5.12.0.
Some of the bug fixes in this release have been backported to subsequent
-releases of 5.12.x. Those are indicated with the 5.12.x version in
+releases of 5.12.x. Those are indicated with the 5.12.x version in
parentheses.
=head1 Notice
-XXX Any important notices here
+As described in L<perlpolicy>, the release of Perl 5.14.0 marks the
+official end of support for Perl 5.10. Users of Perl 5.10 or earlier
+should consider upgrading to a more recent release of Perl.
=head1 Core Enhancements
Perl comes with the Unicode 6.0 data base updated with
L<Corrigendum #8|http://www.unicode.org/versions/corrigendum8.html>,
with one exception noted below.
-See L<http://unicode.org/versions/Unicode6.0.0> for details on the new
+See L<http://unicode.org/versions/Unicode6.0.0/> for details on the new
release. Perl does not support any Unicode provisional properties,
including the new ones for this release.
which is a symbol that looks like a bell, and is used in Japanese cell
phones. This conflicts with the long-standing Perl usage of having
C<BELL> mean the ASCII C<BEL> character, U+0007. In Perl 5.14,
-C<\N{BELL}> will continue to mean U+0007, but its use will generate a
-deprecated warning message, unless such warnings are turned off. The
+C<\N{BELL}> continues to mean U+0007, but its use generates a
+deprecation warning message unless such warnings are turned off. The
new name for U+0007 in Perl is C<ALERT>, which corresponds nicely
with the existing shorthand sequence for it, C<"\a">. C<\N{BEL}>
-means U+0007, with no warning given. The character at U+1F514 will not
-have a name in 5.14, but can be referred to by C<\N{U+1F514}>. The plan
-is that in Perl 5.16, C<\N{BELL}> will refer to U+1F514, and so all code
-that uses C<\N{BELL}> should convert by then to using C<\N{ALERT}>,
-C<\N{BEL}>, or C<"\a"> instead.
+means U+0007, with no warning given. The character at U+1F514 has no
+name in 5.14, but can be referred to by C<\N{U+1F514}>.
+In Perl 5.16, C<\N{BELL}> will refer to U+1F514; all code
+that uses C<\N{BELL}> should be converted to use C<\N{ALERT}>,
+C<\N{BEL}>, or C<"\a"> before upgrading.
=head3 Full functionality for C<use feature 'unicode_strings'>
This release provides full functionality for C<use feature
'unicode_strings'>. Under its scope, all string operations executed and
regular expressions compiled (even if executed outside its scope) have
-Unicode semantics. See L<feature>.
+Unicode semantics. See L<feature/"the 'unicode_strings' feature">.
-This feature avoids most forms of the "Unicode Bug" (See
-L<perlunicode/The "Unicode Bug"> for details.) If there is a
+This feature avoids most forms of the "Unicode Bug" (see
+L<perlunicode/The "Unicode Bug"> for details). If there is any
possibility that your code will process Unicode strings, you are
-B<strongly> encouraged to use this subpragma to avoid nasty surprises.
+I<strongly> encouraged to use this subpragma to avoid nasty surprises.
-=head3 C<\N{I<name>}> and C<charnames> enhancements
+=head3 C<\N{I<NAME>}> and C<charnames> enhancements
=over
=item *
-C<\N{}> and C<charnames::vianame> now know about the abbreviated
-character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc., all
-the customary abbreviations for the C0 and C1 control characters (such as
-ACK, BEL, CAN, etc.), and a few new variants of some C1 full names that
+C<\N{I<NAME>}> and C<charnames::vianame> now know about the abbreviated
+character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc.; all
+customary abbreviations for the C0 and C1 control characters (such as
+ACK, BEL, CAN, etc.); and a few new variants of some C1 full names that
are in common usage.
=item *
-Unicode has a number of named character sequences, in which particular sequences
-of code points are given names. C<\N{...}> now recognizes these.
+Unicode has several I<named character sequences>, in which particular sequences
+of code points are given names. C<\N{I<NAME>}> now recognizes these.
=item *
-C<\N{}>, C<charnames::vianame>, C<charnames::viacode> now know about every
-character in Unicode. Previously, they didn't know about the Hangul syllables
-nor a number of CJK (Chinese/Japanese/Korean) characters.
+C<\N{I<NAME>}>, C<charnames::vianame>, and C<charnames::viacode>
+now know about every character in Unicode. In earlier releases of
+Perl, they didn't know about the Hangul syllables nor several
+CJK (Chinese/Japanese/Korean) characters.
=item *
-In the past, it was ineffective to override one of Perl's abbreviations
-with your own custom alias. Now it works.
+It is now possible to override Perl's abbreviations with your own custom aliases.
=item *
-You can also create a custom alias of the ordinal of a
-character, known by C<\N{...}>, C<charnames::vianame()>, and
-C<charnames::viacode()>. Previously, an alias had to be to an official
-Unicode character name. This made it impossible to create an alias for
-a code point that had no name, such as those reserved for private
+You can now create a custom alias of the ordinal of a
+character, known by C<\N{I<NAME>}>, C<charnames::vianame()>, and
+C<charnames::viacode()>. Previously, aliases had to be to official
+Unicode character names. This made it impossible to create an alias for
+unnamed code points, such as those reserved for private
use.
=item *
-A new function, C<charnames::string_vianame()>, has been added.
-This function is a run-time version of C<\N{...}>, returning the string
-of characters whose Unicode name is its parameter. It can handle
-Unicode named character sequences, whereas the pre-existing
-C<charnames::vianame()> cannot, as the latter returns a single code
-point.
+The new function charnames::string_vianame() is a run-time version
+of C<\N{I<NAME>}}>, returning the string of characters whose Unicode
+name is its parameter. It can handle Unicode named character
+sequences, whereas the pre-existing charnames::vianame() cannot,
+as the latter returns a single code point.
=back
Three new warnings subcategories of "utf8" have been added. These
allow you to turn off some "utf8" warnings, while allowing
-others warnings to remain on. The three categories are:
+other warnings to remain on. The three categories are:
C<surrogate> when UTF-16 surrogates are encountered;
C<nonchar> when Unicode non-character code points are encountered;
-and C<non_unicode> when code points that are above the legal Unicode
+and C<non_unicode> when code points above the legal Unicode
maximum of 0x10FFFF are encountered.
=head3 Any unsigned value can be encoded as a character
-With this release, Perl is adopting a model that any unsigned value can
-be treated as a code point and encoded internally (as utf8) without
-warnings - not just the code points that are legal in Unicode.
+With this release, Perl is adopting a model that any unsigned value
+can be treated as a code point and encoded internally (as utf8)
+without warnings, not just the code points that are legal in Unicode.
However, unless utf8 or the corresponding sub-category (see previous
-item) warnings have been
-explicitly lexically turned off, outputting or performing a
-Unicode-defined operation (such as upper-casing) on such a code point
-will generate a warning. Attempting to input these using strict rules
-(such as with the C<:encoding('UTF-8')> layer) will continue to fail.
-Prior to this release the handling was very inconsistent, and incorrect
-in places. Also, the Unicode non-characters, some of which previously were
-erroneously considered illegal in places by Perl, contrary to the Unicode
-standard, are now always legal internally. But inputting or outputting
-them will work the same as for the non-legal Unicode code points, as the
-Unicode standard says they are illegal for "open interchange".
+item) of lexical warnings have been explicitly turned off, outputting
+or executing a Unicode-defined operation such as upper-casing
+on such a code point generates a warning. Attempting to input these
+using strict rules (such as with the C<:encoding(UTF-8)> layer)
+will continue to fail. Prior to this release, handling was
+inconsistent and in places, incorrect.
+
+Unicode non-characters, some of which previously were erroneously
+considered illegal in places by Perl, contrary to the Unicode Standard,
+are now always legal internally. Inputting or outputting them
+works the same as with the non-legal Unicode code points, because the Unicode
+Standard says they are (only) illegal for "open interchange".
=head3 Unicode database files not installed
The Unicode database files are no longer installed with Perl. This
doesn't affect any functionality in Perl and saves significant disk
-space. If you previously were explicitly opening and reading those
-files, you can download them from
+space. If you need these files, you can download them from
L<http://www.unicode.org/Public/zipped/6.0.0/>.
=head2 Regular Expressions
-=head3 C<(?^...)> construct to signify default modifiers
+=head3 C<(?^...)> construct signifies default modifiers
-An ASCII caret (also called a "circumflex accent") C<"^">
-immediately following a C<"(?"> in a regular expression
-now means that the subexpression does not inherit the
-surrounding modifiers such as C</i>, but reverts to the
-Perl defaults. Any modifiers following the caret override the defaults.
+An ASCII caret C<"^"> immediately following a C<"(?"> in a regular
+expression now means that the subexpression does not inherit surrounding
+modifiers such as C</i>, but reverts to the Perl defaults. Any modifiers
+following the caret override the defaults.
-The stringification of regular expressions now uses this
-notation. E.g., before, C<qr/hlagh/i> would be stringified as
+Stringification of regular expressions now uses this notation.
+For example, C<qr/hlagh/i> would previously be stringified as
C<(?i-xsm:hlagh)>, but now it's stringified as C<(?^i:hlagh)>.
-The main purpose of this is to allow tests that rely on the
-stringification not to have to change when new modifiers are added.
+The main purpose of this change is to allow tests that rely on the
+stringification I<not> to have to change whenever new modifiers are added.
See L<perlre/Extended Patterns>.
+This change is likely to break code that compares stringified regular
+expressions with fixed strings containing C<?-xism>.
+
=head3 C</d>, C</l>, C</u>, C</a>, and C</aa> modifiers
-Four new regular expression modifiers have been added. These are mutually
-exclusive; one only can be turned on at a time.
+Four new regular expression modifiers have been added. These are mutually
+exclusive: one only can be turned on at a time.
+
+=over
+
+=item *
The C</l> modifier says to compile the regular expression as if it were
in the scope of C<use locale>, even if it is not.
+=item *
+
The C</u> modifier says to compile the regular expression as if it were
-in the scope of a C<use feature "unicode_strings"> pragma.
+in the scope of a C<use feature 'unicode_strings'> pragma.
+
+=item *
The C</d> (default) modifier is used to override any C<use locale> and
-C<use feature "unicode_strings"> pragmas that are in effect at the time
+C<use feature 'unicode_strings'> pragmas in effect at the time
of compiling the regular expression.
+=item *
+
The C</a> regular expression modifier restricts C<\s>, C<\d> and C<\w> and
-the Posix (C<[[:posix:]]>) character classes to the ASCII range. Their
+the POSIX (C<[[:posix:]]>) character classes to the ASCII range. Their
complements and C<\b> and C<\B> are correspondingly
affected. Otherwise, C</a> behaves like the C</u> modifier, in that
case-insensitive matching uses Unicode semantics.
-The C</aa> modifier is like C</a>, except that, in case-insensitive matching, no ASCII character will match a
-non-ASCII character. For example,
+=item *
+
+The C</aa> modifier is like C</a>, except that, in case-insensitive
+matching, no ASCII character can match a non-ASCII character.
+For example,
- 'k' =~ /\N{KELVIN SIGN}/ai
+ "k" =~ /\N{KELVIN SIGN}/ai
+ "\xDF" =~ /ss/ai
-will match; it won't under C</aa>.
+match but
+
+ "k" =~ /\N{KELVIN SIGN}/aai
+ "\xDF" =~ /ss/aai
+
+do not match.
+
+=back
See L<perlre/Modifiers> for more detail.
The substitution (C<s///>) and transliteration
(C<y///>) operators now support an C</r> option that
copies the input variable, carries out the substitution on
-the copy and returns the result. The original remains unmodified.
+the copy, and returns the result. The original remains unmodified.
- my $old = 'cat';
+ my $old = "cat";
my $new = $old =~ s/cat/dog/r;
- # $old is 'cat' and $new is 'dog'
+ # $old is "cat" and $new is "dog"
This is particularly useful with C<map>. See L<perlop> for more examples.
-=head3 Reentrant regular expression engine
+=head3 Re-entrant regular expression engine
It is now safe to use regular expressions within C<(?{...})> and
C<(??{...})> code blocks inside regular expressions.
-These block are still experimental, however, and still have problems with
+These blocks are still experimental, however, and still have problems with
lexical (C<my>) variables and abnormal exiting.
-=head3 C<use re '/flags';>
+=head3 C<use re "/flags">
The C<re> pragma now has the ability to turn on regular expression flags
till the end of the lexical scope:
- use re '/x';
+ use re "/x";
"foo" =~ / (.+) /; # /x implied
See L<re/"'/flags' mode"> for details.
=head3 \o{...} for octals
-There is a new octal escape sequence, C<"\o">, in double-quote-like
+There is a new octal escape sequence, C<"\o">, in doublequote-like
contexts. This construct allows large octal ordinals beyond the
current max of 0777 to be represented. It also allows you to specify a
character in octal which can safely be concatenated with other regex
=head3 Regular expression debugging output improvement
-Regular expression debugging output (turned on by C<use re 'debug';>) now
+Regular expression debugging output (turned on by C<use re 'debug'>) now
uses hexadecimal when escaping non-ASCII characters, instead of octal.
=head3 Return value of C<delete $+{...}>
=head3 Array and hash container functions accept references
-All built-in functions that operate directly on array or hash
-containers now also accept hard references to arrays or hashes:
+B<Warning:> This feature is considered experimental, as the exact behaviour
+may change in a future version of Perl.
+
+All builtin functions that operate directly on array or hash
+containers now also accept unblessed hard references to arrays
+or hashes:
|----------------------------+---------------------------|
| Traditional syntax | Terse syntax |
| ($k,$v) = each @$arrayref | ($k,$v) = each $arrayref |
|----------------------------+---------------------------|
-This allows these built-in functions to act on long dereferencing chains
+This allows these builtin functions to act on long dereferencing chains
or on the return value of subroutines without needing to wrap them in
C<@{}> or C<%{}>:
for ( keys %{$hoh->{genres}{artists}} ) {...} # old way
for ( keys $hoh->{genres}{artists} ) {...} # new way
-For C<push>, C<unshift> and C<splice>, the reference will auto-vivify
-if it is not defined, just as if it were wrapped with C<@{}>.
-
-For C<keys>, C<values>, C<each>, when overloaded dereferencing is
-present, the overloaded dereference is used instead of dereferencing the
-underlying reftype. Warnings are issued about assumptions made in
-ambiguous cases.
-
=head3 Single term prototype
-The C<+> prototype is a special alternative to C<$> that will act like
+The C<+> prototype is a special alternative to C<$> that acts like
C<\[@%]> when given a literal array or hash variable, but will otherwise
force scalar context on the argument. See L<perlsub/Prototypes>.
=head3 C<package> block syntax
A package declaration can now contain a code block, in which case the
-declaration is in scope
only inside that block. So C<package Foo { ... }>
+declaration is in scope
inside that block only. So C<package Foo { ... }>
is precisely equivalent to C<{ package Foo; ... }>. It also works with
-a version number in the declaration, as in C<package Foo 1.2 { ... }>.
-See L<perlfunc>.
+a version number in the declaration, as in C<package Foo 1.2 { ... }>,
+
which is its most attractive feature. See L<perlfunc>.
=head3 Statement labels can appear in more places
in addition to the already supported C<0x...> and C<0b...>
syntax [perl #76296].
-C, Ruby, Python and PHP already supported this syntax, and it makes
-Perl more internally consistent. A round-trip with C<eval sprintf
-"%#X", 0x10> now returns C<16>, the way C<eval sprintf "%#x", 0x10> does.
+C, Ruby, Python, and PHP already support this syntax, and it makes
+Perl more internally consistent: a round-trip with C<eval sprintf
+"%#X", 0x10> now returns C<16>, just like C<eval sprintf "%#x", 0x10>.
=head3 Overridable tie functions
=head2 Exception Handling
-Several changes have been made to the way C<die>, C<warn>, and C<$@>
-behave, in order to make them more reliable and consistent.
+To make them more reliable and consistent, several changes have been made
+to how C<die>, C<warn>, and C<$@> behave.
+
+=over
+
+=item *
When an exception is thrown inside an C<eval>, the exception is no
-longer at risk of being clobbered by code running during unwinding
-(e.g., destructors). Previously, the exception was written into C<$@>
+longer at risk of being clobbered by destructor code running during unwinding.
+Previously, the exception was written into C<$@>
early in the throwing process, and would be overwritten if C<eval> was
used internally in the destructor for an object that had to be freed
while exiting from the outer C<eval>. Now the exception is written
corresponding to that C<eval>. (C<$@> is still also set before exiting the
C<eval>, for the sake of destructors that rely on this.)
-Likewise, a C<local $@> inside an C<eval> will no longer clobber any
+Likewise, a C<local $@> inside an C<eval> no longer clobbers any
exception thrown in its scope. Previously, the restoration of C<$@> upon
unwinding would overwrite any exception being thrown. Now the exception
gets to the C<eval> anyway. So C<local $@> is safe before a C<die>.
C<$@> were strings or objects. Now, an exception in this situation is
always emitted as a warning, leaving the surrounding C<$@> untouched.
In addition to object destructors, this also affects any function call
-performed by XS code using the C<G_KEEPERR> flag.
+run by XS code using the C<G_KEEPERR> flag.
+
+=item *
+
+Warnings for C<warn> can now be objects in the same way as exceptions
+for C<die>. If an object-based warning gets the default handling
+of writing to standard error, it is stringified as before with the
+filename and line number appended. But a C<$SIG{__WARN__}> handler now
+receives an object-based warning as an object, where previously it
+was passed the result of stringifying the object.
-Warnings for C<warn> can now be objects, in the same way as exceptions
-for C<die>. If an object-based warning gets the default handling,
-of writing to standard error, it is stringified as
-before, with the file and line number appended. But
-a C<$SIG{__WARN__}> handler will now receive an
-object-based warning as an object, where previously it was passed the
-result of stringifying the object.
+=back
=head2 Other Enhancements
-=head3 Assignment to C<$0> sets the legacy process name with C<prctl()> on Linux
+=head3 Assignment to C<$0> sets the legacy process name with prctl() on Linux
On Linux the legacy process name is now set with L<prctl(2)>, in
-addition to altering the POSIX name via C<argv[0]> as perl has done
+addition to altering the POSIX name via C<argv[0]>, as Perl has done
since version 4.000. Now system utilities that read the legacy process
-name such as ps, top and killall will recognize the name you set when
-assigning to C<$0>. The string you supply will be cut off at 16 bytes;
-this is a limitation imposed by Linux.
+name such as I<ps>, I<top>, and I<killall> recognize the name you set when
+assigning to C<$0>. The string you supply is truncated at 16 bytes;
+this limitation is imposed by Linux.
-=head3 C<srand()> now returns the seed
+=head3 srand() now returns the seed
This allows programs that need to have repeatable results not to have to come
-up with their own seed-generating mechanism. Instead, they can use C<srand()>
-and stash the return value for future use. Typical is a test program which
-has too many combinations to test comprehensively in the time available to it
+up with their own seed-generating mechanism. Instead, they can use srand()
+and stash the return value for future use. One example is a test program with
+too many combinations to test comprehensively in the time available for
each run. It can test a random subset each time and, should there be a failure,
-log the seed used for that run so that it can later be used to reproduce the
-same results.
+log the seed used for that run so this can later be used to produce the same results.
=head3 printf-like functions understand post-1980 size modifiers
Perl's printf and sprintf operators, and Perl's internal printf replacement
function, now understand the C90 size modifiers "hh" (C<char>), "z"
(C<size_t>), and "t" (C<ptrdiff_t>). Also, when compiled with a C99
-compiler, Perl now understands the size modifier "j" (C<intmax_t>).
+compiler, Perl now understands the size modifier "j" (C<intmax_t>)
+(but this is not portable).
-So, for example, on any modern machine, C<sprintf('%hhd', 257)> returns '1'.
+So, for example, on any modern machine, C<sprintf("%hhd", 257)> returns "1".
=head3 New global variable C<${^GLOBAL_PHASE}>
A new global variable, C<${^GLOBAL_PHASE}>, has been added to allow
-introspection of the current phase of the perl interpreter. It's explained in
-detail in L<perlvar/"${^GLOBAL_PHASE}"> and
+introspection of the current phase of the Perl interpreter. It's explained in
+detail in L<perlvar/"${^GLOBAL_PHASE}"> and in
L<perlmod/"BEGIN, UNITCHECK, CHECK, INIT and END">.
=head3 C<-d:-foo> calls C<Devel::foo::unimport>
-The syntax C<-dI<B<:>foo>> was extended in 5.6.1 to make C<-dI<:fooB<=bar>>>
-equivalent to C<-MDevel::foo=bar>, which expands
-internally to C<use Devel::foo 'bar';>.
-F<perl> now allows prefixing the module name with C<->, with the same
-semantics as C<-M>, I<i.e.>
+The syntax B<-d:foo> was extended in 5.6.1 to make B<-d:foo=bar>
+equivalent to B<-MDevel::foo=bar>, which expands
+internally to C<use Devel::foo 'bar'>.
+Perl now allows prefixing the module name with B<->, with the same
+semantics as B<-M>; that is:
=over 4
=item C<-d:-foo>
-Equivalent to C<-M-Devel::foo>, expands to
-C<no Devel::foo;>, calls C<< Devel::foo->unimport() >>
-if the method exists.
+Equivalent to B<-M-Devel::foo>: expands to
+C<no Devel::foo> and calls C<< Devel::foo->unimport() >>
+if that method exists.
=item C<-d:-foo=bar>
-Equivalent to C<-M-Devel::foo=bar>, expands to C<no Devel::foo 'bar';>,
-calls C<< Devel::foo->unimport('bar') >> if the method exists.
+Equivalent to B<-M-Devel::foo=bar>: expands to C<no Devel::foo 'bar'>,
+and calls C<< Devel::foo->unimport("bar") >> if that method exists.
=back
=head3 Filehandle method calls load L<IO::File> on demand
When a method call on a filehandle would die because the method cannot
-be resolved, and L<IO::File> has not been loaded, Perl now loads L<IO::File>
+be resolved and L<IO::File> has not been loaded, Perl now loads L<IO::File>
via C<require> and attempts method resolution again:
open my $fh, ">", $file;
$fh->binmode(":raw"); # loads IO::File and succeeds
-This also works for globs like STDOUT, STDERR and STDIN:
+This also works for globs like C<STDOUT>, C<STDERR>, and C<STDIN>:
STDOUT->autoflush(1);
-Because this on-demand load only happens if method resolution fails, the
+Because this on-demand load happens only if method resolution fails, the
legacy approach of manually loading an L<IO::File> parent class for partial
method support still works as expected:
open my $fh, ">", $file;
$fh->autoflush(1); # IO::File not loaded
-=head3 IPv6 support
+=head3 Improved IPv6 support
The C<Socket> module provides new affordances for IPv6,
including implementations of the C<Socket::getaddrinfo()> and
-C<Socket::getnameinfo()> functions, along with related constants, and a
+C<Socket::getnameinfo()> functions, along with related constants and a
handful of new functions. See L<Socket>.
=head3 DTrace probes now include package name
-The DTrace probes now include an additional argument (C<arg3>) which contains
+The C<DTrace> probes now include an additional argument, C<arg3>, which contains
the package the subroutine being entered or left was compiled in.
-For example using the following DTrace script:
+For example, using the following DTrace script:
perl$target:::sub-entry
{
and then running:
- perl -e'sub test { }; test'
+ $ perl -e 'sub test { }; test'
-DTrace will print:
+C<DTrace> will print:
main::test
=head2 User-defined regular expression properties
-In L<perlunicode/"User-Defined Character Properties">, it says you can
+L<perlunicode/"User-Defined Character Properties"> documented that you can
create custom properties by defining subroutines whose names begin with
"In" or "Is". However, Perl did not actually enforce that naming
-restriction, so \p{foo::bar} could call foo::bar() if it existed. Now this
-convention has been enforced.
+restriction, so C<\p{foo::bar}> could call foo::bar() if it existed. The documented
+convention is now enforced.
-Also, Perl no longer allows a tainted regular expression to invoke a
+Also, Perl no longer allows tainted regular expressions to invoke a
user-defined property. It simply dies instead [perl #82616].
=head1 Incompatible Changes
=head3 \400-\777
-Use of C<\400>-C<\777> in regexes in certain circumstances has given
-different, anomalous behavior than their use in all other
-double-quote-like contexts. Since 5.10.1, a deprecated warning message
-has been raised when this happens. Now, all double-quote-like contexts
-have the same behavior, namely to be equivalent to C<\x{100}> -
-C<\x{1FF}>, with no deprecation warning. Use of these values in the
-command line option C<"-0"> retains the current meaning to slurp input
-files whole; previously, this was documented only for C<"-0777">. It is
-recommended, however, because of various ambiguities, to use the new
-C<\o{...}> construct to represent characters in octal.
+In certain circumstances, C<\400>-C<\777> in regexes have behaved
+differently than they behave in all other doublequote-like contexts.
+Since 5.10.1, Perl has issued a deprecation warning when this happens.
+Now, these literals behave the same in all doublequote-like contexts,
+namely to be equivalent to C<\x{100}>-C<\x{1FF}>, with no deprecation
+warning.
+
+Use of C<\400>-C<\777> in the command-line option B<-0> retain their
+conventional meaning. They slurp whole input files; previously, this
+was documented only for B<-0777>.
+
+Because of various ambiguities, you should use the new
+C<\o{...}> construct to represent characters in octal instead.
=head3 Most C<\p{}> properties are now immune to case-insensitive matching
For most Unicode properties, it doesn't make sense to have them match
-differently under C</i> case-insensitive matching than not. And doing
-so leads to unexpected results and potential security holes. For
-example
+differently under C</i> case-insensitive matching. Doing so can lead
+to unexpected results and potential security holes. For example
m/\p{ASCII_Hex_Digit}+/i
could previously match non-ASCII characters because of the Unicode
-matching rules (although there were a number of bugs with this). Now
+matching rules (although there were several bugs with this). Now
matching under C</i> gives the same results as non-C</i> matching except
for those few properties where people have come to expect differences,
namely the ones where casing is an integral part of their meaning, such
as C<m/\p{Uppercase}/i> and C<m/\p{Lowercase}/i>, both of which match
-the exact same code points, namely those matched by C<m/\p{Cased}/i>.
+the same code points as matched by C<m/\p{Cased}/i>.
Details are in L<perlrecharclass/Unicode Properties>.
-User-defined property handlers that need to match differently under
-C</i> must change to read the new boolean parameter passed to them which is
-non-zero if case-insensitive matching is in effect or 0 otherwise. See
-L<perluniprops/User-Defined Character Properties>.
+User-defined property handlers that need to match differently under C</i>
+must be changed to read the new boolean parameter passed to them, which
+is non-zero if case-insensitive matching is in effect and 0 otherwise.
+
See L<perluniprops/User-Defined Character Properties>.
=head3 \p{} implies Unicode semantics
-Now, a Unicode property match specified in the pattern will indicate
+Specifying a Unicode property in the pattern indicates
that the pattern is meant for matching according to Unicode rules, the way
-C<\N{}> does.
+C<\N{I<NAME>}> does.
=head3 Regular expressions retain their localeness when interpolated
-Regular expressions compiled under C<"use locale"> now retain this when
+Regular expressions compiled under C<use locale> now retain this when
interpolated into a new regular expression compiled outside a
-C<"use locale">, and vice-versa.
+C<use locale>, and vice-versa.
-Previously, a regular expression interpolated into another one inherited
-the localeness of the surrounding one, losing whatever state it
+Previously, one regular expression interpolated into another inherited
+the localeness of the surrounding regex, losing whatever state it
originally had. This is considered a bug fix, but may trip up code that
-has come to rely on the incorrect behavior.
+has come to rely on the incorrect behaviour.
=head3 Stringification of regexes has changed
-Default regular expression modifiers are now notated by using
-C<(?^...)>. Code relying on the old stringification will fail. The
-purpose of this is so that when new modifiers are added, such code will
-not have to change (after this one time), as the stringification will
-automatically incorporate the new modifiers.
+Default regular expression modifiers are now notated using
+C<(?^...)>. Code relying on the old stringification will fail.
+This is so that when new modifiers are added, such code won't
+have to keep changing each time this happens, because the stringification
+will automatically incorporate the new modifiers.
Code that needs to work properly with both old- and new-style regexes
-can avoid the whole issue by using (for Perls since 5.9.5; see L<re>):
+can avoid the whole issue by using (for perls since 5.9.5; see L<re>):
use re qw(regexp_pattern);
my ($pat, $mods) = regexp_pattern($re_ref);
-If the actual stringification is important, or older Perls need to be
+If the actual stringification is important or older Perls need to be
supported, you can use something like the following:
# Accept both old and new-style stringification
- my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? '^' : '-xism';
+ my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? "^" : "-xism";
And then use C<$modifiers> instead of C<-xism>.
=head3 Run-time code blocks in regular expressions inherit pragmata
-Code blocks in regular expressions (C<(?{...})> and C<(??{...})>) used not
-to inherit any pragmata (strict, warnings, etc.) if the regular expression
+Code blocks in regular expressions (C<(?{...})> and C<(??{...})>) previously
+did not inherit pragmata (strict, warnings, etc.) if the regular expression
was compiled at run time as happens in cases like these two:
- use re 'eval';
+ use re "eval";
$foo =~ $bar; # when $bar contains (?{...})
$foo =~ /$bar(?{ $finished = 1 })/;
-This was a bug, which has now been fixed. But
-it has the potential to break
-any code that was relying on it.
+This bug has now been fixed, but code that relied on the buggy behaviour
+may need to be fixed to account for the correct behaviour.
=head2 Stashes and Package Variables
tie @a, ...;
{
- local @a;
- # here, @a is a now a new, untied array
+ local @a;
+ # here, @a is a now a new, untied array
}
# here, @a refers again to the old, tied array
-The new local array used to be made tied too, which was fairly pointless,
-and has now been fixed. This fix could however potentially cause a change
-in behaviour of some code.
+Earlier versions of Perl incorrectly tied the new local array. This has
+now been fixed. This fix could however potentially cause a change in
+behaviour of some code.
=head3 Stashes are now always defined
C<defined %Foo::> now always returns true, even when no symbols have yet been
defined in that package.
-This is a side effect of removing a special case kludge in the tokeniser,
-added for 5.10.0, to hide side effects of changes to the internal storage of
-hashes that drastically reduce their memory usage overhead.
+This is a side-effect of removing a special-case kludge in the tokeniser,
+added for 5.10.0, to hide side-effects of changes to the internal storage of
+hashes. The fix drastically reduces hashes' memory overhead.
Calling defined on a stash has been deprecated since 5.6.0, warned on
-lexicals since 5.6.0, and warned for stashes (and other package
-variables) since 5.12.0. C<defined %hash> has always exposed an
-implementation detail - emptying a hash by deleting all entries from it does
-not make C<defined %hash> false, hence C<defined %hash> is not valid code to
+lexicals since 5.6.0, and warned for stashes and other package
+variables since 5.12.0. C<defined %hash> has always exposed an
+implementation detail: emptying a hash by deleting all entries from it does
+not make C<defined %hash> false. Hence C<defined %hash> is not valid code to
determine whether an arbitrary hash is empty. Instead, use the behaviour
-that an empty C<%hash> always returns false in a scalar context.
+of an empty C<%hash> always returning false in scalar context.
=head3 Clearing stashes
-Stash list assignment C<%foo:: = ()> used to make the stash anonymous
-temporarily while it was being emptied. Consequently, any of its
-subroutines referenced elsewhere would become anonymous (showing up as
-"(unknown)" in C<caller>). Now they retain their package names, such that
-C<caller> will return the original sub name if there is still a reference
-to its typeglob, or "foo::__ANON__" otherwise [perl #79208].
+Stash list assignment C<%foo:: = ()> used to make the stash temporarily
+anonymous while it was being emptied. Consequently, any of its
+subroutines referenced elsewhere would become anonymous, showing up as
+"(unknown)" in C<caller>. They now retain their package names such that
+C<caller> returns the original sub name if there is still a reference
+to its typeglob and "foo::__ANON__" otherwise [perl #79208].
=head3 Dereferencing typeglobs
$glob = *foo;
the glob that is copied to C<$glob> is marked with a special flag
-indicating that the glob is just a copy. This
-allows subsequent assignments to C<$glob> to
-overwrite the glob. The original glob, however, is
-immutable.
+indicating that the glob is just a copy. This allows subsequent
+assignments to C<$glob> to overwrite the glob. The original glob,
+however, is immutable.
Some Perl operators did not distinguish between these two types of globs.
This would result in strange behaviour in edge cases: C<untie $scalar>
would not untie the scalar if the last thing assigned to it was a glob
(because it treated it as C<untie *$scalar>, which unties a handle).
-Assignment to a glob slot (e.g., C<*$glob = \@some_array>) would simply
+Assignment to a glob slot (such as C<*$glob = \@some_array>) would simply
assign C<\@some_array> to C<$glob>.
-To fix this, the C<*{}> operator (including the C<*foo> and C<*$foo> forms)
+To fix this, the C<*{}> operator (including its C<*foo> and C<*$foo> forms)
has been modified to make a new immutable glob if its operand is a glob
copy. This allows operators that make a distinction between globs and
scalars to be modified to treat only immutable globs as globs. (C<tie>,
$glob = *foo;
*$glob = *bar;
-The C<*$glob> on the second line returns a new immutable glob. That new
-glob is made an alias to C<*bar>. Then it is discarded. So the second
+The C<*$glob> on the second line returns a new immutable glob. That new
+glob is made an alias to C<*bar>. Then it is discarded. So the second
assignment has no effect.
-See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for even
+See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for
more detail.
=head3 Magic variables outside the main package
In previous versions of Perl, magic variables like C<$!>, C<%SIG>, etc. would
-'leak' into other packages. So C<%foo::SIG> could be used to access signals,
+"leak" into other packages. So C<%foo::SIG> could be used to access signals,
C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
-This was a bug, or an 'unintentional' feature, which caused various ill effects,
+This was a bug, or an "unintentional" feature, which caused various ill effects,
such as signal handlers being wiped when modules were loaded, etc.
This has been fixed (or the feature has been removed, depending on how you see
it).
+=head3 local($_) strips all magic from $_
+
+local() on scalar variables gives them a new value but keeps all
+their magic intact. This has proven problematic for the default
+scalar variable $_, where L<perlsub> recommends that any subroutine
+that assigns to $_ should first localize it. This would throw an
+exception if $_ is aliased to a read-only variable, and could in general have
+various unintentional side-effects.
+
+Therefore, as an exception to the general rule, local($_) will not
+only assign a new value to $_, but also remove all existing magic from
+it as well.
+
+=head3 Parsing of package and variable names
+
+Parsing the names of packages and package variables has changed:
+multiple adjacent pairs of colons, as in C<foo::::bar>, are now all
+treated as package separators.
+
+Regardless of this change, the exact parsing of package separators has
+never been guaranteed and is subject to change in future Perl versions.
+
=head2 Changes to Syntax or to Perl Operators
=head3 C<given> return values
C<given> blocks now return the last evaluated
-expression, or an empty list if the block was exited by C<break>. Thus you
+expression, or an empty list if the block was exited by C<break>. Thus you
can now write:
my $type = do {
given ($num) {
break when undef;
- 'integer' when /^[+-]?[0-9]+$/;
- 'float' when /^[+-]?[0-9]+(?:\.[0-9]+)?$/;
- 'unknown';
+ "integer" when /^[+-]?[0-9]+$/;
+ "float" when /^[+-]?[0-9]+(?:\.[0-9]+)?$/;
+ "unknown";
}
};
See L<perlsyn/Return value> for details.
-=head3 Change in the parsing of certain prototypes
+=head3 Change in parsing of certain prototypes
Functions declared with the following prototypes now behave correctly as unary
functions:
Due to this bug fix [perl #75904], functions
using the C<(*)>, C<(;$)> and C<(;*)> prototypes
-are parsed with higher precedence than before. So in the following example:
+are parsed with higher precedence than before. So
+in the following example:
sub foo($);
foo $a < $b;
the second line is now parsed correctly as C<< foo($a) < $b >>, rather than
-C<< foo($a < $b) >>. This happens when one of these operators is used in
+C<< foo($a < $b) >>. This happens when one of these operators is used in
an unparenthesised argument:
< > <= >= lt gt le ge
=head3 Negation treats strings differently from before
-The unary negation operator C<-> now treats strings that look like numbers
+The unary negation operator, C<->, now treats strings that look like numbers
as numbers [perl #57706].
=head3 Negative zero
Negative zero (-0.0), when converted to a string, now becomes "0" on all
-platforms. It used to become "-0" on some, but "0" on others.
+platforms. It used to become "-0" on some, but "0" on others.
If you still need to determine whether a zero is negative, use
C<sprintf("%g", $zero) =~ /^-/> or the L<Data::Float> module on CPAN.
=head3 C<:=> is now a syntax error
-Previously C<my $pi := 4;> was exactly equivalent to C<my $pi : = 4;>,
+Previously C<my $pi := 4> was exactly equivalent to C<my $pi : = 4>,
with the C<:> being treated as the start of an attribute list, ending before
-the C<=>. The use of C<:=> to mean C<: => was deprecated in 5.12.0, and is now
-a syntax error. This will allow the future use of C<:=> as a new token.
+the C<=>. The use of C<:=> to mean C<: => was deprecated in 5.12.0, and is
+now a syntax error. This allows future use of C<:=> as a new token.
-We find no Perl 5 code on CPAN using this construction, outside the core's
-tests for it, so we believe that this change will have very little impact on
-real-world codebases.
+Outside the core's tests for it, we find no Perl 5 code on CPAN
+using this construction, so we believe that this change will have
+little impact on real-world codebases.
If it is absolutely necessary to have empty attribute lists (for example,
-because of a code generator) then avoid the error by adding a space before
+because of a code generator), simply avoid the error by adding a space before
the C<=>.
+=head3 Change in the parsing of identifiers
+
+Characters outside the Unicode "XIDStart" set are no longer allowed at the
+beginning of an identifier. This means that certain accents and marks
+that normally follow an alphabetic character may no longer be the first
+character of an identifier.
+
=head2 Threads and Processes
=head3 Directory handles not copied to threads
On systems other than Windows that do not have
a C<fchdir> function, newly-created threads no
-longer inherit directory handles from their parent threads. Such programs
+longer inherit directory handles from their parent threads. Such programs
would usually have crashed anyway [perl #75154].
=head3 C<close> on shared pipes
-The C<close> function no longer waits for the child process to exit if the
-underlying file descriptor is still in use by another thread, to avoid
-deadlocks. It returns true in such cases.
+To avoid deadlocks, the C<close> function no longer waits for the
+child process to exit if the underlying file descriptor is still
+in use by another thread. It returns true in such cases.
=head3 fork() emulation will not wait for signalled children
On Windows parent processes would not terminate until all forked
-childred had terminated first. However, C<kill('KILL', ...)> is
-inherently unstable on pseudo-processes, and C<kill('TERM', ...)>
-might not get delivered if the child if blocked in a system call.
+children had terminated first. However, C<kill("KILL", ...)> is
+inherently unstable on pseudo-processes, and C<kill("TERM", ...)>
+might not get delivered if the child is blocked in a system call.
To avoid the deadlock and still provide a safe mechanism to terminate
-the hosting process, Perl will now no longer wait for children that
+the hosting process, Perl now no longer waits for children that
have been sent a SIGTERM signal. It is up to the parent process to
-waitpid() for these children if child clean-up processing must be
-allowed to finish. However, it is also the responsibility of the
-parent then to avoid the deadlock by making sure the child process
-can't be blocked on I/O either.
+waitpid() for these children if child-cleanup processing must be
+allowed to finish. However, it is also then the responsibility of the
+parent to avoid the deadlock by making sure the child process
+can't be blocked on I/O.
See L<perlfork> for more information about the fork() emulation on
Windows.
=head3 Naming fixes in Policy_sh.SH may invalidate Policy.sh
-Several long-standing typos and naming confusions in Policy_sh.SH have
-been fixed, standardizing on the variable names used in config.sh.
+Several long-standing typos and naming confusions in F<Policy_sh.SH> have
+been fixed, standardizing on the variable names used in F<config.sh>.
-This will change the behavior of Policy.sh if you happen to have been
-accidentally relying on the Policy.sh incorrect behavior.
+This will change the behaviour of F<Policy.sh> if you happen to have been
+accidentally relying on its incorrect behaviour.
=head3 Perl source code is read in text mode on Windows
Perl scripts used to be read in binary mode on Windows for the benefit
-of the ByteLoader module (which is no longer part of core Perl). This
-had the side effect of breaking various operations on the DATA filehandle,
-including seek()/tell(), and even simply reading from DATA after file handles
+of the L<ByteLoader> module (which is no longer part of core Perl). This
+had the side-effect of breaking various operations on the C<DATA> filehandle,
+including seek()/tell(), and even simply reading from C<DATA> after filehandles
have been flushed by a call to system(), backticks, fork() etc.
The default build options for Windows have been changed to read Perl source
-code on Windows in text mode now. Hopefully ByteLoader will be updated on
+code on Windows in text mode now. L<ByteLoader> will (hopefully) be updated on
CPAN to automatically handle this situation [perl #28106].
=head1 Deprecations
=head2 Omitting a space between a regular expression and subsequent word
-Omitting a space between a regular expression operator or
+Omitting the space between a regular expression operator or
its modifiers and the following word is deprecated. For
-example, C<< m/foo/sand $bar >> will still be parsed
-as C<< m/foo/s and $bar >> but will issue a warning.
+example, C<< m/foo/sand $bar >> is for now still parsed
+as C<< m/foo/s and $bar >>, but will now issue a warning.
=head2 C<\cI<X>>
(not in a bracketed character class) or a C<"\B{"> is now deprecated
to allow for its future use by Perl itself.
-=head2 Deprecation warning added for deprecated-in-core .pl libs
+=head2 Deprecation warning added for deprecated-in-core Perl 4-era .pl libraries
-This is a mandatory warning, not obeying -X or lexical warning bits.
-The warning is modelled on that supplied by deprecate.pm for
-deprecated-in-core .pm libraries. It points to the specific CPAN
-distribution that contains the .pl libraries. The CPAN version, of
-course, does not generate the warning.
+This is a mandatory warning, not obeying B<-X> or lexical warning bits.
+The warning is modelled on that supplied by F<deprecate.pm> for
+deprecated-in-core F<.pm> libraries. It points to the specific CPAN
+distribution that contains the F<.pl> libraries. The CPAN versions, of
+course, do not generate the warning.
=head2 List assignment to C<$[>
Assignment to C<$[> was deprecated and started to give warnings in
-Perl version 5.12.0. This version of perl also starts to emit a warning when
-assigning to C<$[> in list context. This fixes an oversight in 5.12.0.
+Perl version 5.12.0. This version of Perl (5.14) now also emits a warning
+when assigning to C<$[> in list context. This fixes an oversight in 5.12.0.
=head2 Use of qw(...) as parentheses
for $x qw(a b c) { ... }
The parser no longer lies to itself in this way. Wrap the list literal in
-parentheses, like this:
+parentheses like this:
for $x (qw(a b c)) { ... }
-=head2 C<\N{BELL}> is deprecated
+This is being deprecated because C<qw(a b c)> is supposed to mean
+C<"a", "b", "c"> not C<("a", "b", "c")>. In other words, this doesn't compile:
+
+ for my $i "a", "b", "c" { }
+
+So neither should this:
+
+ for my $i qw(a b c) {}
+
+But these both work:
+
+ for my $i ("a", "b", "c") { }
+ for my $i (qw(a b c)) {}
+
+Note that this does not change the behaviour of cases like:
+
+ use POSIX qw(setlocale localeconv)
+ our @EXPORT = qw(foo bar baz);
+
+Where a list with or without parentheses could have been provided.
+
+=head2 C<\N{BELL}>
This is because Unicode is using that name for a different character.
See L</Unicode Version 6.0 is now supported (mostly)> for more
explanation.
-=head2 C<?PATTERN?> is deprecated
+=head2 C<?PATTERN?>
-C<?PATTERN?> (without the initial m) has been deprecated and now produces
+C<?PATTERN?> (without the initial C<m>) has been deprecated and now produces
a warning. This is to allow future use of C<?> in new operators.
-The match-once functionality is still available in the form of C<m?PATTERN?>.
+The match-once functionality is still available as C<m?PATTERN?>.
=head2 Tie functions on scalars holding typeglobs
Calling a tie function (C<tie>, C<tied>, C<untie>) with a scalar argument
-acts on a file handle if the scalar happens to hold a typeglob.
+acts on a filehandle if the scalar happens to hold a typeglob.
This is a long-standing bug that will be removed in Perl 5.16, as
there is currently no way to tie the scalar itself when it holds
This feature is being deprecated due to its many issues, as documented in
L<perlunicode/User-Defined Case Mappings (for serious hackers only)>.
-It is planned to remove this feature in Perl 5.16. Instead use the CPAN module
+This feature will be removed in Perl 5.16. Instead use the CPAN module
L<Unicode::Casing>, which provides improved functionality.
=head2 Deprecated modules
The following modules will be removed from the core distribution in a
-future release, and should be installed from CPAN instead. Distributions
-on CPAN which require these should add them to their prerequisites. The
-core versions of these modules will issue a deprecation warning.
+future release, and should be installed from CPAN instead. Distributions
+on CPAN that require these should add them to their prerequisites. The
+core versions of these modules now issue a deprecation warning.
If you ship a packaged version of Perl, either alone or as part of a
larger system, then you should carefully consider the repercussions of
core module deprecations. You may want to consider shipping your default
-build of Perl with packages for some or all deprecated modules which
-install into C<vendor> or C<site> perl library directories. This will
+build of Perl with packages for some or all deprecated modules that
+install into C<vendor> or C<site> Perl library directories. This will
inhibit the deprecation warnings.
Alternatively, you may want to consider patching F<lib/deprecate.pm>
=item L<Devel::DProf>
-We strongly recommend that you install and used L<Devel::NYTProf> in
-preference, as it offers significantly improved profiling and reporting.
+We strongly recommend that you install and use L<Devel::NYTProf> instead
+of L<Devel::Dprof>, as L<Devel::NYTProf> offers significantly
+improved profiling and reporting.
=back
=head2 "Safe signals" optimisation
-Signal dispatch has been moved from the runloop into control ops. This
-should give a few percent speed increase, and eliminates almost all of
-the speed penalty caused by the introduction of "safe signals" in
-5.8.0. Signals should still be dispatched within the same statement as
-they were previously - if this is not the case, or it is possible to
-create uninterruptible loops, this is a bug, and reports are encouraged
-of how to recreate such issues.
+Signal dispatch has been moved from the runloop into control ops.
+This should give a few percent speed increase, and eliminates nearly
+all the speed penalty caused by the introduction of "safe signals"
+in 5.8.0. Signals should still be dispatched within the same
+statement as they were previously. If this does I<not> happen, or
+if you find it possible to create uninterruptible loops, this is a
+bug, and reports are encouraged of how to recreate such issues.
-=head2 Optimisation of shift; and pop; calls without arguments
+=head2 Optimisation of shift() and pop() calls without arguments
-Two fewer OPs are used for shift and pop calls with no argument (with
-implicit C<@_>). This change makes C<shift;> 5% faster than C<shift @_;>
-on non-threaded perls and 25% faster on threaded.
+Two fewer OPs are used for shift() and pop() calls with no argument (with
+implicit C<@_>). This change makes shift() 5% faster than C<shift @_>
+on non-threaded perls, and 25% faster on threaded ones.
=head2 Optimisation of regexp engine string comparison work
-The foldEQ_utf8 API function for case-insensitive comparison of strings (which
+The C<foldEQ_utf8> API function for case-insensitive comparison of strings (which
is used heavily by the regexp engine) was substantially refactored and
-optimised - and its documentation much improved as a free bonus gift.
+optimised -- and its documentation much improved as a free bonus.
=head2 Regular expression compilation speed-up
-Compiling regular expressions has been made faster for the case where upgrading
-the regex to utf8 is necessary but that isn't known when the compilation begins.
+Compiling regular expressions has been made faster when upgrading
+the regex to utf8 is necessary but this isn't known when the compilation begins.
=head2 String appending is 100 times faster
-When doing a lot of string appending, perl could end up allocating a lot more
-memory than needed in a very inefficient way, if perl was configured to use the
-system's C<malloc> implementation instead of its own.
+When doing a lot of string appending, perls built to use the system's
+C<malloc> could end up allocating a lot more memory than needed in a
+inefficient way.
-C<sv_grow>, which is what's being used to allocate more memory if necessary
-when appending to a string, has now been taught how to round up the memory
+C<sv_grow>, the function used to allocate more memory if necessary
+when appending to a string, has been taught to round up the memory
it requests to a certain geometric progression, making it much faster on
certain platforms and configurations. On Win32, it's now about 100 times
faster.
=head2 Eliminate C<PL_*> accessor functions under ithreads
When C<MULTIPLICITY> was first developed, and interpreter state moved into
-an interpreter struct, thread and interpreter local C<PL_*> variables were
-defined as macros that called accessor functions, returning the address of
-the value, outside of the perl core. The intent was to allow members
-within the interpreter struct to change size without breaking binary
-compatibility, so that bug fixes could be merged to a maintenance branch
-that necessitated such a size change.
-
-However, some non-core code defines C<PERL_CORE>, sometimes intentionally
-to bypass this mechanism for speed reasons, sometimes for other reasons but
-with the inadvertent side effect of bypassing this mechanism. As some of
-this code is widespread in production use, the result is that the core
-I<can't> change the size of members of the interpreter struct, as it will
-break such modules compiled against a previous release on that maintenance
-branch. The upshot is that this mechanism is redundant, and well-behaved
-code is penalised by it. Hence it can and should be removed (and has
-been).
+an interpreter struct, thread- and interpreter-local C<PL_*> variables
+were defined as macros that called accessor functions (returning the
+address of the value) outside the Perl core. The intent was to allow
+members within the interpreter struct to change size without breaking
+binary compatibility, so that bug fixes could be merged to a maintenance
+branch that necessitated such a size change. This mechanism was redundant
+and penalised well-behaved code. It has been removed.
=head2 Freeing weak references
-When an object has many weak references to it, freeing that object
-can under some some circumstances take O(N^2) time to free (where N is the
-number of references). The number of circumstances has been reduced
-[perl #75254]
+When there are many weak references to an object, freeing that object
+can under some circumstances take O(I<NE<0xB2>>) time to free, where
+I<N> is the number of references. The circumstances in which this can happen
+have been reduced [perl #75254]
=head2 Lexical array and hash assignments
=head2 Size optimisations to SV and HV structures
-xhv_fill has been eliminated from struct xpvhv, saving 1 IV per hash and
-on some systems will cause struct xpvhv to become cache-aligned. To avoid
-this memory saving causing a slowdown elsewhere, boolean use of HvFILL
-now calls HvTOTALKEYS instead (which is equivalent) - so while the fill
-data when actually required are now calculated on demand, the cases when
-this needs to be done should be few and far between.
+C<xhv_fill> has been eliminated from C<struct xpvhv>, saving 1 IV per hash and
+on some systems will cause C<struct xpvhv> to become cache-aligned. To avoid
+this memory saving causing a slowdown elsewhere, boolean use of C<HvFILL>
+now calls C<HvTOTALKEYS> instead (which is equivalent), so while the fill
+data when actually required are now calculated on demand, cases when
+this needs to be done should be rare.
The order of structure elements in SV bodies has changed. Effectively,
the NV slot has swapped location with STASH and MAGIC. As all access to
change allows the space saving for PVHVs documented above, and may reduce
the memory allocation needed for PVIVs on some architectures.
-C<XPV>, C<XPVIV>, and C<XPVNV> now only allocate the parts of the C<SV> body
+C<XPV>, C<XPVIV>, and C<XPVNV> now allocate only the parts of the C<SV> body
they actually use, saving some space.
-Scalars containing regular expressions now only allocate the part of the C<SV>
+Scalars containing regular expressions now allocate only the part of the C<SV>
body they actually use, saving some space.
=head2 Memory consumption improvements to Exporter
-The @EXPORT_FAIL AV is no longer created unless required, hence neither is
+The C<@EXPORT_FAIL> AV is no longer created unless needed, hence neither is
the typeglob backing it. This saves about 200 bytes for every package that
uses Exporter but doesn't use this functionality.
=head2 Memory savings for weak references
-For weak references, the common case of just a single weak reference per
-referent has been optimised to reduce the storage required. In this case it
-saves the equivalent of one small Perl array per referent.
+For weak references, the common case of just a single weak reference
+per referent has been optimised to reduce the storage required. In this
+case it saves the equivalent of one small Perl array per referent.
=head2 C<%+> and C<%-> use less memory
-The bulk of the C<Tie::Hash::NamedCapture> module used to be in the perl
-core. It has now been moved to an XS module, to reduce the overhead for
+The bulk of the C<Tie::Hash::NamedCapture> module used to be in the Perl
+core. It has now been moved to an XS module to reduce overhead for
programs that do not use C<%+> or C<%->.
=head2 Multiple small improvements to threads
The internal structures of threading now make fewer API calls and fewer
allocations, resulting in noticeably smaller object code. Additionally,
-many thread context checks have been deferred so that they're only done
-when required (although this is only possible for non-debugging builds).
+many thread context checks have been deferred so they're done only
+as needed (although this is only possible for non-debugging builds).
=head2 Adjacent pairs of nextstate opcodes are now optimized away
print "stuff\n";
}
-the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
+the ops for C<warn if DEBUG> would be folded to a C<null> op (C<ex-const>), but
the C<nextstate> op would remain, resulting in a runtime op dispatch of
-C<nextstate>, C<nextstate>, ....
+C<nextstate>, C<nextstate>, etc.
The execution of a sequence of C<nextstate> ops is indistinguishable from just
the last C<nextstate> op so the peephole optimizer now eliminates the first of
-a pair of C<nextstate> ops, except where the first carries a label, since labels
-must not be eliminated by the optimizer and label usage isn't conclusively known
+a pair of C<nextstate> ops except when the first carries a label, since labels
+must not be eliminated by the optimizer, and label usage isn't conclusively known
at compile time.
=head1 Modules and Pragmata
=item *
-C<CPAN::Meta::YAML> 0.003 has been added as a dual-life module. It supports a
-subset of YAML sufficient for reading and writing META.yml and MYMETA.yml files
+L<CPAN::Meta::YAML> 0.003 has been added as a dual-life module. It supports a
+subset of YAML sufficient for reading and writing F<META.yml> and F<MYMETA.yml> files
included with CPAN distributions or generated by the module installation
-toolchain. It should not be used for any other general YAML parsing or
+toolchain. It should not be used for any other general YAML parsing or
generation task.
=item *
-C<CPAN::Meta> version 2.110440 has been added as a dual-life module. It
+L<CPAN::Meta> version 2.110440 has been added as a dual-life module. It
provides a standard library to read, interpret and write CPAN distribution
-metadata files (e.g. META.json and META.yml) which describes a
+metadata files (like F<META.json> and F<META.yml)> that describe a
distribution, its contents, and the requirements for building it and
-installing it. The latest CPAN distribution metadata specification is
-included as C<CPAN::Meta::Spec> and notes on changes in the specification
-over time are given in C<CPAN::Meta::History>.
+installing it. The latest CPAN distribution metadata specification is
+included as L<CPAN::Meta::Spec> and notes on changes in the specification
+over time are given in L<CPAN::Meta::History>.
=item *
-C<HTTP::Tiny> 0.011 has been added as a dual-life module. It is a very
+L<HTTP::Tiny> 0.012 has been added as a dual-life module. It is a very
small, simple HTTP/1.1 client designed for simple GET requests and file
-mirroring. It has has been added to enable CPAN.pm and CPANPLUS to
+mirroring. It has been added so that F<CPAN.pm> and L<CPANPLUS> can
"bootstrap" HTTP access to CPAN using pure Perl without relying on external
-binaries like F<curl> or F<wget>.
+binaries like L<curl(1)> or L<wget(1)>.
=item *
-C<JSON::PP> 2.27105 has been added as a dual-life module, for the sake of
-reading F<META.json> files in CPAN distributions.
+L<JSON::PP> 2.27105 has been added as a dual-life module to allow CPAN
+clients to read F<META.json> files in CPAN distributions.
=item *
-C<Module::Metadata> 1.000004 has been added as a dual-life module. It gathers
+L<Module::Metadata> 1.000004 has been added as a dual-life module. It gathers
package and POD information from Perl module files. It is a standalone module
-based on Module::Build::ModuleInfo for use by other module installation
-toolchain components. Module::Build::ModuleInfo has been deprecated in
+based on L<Module::Build::ModuleInfo> for use by other module installation
+toolchain components. L<Module::Build::ModuleInfo> has been deprecated in
favor of this module instead.
=item *
-
C<Perl::OSType> 1.002 has been added as a dual-life module. It maps Perl
-operating system names (e.g. 'dragonfly' or 'MSWin32') to more generic types
-with standardized names (e.g. "Unix" or "Windows"). It has been refactored
-out of Module::Build and ExtUtils::CBuilder and consolidates such mappings into
+
L<Perl::OSType> 1.002 has been added as a dual-life module. It maps Perl
+operating system names (like "dragonfly" or "MSWin32") to more generic types
+with standardized names (like "Unix" or "Windows"). It has been refactored
+out of L<Module::Build> and L<ExtUtils::CBuilder> and consolidates such mappings into
a single location for easier maintenance.
=item *
-The following modules were added by the C<Unicode::Collate>
-upgrade. See below for details.
+The following modules were added by the L<Unicode::Collate>
+upgrade. See below for details.
-C<Unicode::Collate::CJK::Big5>
+L<Unicode::Collate::CJK::Big5>
-C<Unicode::Collate::CJK::GB2312>
+L<Unicode::Collate::CJK::GB2312>
-C<Unicode::Collate::CJK::JISX0208>
+L<Unicode::Collate::CJK::JISX0208>
-C<Unicode::Collate::CJK::Korean>
+L<Unicode::Collate::CJK::Korean>
-C<Unicode::Collate::CJK::Pinyin>
+L<Unicode::Collate::CJK::Pinyin>
-C<Unicode::Collate::CJK::Stroke>
+L<Unicode::Collate::CJK::Stroke>
=item *
-C<Version::Requirements> version 0.101020 has been added as a dual-life
+L<Version::Requirements> version 0.101020 has been added as a dual-life
module. It provides a standard library to model and manipulates module
-prerequisites and version constraints as defined in the L<CPAN::Meta::Spec>.
+prerequisites and version constraints defined in L<CPAN::Meta::Spec>.
=back
=item *
-
C<attributes> has been upgraded from version 0.12 to 0.14.
+
L<attributes> has been upgraded from version 0.12 to 0.14.
=item *
-
C<Archive::Extract> has been upgraded from version 0.38 to 0.48.
+
L<Archive::Extract> has been upgraded from version 0.38 to 0.48.
Updates since 0.38 include: a safe print method that guards
-Archive::Extract from changes to $\; a fix to the tests when run in core
-perl; support for TZ files; a modification for the lzma
-logic to favour IO::Uncompress::Unlzma; and a fix
-for an issue with NetBSD-current and its new unzip
+L<Archive::Extract> from changes to C<$\>; a fix to the tests when run in core
+Perl; support for TZ files; a modification for the lzma
+logic to favour L<IO::Uncompress::Unlzma>; and a fix
+for an issue with NetBSD-current and its new L<unzip(1)>
executable.
=item *
-
C<Archive::Tar> has been upgraded from version 1.54 to 1.76.
+
L<Archive::Tar> has been upgraded from version 1.54 to 1.76.
Important changes since 1.54 include the following:
=item *
-Compatibility with busybox implementations of tar
+Compatibility with busybox implementations of L<tar(1)>.
=item *
-A fix so that C<write()> and C<create_archive()>
-close only handles they opened
+A fix so that write() and create_archive()
+close only filehandles they themselves opened.
=item *
=item *
-The C<ptar> utility has a new option to allow safe
-creation of tarballs without world-writable files on Windows, allowing those
+The L<ptar(1)> utility has a new option to allow safe creation of
+tarballs without world-writable files on Windows, allowing those
archives to be uploaded to CPAN.
=item *
-A new ptargrep utility for using regular expressions against
+A new L<ptargrep(1)> utility for using regular expressions against
the contents of files in a tar archive.
=item *
-Pax extended headers are now skipped.
+L<pax> extended headers are now skipped.
=back
=item *
-
C<Attribute::Handlers> has been upgraded from version 0.87 to 0.89.
+
L<Attribute::Handlers> has been upgraded from version 0.87 to 0.89.
=item *
-
C<autodie> has been upgraded from version 2.06_01 to 2.1001.
+
L<autodie> has been upgraded from version 2.06_01 to 2.1001.
=item *
-
C<AutoLoader> has been upgraded from version 5.70 to 5.71.
+
L<AutoLoader> has been upgraded from version 5.70 to 5.71.
=item *
-C<B> has been upgraded from version 1.23 to 1.29.
+The L<B> module has been upgraded from version 1.23 to 1.29.
It no longer crashes when taking apart a C<y///> containing characters
outside the octet range or compiled in a C<use utf8> scope.
=item *
-C<B::Concise> has been upgraded from version 0.78 to 0.83.
+L<B::Concise> has been upgraded from version 0.78 to 0.83.
-B::Concise marks rv2sv, rv2av and rv2hv ops with the new OPpDEREF flag
-as "DREFed".
+L<B::Concise> marks rv2sv(), rv2av(), and rv2hv() ops with the new
+C<OPpDEREF> flag as "DREFed".
-It no longer produces mangled output with the C<-tree> option
+It no longer produces mangled output with the B<-tree> option
[perl #80632].
=item *
-C<B::Debug> has been upgraded from version 1.12 to 1.16.
+L<B::Debug> has been upgraded from version 1.12 to 1.16.
=item *
-C<B::Deparse> has been upgraded from version 0.96 to 1.03.
+L<B::Deparse> has been upgraded from version 0.96 to 1.03.
-The deparsing of a nextstate op has changed when it has both a
-change of package (relative to the previous nextstate), or a change of
-C<%^H> or other state, and a label. Previously the label was emitted
-first, but now the label is emitted last (5.12.1).
+The deparsing of a C<nextstate> op has changed when it has both a
+change of package relative to the previous nextstate, or a change of
+C<%^H> or other state and a label. The label was previously emitted
+first, but is now emitted last (5.12.1).
-The C<no 5.13.2> or similar form is now correctly handled by B::Deparse
+The C<no 5.13.2> or similar form is now correctly handled by L<B::Deparse>
(5.12.3).
-B::Deparse now properly handles the code that applies a conditional
+L<B::Deparse> now properly handles the code that applies a conditional
pattern match against implicit C<$_> as it was fixed in [perl #20444].
Deparsing of C<our> followed by a variable with funny characters
-(as permitted under the C<utf8> pragma) has also been fixed [perl #33752].
+(as permitted under the C<use utf8> pragma) has also been fixed [perl #33752].
=item *
-C<B::Lint> has been upgraded from version 1.11_01 to 1.13.
+L<B::Lint> has been upgraded from version 1.11_01 to 1.13.
=item *
-C<base> has been upgraded from version 2.15 to 2.16.
+L<base> has been upgraded from version 2.15 to 2.16.
=item *
-C<Benchmark> has been upgraded from version 1.11 to 1.12.
+L<Benchmark> has been upgraded from version 1.11 to 1.12.
=item *
-C<bignum> has been upgraded from version 0.23 to 0.26.
+L<bignum> has been upgraded from version 0.23 to 0.27.
=item *
-C<Carp> has been upgraded from version 1.15 to 1.20.
+L<Carp> has been upgraded from version 1.15 to 1.20.
-L<Carp> now detects incomplete L<caller()|perlfunc/"caller EXPR"> overrides and
-avoids using bogus C<@DB::args>. To provide backtraces,
-Carp relies on particular behaviour of the C<caller>
-built-in. Carp now detects if other code has
-overridden this with an incomplete implementation, and modifies its backtrace
-accordingly. Previously incomplete overrides would cause incorrect values
-in backtraces (best case), or obscure fatal errors (worst case).
+L<Carp> now detects incomplete L<caller()|perlfunc/"caller EXPR">
+overrides and avoids using bogus C<@DB::args>. To provide backtraces,
+Carp relies on particular behaviour of the caller() builtin.
+L<Carp> now detects if other code has overridden this with an
+incomplete implementation, and modifies its backtrace accordingly.
+Previously incomplete overrides would cause incorrect values in
+backtraces (best case), or obscure fatal errors (worst case).
-This fixes certain cases of C<Bizarre copy of ARRAY> caused by modules
-overriding C<caller()> incorrectly (5.12.2).
+This fixes certain cases of "Bizarre copy of ARRAY" caused by modules
+overriding caller() incorrectly (5.12.2).
-It now also avoids using regular expressions that cause perl to
-load its Unicode tables, in order to avoid the 'BEGIN not safe after
-errors' error that will ensue if there has been a syntax error
+It now also avoids using regular expressions that cause Perl to
+load its Unicode tables, so as to avoid the "BEGIN not safe after
+errors" error that ensue if there has been a syntax error
[perl #82854].
=item *
-C<CGI> has been upgraded from version 3.48 to 3.52.
+L<CGI> has been upgraded from version 3.48 to 3.52.
This provides the following security fixes: the MIME boundary in
-multipart_init is now random and the handling of
+multipart_init() is now random and the handling of
newlines embedded in header values has been improved.
=item *
-C<Compress::Raw::Bzip2> has been upgraded from version 2.024 to 2.033.
+L<Compress::Raw::Bzip2> has been upgraded from version 2.024 to 2.033.
+
+It has been updated to use L<bzip2(1)> 1.0.6.
+
+=item *
-It has been updated to use bzip2 1.0.6.
+L<Compress::Raw::Zlib> has been upgraded from version 2.024 to 2.033.
=item *
-C<Compress::Raw::Zlib> has been upgraded from version 2.024 to 2.033.
+L<constant> has been upgraded from version 1.20 to 1.21.
+
+Unicode constants work once more. They have been broken since Perl 5.10.0
+[CPAN RT #67525].
=item *
-C<CPAN> has been upgraded from version 1.94_56 to 1.9600.
+L<CPAN> has been upgraded from version 1.94_56 to 1.9600.
Major highlights:
=item * much less configuration dialog hassle
-=item * support for META/MYMETA.json
+=item * support for F<META/MYMETA.json>
-=item * support for local::lib
+=item * support for L<local::lib>
-=item * support for HTTP::Tiny to reduce the dependency on ftp sites
+=item * support for L<HTTP::Tiny> to reduce the dependency on FTP sites
=item * automatic mirror selection
=item * iron out all known bugs in configure_requires
-=item * support for distributions compressed with bzip2
+=item * support for distributions compressed with L<bzip2(1)>
-=item * allow Foo/Bar.pm on the commandline to mean Foo::Bar
+=item * allow F<Foo/Bar.pm> on the command line to mean C<Foo::Bar>
=back
=item *
-C<CPANPLUS> has been upgraded from version 0.90 to 0.9103.
+L<CPANPLUS> has been upgraded from version 0.90 to 0.9103.
A change to F<cpanp-run-perl>
resolves L<RT #55964|http://rt.cpan.org/Public/Bug/Display.html?id=55964>
of which related to failures to install distributions that use
C<Module::Install::DSL> (5.12.2).
-A dependency on Config was not recognised as a
+A dependency on L<Config> was not recognised as a
core module dependency. This has been fixed.
-CPANPLUS now includes support for META.json and MYMETA.json.
+L<CPANPLUS> now includes support for F<META.json> and F<MYMETA.json>.
=item *
-C<CPANPLUS::Dist::Build> has been upgraded from version 0.46 to 0.54.
+L<CPANPLUS::Dist::Build> has been upgraded from version 0.46 to 0.54.
=item *
-C<Data::Dumper> has been upgraded from version 2.125 to 2.130_02.
+L<Data::Dumper> has been upgraded from version 2.125 to 2.130_02.
-The indentation used to be off when C<$Data::Dumper::Terse> was set. This
+The indentation used to be off when C<$Data::Dumper::Terse> was set. This
has been fixed [perl #73604].
This upgrade also fixes a crash when using custom sort functions that might
cause the stack to change [perl #74170].
-C<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
+L<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
[perl #72332].
=item *
-C<DB_File> has been upgraded from version 1.820 to 1.821.
+L<DB_File> has been upgraded from version 1.820 to 1.821.
=item *
-C<DBM_Filter> has been upgraded from version 0.03 to 0.04.
+L<DBM_Filter> has been upgraded from version 0.03 to 0.04.
=item *
-C<Devel::DProf> has been upgraded from version 20080331.00 to 20110228.00.
+L<Devel::DProf> has been upgraded from version 20080331.00 to 20110228.00.
-Merely loading C<Devel::DProf> now no longer triggers profiling to start.
-C<use Devel::DProf> and C<perl -d:DProf ...> still behave as before and start
+Merely loading L<Devel::DProf> now no longer triggers profiling to start.
+Both C<use Devel::DProf> and C<perl -d:DProf ...> behave as before and start
the profiler.
-NOTE: C<Devel::DProf> is deprecated and will be removed from a future
+B<NOTE>: L<Devel::DProf> is deprecated and will be removed from a future
version of Perl. We strongly recommend that you install and use
L<Devel::NYTProf> instead, as it offers significantly improved
profiling and reporting.
=item *
-C<Devel::Peek> has been upgraded from version 1.04 to 1.07.
+L<Devel::Peek> has been upgraded from version 1.04 to 1.07.
=item *
-C<Devel::SelfStubber> has been upgraded from version 1.03 to 1.05.
+L<Devel::SelfStubber> has been upgraded from version 1.03 to 1.05.
=item *
-C<diagnostics> has been upgraded from version 1.19 to 1.22.
+L<diagnostics> has been upgraded from version 1.19 to 1.22.
It now renders pod links slightly better, and has been taught to find
descriptions for messages that share their descriptions with other
=item *
-C<Digest::MD5> has been upgraded from version 2.39 to 2.51.
+L<Digest::MD5> has been upgraded from version 2.39 to 2.51.
It is now safe to use this module in combination with threads.
=item *
-C<Digest::SHA> has been upgraded from version 5.47 to 5.61.
+L<Digest::SHA> has been upgraded from version 5.47 to 5.61.
-C<shasum> now more closely mimics C<sha1sum>/C<md5sum>.
+L<shasum> now more closely mimics L<sha1sum(1)>/L<md5sum(1)>.
-
C<Addfile> accepts all POSIX filenames.
+
L<Addfile> accepts all POSIX filenames.
New SHA-512/224 and SHA-512/256 transforms (ref. NIST Draft FIPS 180-4
[February 2011])
=item *
-C<DirHandle> has been upgraded from version 1.03 to 1.04.
+L<DirHandle> has been upgraded from version 1.03 to 1.04.
=item *
-C<Dumpvalue> has been upgraded from version 1.13 to 1.16.
+L<Dumpvalue> has been upgraded from version 1.13 to 1.16.
=item *
-C<DynaLoader> has been upgraded from version 1.10 to 1.13.
+L<DynaLoader> has been upgraded from version 1.10 to 1.13.
It fixes a buffer overflow when passed a very long file name.
-It no longer inherits from AutoLoader; hence it no longer
+It no longer inherits from L<AutoLoader>; hence it no longer
produces weird error messages for unsuccessful method calls on classes that
-inherit from DynaLoader [perl #84358].
+inherit from L<DynaLoader> [perl #84358].
=item *
-C<Encode> has been upgraded from version 2.39 to 2.42.
+L<Encode> has been upgraded from version 2.39 to 2.42.
Now, all 66 Unicode non-characters are treated the same way U+FFFF has
-always been treated; in cases when it was disallowed, all 66 are
-disallowed; in those cases where it warned, all 66 warn.
+always been treated: in cases when it was disallowed, all 66 are
+disallowed, and in cases where it warned, all 66 warn.
=item *
-C<Env> has been upgraded from version 1.01 to 1.02.
+L<Env> has been upgraded from version 1.01 to 1.02.
=item *
-C<Errno> has been upgraded from version 1.11 to 1.13.
+L<Errno> has been upgraded from version 1.11 to 1.13.
-The implementation of C<Errno> has been refactored to use about 55% less memory.
+The implementation of L<Errno> has been refactored to use about 55% less memory.
-On some platforms with unusual header files, like Win32/gcc using mingw64
-headers, some constants which weren't actually error numbers have been exposed
-by C<Errno>. This has been fixed [perl #77416].
+On some platforms with unusual header files, like Win32 L<gcc(1)> using C<mingw64>
+headers, some constants that weren't actually error numbers have been exposed
+by L<Errno>. This has been fixed [perl #77416].
=item *
-C<Exporter> has been upgraded from version 5.64_01 to 5.64_03.
+L<Exporter> has been upgraded from version 5.64_01 to 5.64_03.
Exporter no longer overrides C<$SIG{__WARN__}> [perl #74472]
=item *
-C<ExtUtils::CBuilder> has been upgraded from version 0.27 to 0.280202.
+L<ExtUtils::CBuilder> has been upgraded from version 0.27 to 0.280203.
=item *
-C<ExtUtils::Command> has been upgraded from version 1.16 to 1.17.
+L<ExtUtils::Command> has been upgraded from version 1.16 to 1.17.
=item *
-C<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
+L<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
-The
C<AUTOLOAD> helper code generated by C<ExtUtils::Constant::ProxySubs>
-can now
C<croak> for missing constants, or generate a complete C<AUTOLOAD>
+The
L<AUTOLOAD> helper code generated by C<ExtUtils::Constant::ProxySubs>
+can now
croak() for missing constants, or generate a complete C<AUTOLOAD>
subroutine in XS, allowing simplification of many modules that use it
-(
C<Fcntl>, C<File::Glob>, C<GDBM_File>, C<I18N::Langinfo>, C<POSIX>,
-C<Socket>).
+(
L<Fcntl>, L<File::Glob>, L<GDBM_File>, L<I18N::Langinfo>, L<POSIX>,
+L<Socket>).
-C<ExtUtils::Constant::ProxySubs> can now optionally push the names of all
+L<ExtUtils::Constant::ProxySubs> can now optionally push the names of all
constants onto the package's C<@EXPORT_OK>.
=item *
-C<ExtUtils::Install> has been upgraded from version 1.55 to 1.56.
+L<ExtUtils::Install> has been upgraded from version 1.55 to 1.56.
=item *
-C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
+L<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
=item *
-C<ExtUtils::Manifest> has been upgraded from version 1.57 to 1.58.
+L<ExtUtils::Manifest> has been upgraded from version 1.57 to 1.58.
=item *
-C<ExtUtils::ParseXS> has been upgraded from version 2.21 to 2.2210.
+L<ExtUtils::ParseXS> has been upgraded from version 2.21 to 2.2210.
=item *
-C<Fcntl> has been upgraded from version 1.06 to 1.11.
+L<Fcntl> has been upgraded from version 1.06 to 1.11.
=item *
-C<File::Basename> has been upgraded from version 2.78 to 2.81.
+L<File::Basename> has been upgraded from version 2.78 to 2.82.
=item *
-C<File::CheckTree> has been upgraded from version 4.4 to 4.41.
+L<File::CheckTree> has been upgraded from version 4.4 to 4.41.
=item *
-C<File::Copy> has been upgraded from version 2.17 to 2.21.
+L<File::Copy> has been upgraded from version 2.17 to 2.21.
=item *
-C<File::DosGlob> has been upgraded from version 1.01 to 1.04.
+L<File::DosGlob> has been upgraded from version 1.01 to 1.04.
-It allows patterns containing literal parentheses (they no longer need to
-be escaped). On Windows, it no longer
-adds an extra F<./> to the file names
+It allows patterns containing literal parentheses: they no longer need to
+be escaped. On Windows, it no longer
+adds an extra F<./> to file names
returned when the pattern is a relative glob with a drive specification,
-like F<c:*.pl> [perl #71712].
+like F<C:*.pl> [perl #71712].
=item *
-C<File::Fetch> has been upgraded from version 0.24 to 0.32.
+L<File::Fetch> has been upgraded from version 0.24 to 0.32.
-C<HTTP::Lite> is now supported for 'http' scheme.
+L<HTTP::Lite> is now supported for the "http" scheme.
-The C<fetch> utility is supported on FreeBSD, NetBSD and
+The L<fetch(1)> utility is supported on FreeBSD, NetBSD, and
Dragonfly BSD for the C<http> and C<ftp> schemes.
=item *
-C<File::Find> has been upgraded from version 1.15 to 1.19.
+L<File::Find> has been upgraded from version 1.15 to 1.19.
It improves handling of backslashes on Windows, so that paths like
-F<c:\dir\/file> are no longer generated [perl #71710].
+F<C:\dir\/file> are no longer generated [perl #71710].
=item *
-C<File::Glob> has been upgraded from version 1.07 to 1.12.
+L<File::Glob> has been upgraded from version 1.07 to 1.12.
=item *
-C<File::Spec> has been upgraded from version 3.31 to 3.33.
+L<File::Spec> has been upgraded from version 3.31 to 3.33.
-Several portability fixes were made in C<File::Spec::VMS>: a colon is now
+Several portability fixes were made in L<File::Spec::VMS>: a colon is now
recognized as a delimiter in native filespecs; caret-escaped delimiters are
-recognized for better handling of extended filespecs; C<catpath()> returns
+recognized for better handling of extended filespecs; catpath() returns
an empty directory rather than the current directory if the input directory
-name is empty; C<abs2rel()> properly handles Unix-style input (5.12.2).
+name is empty; and abs2rel() properly handles Unix-style input (5.12.2).
=item *
-C<File::stat> has been upgraded from 1.02 to 1.05.
+L<File::stat> has been upgraded from 1.02 to 1.05.
-The C<-x> and C<-X> file test operators now work correctly under the root
-user.
+The C<-x> and C<-X> file test operators now work correctly when run
+by the superuser.
=item *
-C<Filter::Simple> has been upgraded from version 0.84 to 0.86.
+L<Filter::Simple> has been upgraded from version 0.84 to 0.86.
=item *
-C<GDBM_File> has been upgraded from 1.10 to 1.14.
+L<GDBM_File> has been upgraded from 1.10 to 1.14.
This fixes a memory leak when DBM filters are used.
=item *
-C<Hash::Util> has been upgraded from 0.07 to 0.11.
+L<Hash::Util> has been upgraded from 0.07 to 0.11.
-Hash::Util no longer emits spurious "uninitialized" warnings when
+L<Hash::Util> no longer emits spurious "uninitialized" warnings when
recursively locking hashes that have undefined values [perl #74280].
=item *
-C<Hash::Util::FieldHash> has been upgraded from version 1.04 to 1.09.
+L<Hash::Util::FieldHash> has been upgraded from version 1.04 to 1.09.
=item *
-C<I18N::Collate> has been upgraded from version 1.01 to 1.02.
+L<I18N::Collate> has been upgraded from version 1.01 to 1.02.
=item *
-C<I18N::Langinfo> has been upgraded from version 0.03 to 0.08.
+L<I18N::Langinfo> has been upgraded from version 0.03 to 0.08.
-C<langinfo()> now defaults to using C<$_> if there is no argument given, just
+langinfo() now defaults to using C<$_> if there is no argument given, just
as the documentation has always claimed.
=item *
-C<I18N::LangTags> has been upgraded from version 0.35 to 0.35_01.
+L<I18N::LangTags> has been upgraded from version 0.35 to 0.35_01.
=item *
-C<if> has been upgraded from version 0.05 to 0.0601.
+L<if> has been upgraded from version 0.05 to 0.0601.
=item *
-C<IO> has been upgraded from version 1.25_02 to 1.25_04.
+L<IO> has been upgraded from version 1.25_02 to 1.25_04.
-This version of C<IO> includes a new C<IO::Select>, which now allows IO::Handle
-objects (and objects in derived classes) to be removed from an IO::Select set
+This version of L<IO> includes a new L<IO::Select>, which now allows L<IO::Handle>
+objects (and objects in derived classes) to be removed from an L<IO::Select> set
even if the underlying file descriptor is closed or invalid.
=item *
-C<IPC::Cmd> has been upgraded from version 0.54 to 0.70.
+L<IPC::Cmd> has been upgraded from version 0.54 to 0.70.
Resolves an issue with splitting Win32 command lines. An argument
consisting of the single character "0" used to be omitted (CPAN RT #62961).
=item *
-C<IPC::Open3> has been upgraded from 1.05 to 1.09.
+L<IPC::Open3> has been upgraded from 1.05 to 1.09.
-C<open3> now produces an error if the C<exec> call fails, allowing this
+open3() now produces an error if the C<exec> call fails, allowing this
condition to be distinguished from a child process that exited with a
non-zero status [perl #72016].
-The internal C<xclose> routine now knows how to handle file descriptors, as
-documented, so duplicating STDIN in a child process using its file
+The internal xclose() routine now knows how to handle file descriptors as
+documented, so duplicating C<STDIN> in a child process using its file
descriptor now works [perl #76474].
=item *
-C<IPC::SysV> has been upgraded from version 2.01 to 2.03.
+L<IPC::SysV> has been upgraded from version 2.01 to 2.03.
=item *
-C<lib> has been upgraded from version 0.62 to 0.63.
+L<lib> has been upgraded from version 0.62 to 0.63.
=item *
-C<Locale::Maketext> has been upgraded from version 1.14 to 1.19.
+L<Locale::Maketext> has been upgraded from version 1.14 to 1.19.
-Locale::Maketext now supports external caches.
+L<Locale::Maketext> now supports external caches.
This upgrade also fixes an infinite loop in
C<Locale::Maketext::Guts::_compile()> when
working with tainted values (CPAN RT #40727).
-C<< ->maketext >> calls will now back up and restore C<$@> so that error
+C<< ->maketext >> calls now back up and restore C<$@> so error
messages are not suppressed (CPAN RT #34182).
=item *
-C<Log::Message> has been upgraded from version 0.02 to 0.04.
+L<Log::Message> has been upgraded from version 0.02 to 0.04.
=item *
-C<Log::Message::Simple> has been upgraded from version 0.06 to 0.08.
+L<Log::Message::Simple> has been upgraded from version 0.06 to 0.08.
=item *
-C<Math::BigInt> has been upgraded from version 1.89_01 to 1.994.
+L<Math::BigInt> has been upgraded from version 1.89_01 to 1.994.
This fixes, among other things, incorrect results when computing binomial
coefficients [perl #77640].
-It also prevents C<sqrt($int)> from crashing under C<use bigrat;>
+It also prevents C<sqrt($int)> from crashing under C<use bigrat>.
[perl #73534].
=item *
-C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.28.
+L<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.28.
=item *
-C<Math::BigRat> has been upgraded from version 0.24 to 0.26_02.
+L<Math::BigRat> has been upgraded from version 0.24 to 0.26_02.
=item *
-C<Memoize> has been upgraded from version 1.01_03 to 1.02.
+L<Memoize> has been upgraded from version 1.01_03 to 1.02.
=item *
-C<MIME::Base64> has been upgraded from 3.08 to 3.13.
+L<MIME::Base64> has been upgraded from 3.08 to 3.13.
Includes new functions to calculate the length of encoded and decoded
base64 strings.
-Now provides C<encode_base64url> and C<decode_base64url> functions to process
+Now provides encode_base64url() and decode_base64url() functions to process
the base64 scheme for "URL applications".
=item *
-C<Module::Build> has been upgraded from version 0.3603 to 0.3800.
+L<Module::Build> has been upgraded from version 0.3603 to 0.3800.
A notable change is the deprecation of several modules.
-Module::Build::Version has been deprecated and Module::Build now relies
-directly upon L<version>. Module::Build::ModuleInfo has been deprecated in
-favor of a standalone copy of it called L<Module::Metadata>.
-Module::Build::YAML has been deprecated in favor of L<CPAN::Meta::YAML>.
+L<Module::Build::Version> has been deprecated and L<Module::Build> now
+relies on the L<version> pragma directly. L<Module::Build::ModuleInfo> has
+been deprecated in favor of a standalone copy called L<Module::Metadata>.
+L<Module::Build::YAML> has been deprecated in favor of L<CPAN::Meta::YAML>.
-Module::Build now also generates META.json and MYMETA.json files
+L<Module::Build> now also generates F<META.json> and F<MYMETA.json> files
in accordance with version 2 of the CPAN distribution metadata specification,
-L<CPAN::Meta::Spec>. The older format META.yml and MYMETA.yml files are
-still generated, as well.
+L<CPAN::Meta::Spec>. The older format F<META.yml> and F<MYMETA.yml> files are
+still generated.
=item *
-C<Module::CoreList> has been upgraded from version 2.29 to 2.47.
+L<Module::CoreList> has been upgraded from version 2.29 to 2.47.
Besides listing the updated core modules of this release, it also stops listing
the C<Filespec> module. That module never existed in core. The scripts
-generating C<Module::CoreList> confused it with C<VMS::Filespec>, which actually
-is a core module as of perl 5.8.7.
+generating L<Module::CoreList> confused it with L<VMS::Filespec>, which actually
+is a core module as of Perl 5.8.7.
=item *
-C<Module::Load> has been upgraded from version 0.16 to 0.18.
+L<Module::Load> has been upgraded from version 0.16 to 0.18.
=item *
-C<Module::Load::Conditional> has been upgraded from version 0.34 to 0.44.
+L<Module::Load::Conditional> has been upgraded from version 0.34 to 0.44.
=item *
-C<mro> has been upgraded from version 1.02 to 1.07.
+The L<mro> pragma has been upgraded from version 1.02 to 1.07.
+
=item *
-C<NDBM_File> has been upgraded from version 1.08 to 1.12.
+L<NDBM_File> has been upgraded from version 1.08 to 1.12.
This fixes a memory leak when DBM filters are used.
=item *
-C<Net::Ping> has been upgraded from version 2.36 to 2.38.
+L<Net::Ping> has been upgraded from version 2.36 to 2.38.
=item *
-C<NEXT> has been upgraded from version 0.64 to 0.65.
+L<NEXT> has been upgraded from version 0.64 to 0.65.
=item *
-C<Object::Accessor> has been upgraded from version 0.36 to 0.38.
+L<Object::Accessor> has been upgraded from version 0.36 to 0.38.
=item *
-C<ODBM_File> have been upgraded from version 1.07 to 1.10.
+L<ODBM_File> has been upgraded from version 1.07 to 1.10.
This fixes a memory leak when DBM filters are used.
=item *
-C<Opcode> has been upgraded from version 1.15 to 1.18.
+L<Opcode> has been upgraded from version 1.15 to 1.18.
=item *
-C<overload> has been upgraded from 1.10 to 1.13.
+The L<overload> pragma has been upgraded from 1.10 to 1.13.
C<overload::Method> can now handle subroutines that are themselves blessed
into overloaded classes [perl #71998].
-The documentation has greatly improved. See L</Documentation> below.
+The documentation has greatly improved. See L</Documentation> below.
=item *
-
C<Params::Check> has been upgraded from version 0.26 to 0.28.
+
L<Params::Check> has been upgraded from version 0.26 to 0.28.
=item *
-C<parent> has been upgraded from version 0.223 to 0.225.
+The L<parent> pragma has been upgraded from version 0.223 to 0.225.
=item *
-
C<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
+
L<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
The latest Parse::CPAN::Meta can now read YAML and JSON files using
L<CPAN::Meta::YAML> and L<JSON::PP>, which are now part of the Perl core.
=item *
-
C<PerlIO::encoding> has been upgraded from version 0.12 to 0.14.
+
L<PerlIO::encoding> has been upgraded from version 0.12 to 0.14.
=item *
-
C<PerlIO::scalar> has been upgraded from 0.07 to 0.11.
+
L<PerlIO::scalar> has been upgraded from 0.07 to 0.11.
-A C<read> after a C<seek> beyond the end of the string no longer thinks it
+A read() after a seek() beyond the end of the string no longer thinks it
has data to read [perl #78716].
=item *
-
C<PerlIO::via> has been upgraded from version 0.09 to 0.11.
+
L<PerlIO::via> has been upgraded from version 0.09 to 0.11.
=item *
-C<Pod::Html> has been upgraded from version 1.09 to 1.1.
+L<Pod::Html> has been upgraded from version 1.09 to 1.11.
=item *
-
C<Pod::LaTeX> has been upgraded from version 0.58 to 0.59.
+
L<Pod::LaTeX> has been upgraded from version 0.58 to 0.59.
=item *
-
C<Pod::Perldoc> has been upgraded from version 3.15_02 to 3.15_03.
+
L<Pod::Perldoc> has been upgraded from version 3.15_02 to 3.15_03.
=item *
-
C<Pod::Simple> has been upgraded from version 3.13 to 3.16.
+
L<Pod::Simple> has been upgraded from version 3.13 to 3.16.
=item *
-
C<POSIX> has been upgraded from 1.19 to 1.24.
+
L<POSIX> has been upgraded from 1.19 to 1.24.
It now includes constants for POSIX signal constants.
=item *
-C<re> has been upgraded from version 0.11 to 0.17.
+The L<re> pragma has been upgraded from version 0.11 to 0.18.
-New C<use re "/flags"> pragma
+The C<use re "/flags"> subpragma is new.
-The C<regmust> function used to crash when called on a regular expression
+The regmust() function used to crash when called on a regular expression
belonging to a pluggable engine. Now it croaks instead.
-C<regmust> no longer leaks memory.
+regmust() no longer leaks memory.
=item *
-C<Safe> has been upgraded from version 2.25 to 2.29.
+L<Safe> has been upgraded from version 2.25 to 2.29.
-Coderefs returned by C<reval()> and C<rdo()> are now wrapped via
-C<wrap_code_refs> (5.12.1).
+Coderefs returned by reval() and rdo() are now wrapped via
+wrap_code_refs() (5.12.1).
This fixes a possible infinite loop when looking for coderefs.
-It adds several version::vxs::* routines to the default share.
+It adds several C<version::vxs::*> routines to the default share.
=item *
-C<SDBM_File> has been upgraded from version 1.06 to 1.09.
+L<SDBM_File> has been upgraded from version 1.06 to 1.09.
=item *
-C<SelfLoader> has been upgraded from 1.17 to 1.18.
+L<SelfLoader> has been upgraded from 1.17 to 1.18.
It now works in taint mode [perl #72062].
=item *
-C<sigtrap> has been upgraded from version 1.04 to 1.05.
+The L<sigtrap> pragma has been upgraded from version 1.04 to 1.05.
It no longer tries to modify read-only arguments when generating a
backtrace [perl #72340].
=item *
-C<Socket> has been upgraded from version 1.87 to 1.94.
+L<Socket> has been upgraded from version 1.87 to 1.94.
-See L</IPv6 support>, above.
+See L</Improved IPv6 support> above.
=item *
-C<Storable> has been upgraded from version 2.22 to 2.27.
+L<Storable> has been upgraded from version 2.22 to 2.27.
Includes performance improvement for overloaded classes.
This adds support for serialising code references that contain UTF-8 strings
-correctly. The Storable minor version
+correctly. The L<Storable> minor version
number changed as a result, meaning that
-Storable users who set C<$Storable::accept_future_minor> to a C<FALSE> value
+L<Storable> users who set C<$Storable::accept_future_minor> to a C<FALSE> value
will see errors (see L<Storable/FORWARD COMPATIBILITY> for more details).
Freezing no longer gets confused if the Perl stack gets reallocated
=item *
-C<Sys::Hostname> has been upgraded from version 1.11 to 1.16.
+L<Sys::Hostname> has been upgraded from version 1.11 to 1.16.
=item *
-C<Term::ANSIColor> has been upgraded from version 2.02 to 3.00.
+L<Term::ANSIColor> has been upgraded from version 2.02 to 3.00.
=item *
-C<Term::UI> has been upgraded from version 0.20 to 0.26.
+L<Term::UI> has been upgraded from version 0.20 to 0.26.
=item *
-C<Test::Harness> has been upgraded from version 3.17 to 3.23.
+L<Test::Harness> has been upgraded from version 3.17 to 3.23.
=item *
-C<Test::Simple> has been upgraded from version 0.94 to 0.98.
+L<Test::Simple> has been upgraded from version 0.94 to 0.98.
Among many other things, subtests without a C<plan> or C<no_plan> now have an
-implicit C<done_testing()> added to them.
+implicit done_testing() added to them.
=item *
-C<Thread::Semaphore> has been upgraded from version 2.09 to 2.12.
+L<Thread::Semaphore> has been upgraded from version 2.09 to 2.12.
It provides two new methods that give more control over the decrementing of
semaphores: C<down_nb> and C<down_force>.
=item *
-C<Thread::Queue> has been upgraded from version 2.11 to 2.12.
+L<Thread::Queue> has been upgraded from version 2.11 to 2.12.
=item *
-C<threads> has been upgraded from version 1.75 to 1.83.
+The L<threads> pragma has been upgraded from version 1.75 to 1.83.
=item *
-C<threads::shared> has been upgraded from version 1.32 to 1.36.
+The L<threads::shared> pragma has been upgraded from version 1.32 to 1.37.
=item *
-C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
+L<Tie::Hash> has been upgraded from version 1.03 to 1.04.
-Calling C<< Tie::Hash-E<gt>TIEHASH() >> used to loop forever. Now it C<croak>s.
+Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
=item *
-C<Tie::Hash::NamedCapture> has been upgraded from version 0.06 to 0.08.
+L<Tie::Hash::NamedCapture> has been upgraded from version 0.06 to 0.08.
=item *
-C<Tie::RefHash> has been upgraded from version 1.38 to 1.39.
+L<Tie::RefHash> has been upgraded from version 1.38 to 1.39.
=item *
-C<Time::HiRes> has been upgraded from version 1.9719 to 1.9721_01.
+L<Time::HiRes> has been upgraded from version 1.9719 to 1.9721_01.
=item *
-C<Time::Local> has been upgraded from version 1.1901_01 to 1.2000.
+L<Time::Local> has been upgraded from version 1.1901_01 to 1.2000.
=item *
-C<Time::Piece> has been upgraded from version 1.15_01 to 1.20_01.
+L<Time::Piece> has been upgraded from version 1.15_01 to 1.20_01.
=item *
-C<Unicode::Collate> has been upgraded from version 0.52_01 to 0.73.
+L<Unicode::Collate> has been upgraded from version 0.52_01 to 0.73.
-Unicode::Collate has been updated to use Unicode 6.0.0.
+L<Unicode::Collate> has been updated to use Unicode 6.0.0.
-Unicode::Collate::Locale now supports a plethora of new locales: ar, be,
+L<Unicode::Collate::Locale> now supports a plethora of new locales: I<ar, be,
bg, de__phonebook, hu, hy, kk, mk, nso, om, tn, vi, hr, ig, ja, ko, ru, sq,
-se, sr, to, uk, zh, zh__big5han, zh__gb2312han, zh__pinyin and zh__stroke.
+se, sr, to, uk, zh, zh__big5han, zh__gb2312han, zh__pinyin>, and I<zh__stroke>.
The following modules have been added:
-C<Unicode::Collate::CJK::Big5> for C<zh__big5han> which makes
+L<Unicode::Collate::CJK::Big5> for C<zh__big5han> which makes
tailoring of CJK Unified Ideographs in the order of CLDR's big5han ordering.
-C<Unicode::Collate::CJK::GB2312> for C<zh__gb2312han> which makes
+L<Unicode::Collate::CJK::GB2312> for C<zh__gb2312han> which makes
tailoring of CJK Unified Ideographs in the order of CLDR's gb2312han ordering.
-C<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
+L<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
(CJK Unified Ideographs) in the JIS X 0208 order.
-C<Unicode::Collate::CJK::Korean> which makes tailoring of CJK Unified Ideographs
+L<Unicode::Collate::CJK::Korean> which makes tailoring of CJK Unified Ideographs
in the order of CLDR's Korean ordering.
-C<Unicode::Collate::CJK::Pinyin> for C<zh__pinyin> which makes
+L<Unicode::Collate::CJK::Pinyin> for C<zh__pinyin> which makes
tailoring of CJK Unified Ideographs in the order of CLDR's pinyin ordering.
-C<Unicode::Collate::CJK::Stroke> for C<zh__stroke> which makes
+L<Unicode::Collate::CJK::Stroke> for C<zh__stroke> which makes
tailoring of CJK Unified Ideographs in the order of CLDR's stroke ordering.
-This also sees the switch from using the pure-perl version of this
+This also sees the switch from using the pure-Perl version of this
module to the XS version.
=item *
-C<Unicode::Normalize> has been upgraded from version 1.03 to 1.10.
+L<Unicode::Normalize> has been upgraded from version 1.03 to 1.10.
=item *
-C<Unicode::UCD> has been upgraded from version 0.27 to 0.32.
+L<Unicode::UCD> has been upgraded from version 0.27 to 0.32.
-A new function, C<Unicode::UCD::num()>, has been added. This function
+A new function, Unicode::UCD::num(), has been added. This function
returns the numeric value of the string passed it or C<undef> if the string
in its entirety has no "safe" numeric value. (For more detail, and for the
definition of "safe", see L<Unicode::UCD/num>.)
-This upgrade also includes a number of bug fixes:
+This upgrade also includes several bug fixes:
=over 4
=item *
-It is now updated to Unicode Version 6 with Corrigendum #8, except,
-as with Perl 5.14, the code point at U+1F514 has no name.
+It is now updated to Unicode Version 6.0.0 with I<Corrigendum #8>,
+excepting that, just as with Perl 5.14, the code point at U+1F514 has no name.
=item *
-The Hangul syllable code points have the correct names, and their
+Hangul syllable code points have the correct names, and their
decompositions are always output without requiring L<Lingua::KO::Hangul::Util>
to be installed.
=item *
-The CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
+CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
and U+2B740 to U+2B81D are now properly handled.
=item *
-The numeric values are now output for those CJK code points that have them.
+Numeric values are now output for those CJK code points that have them.
=item *
-The names that are output for code points with multiple aliases are now the
+Names output for code points with multiple aliases are now the
corrected ones.
=back
=item *
-C<version> has been upgraded from 0.82 to 0.88.
+The L<version> pragma has been upgraded from 0.82 to 0.88.
-Due to a bug, now fixed, the C<is_strict> and C<is_lax> functions did not
+Because of a bug, now fixed, the is_strict() and is_lax() functions did not
work when exported (5.12.1).
=item *
-C<warnings> has been upgraded from version 1.09 to 1.12.
+The L<warnings> pragma has been upgraded from version 1.09 to 1.12.
Calling C<use warnings> without arguments is now significantly more efficient.
=item *
-C<warnings::register> have been upgraded from version 1.01 to 1.02.
+The L<warnings::register> pragma has been upgraded from version 1.01 to 1.02.
It is now possible to register warning categories other than the names of
-packages using C<warnings::register>. See L<perllexwarn> for more information.
+packages using L<warnings::register>. See L<perllexwarn(1)> for more information.
=item *
-C<XSLoader> has been upgraded from version 0.10 to 0.13.
+L<XSLoader> has been upgraded from version 0.10 to 0.13.
=item *
-C<VMS::DCLsym> has been upgraded from version 1.03 to 1.05.
+L<VMS::DCLsym> has been upgraded from version 1.03 to 1.05.
Two bugs have been fixed [perl #84086]:
The symbol table name was lost when tying a hash, due to a thinko in
-C<TIEHASH>. The result was that all tied hashes interacted with the
+C<TIEHASH>. The result was that all tied hashes interacted with the
local symbol table.
Unless a symbol table name had been explicitly specified in the call
-to the constructor, querying the special key ':LOCAL' failed to
+to the constructor, querying the special key C<:LOCAL> failed to
identify objects connected to the local symbol table.
=item *
-C<Win32> has been upgraded from version 0.39 to 0.44.
+The L<Win32> module has been upgraded from version 0.39 to 0.44.
-This release has several new functions: C<Win32::GetSystemMetrics>,
-C<Win32::GetProductInfo>, C<Win32::GetOSDisplayName>.
+This release has several new functions: Win32::GetSystemMetrics(),
+Win32::GetProductInfo(), Win32::GetOSDisplayName().
-The names returned by C<Win32::GetOSName> and C<Win32::GetOSDisplayName>
+The names returned by Win32::GetOSName() and Win32::GetOSDisplayName()
have been corrected.
=item *
-C<XS::Typemap> has been upgraded from version 0.03 to 0.05.
+L<XS::Typemap> has been upgraded from version 0.03 to 0.05.
=back
=head2 Removed Modules and Pragmata
-The following modules have been removed from the core distribution, and if
-needed should be installed from CPAN instead.
+As promised in Perl 5.12.0's release notes, the following modules have
+been removed from the core distribution, and if needed should be installed
+from CPAN instead.
=over
=item *
-C<Class::ISA> has been removed from the Perl core. Prior version was 0.36.
+L<Class::ISA> has been removed from the Perl core. Prior version was 0.36.
=item *
-C<Pod::Plainer> has been removed from the Perl core. Prior version was 1.02.
+L<Pod::Plainer> has been removed from the Perl core. Prior version was 1.02.
=item *
-C<Switch> has been removed from the Perl core. Prior version was 2.16.
+L<Switch> has been removed from the Perl core. Prior version was 2.16.
=back
-The removal of C<Shell> has been deferred until after 5.14, as the
-implementation of C<Shell> shipped with 5.12.0 did not correctly issue the
+The removal of L<Shell> has been deferred until after 5.14, as the
+implementation of L<Shell> shipped with 5.12.0 did not correctly issue the
warning that it was to be removed from core.
=head1 Documentation
=head3 L<perlgpl>
L<perlgpl> has been updated to contain GPL version 1, as is included in the
-F<README> distributed with perl (5.12.1).
+F<README> distributed with Perl (5.12.1).
=head3 Perl 5.12.x delta files
=head3 L<perlpodstyle>
New style guide for POD documentation,
-split mostly from the NOTES section of the pod2man man page.
+split mostly from the NOTES section of the L<pod2man(1)> manpage.
=head3 L<perlsource>, L<perlinterp>, L<perlhacktut>, and L<perlhacktips>
=head3 L<perlmodlib> is now complete
-The perlmodlib page that came with Perl 5.12.0 was missing a lot of
-modules, due to a bug in the script that generates the list. This has been
+The L<perlmodlib> manpage that came with Perl 5.12.0 was missing several
+modules due to a bug in the script that generates the list. This has been
fixed [perl #74332] (5.12.1).
-=head3 Replace
wrong tr/// table in L<perlebcdic>
+=head3 Replace
incorrect tr/// table in L<perlebcdic>
-L<perlebcdic> contains a helpful table to use in tr/// to convert
-between EBCDIC and Latin1/ASCII. Unfortunately, the table was the
-inverse of the one it describes, though the code that used the table
-worked correctly for the specific example given.
+L<perlebcdic> contains a helpful table to use in C<tr///> to convert
+between EBCDIC and Latin1/ASCII. The table was the inverse of the one
+it describes, though the code that used the table worked correctly for
+the specific example given.
-The table has been changed to its inverse, and the sample code changed
-to correspond, as this is easier for the person trying to follow the
-instructions since deriving the old table is somewhat more complicated.
+The table has been corrected and the sample code changed to correspond.
-The table has also been changed to hex from octal, as that is more the norm
-these days, and the recipes in the pod altered to print out leading
-zeros to make all the values the same length.
+The table has also been changed to hex from octal, and the recipes in the
+pod have been altered to print out leading zeros to make all values
+the same length.
=head3 Tricks for user-defined casing
L<perlunicode> now contains an explanation of how to override, mangle
-and otherwise tweak the way perl handles upper-, lower- and other-case
+and otherwise tweak the way Perl handles upper-, lower- and other-case
conversions on Unicode data, and how to provide scoped changes to alter
-one's own code's behaviour without stomping on anybody else.
+one's own code's behaviour without stomping on anybody else's.
-=head3 INSTALL explicitly states the requirement for C89
+=head3 INSTALL explicitly states that Perl requires a C89 compiler
-This was already true but it's now Officially Stated For The Record
+This was already true, but it's now Officially Stated For The Record
(5.12.2).
=head3 Explanation of C<\xI<HH>> and C<\oI<OOO>> escapes
L<perlop> has been updated with more detailed explanation of these two
character escapes.
-=head3 C<-0I<NNN>> switch
+=head3 B<-0I<NNN>> switch
-In L<perlrun>, the behavior of the C<-0NNN> switch for C<-0400> or higher
+In L<perlrun>, the behaviour of the B<-0NNN> switch for B<-0400> or higher
has been clarified (5.12.2).
=head3 Maintenance policy
The documentation for the C<SvTRUE> macro in
L<perlapi> was simply wrong in stating that
-get-magic is not processed. It has been corrected.
+get-magic is not processed. It has been corrected.
=head3 L<perlvar> revamp
=head3 L<overload>
-L<overload>'s documentation has practically undergone a rewrite. It
+L<overload>'s documentation has practically undergone a rewrite. It
is now much more straightforward and clear.
=head3 perlhack and perlrepository revamp
-The L<perlhack> and perlrepository documents have been heavily edited and
-split up into several new documents.
-
The L<perlhack> document is now much shorter, and focuses on the Perl 5
-development process and submitting patches to Perl. The technical content has
-been moved to several new documents, L<perlsource>, L<perlinterp>,
-L<perlhacktut>, and L<perlhacktips>. This technical content has only been
-lightly edited.
+development process and submitting patches to Perl. The technical content
+
has been moved to several new documents, L<perlsource>, L<perlinterp>,
+L<perlhacktut>, and L<perlhacktips>. This technical content has
+been only lightly edited.
-The perlrepository document has been renamed to L<perlgit>. This new document
-is just a how-to on using git with the Perl source code. Any other content
-that used to be in perlrepository has been moved to perlhack.
+The perlrepository document has been renamed to L<perlgit>. This new
+document is just a how-to on using git with the Perl source code.
+Any other content that used to be in perlrepository has been moved
+to L<perlhack>.
=head3 Time::Piece examples
Perl detected tainted data when trying to compile a regular
expression that contains a call to a user-defined character property
-function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
+function, meaning C<\p{IsFoo}> or C<\p{InFoo}>.
See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
=item panic: gp_free failed to free glob pointer - something is repeatedly re-creating entries
This new error is triggered if a destructor called on an object in a
typeglob that is being freed creates a new typeglob entry containing an
-object with a destructor that creates a new entry containing an object....
+object with a destructor that creates a new entry containing an object etc.
=item Parsing code internal error (%s)
=item "\B{" is deprecated; use "\B\{" instead
Use of an unescaped "{" immediately following a C<\b> or C<\B> is now
-deprecated so as to reserve its use for Perl itself in a future release.
+deprecated in order to reserve its use for Perl itself in a future release.
=item Operation "%s" returns its argument for ...
Performing an operation requiring Unicode semantics (such as case-folding)
-on a Unicode surrogate or a non-Unicode character now triggers a warning:
-'Operation "%s" returns its argument for ...'.
+on a Unicode surrogate or a non-Unicode character now triggers this
+warning.
=item Use of qw(...) as parentheses is deprecated
=item *
-C<warn> and C<die> now produce 'Wide character' warnings when fed a
-character outside the byte range if STDERR is a byte-sized handle.
+warn() and die() now produce "Wide character" warnings when fed a
+character outside the byte range if C<STDERR> is a byte-sized handle.
=item *
-The 'Layer does not match this perl' error message has been replaced with
+The "Layer does not match this perl" error message has been replaced with
these more helpful messages [perl #73754]:
=over 4
=item *
-Previously, if none of the C<gethostbyaddr>, C<gethostbyname> and
-C<gethostent> functions were implemented on a given platform, they would
-all die with the message 'Unsupported socket function "gethostent" called',
-with analogous messages for C<getnet*> and C<getserv*>. This has been
+Previously, if none of the gethostbyaddr(), gethostbyname() and
+gethostent() functions were implemented on a given platform, they would
+all die with the message "Unsupported socket function 'gethostent' called",
+with analogous messages for getnet*() and getserv*(). This has been
corrected.
=item *
The warning message about unrecognized regular expression escapes passed
-through has been changed to include any literal '{' following the
-two-character escape. E.g., "\q{" is now emitted instead of "\q".
+through has been changed to include any literal "{" following the
+two-character escape. For example, "\q{" is now emitted instead of "\q".
=back
=head1 Utility Changes
-=head3 L<perlbug>
+=head3 L<perlbug(1)>
=over 4
=item *
-L<perlbug> did not previously generate a From: header, potentially
-resulting in dropped mail. Now it does include that header.
+L<perlbug> did not previously generate a "From:" header, potentially
+resulting in dropped mail; it now includes that header.
=item *
-The user's address is now used as the return-path.
+The user's address is now used as the Return-Path.
-Many systems these days don't have a valid Internet domain name and
+Many systems these days don't have a valid Internet domain name, and
perlbug@perl.org does not accept email with a return-path that does
not resolve. So the user's address is now passed to sendmail so it's
less likely to get stuck in a mail queue somewhere [perl #82996].
=item *
-L<perlbug> should no longer warn about uninitialized values when using the C<-d>
-and C<-v> options (5.12.2).
+L<perlbug> should no longer warn about uninitialized values when using the B<-d>
+and B<-v> options (5.12.2).
=back
=item *
-The remote terminal works after forking and spawns new sessions - one
-for each forked process.
+The remote terminal works after forking and spawns new sessions, one
+per forked process.
=back
=item *
-CCINCDIR and CCLIBDIR for the mingw64
-cross-compiler are now correctly under
-$(CCHOME)\mingw\include and \lib rather than immediately below $(CCHOME).
+CCINCDIR and CCLIBDIR for the mingw64 cross-compiler are now correctly
+under F<$(CCHOME)\mingw\include> and F<\lib> rather than immediately below
+F<$(CCHOME)>.
-This means the 'incpath', 'libpth', 'ldflags', 'lddlflags' and
-'ldflags_nolargefiles' values in Config.pm and Config_heavy.pl are now
+This means the "incpath", "libpth", "ldflags", "lddlflags" and
+"ldflags_nolargefiles" values in F<Config.pm> and F<Config_heavy.pl> are now
set correctly.
=item *
-'make test.valgrind' has been adjusted to account for cpan/dist/ext
+C<make test.valgrind> has been adjusted to account for F<cpan/dist/ext>
separation.
=item *
-On compilers that support it, C<-Wwrite-strings> is now added to cflags by
+On compilers that support it, B<-Wwrite-strings> is now added to cflags by
default.
=item *
-The C<Encode> module can now (once again) be included in a static Perl
+The L<Encode> module can now (once again) be included in a static Perl
build. The special-case handling for this situation got broken in Perl
5.11.0, and has now been repaired.
The previous default size of a PerlIO buffer (4096 bytes) has been increased
to the larger of 8192 bytes and your local BUFSIZ. Benchmarks show that doubling
-this decade-old default increases read and write performance in the neighborhood
-of 25% to 50% when using the default layers of perlio on top of unix. To choose
+this decade-old default increases read and write performance by around
+25% to 50% when using the default layers of perlio on top of unix. To choose
a non-default size, such as to get back the old value or to obtain an even
larger value, configure with:
=item *
-Perl now skips setuid C<File::Copy> tests on partitions it detects to be mounted
+Perl now skips setuid L<File::Copy> tests on partitions it detects mounted
as C<nosuid> (5.12.2).
=back
=item Apollo DomainOS
-The last vestiges of support for this platform have been excised from the
-Perl distribution. It was officially discontinued in version 5.12.0. It had
-not worked for years before that.
+The last vestiges of support for this platform have been excised from
+the Perl distribution. It was officially discontinued in version 5.12.0.
+It had not worked for years before that.
=item MacOS Classic
The last vestiges of support for this platform have been excised from the
-Perl distribution. It was officially discontinued in an earlier version.
+Perl distribution. It was officially discontinued in an earlier version.
=back
=item *
-MakeMaker has been updated to build man pages on cygwin.
+L<MakeMaker> has been updated to build manpages on cygwin.
=item *
Improved rebase behaviour
-If a dll is updated on cygwin the old imagebase address is reused.
-This solves most rebase errors, especially when updating on core dll's.
-See L<http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README> for more information.
+If a DLL is updated on cygwin the old imagebase address is reused.
+This solves most rebase errors, especially when updating on core DLL's.
+See L<http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README>
+for more information.
=item *
-Support for the standard cygwin dll prefix, which is e.g. needed for FFI's
+Support for the standard cygwin dll prefix (needed for FFIs)
=item *
=item *
-FreeBSD 7 no longer contains F</usr/bin/objformat>. At build time,
+FreeBSD 7 no longer contains F</usr/bin/objformat>. At build time,
Perl now skips the F<objformat> check for versions 7 and higher and
assumes ELF (5.12.1).
=item *
-Perl now allows -Duse64bitint without promoting to use64bitall on HP-UX
+Perl now allows B<-Duse64bitint> without promoting to C<use64bitall> on HP-UX
(5.12.1).
=back
=head3 IRIX
+=over
+
+=item *
+
Conversion of strings to floating-point numbers is now more accurate on
IRIX systems [perl #32380].
+=back
+
=head3 Mac OS X
+=over
+
+=item *
+
Early versions of Mac OS X (Darwin) had buggy implementations of the
-C<setregid>, C<setreuid>, C<setrgid> and C<setruid> functions, so perl
+setregid(), setreuid(), setrgid(,) and setruid() functions, so Perl
would pretend they did not exist.
These functions are now recognised on Mac OS 10.5 (Leopard; Darwin 9) and
higher, as they have been fixed [perl #72990].
+=back
+
=head3 MirBSD
-Previously if you built perl with a shared libperl.so on MirBSD (the
+=over
+
+=item *
+
+Previously if you built Perl with a shared F<libperl.so> on MirBSD (the
default config), it would work up to the installation; however, once
-installed, it would be unable to find libperl. So path handling is now
+installed, it would be unable to find F<libperl>. Path handling is now
treated as in the other BSD dialects.
+=back
+
=head3 NetBSD
-The NetBSD hints file has been changed to make the system's malloc the
+=over
+
+=item *
+
+The NetBSD hints file has been changed to make the system malloc the
default.
-=head3 Recent OpenBSDs now use perl's malloc
+=back
-OpenBSD E<gt> 3.7 has a new malloc implementation which is mmap-based
-and as such can release memory back to the OS; however, perl's use of
-this malloc causes a substantial slowdown so we now default to using
-perl's malloc instead [perl #75742].
+=head3 OpenBSD
-=head3 OpenVOS
+=over
-perl now builds again with OpenVOS (formerly known as Stratus VOS)
-[perl #78132] (5.12.3).
+=item *
-=head3 Solaris
+OpenBSD E<gt> 3.7 has a new malloc implementation which is I<mmap>-based,
+and as such can release memory back to the OS; however, Perl's use of
+this malloc causes a substantial slowdown, so we now default to using
+Perl's malloc instead [perl #75742].
-DTrace is now supported on Solaris. There used to be build failures, but
-these have been fixed [perl #73630] (5.12.3).
+=back
-=head3 VMS
+=head3 OpenVOS
=over
=item *
-It's now possible to build extensions on older (pre 7.3-2) VMS systems.
-
-DCL symbol length was limited to 1K up until about seven years or
-so ago, but there was no particularly deep reason to prevent those
-older systems from configuring and building Perl (5.12.1).
+Perl now builds again with OpenVOS (formerly known as Stratus VOS)
+[perl #78132] (5.12.3).
-=item *
+=back
-We fixed the previously-broken C<-Uuseperlio> build on VMS.
+=head3 Solaris
-We were checking a variable that doesn't exist in the non-default
-case of disabling perlio. Now we only look at it when it exists (5.12.1).
+=over
=item *
-We fixed the -Uuseperlio command-line option in configure.com.
+DTrace is now supported on Solaris. There used to be build failures, but
+these have been fixed [perl #73630] (5.12.3).
+
+=back
+
+=head3 VMS
-Formerly it only worked if you went through all the questions
-interactively and explicitly answered no (5.12.1).
+=over
=item *
-C<PerlIOUnix_open> now honours the default permissions on VMS.
+Extension building on older (pre 7.3-2) VMS systems was broken because
+configure.com hit the DCL symbol length limit of 1K. We now work within
+this limit when assembling the list of extensions in the core build (5.12.1).
-When C<perlio> became the default and C<unixio> became the default bottom layer,
-the most common path for creating files from Perl became C<PerlIOUnix_open>,
-which has always explicitly used C<0666> as the permission mask.
+=item *
-To avoid this, C<0777> is now passed as the permissions to C<open()>. In the
-VMS CRTL, C<0777> has a special meaning over and above intersecting with the
-current umask; specifically, it allows Unix syscalls to preserve native default
-permissions (5.12.3).
+We fixed configuring and building Perl with B<-Uuseperlio> (5.12.1).
=item *
-Spurious record boundaries are no longer
-introduced by the PerlIO layer during output (5.12.3).
+C<PerlIOUnix_open> now honours the default permissions on VMS.
+
+When C<perlio> became the default and C<unix> became the default bottom layer,
+the most common path for creating files from Perl became C<PerlIOUnix_open>,
+which has always explicitly used C<0666> as the permission mask. This prevents
+inheriting permissions from RMS defaults and ACLs, so to avoid that problem,
+we now pass C<0777> to open(). In theVMS CRTL, C<0777> has a special
+meaning over and above intersecting with the current umask; specifically, it
+allows Unix syscalls to preserve native default permissions (5.12.3).
=item *
-The shortening of symbols longer than 31 characters in the C sources is
-now done by the compiler rather than by xsubpp (which could only do so
-for generated symbols in XS code).
+The shortening of symbols longer than 31 characters in the core C sources
+and in extensions is now by default done by the C compiler rather than by
+xsubpp (which could only do so for generated symbols in XS code). You can
+reenable xsubpp's symbol shortening by configuring with -Uuseshortenedsymbols,
+but you'll have some work to do to get the core sources to compile.
=item *
Record-oriented files (record format variable or variable with fixed control)
-opened for write by the perlio layer will now be line-buffered to prevent the
+opened for write by the C<perlio> layer will now be line-buffered to prevent the
introduction of spurious line breaks whenever the perlio buffer fills up.
=item *
-F<git_version.h> is now installed on VMS. This was an oversight in v5.12.0 which
+F<git_version.h> is now installed on VMS. This was an oversight in v5.12.0 which
caused some extensions to fail to build (5.12.2).
=item *
=item *
-A memory leak in C<Perl_rename()> due to a double allocation has been
+A memory leak in Perl_rename() due to a double allocation has been
fixed (5.12.2).
=item *
-A memory leak in C<vms_fid_to_name()> (used by C<realpath()> and
-C<realname()>) has been fixed (5.12.2).
+A memory leak in vms_fid_to_name() (used by realpath() and
+realname()> has been fixed (5.12.2).
=back
=item *
-When using old 32-bit compilers, the define C<_USE_32BIT_TIME_T> will now
-be set in C<$Config{ccflags}>. This improves portability when compiling
-XS extensions using new compilers, but for a perl compiled with old 32-bit
+When using old 32-bit compilers, the define C<_USE_32BIT_TIME_T> is now
+set in C<$Config{ccflags}>. This improves portability when compiling
+XS extensions using new compilers, but for a Perl compiled with old 32-bit
compilers.
=item *
-C<$Config{gccversion}> is now set correctly when perl is built using the
+C<$Config{gccversion}> is now set correctly when Perl is built using the
mingw64 compiler from L<http://mingw64.org> [perl #73754].
=item *
=item *
-The option to use an externally-supplied C<crypt()>, or to build with no
-C<crypt()> at all, has been removed. Perl supplies its own C<crypt()>
+The option to use an externally-supplied crypt(), or to build with no
+crypt() at all, has been removed. Perl supplies its own crypt()
implementation for Windows, and the political situation that required
this part of the distribution to sometimes be omitted is long gone.
=head3 CLONE_PARAMS structure added to ease correct thread creation
Modules that create threads should now create C<CLONE_PARAMS> structures
-by calling the new function C<Perl_clone_params_new()>, and free them with
-C<Perl_clone_params_del()>. This will ensure compatibility with any future
+by calling the new function Perl_clone_params_new(), and free them with
+Perl_clone_params_del(). This will ensure compatibility with any future
changes to the internals of the C<CLONE_PARAMS> structure layout, and that
it is correctly allocated and initialised.
L<C<parse_listexpr()>|perlapi/parse_listexpr>,
L<C<parse_termexpr()>|perlapi/parse_termexpr>, and
L<C<parse_arithexpr()>|perlapi/parse_arithexpr>
-functions have been added to the API. They perform
+functions have been added to the API. They run
recursive-descent parsing of expressions at various precedence levels.
They are expected to be used by syntax plugins.
structure that Perl uses for C<%^H>. See the functions beginning with
C<cophh_> in L<perlapi>.
-=head3 C interface to C<caller()>
+=head3 C interface to caller()
The C<caller_cx> function has been added as an XSUB-writer's equivalent of
-
C<caller()>. See L<perlapi> for details.
+
caller(). See L<perlapi> for details.
=head3 Custom per-subroutine check hooks
properties of custom ops in the future. Two new properties have been added
already, C<xop_class> and C<xop_peep>.
-C<xop_class> is one of the OA_*OP constants, and allows L<B> and other
+C<xop_class> is one of the OA_*OP constants. It allows L<B> and other
introspection mechanisms to work with custom ops
that aren't BASEOPs. C<xop_peep> is a pointer to
a function that will be called for ops of this
It is now possible for XS code to hook into Perl's lexical scope
mechanism at compile time, using the new C<Perl_blockhook_register>
-function. See L<perlguts/"Compile-time scope hooks">.
+function.
See L<perlguts/"Compile-time scope hooks">.
=head3 The recursive part of the peephole optimizer is now hookable
=head3 New non-magical variants of existing functions
The following functions/macros have been added to the API. The C<*_nomg>
-macros are equivalent to their non-_nomg variants, except that they ignore
-get-magic. Those ending in C<_flags> allow one to specify whether
-get-magic is processed.
+macros are equivalent to their non-C<_nomg> variants, except that they ignore
+C<get-magic>. Those ending in C<_flags> allow one to specify whether
+C<get-magic> is processed.
sv_2bool_flags
SvTRUE_nomg
sv_eq_flags
sv_collxfrm_flags
-In some of these cases, the non-_flags functions have
+In some of these cases, the non-C<_flags> functions have
been replaced with wrappers around the new functions.
=head3 pv/pvs/sv versions of existing functions
-Many functions ending with pvn now have equivalent pv/pvs/sv versions.
+Many functions ending with pvn now have equivalent C<pv/pvs/sv> versions.
=head3 List op-building functions
functions have been added to the API.
They allow extension authors to find and remove magic attached to
scalars based on both the magic type and the magic virtual table, similar to how
-C<sv_magicext()> attaches magic of a certain type and with a given virtual table
-to a scalar. This eliminates the need for extensions to walk the list of
+sv_magicext() attaches magic of a certain type and with a given virtual table
+to a scalar. This eliminates the need for extensions to walk the list of
C<MAGIC> pointers of an C<SV> to find the magic that belongs to them.
=head3 C<find_rundefsv>
=head3 C<Perl_croak_no_modify>
-C<Perl_croak_no_modify()> is short-hand for
+Perl_croak_no_modify() is short-hand for
C<Perl_croak("%s", PL_no_modify)>.
=head3 C<PERL_STATIC_INLINE> define
C<lex_start> has been added to the API, but is considered experimental.
-=head3 C<op_scope()> and C<op_lvalue()>
+=head3 op_scope() and op_lvalue()
-The C<op_scope()> and C<op_lvalue()> functions have been added to the API,
+The op_scope() and op_lvalue() functions have been added to the API,
but are considered experimental.
=head2 C API Changes
=head3 C<PERL_POLLUTE> has been removed
The option to define C<PERL_POLLUTE> to expose older 5.005 symbols for
-backwards compatibility has been removed. It's use was always discouraged,
+backwards compatibility has been removed. Its use was always discouraged,
and MakeMaker contains a more specific escape hatch:
perl Makefile.PL POLLUTE=1
=head3 Check API compatibility when loading XS modules
-When perl's API changes in incompatible ways (which usually happens between
-major releases), XS modules compiled for previous versions of perl will not
-work anymore. They will need to be recompiled against the new perl.
+When Perl's API changes in incompatible ways (which usually happens between
+major releases), XS modules compiled for previous versions of Perl will no
+longer work. They need to be recompiled against the new Perl.
-In order to ensure that modules are recompiled, and to prevent users from
-accidentally loading modules compiled for old perls into newer ones, the
-C<XS_APIVERSION_BOOTCHECK> macro has been added. That macro, which is
-called when loading every newly compiled extension, compares the API
-version of the running perl with the version a module has been compiled for
-and raises an exception if they don't match.
+The C<XS_APIVERSION_BOOTCHECK> macro has been added to ensure that modules
+are recompiled and to prevent users from accidentally loading modules
+compiled for old perls into newer perls. That macro, which is called when
+loading every newly compiled extension, compares the API version of the
+running perl with the version a module has been compiled for and raises an
+exception if they don't match.
=head3 Perl_fetch_cop_label
implementation details.
This API function was marked as "may change", and likely isn't in use outside
-the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
+the core. (Neither an unpacked CPAN nor Google's codesearch finds any other
references to it.)
=head3 GvCV() and GvGP() are no longer lvalues
This allows a future commit to eliminate some backref magic between GV
and CVs, which will require complete control over assignment to the
-gp_cv slot.
+C<gp_cv> slot.
=head3 CvGV() is no longer an lvalue
-Under some circumstances, the C<CvGV()> field of a CV is now
+Under some circumstances, the CvGV() field of a CV is now
reference-counted. To ensure consistent behaviour, direct assignment to
it, for example C<CvGV(cv) = gv> is now a compile-time error. A new macro,
-C<CvGV_set(cv,gv)> has been introduced to perform this operation
+C<CvGV_set(cv,gv)> has been introduced to run this operation
safely. Note that modification of this field is not part of the public
API, regardless of this new macro (and despite its being listed in this section).
=head3 CvSTASH() is no longer an lvalue
-The C<CvSTASH()> macro can now only be used as an rvalue. C<CvSTASH_set()>
-has been added to replace assignment to C<CvSTASH()>. This is to ensure
+The CvSTASH() macro can now only be used as an rvalue. CvSTASH_set()
+has been added to replace assignment to CvSTASH(). This is to ensure
that backreferences are handled properly. These macros are not part of the
API.
=head3 Calling conventions for C<newFOROP> and C<newWHILEOP>
-The way the parser handles labels has been cleaned up and refactored. As a
-result, the C<newFOROP()> constructor function no longer takes a parameter
+The way the parser handles labels has been cleaned up and refactored. As a
+result, the newFOROP() constructor function no longer takes a parameter
stating what label is to go in the state op.
-The C<newWHILEOP()> and C<newFOROP()> functions no longer accept a line
+The newWHILEOP() and newFOROP() functions no longer accept a line
number as a parameter.
=head3 Flags passed to C<uvuni_to_utf8_flags> and C<utf8n_to_uvuni>
C<UNICODE_IS_ILLEGAL> have been removed, as they stem from a
fundamentally broken model of how the Unicode non-character code points
should be handled, which is now described in
-L<perlunicode/Non-character code points>. See also L</Selected Bug Fixes>.
-
-XXX Which bugs in particular? Selected Bug Fixes is too long for this link
-to be meaningful right now
-I don't see the bugs in that section currently -- khw
+L<perlunicode/Non-character code points>. See also the Unicode section
+under L</Selected Bug Fixes>.
=head2 Deprecated C APIs
=item C<sv_compile_2op>
-The C<sv_compile_2op()> API function is now deprecated. Searches suggest
+The sv_compile_2op() API function is now deprecated. Searches suggest
that nothing on CPAN is using it, so this should have zero impact.
It attempted to provide an API to compile code down to an optree, but failed
run-time.
Use the new C<find_rundefsv> function or the C<UNDERBAR> macro
-instead. They directly return the right SV representing C<$_>, whether it's
+instead. They directly return the right SV
+representing C<$_>, whether it's
lexical or dynamic.
=item C<CALL_FPTR> and C<CPERLscope>
=head3 String comparison routines renamed
-The ibcmp_* functions have been renamed and are now called foldEQ,
-foldEQ_locale and foldEQ_utf8. The old names are still available as
+The C<ibcmp_*> functions have been renamed and are now called C<foldEQ>,
+C<foldEQ_locale>, and C<foldEQ_utf8>. The old names are still available as
macros.
=head3 C<chop> and C<chomp> implementations merged
The opcode bodies for C<chop> and C<chomp> and for C<schop> and C<schomp>
-have been merged. The implementation functions C<Perl_do_chop()> and
-C<Perl_do_chomp()>, never part of the public API, have been merged and
-moved to a static function in F<pp.c>. This shrinks the perl binary
+have been merged. The implementation functions Perl_do_chop() and
+Perl_do_chomp(), never part of the public API, have been merged and
+moved to a static function in F<pp.c>. This shrinks the Perl binary
slightly, and should not affect any code outside the core (unless it is
-relying on the order of side effects when C<chomp> is passed a I<list> of
+relying on the order of side-effects when C<chomp> is passed a I<list> of
values).
=head1 Selected Bug Fixes
Perl no longer produces this warning:
- $ perl -we 'open my $f, ">", \my $x; binmode $f, "scalar"'
+ $ perl -we 'open(my $f, ">", \my $x); binmode($f, "scalar")'
Use of uninitialized value in binmode at -e line 1.
=item *
-Opening a glob reference via C<< open $fh, "E<gt>", \*glob >> will no longer
-cause the glob to be corrupted when the filehandle is printed to. This would
-cause perl to crash whenever the glob's contents were accessed
+Opening a glob reference via C<< open($fh, ">", \*glob) >> no longer
+causes the glob to be corrupted when the filehandle is printed to. This would
+cause Perl to crash whenever the glob's contents were accessed
[perl #77492].
=item *
-PerlIO no longer crashes when called recursively, e.g., from a signal
-handler. Now it just leaks memory [perl #75556].
+PerlIO no longer crashes when called recursively, such as from a signal
+handler. Now it just leaks memory [perl #75556].
=item *
Most I/O functions were not warning for unopened handles unless the
-'closed' and 'unopened' warnings categories were both enabled. Now only
-C<use warnings 'unopened'> is necessary to trigger these warnings (as was
-always meant to be the case).
+"closed" and "unopened" warnings categories were both enabled. Now only
+C<use warnings 'unopened'> is necessary to trigger these warnings, as
+had always been the intention.
=item *
There have been several fixes to PerlIO layers:
-When C<binmode FH, ":crlf"> pushes the C<:crlf> layer on top of the stack,
-it no longer enables crlf layers lower in the stack, to avoid unexpected
-results [perl #38456].
+When C<binmode(FH, ":crlf")> pushes the C<:crlf> layer on top of the stack,
+it no longer enables crlf layers lower in the stack so as to avoid
+unexpected results [perl #38456].
Opening a file in C<:raw> mode now does what it advertises to do (first
-open the file, then binmode it), instead of simply leaving off the top
+open the file, then C<binmode> it), instead of simply leaving off the top
layer [perl #80764].
-The three layers C<:pop>, C<:utf8> and C<:bytes> didn't allow stacking when
+The three layers C<:pop>, C<:utf8>, and C<:bytes> didn't allow stacking when
opening a file. For example
this:
- open FH, '>:pop:perlio', 'some.file' or die $!;
+ open(FH, ">:pop:perlio", "some.file") or die $!;
-Would throw an error: "Invalid argument". This has been fixed in this
+would throw an "Invalid argument" error. This has been fixed in this
release [perl #82484].
=back
A regular expression match in the right-hand side of a global substitution
(C<s///g>) that is in the same scope will no longer cause match variables
-to have the wrong values on subsequent iterations. This can happen when an
+to have the wrong values on subsequent iterations. This can happen when an
array or hash subscript is interpolated in the right-hand side, as in
C<s|(.)|@a{ print($1), /./ }|g> [perl #19078].
=item *
Several cases in which characters in the Latin-1 non-ASCII range (0x80 to
-0xFF) used not to match themselves or used to match both a character class
-and its complement have been fixed. For instance, U+00E2 could match both
+0xFF) used not to match themselves, or used to match both a character class
+and its complement, have been fixed. For instance, U+00E2 could match both
C<\w> and C<\W> [perl #78464] [perl #18281] [perl #60156].
=item *
Matching a Unicode character against an alternation containing characters
that happened to match continuation bytes in the former's UTF8
-representation (C<qq{\x{30ab}} =~ /\xab|\xa9/>) would cause erroneous
+representation (like C<qq{\x{30ab}} =~ /\xab|\xa9/>) would cause erroneous
warnings [perl #70998].
=item *
The trie optimisation was not taking empty groups into account, preventing
-'foo' from matching C</\A(?:(?:)foo|bar|zot)\z/> [perl #78356].
+"foo" from matching C</\A(?:(?:)foo|bar|zot)\z/> [perl #78356].
=item *
A pattern containing a C<+> inside a lookahead would sometimes cause an
-incorrect match failure in a global match (e.g., C</(?=(\S+))/g>)
+incorrect match failure in a global match (for example, C</(?=(\S+))/g>)
[perl #68564].
=item *
A regular expression optimisation would sometimes cause a match with a
-C<{n,m}> quantifier to fail when it should match [perl #79152].
-
-=item *
-
-Case insensitive matching in regular expressions compiled under C<use
-locale> now works much more sanely when the pattern or
-target string is encoded internally in
-UTF8. Previously, under these conditions the localeness
-was completely lost. Now, code points above 255 are treated as Unicode,
-but code points between 0 and 255 are treated using the current locale
-rules, regardless of whether the pattern or the string is encoded in UTF8.
-The few case-insensitive matches that cross the 255/256 boundary are not
-allowed. For example, 0xFF does not caselessly match the character at
-0x178, LATIN CAPITAL LETTER Y WITH DIAERESIS, because 0xFF may not be
-LATIN SMALL LETTER Y in the current locale, and Perl has no way of
-knowing if that character even exists in the locale, much less what code
+C<{n,m}> quantifier to fail when it should have matched [perl #79152].
+
+=item *
+
+Case-insensitive matching in regular expressions compiled under
+C<use locale> now works much more sanely when the pattern or target
+string is internally encoded in UTF8. Previously, under these
+conditions the localeness was completely lost. Now, code points
+above 255 are treated as Unicode, but code points between 0 and 255
+are treated using the current locale rules, regardless of whether
+the pattern or the string is encoded in UTF8. The few case-insensitive
+matches that cross the 255/256 boundary are not allowed. For
+example, 0xFF does not caselessly match the character at 0x178,
+LATIN CAPITAL LETTER Y WITH DIAERESIS, because 0xFF may not be LATIN
+SMALL LETTER Y in the current locale, and Perl has no way of knowing
+if that character even exists in the locale, much less what code
point it is.
=item *
The C<(?|...)> regular expression construct no longer crashes if the final
-branch has more sets of capturing parentheses than any other branch. This
+branch has more sets of capturing parentheses than any other branch. This
was fixed in Perl 5.10.1 for the case of a single branch, but that fix did
not take multiple branches into account [perl #84746].
=item *
-C<when(scalar){...}> no longer crashes, but produces a syntax error
+C<when (scalar) {...}> no longer crashes, but produces a syntax error
[perl #74114] (5.12.1).
=item *
=item *
-The C<no 5.13.2;> form of C<no> no longer tries to turn on features or
-pragmata (i.e., strict) [perl #70075] (5.12.2).
+The C<no 5.13.2> form of C<no> no longer tries to turn on features or
+pragmata (like L<strict>) [perl #70075] (5.12.2).
=item *
C<BEGIN {require 5.12.0}> now behaves as documented, rather than behaving
-identically to C<use 5.12.0;>. Previously, C<require> in a C<BEGIN> block
-was erroneously executing the C<use feature ':5.12.0'> and
-C<use strict;> behaviour, which only C<use> was documented to
+identically to C<use 5.12.0>. Previously, C<require> in a C<BEGIN> block
+was erroneously executing the C<use feature ":5.12.0"> and
+C<use strict> behaviour, which only C<use> was documented to
provide [perl #69050].
=item *
=item *
-When strict 'refs' mode is off, C<%{...}> in rvalue context returns
-C<undef> if its argument is undefined. An optimisation introduced in perl
+When strict "refs" mode is off, C<%{...}> in rvalue context returns
+C<undef> if its argument is undefined. An optimisation introduced in Perl
5.12.0 to make C<keys %{...}> faster when used as a boolean did not take
this into account, causing C<keys %{+undef}> (and C<keys %$foo> when
-C<$foo> is undefined) to be an error, which it should only be in strict
-mode [perl #81750].
+C<$foo> is undefined) to be an error, which it should be so in strict
+mode only [perl #81750].
=item *
$text =~ /phoo/
-at compile time. Now it correctly matches against C<$_> [perl #20444].
+at compile time. Now it correctly matches against C<$_> [perl #20444].
=item *
=item *
-String evals no longer fail after 2 billion scopes have been
+String C<eval>s no longer fail after 2 billion scopes have been
compiled [perl #83364].
=item *
=item *
-Several contexts no longer allow a Unicode character to begin a word
-that should never begin words, for an example an accent that must follow
-another character previously could precede all other characters.
-
-=item *
-
-Defining a constant with the same name as one of perl's special blocks
-(e.g., INIT) stopped working in 5.12.0, but has now been fixed
+Defining a constant with the same name as one of Perl's special blocks
+(like C<INIT>) stopped working in 5.12.0, but has now been fixed
[perl #78634].
=item *
=item *
-C<state> can now be used with attributes. It used to mean the same thing as
-C<my> if attributes were present [perl #68658].
+C<state> can now be used with attributes. It
+used to mean the same thing as
+C<my> if any attributes were present [perl #68658].
=item *
Expressions like C<< @$a > 3 >> no longer cause C<$a> to be mentioned in
the "Use of uninitialized value in numeric gt" warning when C<$a> is
-undefined (since it is not part of the C<E<gt>> expression, but the operand
+undefined (since it is not part of the C<< > >> expression, but the operand
of the C<@>) [perl #72090].
=item *
=item *
-The C<-C> command line option, when used on the shebang line, can now be
+The B<-C> command-line option, when used on the shebang line, can now be
followed by other options [perl #72434].
=item *
-The C<B> module was returning C<B::OP>s instead of C<B::LOGOP>s for C<entertry> [perl #80622].
-This was due to a bug in the perl core, not in C<B> itself.
+The C<B> module was returning C<B::OP>s instead of C<B::LOGOP>s for
+C<entertry> [perl #80622]. This was due to a bug in the Perl core,
+not in C<B> itself.
=back
Perl 5.10.0 introduced a new internal mechanism for caching MROs (method
resolution orders, or lists of parent classes; aka "isa" caches) to make
-method lookup faster (so @ISA arrays would not have to be searched
+method lookup faster (so C<@ISA> arrays would not have to be searched
repeatedly). Unfortunately, this brought with it quite a few bugs. Almost
all of these have been fixed now, along with a few MRO-related bugs that
existed before 5.10.0:
=item *
Typeglob assignments would crash if the glob's stash no longer existed, so
-long as the glob assigned to was named 'ISA' or the glob on either side of
+long as the glob assigned to were named C<ISA> or the glob on either side of
the assignment contained a subroutine.
=item *
C<PL_isarev>, which is accessible to Perl via C<mro::get_isarev> is now
updated properly when packages are deleted or removed from the C<@ISA> of
-other classes. This allows many packages to be created and deleted without
+other classes. This allows many packages to be created and deleted without
causing a memory leak [perl #75176].
=back
=item *
Some work has been done on the internal pointers that link between symbol
-tables (stashes), typeglobs and subroutines. This has the effect that
-various edge cases related to deleting stashes or stash entries (e.g.
-<%FOO:: = ()>), and complex typeglob or code reference aliasing, will no
+tables (stashes), typeglobs, and subroutines. This has the effect that
+various edge cases related to deleting stashes or stash entries (for example,
+<%FOO:: = ()>), and complex typeglob or code-reference aliasing, will no
longer crash the interpreter.
=item *
=item *
-Assigning a glob to a PVLV used to convert it to a plain string. Now it
-works correctly, and a PVLV can hold a glob. This would happen when a
+Assigning a glob to a PVLV used to convert it to a plain string. Now it
+works correctly, and a PVLV can hold a glob. This would happen when a
nonexistent hash or array element was passed to a subroutine:
sub { $_[0] = *foo }->($hash{key});
When trying to report C<Use of uninitialized value $Foo::BAR>, crashes could
occur if the glob holding the global variable in question had been detached
-from its original stash by, for example, C<delete $::{'Foo::'}>. This has
+from its original stash by, for example, C<delete $::{"Foo::"}>. This has
been fixed by disabling the reporting of variable names in those
cases.
During the restoration of a localised typeglob on scope exit, any
destructors called as a result would be able to see the typeglob in an
inconsistent state, containing freed entries, which could result in a
-crash. This would affect code like this:
+crash. This would affect code like this:
local *@;
eval { die bless [] }; # puts an object in $@
local $@; # boom
}
-Now the glob entries are cleared before any destructors are called. This
-also means that destructors can vivify entries in the glob. So perl tries
+Now the glob entries are cleared before any destructors are called. This
+also means that destructors can vivify entries in the glob. So Perl tries
again and, if the entries are re-created too many times, dies with a
-'panic: gp_free...' error message.
+"panic: gp_free ..." error message.
+
+=item *
+
+If a typeglob is freed while a subroutine attached to it is still
+referenced elsewhere, the subroutine is renamed to C<__ANON__> in the same
+package, unless the package has been undefined, in which case the C<__ANON__>
+package is used. This could cause packages to be sometimes autovivified,
+such as if the package had been deleted. Now this no longer occurs.
+The C<__ANON__> package is also now used when the original package is
+no longer attached to the symbol table. This avoids memory leaks in some
+cases [perl #87664].
+
+=item *
+
+Subroutines and package variables inside a package whose name ends with
+C<::> can now be accessed with a fully qualified name.
=back
=item *
-What has become known as the "Unicode Bug" is almost completely resolved in
-this release. Under C<use feature 'unicode_strings'> (which is
+What has become known as "the Unicode Bug" is almost completely resolved in
+this release. Under C<use feature "unicode_strings"> (which is
automatically selected by C<use 5.012> and above), the internal
storage format of a string no longer affects the external semantics.
[perl #58182].
=item 1
-The now-deprecated user-defined case changing
-functions require utf8-encoded strings to function. The CPAN module
-L<Unicode::Casing> has been written to replace this feature, without its
-drawacks, and the feature is scheduled to be removed in 5.16
+The now-deprecated, user-defined case-changing
+functions require utf8-encoded strings to operate. The CPAN module
+L<Unicode::Casing> has been written to replace this feature without its
+drawbacks, and the feature is scheduled to be removed in 5.16.
=item 2
-C<quotemeta> (and its in-line equivalent C<\Q>) also can give different
-results if a string is encoded in UTF-8 or not. See
+quotemeta() (and its in-line equivalent C<\Q>) can also give different
+results depending on whether a string is encoded in UTF-8. See
L<perlunicode/The "Unicode Bug">.
=back
=item *
-The handling of Unicode non-character code points has changed.
-Previously they were mostly considered illegal, except that only one of
-the 66 of them was known about in places. The Unicode standard
-considers them legal, but forbids the "open interchange" of them.
-This is part of the change to allow the internal use of any code point
-(see L</Core Enhancements>). Together, these changes resolve
-[perl #38722], [perl #51918], [perl #51936], [perl #63446].
+Handling of Unicode non-character code points has changed.
+Previously they were mostly considered illegal, except that in some
+place only one of the 66 of them was known. The Unicode Standard
+considers them all legal, but forbids their "open interchange".
+This is part of the change to allow internal use of any code
+point (see L</Core Enhancements>). Together, these changes resolve
+[perl #38722], [perl #51918], [perl #51936], and [perl #63446].
=item *
Case-insensitive C<"/i"> regular expression matching of Unicode
-characters which match multiple characters now works much more as
+characters that match multiple characters now works much more as
intended. For example
"\N{LATIN SMALL LIGATURE FFI}" =~ /ffi/ui
None of these match.
Also, this matching doesn't fully conform to the current Unicode
-standard, which asks that the matching be made upon the NFD
-(Normalization Form .ecomposed) of the text. However, as of this
-writing, March 2010, the Unicode standard is currently in flux about
-what they will recommend doing with regard to such cases. It may be
+Standard, which asks that the matching be made upon the NFD
+(Normalization Form Decomposed) of the text. However, as of this
+writing (April 2010), the Unicode Standard is currently in flux about
+what they will recommend doing with regard in such scenarios. It may be
that they will throw out the whole concept of multi-character matches.
[perl #71736].
=item *
-Naming a deprecated character in \N{...} no longer leaks memory.
+Naming a deprecated character in C<\N{I<NAME>}> no longer leaks memory.
=item *
-We fixed a bug that could cause \N{} constructs followed by a single . to
-be parsed incorrectly [perl #74978] (5.12.1).
+We fixed a bug that could cause C<\N{I<NAME>}> constructs followed by
+a single C<"."> to be parsed incorrectly [perl #74978] (5.12.1).
=item *
-C<chop> now correctly handles characters above "\x{7fffffff}"
+C<chop> now correctly handles characters above C<"\x{7fffffff}">
[perl #73246].
=item *
=item *
-C<warn()> and C<die()> now respect utf8-encoded scalars [perl #45549].
+warn() and die() now respect utf8-encoded scalars [perl #45549].
=item *
Sometimes the UTF8 length cache would not be reset on a value
-returned by substr, causing C<length(substr($uni_string,...))> to give
-wrong answers. With C<${^UTF8CACHE}> set to -1, it would produce a 'panic'
-error message, too [perl #77692].
+returned by substr, causing C<length(substr($uni_string, ...))> to give
+wrong answers. With C<${^UTF8CACHE}> set to -1, it would also produce
+a "panic" error message [perl #77692].
=back
=item *
-Various cases of magic (e.g., tie methods) being called on tied variables
+Various instances of magic (like tie methods) being called on tied variables
too many or too few times have been fixed:
=over
=item *
-FETCH is no longer called on tied variables in void context.
-
-=item *
-
-C<$tied-E<gt>()> did not always call FETCH [perl #8438].
+C<< $tied->() >> did not always call FETCH [perl #8438].
=item *
=item *
Dereference operators used to ignore magic if the argument was a
-reference already (e.g., from a previous FETCH) [perl #72144].
+reference already (such as from a previous FETCH) [perl #72144].
=item *
-C<splice> now calls set-magic (so changes made
+C<splice> now calls C<set-magic> (so changes made
by C<splice @ISA> are respected by method calls) [perl #78400].
=item *
-In-memory files created by C<open $fh, 'E<gt>' \$buffer> were not calling
+In-memory files created by C<< open($fh, ">", \$buffer) >> were not calling
FETCH/STORE at all [perl #43789] (5.12.2).
+=item *
+
+utf8::is_utf8() now respects C<get-magic> (like C<$1>) (5.12.1).
+
=back
=item *
+Non-commutative binary operators used to swap their operands if the same
+tied scalar was used for both operands and returned a different value for
+each FETCH. For instance, if C<$t> returned 2 the first time and 3 the
+second, then C<$t/$t> would evaluate to 1.5. This has been fixed
+[perl #87708].
+
+=item *
+
String C<eval> now detects taintedness of overloaded or tied
arguments [perl #75716].
=item *
String C<eval> and regular expression matches against objects with string
-overloading no longer cause memory corruption or crashes [perl 77084].
+overloading no longer cause memory corruption or crashes [perl #77084].
=item *
=item *
-C<< E<lt>exprE<gt> >> always respects overloading now if the expression is
+C<< <expr> >> always respects overloading now if the expression is
overloaded.
-Due to the way that 'E<lt>E<gt> as glob' was parsed differently from
-'E<lt>E<gt> as filehandle' from 5.6 onwards, something like C<< E<lt>$foo[0]E<gt> >> did
+Because "S<< <> as >> glob" was parsed differently from
+"S<< <> as >> filehandle" from 5.6 onwards, something like C<< <$foo[0]> >> did
not handle overloading, even if C<$foo[0]> was an overloaded object. This
-was contrary to the documentation for overload, and meant that C<< E<lt>E<gt> >>
+was contrary to the documentation for L<overload>, and meant that C<< <> >>
could not be used as a general overloaded iterator operator.
=item *
=item *
-C<$AUTOLOAD> used to remain tainted forever if it ever became tainted. Now
+C<$AUTOLOAD> used to remain tainted forever if it ever became tainted. Now
it is correctly untainted if an autoloaded method is called and the method
name was not tainted.
=item *
-C<sprintf> now dies when passed a tainted scalar for the format. It did
+C<sprintf> now dies when passed a tainted scalar for the format. It did
already die for arbitrary expressions, but not for simple scalars
[perl #82250].
=item *
-utf8::is_utf8 now respects get-magic (e.g. $1) (5.12.1).
+C<lc>, C<uc>, C<lcfirst>, and C<ucfirst> no longer return untainted strings
+when the argument is tainted. This has been broken since perl 5.8.9
+[perl #87336].
=back
=item *
-When C<-d> is used on the shebang (C<#!>) line, the debugger now has access
+When B<-d> is used on the shebang (C<#!>) line, the debugger now has access
to the lines of the main program. In the past, this sometimes worked and
-sometimes did not, depending on what order things happened to be arranged
-in memory [perl #71806].
+sometimes did not, depending on the order in which things happened to be
+arranged in memory [perl #71806].
=item *
=item *
-Perl no longer stomps on $DB::single, $DB::trace and $DB::signal if they
-already have values when $^P is assigned to [perl #72422].
+Perl no longer stomps on C<$DB::single>, C<$DB::trace>, and C<$DB::signal>
+if these variables already have values when C<$^P> is assigned to [perl #72422].
=item *
C<#line> directives in string evals were not properly updating the arrays
-of lines of code (C<< @{"_<..."} >>) that the debugger (or any debugging or
-profiling module) uses. In threaded builds, they were not being updated at
-all. In non-threaded builds, the line number was ignored, so any change to
+of lines of code (C<< @{"_< ..."} >>) that the debugger (or any debugging or
+profiling module) uses. In threaded builds, they were not being updated at
+all. In non-threaded builds, the line number was ignored, so any change to
the existing line number would cause the lines to be misnumbered
[perl #79442].
crash, because the handles were not cloned, but simply passed to the new
thread, resulting in a double free.
-Now directory handles are cloned properly, on systems that have a C<fchdir>
-function. On other systems, new threads simply do not inherit directory
+Now directory handles are cloned properly on Windows
+and on systems that have a C<fchdir> function. On other
+systems, new threads simply do not inherit directory
handles from their parent threads [perl #75154].
=item *
=item *
-Perl now does a timely cleanup of SVs that are cloned into a new thread but
-then discovered to be orphaned (i.e., their owners are I<not> cloned). This
-eliminates several "scalars leaked" warnings when joining threads.
+Perl now does a timely cleanup of SVs that are cloned into a new
+thread but then discovered to be orphaned (that is, their owners
+are I<not> cloned). This eliminates several "scalars leaked"
+warnings when joining threads.
=back
=item *
-C<sort> with a ($$)-prototyped comparison routine used to cause the value
-of @_ to leak out of the sort. Taking a reference to @_ within the
+C<sort> with a C<($$)>-prototyped comparison routine used to cause the value
+of C<@_> to leak out of the sort. Taking a reference to C<@_> within the
sorting routine could cause a crash [perl #72334].
=item *
-Match variables (e.g., C<$1>) no longer persist between calls to a sort
+Match variables (like C<$1>) no longer persist between calls to a sort
subroutine [perl #76026].
=item *
=item *
A signal handler called within a signal handler could cause leaks or
-double-frees. Now fixed. [perl #76248].
+double-frees. Now fixed [perl #76248].
=back
L<pos()|perlfunc/"index STR,SUBSTR,POSITION">, L<keys()|perlfunc/"keys HASH">,
and L<vec()|perlfunc/"vec EXPR,OFFSET,BITS"> could, when used in combination
with lvalues, result in leaking the scalar value they operate on, and cause its
-destruction to happen too late. This has now been fixed.
+destruction to happen too late. This has now been fixed.
=item *
The postincrement and postdecrement operators, C<++> and C<-->, used to cause
-leaks when being used on references. This has now been fixed.
+leaks when used on references. This has now been fixed.
=item *
=item *
-glob() no longer crashes when %File::Glob:: is empty and
-CORE::GLOBAL::glob isn't present [perl #75464] (5.12.2).
+glob() no longer crashes when C<%File::Glob::> is empty and
+C<CORE::GLOBAL::glob> isn't present [perl #75464] (5.12.2).
=item *
pointers to freed SVs, meaning Perl users could see corrupted state
during destruction.
-Perl now only frees the affected slots of the GV, rather than freeing
+Perl now frees only the affected slots of the GV, rather than freeing
the GV itself. This makes sure that there are no dangling refs or
corrupted state during destruction.
=item *
-Concatenating long strings under C<use encoding> no longer causes perl to
+Concatenating long strings under C<use encoding> no longer causes Perl to
crash [perl #78674].
=item *
Calling C<< ->import >> on a class lacking an import method could corrupt
-the stack, resulting in strange behaviour. For instance,
+the stack, resulting in strange behaviour. For instance,
push @a, "foo", $b = bar->import;
-would assign 'foo' to C<$b> [perl #63790].
+would assign "foo" to C<$b> [perl #63790].
=item *
=item *
-C<formline> no longer crashes when passed a tainted format picture. It also
+C<formline> no longer crashes when passed a tainted format picture. It also
taints C<$^A> now if its arguments are tainted [perl #79138].
=item *
A bug in how we process filetest operations could cause a segfault.
Filetests don't always expect an op on the stack, so we now use
-TOPs only if we're sure that we're not stat'ing the _ filehandle.
-This is indicated by OPf_KIDS (as checked in ck_ftst) [perl #74542]
+TOPs only if we're sure that we're not C<stat>ing the C<_> filehandle.
+This is indicated by C<OPf_KIDS> (as checked in ck_ftst) [perl #74542]
(5.12.1).
=item *
-C<unpack()> now handles scalar context correctly for C<%32H> and C<%32u>,
-fixing a potential crash. C<split()> would crash because the third item
+unpack() now handles scalar context correctly for C<%32H> and C<%32u>,
+fixing a potential crash. split() would crash because the third item
on the stack wasn't the regular expression it expected. C<unpack("%2H",
...)> would return both the unpacked result and the checksum on the stack,
as would C<unpack("%2u", ...)> [perl #73814] (5.12.2).
=item *
-The C<&> C<|> C<^> bitwise operators no longer coerce read-only arguments
+The C<&>, C<|>, and C<^> bitwise operators no longer coerce read-only arguments
[perl #20661].
=item *
-Stringifying a scalar containing -0.0 no longer has the affect of turning
+Stringifying a scalar containing "-0.0" no longer has the effect of turning
false into true [perl #45133].
=item *
=item *
-C<sprintf> was ignoring locales when called with constant arguments
+sprintf() was ignoring locales when called with constant arguments
[perl #78632].
=item *
-Combining the vector (%v) flag and dynamic precision would
-cause sprintf to confuse the order of its arguments, making it treat the
-string as the precision and vice versa [perl #83194].
+Combining the vector (C<%v>) flag and dynamic precision would
+cause C<sprintf> to confuse the order of its arguments, making it
+treat the string as the precision and vice-versa [perl #83194].
=back
The XS multicall API no longer causes subroutines to lose reference counts
if called via the multicall interface from within those very subroutines.
-This affects modules like List::Util. Calling one of its functions with an
+This affects modules like L<List::Util>. Calling one of its functions with an
active subroutine as the first argument could cause a crash [perl #78070].
=item *
=item *
C<sv_catsv_flags> no longer calls C<mg_get> on its second argument (the
-source string) if the flags passed to it do not include SV_GMAGIC. So it
+source string) if the flags passed to it do not include SV_GMAGIC. So it
now matches the documentation.
=item *
=item *
-XSUB.h now correctly redefines fgets under PERL_IMPLICIT_SYS [perl #55049]
+F<XSUB.h> now correctly redefines fgets under PERL_IMPLICIT_SYS [perl #55049]
(5.12.1).
=item *
-XS code using C<fputc()> or C<fputs()>: on Windows could cause an error
+XS code using fputc() or fputs() on Windows could cause an error
due to their arguments being swapped [perl #72704] (5.12.1).
=item *
=item *
C<List::Util::first> misbehaves in the presence of a lexical C<$_>
-(typically introduced by C<my $_> or implicitly by C<given>). The variable
-which gets set for each iteration is the package variable C<$_>, not the
+(typically introduced by C<my $_> or implicitly by C<given>). The variable
+that gets set for each iteration is the package variable C<$_>, not the
lexical C<$_>.
A similar issue may occur in other modules that provide functions which
=item *
readline() returns an empty string instead of undef when it is
-interrupted by a signal
-
-=item *
-
-Test-Harness was updated from 3.17 to 3.21 for this release. A rewrite
-in how it handles non-Perl tests (in 3.17_01) broke argument passing to
-non-Perl tests with L<prove> (RT #59186), and required that non-Perl
-tests be run as C<prove ./test.sh> instead of C<prove test.sh> These
-issues are being solved upstream, but didn't make it into this release.
-They're expected to be fixed in time for perl v5.13.4. (RT #59457)
+interrupted by a signal.
=item *
-C<version> now prevents object methods from being called as class methods
+L<version> now prevents object methods from being called as class methods
(d808b68)
=item *
The changes in L<substr()|perlfunc/"substr EXPR,OFFSET,LENGTH,REPLACEMENT">
-broke C<HTML::Parser> <= 3.66. A fixed C<HTML::Parser> is available as versions
+broke C<HTML::Parser> <= 3.66. A fixed C<HTML::Parser> is available as versions
3.67 on CPAN.
=item *
-The changes in prototype handling break C<Switch>. A patch has been sent
+The changes in prototype handling break L<Switch>. A patch has been sent
upstream and will hopefully appear on CPAN soon.
=item *
-The upgrade to Encode-2.40 has caused some tests in the libwww-perl distribution
+The upgrade to F<Encode-2.40> has caused some tests in the F<libwww-perl> distribution
on CPAN to fail. (Specifically, F<base/message-charset.t> tests 33-36 in version
5.836 of that distribution now fail.)
=item *
-The upgrade to ExtUtils-MakeMaker-6.57_05 has caused some tests in the
-Module-Install distribution on CPAN to fail. (Specifically, F<02_mymeta.t> tests
-5 and 21, F<18_all_from.t> tests 6 and 15, F<19_authors.t> tests 5, 13, 21 and
-29, and F<20_authors_with_special_characters.t> tests 6, 15 and 23 in version
+The upgrade to F<ExtUtils-MakeMaker-6.57_05> has caused some tests in the
+F<Module-Install> distribution on CPAN to fail. (Specifically, F<02_mymeta.t> tests
+5 and 21l; F<18_all_from.t> tests 6 and 15; F<19_authors.t> tests 5, 13, 21, and
+29; and F<20_authors_with_special_characters.t> tests 6, 15, and 23 in version
1.00 of that distribution now fail.)
=back
=head1 Errata
-=head2 C<keys>, C<values> and C<each> work on arrays
+=head2 keys(), values(), and each() work on arrays
-You can now use the C<keys>, C<values>, C<each> builtin functions on arrays
-
(previously you could only use them on hashes). See L<perlfunc> for details.
+You can now use the keys(), values(), and each() builtins on arrays;
+
previously you could use them only on hashes. See L<perlfunc> for details.
This is actually a change introduced in perl 5.12.0, but it was missed from
-that release's perldelta.
+that release's L<perl5120delta>.
+
+=head2 split() and C<@_>
+
+split() no longer modifies C<@_> when called in scalar or void context.
+In void context it now produces a "Useless use of split" warning.
+This was also a perl 5.12.0 changed that missed the perldelta.
=head1 Obituary
-Randy Kobes, creator of the kobesearch alternative to search.cpan.org and
-contributor/maintainer to several core Perl toolchain modules, passed away
-on September 18, 2010 after a battle with lung cancer. His contributions
-to the Perl community will be missed.
+Randy Kobes, creator of http://kobesearch.cpan.org/ and
+contributor/maintainer to several core Perl toolchain modules, passed
+away on September 18, 2010 after a battle with lung cancer. The community
+was richer for his involvement. He will be missed.
=head1 Acknowledgements
-XXX The list of people to thank goes here.
+
+Perl 5.14.0 represents one year of development since
+Perl 5.12.0 and contains nearly 550,000 lines of changes across nearly
+3,000 files from 150 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 5.14.0:
+
+A. Sinan Unur, Aaron Crane, Abhijit Menon-Sen, Abigail, Alastair Douglas,
+Alex Davies, Alex Vandiver, Alexander Alekseev, Alexander Hartmaier,
+Alexandr Ciornii, Ali Polatel, Allen Smith, Andreas König, Andrew
+Rodland, Andy Armstrong, Andy Dougherty, Aristotle Pagaltzis, Arkturuz,
+Arvan, Ben Morrow, Bo Lindbergh, Boris Ratner, Brad Gilbert, Bram,
+brian d foy, Brian Phillips, Casey West, Charles Bailey, Chas. Owens,
+Chip Salzenberg, Chris 'BinGOs' Williams, chromatic, Craig A. Berry,
+Curtis Jewell, Dagfinn Ilmari Mannsåker, Dan Dascalescu, Dave Rolsky,
+David Caldwell, David Cantrell, David Golden, David Leadbeater, David
+Mitchell, David Wheeler, Eric Brine, Father Chrysostomos, Fingle
+Nark, Florian Ragwitz, Frank Wiegand, Franz Fasching, Gene Sullivan,
+George Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Grant McLean,
+gregor herrmann, H.Merijn Brand, Hongwen Qiu, Hugo van der Sanden, Ian
+Goodacre, James E Keenan, James Mastros, Jan Dubois, Jay Hannah, Jerry
+D. Hedden, Jesse Vincent, Jim Cromie, Jirka Hruška, John Peacock,
+Joshua ben Jore, Joshua Pritikin, Karl Williamson, Kevin Ryde, kmx,
+Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Larwan Berke, Leon Brocard, Leon
+Timmermans, Lubomir Rintel, Lukas Mai, Maik Hentsche, Marty Pauley,
+Marvin Humphrey, Matt Johnson, Matt S Trout, Max Maischein, Michael
+Breen, Michael Fig, Michael G Schwern, Michael Parker, Michael Stevens,
+Michael Witten, Mike Kelly, Moritz Lenz, Nicholas Clark, Nick Cleaton,
+Nick Johnston, Nicolas Kaiser, Niko Tyni, Noirin Shirley, Nuno Carvalho,
+Paul Evans, Paul Green, Paul Johnson, Paul Marquess, Peter J. Holzer,
+Peter John Acklam, Peter Martini, Philippe Bruhat (BooK), Piotr Fusik,
+Rafael Garcia-Suarez, Rainer Tammer, Reini Urban, Renee Baecker, Ricardo
+Signes, Richard Möhn, Richard Soderberg, Rob Hoelz, Robin Barker,
+Ruslan Zakirov, Salvador Fandiño, Salvador Ortiz Garcia, Shlomi Fish,
+Sinan Unur, Sisyphus, Slaven Rezic, Steffen Müller, Steve Hay, Steve
+Peters, Steven Schubiger, Sullivan Beck, Tatsuhiko Miyagawa, Tim Bunce,
+Todd Rinaldo, Tom Christiansen, Tom Hukins, Tony Cook, Tye McQueen, Vadim
+Konovalov, Vernon Lyon, Vincent Pit, Walt Mankowski, Wolfram Humann,
+Yves Orton, Zefram, Zsbán Ambrus and Ævar Arnfjörð Bjarmason.
+
+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 5.14.0 better. For a more complete
+list of all of Perl's historical contributors, please see the C<AUTHORS>
+file in the Perl 5.14.0 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
+community for helping Perl to flourish.
+
=head1 Reporting Bugs
If you find what you think is a bug, you might check the articles
-recently posted to the comp.lang.perl.misc newsgroup and the perl
+recently posted to the comp.lang.perl.misc newsgroup and the Perl
bug database at http://rt.perl.org/perlbug/ . There may also be
information at http://www.perl.org/ , the Perl Home Page.
If the bug you are reporting has security implications, which make it
inappropriate to send to a publicly archived mailing list, then please send
-it to perl5-security-report@perl.org. This points to a closed subscription
+it to perl5-security-report@perl.org. This points to a closed subscription
unarchived mailing list, which includes all the core committers, who be able
to help assess the impact of issues, figure out a resolution, and help
co-ordinate the release of patches to mitigate or fix the problem across all
-platforms on which Perl is supported. Please only use this address for
-security issues in the Perl core, not for modules independently
+platforms on which Perl is supported. Please use this address for
+security issues in the Perl core I<only>, not for modules independently
distributed on CPAN.
=head1 SEE ALSO
https://perl5.git.perl.org / perl5.git / blobdiff