point recovery is not
-possible.
-
-=item *
-
-C<Deep recursion on subroutine "%s">
-
-It is now possible to change the depth threshold for this warning from the
-default of 100, by recompiling the F<perl> binary, setting the C
-pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
-
-=item *
-
Perl now properly returns a syntax error instead of segfaulting
if C<each>, C<keys>, or C<values> is used without an argument.
=item *
-The Windows select() implementation now supports all empty C<fd_set>s
-more correctly.
-
-=item *
-
-The "syntax" category was removed from 5 warnings that should only be in
-"deprecated".
+The C<syntax> category was removed from 5 warnings that should only be in
+C<deprecated>.
=item *
Three fatal C<pack>/C<unpack> error messages have been normalized to
-"panic: %s"
+C<panic: %s>
=item *
-"Unicode character is illegal" has been rephrased to be more accurate
+C<Unicode character is illegal> has been rephrased to be more accurate
It now reads C<Unicode non-character is illegal in interchange> and the
perldiag documentation has been expanded a bit.
=item *
-The fatal error C<Malformed UTF-8 returned by \N> is now produced if the
-C<charnames> handler returns malformed UTF-8.
-
-=item *
-
-If an unresolved named character or sequence was encountered when compiling a
-regex pattern then the fatal error C<\\N{NAME} must be resolved by the lexer>
-is now produced. This can happen, for example, when using a single-quotish
-context like C<$re = '\N{SPACE}'; $re;>. See L<perldiag> for more examples of
-how the lexer can get bypassed.
-
-=item *
-
-The fatal error C<Invalid hexadecimal number in \\N{U+...}> will be produced
-if the character constant represented by C<...> is not a valid hexadecimal
-number.
-
-=item *
-
-The new meaning of C<\N> as C<[^\n]> is not valid in a bracketed character
-class, just like C<.> in a character class loses its special meaning, and will
-cause the fatal error C<\\N in a character class must be a named character:
-\\N{...}>.
-
-=item *
-
-The rules on what is legal for the C<...> in C<\N{...}> have been tightened
-up so that unless the C<...> begins with an alphabetic character and continues
-with a combination of alphanumerics, dashes, spaces, parentheses or colons
-then the warning C<Deprecated character(s) in \\N{...} starting at '%s'> is
-now issued.
-
-=item *
-
-The warning C<Using just the first characters returned by \N{}> will be
-issued if the C<charnames> handler returns a sequence of characters which
-exceeds the limit of the number of characters that can be used. The message
-will indicate which characters were used and which were discarded.
-
-=item *
-
Currently, all but the first of the several characters that the C<charnames>
handler may return are discarded when used in a regular expression pattern
bracketed character class. If this happens then the warning C<Using just the
=item *
-The warning C<Missing right brace on \\N{} or unescaped left brace after \\N.
+The warning C<Missing right brace on \N{} or unescaped left brace after \N.
Assuming the latter> will be issued if Perl encounters a C<\N{> but doesn't
find a matching C<}>. In this case Perl doesn't know if it was mistakenly
omitted, or if "match non-newline" followed by "match a C<{>" was desired.
=back
-The following diagnostics have been removed:
+The following diagnostic messages have been removed:
=over 4
C<Can't locate package %s for the parents of %s>
-This warning has been removed. In general, it only got produced in
+In general this warning it only got produced in
conjunction with other warnings, and removing it allowed an ISA lookup
optimisation to be added.
=item *
-F<h2ph>
-
-Now looks in C<include-fixed> too, which is a recent addition to gcc's
+F<h2ph> now looks in C<include-fixed> too, which is a recent addition to gcc's
search path.
=item *
-F<h2xs>
-
-No longer incorrectly treats enum values like macros (Daniel Burr).
-
-Now handles C++ style constants (C<//>) properly in enums. (A patch from
-Rainer Weikusat was used; Daniel Burr also proposed a similar fix).
+F<h2xs> no longer incorrectly treats enum values like macros.
+It also now handles C++ style comments (C<//>) properly in enums.
=item *
-F<perl5db.pl>
-
-C<LVALUE> subroutines now work under the debugger.
-
-The debugger now correctly handles proxy constant subroutines, and
+F<perl5db.pl> now supports C<LVALUE> subroutines. Additionally, the
+debugger now correctly handles proxy constant subroutines, and
subroutine stubs.
=item *
-F<perlbug>
-
-F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out upstream bug
-tracker URLs.
-
-Where the user names a module that their bug report is about, and we know the
-URL for its upstream bug tracker, provide a message to the user explaining
-that the core copies the CPAN version directly, and provide the URL for
-reporting the bug directly to upstream.
-
-=item *
-
-F<perlthanks>
+F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out
+upstream bug tracker URLs. If a user identifies a particular module
+as the topic of their bug report and we're able to divine the URL for
+its upstream bug tracker, perlbug now provide a message to the user
+explaining that the core copies the CPAN version directly, and provide
+the URL for reporting the bug directly to the upstream author.
-Perl 5.11.0 added a new utility F<perlthanks>, which is a variant of
-F<perlbug>, but for sending non-bug-reports to the authors and maintainers
-of Perl. Getting nothing but bug reports can become a bit demoralising:
-we'll see if this changes things.
+F<perlbug> no longer reports "Message sent" when it hasn't actually sent the message
=item *
-F<perlbug>
-
-No longer reports "Message sent" when it hasn't actually sent the message
+F<perlthanks> is a new utility for sending non-bug-reports to the
+authors and maintainers of Perl. Getting nothing but bug reports can
+become a bit demoralising. If Perl 5.12 works well for you, please try
+out F<perlthanks>. It will make the developers smile.
=item *
-F<a2p>
-
-Fixed bugs with the match() operator in list context, remove mention of
-C<$[>.
+Perl's developers have fixed bugs in F<a2p> having to do with the
+C<match()> operator in list context. Additionally, F<a2p> no longer
+generates code that uses the C<$[> variable.
=back
=item *
-Ensure that pp_qr returns a new regexp SV each time. Resolves RT #69852.
+U+0FFFF is now a legal character in regular expressions.
+
+=item *
+
+pp_qr now always returns a new regexp SV. Resolves RT #69852.
Instead of returning a(nother) reference to the (pre-compiled) regexp in the
optree, use reg_temp_copy() to create a copy of it, and return a reference to
=item *
-On Windows, C<'.\foo'> and C<'..\foo'> were treated differently than
-C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492].
-
-=item *
-
Assigning a format to a glob could corrupt the format; e.g.:
*bar=*foo{FORMAT}; # foo format now bad
=item *
-Previously missing files from Unicode 5.1 Character Database are now included.
+Perl now includes previously missing files from the Unicode Character Database.
=item *
-C<TMPDIR> is now honored when opening an anonymous temporary file
+Perl now honors C<TMPDIR> when opening an anonymous temporary file.
=back
+
=head1 Platform Specific Changes
+Perl is incredibly portable. In general, if a platform has a C compiler,
+someone has ported Perl to it (or will soon). We're happy to announce
+that Perl 5.12 includes support for several new platforms. At the same
+time, it's time to bid farewell to some (very) old friends.
+
=head2 New Platforms
=over
=item Haiku
-Patches from the Haiku maintainers have been merged in. Perl should now
+Perl's developers have merged patches from Haiku's maintainers. Perl should now
build on Haiku.
=item MirOS BSD
Perl should now build on MirOS BSD.
-
=back
=head2 Discontinued Platforms
=over
-=item DomainOS
+=item Domain/OS
-Support for Apollo DomainOS was removed in Perl 5.11.0
+=item MiNT
-=item MachTen
+=item Tenon MachTen
-Support for Tenon Intersystems MachTen Unix layer for MacOS Classic was
-removed in Perl 5.11.0
+=back
-=item MiNT
+=head2 Updated Platforms
+
+=over 4
+
+=item AIX
+
+=over 4
+
+=item *
+
+Removed F<libbsd> for AIX 5L and 6.1. Only C<flock()> was used from F<libbsd>.
+
+=item *
+
+Removed F<libgdbm> for AIX 5L and 6.1 if F<libgdbm> < 1.8.3-5 is installed.
+The F<libgdbm> is delivered as an optional package with the AIX Toolbox.
+Unfortunately the versions below 1.8.3-5 are broken.
+
+=item *
-Support for Atari MiNT was removed in Perl 5.11.0.
+Hints changes mean that AIX 4.2 should work again.
=back
-=head2 Updated Platforms
+=item Cygwin
=over 4
+=item *
+
+Perl now supports IPv6 on Cygwin 1.7 and newer.
+
+=item *
+
+On Cygwin we now strip the last number from the DLL. This has been the
+behaviour in the cygwin.com build for years. The hints files have been
+updated.
+
+=back
+
=item Darwin (Mac OS X)
=over 4
=back
-=item Win32
+=item FreeBSD
=over 4
=item *
-Initial support for mingw64 is now available
-
-=item *
-
-Various bits of Perl's build infrastructure are no longer converted to
-win32 line endings at release time. If this hurts you, please report the
-problem with the L<perlbug> program included with perl.
-
-=item *
+The hints files now identify the correct threading libraries on FreeBSD 7
+and later.
-Always add a manifest resource to C<perl.exe> to specify the C<trustInfo>
-settings for Windows Vista and later. Without this setting Windows
-will treat C<perl.exe> as a legacy application and apply various
-heuristics like redirecting access to protected file system areas
-(like the "Program Files" folder) to the users "VirtualStore"
-instead of generating a proper "permission denied" error.
+=back
-For VC8 and VC9 this manifest setting is automatically generated by
-the compiler/linker (together with the binding information for their
-respective runtime libraries); for all other compilers we need to
-embed the manifest resource explicitly in the external resource file.
+=item Irix
-This change also requests the Microsoft Common-Controls version 6.0
-(themed controls introduced in Windows XP) via the dependency list
-in the assembly manifest. For VC8 and VC9 this is specified using the
-C</manifestdependency> linker commandline option instead.
+=over 4
=item *
-Improved message window handling means that C<alarm> and C<kill> messages
-will no longer be dropped under race conditions.
+We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
+C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't.
=back
-=item cygwin
+=item NetBSD
=over 4
=item *
-Enable IPv6 support on cygwin 1.7 and newer
+Hints now supports versions 5.*.
=back
=item *
-Make -UDEBUGGING the default on VMS for 5.12.0.
+C<-UDEBUGGING> is now the default on VMS.
Like it has been everywhere else for ages and ages. Also make
command-line selection of -UDEBUGGING and -DDEBUGGING work in
=back
-=item AIX
+=item Stratus VOS
-Removed F<libbsd> for AIX 5L and 6.1. Only C<flock()> was used from F<libbsd>.
+=over 4
-Removed F<libgdbm> for AIX 5L and 6.1. The F<libgdbm> is delivered as an
-optional package with the AIX Toolbox. Unfortunately the 64 bit version
-is broken.
+=item *
-Hints changes mean that AIX 4.2 should work again.
+Various changes from Stratus have been merged in.
-=item Cygwin
+=back
-On Cygwin we now strip the last number from the DLL. This has been the
-behaviour in the cygwin.com build for years. The hints files have been
-updated.
+=item Symbian
+=over 4
-=item FreeBSD
+=item *
-The hints files now identify the correct threading libraries on FreeBSD 7
-and later.
+There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
-=item Irix
+=back
-We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
-C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't.
+=item Windows
-=item NetBSD
+=over 4
-Hints now supports versions 5.*.
+=item *
-=item Stratus VOS
+Perl 5.12 supports Windows 2000 and later. The supporting code for
+legacy versions of Windows is still included, but will be removed
+during the next development cycle.
-Various changes from Stratus have been merged in.
+=item *
-=item Symbian
+Initial support for building Perl with MinGW-w64 is now available.
-There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
+=item *
+
+F<perl.exe> now includes a manifest resource to specify the C<trustInfo>
+settings for Windows Vista and later. Without this setting Windows
+would treat F<perl.exe> as a legacy application and apply various
+heuristics like redirecting access to protected file system areas
+(like the "Program Files" folder) to the users "VirtualStore"
+instead of generating a proper "permission denied" error.
+
+The manifest resource also requests the Microsoft Common-Controls
+version 6.0 (themed controls introduced in Windows XP). Check out the
+Win32::VisualStyles module on CPAN to switch back to old style
+unthemed controls for legacy applications.
+
+=item *
+
+The C<-t> filetest operator now only returns true if the filehandle
+is connected to a console window. In previous versions of Perl it
+would return true for all character mode devices, including F<NUL>
+and F<LPT1>.
+
+=item *
+
+The C<-p> filetest operator now works correctly, and the
+Fcntl::S_IFIFO constant is defined when Perl is compiled with
+Microsoft Visual C. In previous Perl versions C<-p> always
+returned a false value, and the Fcntl::S_IFIFO constant
+was not defined.
+
+This bug is specific to Microsoft Visual C and never affected
+Perl binaries built with MinGW.
+
+=item *
+
+The socket error codes are now more widely supported: The POSIX
+module will define the symbolic names, like POSIX::EWOULDBLOCK,
+and stringification of socket error codes in $! works as well
+now;
+
+ C:\>perl -MPOSIX -E "$!=POSIX::EWOULDBLOCK; say $!"
+ A non-blocking socket operation could not be completed immediately.
+
+=item *
+
+flock() will now set sensible error codes in $!. Previous Perl versions
+copied the value of $^E into $!, which caused much confusion.
+
+=item *
+
+select() now supports all empty C<fd_set>s more correctly.
+
+=item *
+
+C<'.\foo'> and C<'..\foo'> were treated differently than
+C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492].
+
+=item *
+
+Improved message window handling means that C<alarm> and C<kill> messages
+will no longer be dropped under race conditions.
+
+=item *
+
+Various bits of Perl's build infrastructure are no longer converted to
+win32 line endings at release time. If this hurts you, please report the
+problem with the L<perlbug> program included with perl.
+
+=back
=back
+
=head1 Known Problems
This is a list of some significant unfixed bugs, which are regressions
=item *
-Untriaged test crashes on Windows 2000
+Several porters have reported mysterious crashes when Perl's entire
+test suite is run after a build on certain Windows 2000 systems. When
+run by hand, the individual tests reportedly work fine.
-Several porters have reported mysterious crashes when Perl's entire test suite is run after a build on certain Windows 2000 systems. When run by hand, the individual tests reportedly work fine.
+=back
+
+=head1 Errata
+
+=over
=item *
-Known test failures on VMS
+This one is actually a change introduced in 5.10.0, but it was missed
+from that release's perldelta, so it is mentioned here instead.
+
+A bugfix related to the handling of the C</m> modifier and C<qr> resulted
+in a change of behaviour between 5.8.x and 5.10.0:
-Perl 5.11.1 fails a small set of core and CPAN tests as of this release.
-With luck, that'll be sorted out for 5.11.2
+ # matches in 5.8.x, doesn't match in 5.10.0
+ $re = qr/^bar/; "foo\nbar" =~ /$re/m;
=back
=head1 Acknowledgements
Perl 5.12.0 represents approximately two years of development since
-Perl 5.10.0 and contains __ lines of changes across ___ files
-from __ authors and committers:
-
-XXX TODO LIST
+Perl 5.10.0 and contains over 750,000 lines of changes across over
+3,000 files from over 200 authors and committers.
+
+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 5.12.0:
+
+Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam Russell,
+Adriano Ferreira, Ævar Arnfjörð Bjarmason, Alan Grover, Alexandr
+Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig, Andrew Rodland,
+andrew@sundale.net, Andy Armstrong, Andy Dougherty, Jose AUGUSTE-ETIENNE,
+Benjamin Smith, Ben Morrow, bharanee rathna, Bo Borgerson, Bo Lindbergh,
+Brad Gilbert, Bram, Brendan O'Dea, brian d foy, Charles Bailey,
+Chip Salzenberg, Chris 'BinGOs' Williams, Christoph Lamprecht, Chris
+Williams, chromatic, Claes Jakobsson, Craig A. Berry, Dan Dascalescu,
+Daniel Frederick Crisman, Daniel M. Quinlan, Dan Jacobson, Dan Kogai,
+Dave Mitchell, Dave Rolsky, David Cantrell, David Dick, David Golden,
+David Mitchell, David M. Syzdek, David Nicol, David Wheeler, Dennis
+Kaarsemaker, Dintelmann, Peter, Dominic Dunlop, Dr.Ruud, Duke Leto,
+Enrico Sorcinelli, Eric Brine, Father Chrysostomos, Florian Ragwitz,
+Frank Wiegand, Gabor Szabo, Gene Sullivan, Geoffrey T. Dairiki, George
+Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Graham Barr, Green, Paul,
+Hans Dieter Pearcey, Harmen, H. Merijn Brand, Hugo van der Sanden,
+Ian Goodacre, Igor Sutton, Ingo Weinhold, James Bence, James Mastros,
+Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah, Jerry Hedden,
+Jesse Vincent, Jim Cromie, Jody Belka, John E. Malmberg, John Malmberg,
+John Peacock, John Peacock via RT, John P. Linderman, John Wright,
+Josh ben Jore, Jos I. Boumans, Karl Williamson, Kenichi Ishigaki, Ken
+Williams, Kevin Brintnall, Kevin Ryde, Kurt Starsinic, Leon Brocard,
+Lubomir Rintel, Luke Ross, Marcel Grünauer, Marcus Holland-Moritz, Mark
+Jason Dominus, Marko Asplund, Martin Hasch, Mashrab Kuvatov, Matt Kraai,
+Matt S Trout, Max Maischein, Michael Breen, Michael Cartmell, Michael
+G Schwern, Michael Witten, Mike Giroux, Milosz Tanski, Moritz Lenz,
+Nicholas Clark, Nick Cleaton, Niko Tyni, Offer Kaye, Osvaldo Villalon,
+Paul Fenwick, Paul Gaborit, Paul Green, Paul Johnson, Paul Marquess,
+Philip Hazel, Philippe Bruhat, Rafael Garcia-Suarez, Rainer Tammer,
+Rajesh Mandalemula, Reini Urban, Renée Bäcker, Ricardo Signes,
+Ricardo SIGNES, Richard Foley, Rich Rauenzahn, Rick Delaney, Risto
+Kankkunen, Robert May, Roberto C. Sanchez, Robin Barker, SADAHIRO
+Tomoyuki, Salvador Ortiz Garcia, Sam Vilain, Scott Lanning, Sébastien
+Aperghis-Tramoni, Sérgio Durigan Júnior, Shlomi Fish, Simon 'corecode'
+Schubert, Sisyphus, Slaven Rezic, Smylers, Steffen Müller, Steffen
+Ullrich, Stepan Kasal, Steve Hay, Steven Schubiger, Steve Peters, Tels,
+The Doctor, Tim Bunce, Tim Jenness, Todd Rinaldo, Tom Christiansen,
+Tom Hukins, Tom Wyant, Tony Cook, Torsten Schoenfeld, Tye McQueen,
+Vadim Konovalov, Vincent Pit, Hio YAMASHINA, Yasuhiro Matsumoto,
+Yitzchak Scott-Thoennes, Yuval Kogman, Yves Orton, Zefram, Zsban Ambrus
+
+This is woefully incomplete as it's automatically generated from version
+control history. In particular, it doesn't include the names of the
+(very much appreciated) contributors who reported issues in previous
+versions of Perl that helped make Perl 5.12.0 better. For a more complete
+list of all of Perl's historical contributors, please see the C<AUTHORS>
+file in the Perl 5.12.0 distribution.
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
projects / p5sagit/p5-mst-13.2.git / blobdiff