FM / pod

/usr/share/perl5/pod

Name	Size	Mode	Actions
a2p.pod	6107	0644	edit dl rm
perl.pod	15748	0644	edit dl rm
perl56delta.pod	107184	0644	edit dl rm
perl58delta.pod	114908	0644	edit dl rm
perl561delta.pod	124697	0644	edit dl rm
perl570delta.pod	21655	0644	edit dl rm
perl571delta.pod	30382	0644	edit dl rm
perl572delta.pod	25551	0644	edit dl rm
perl573delta.pod	4644	0644	edit dl rm
perl581delta.pod	38060	0644	edit dl rm
perl582delta.pod	4470	0644	edit dl rm
perl583delta.pod	6335	0644	edit dl rm
perl584delta.pod	7363	0644	edit dl rm
perl585delta.pod	5889	0644	edit dl rm
perl586delta.pod	4651	0644	edit dl rm
perl587delta.pod	8357	0644	edit dl rm
perl588delta.pod	25267	0644	edit dl rm
perl589delta.pod	53905	0644	edit dl rm
perl590delta.pod	34951	0644	edit dl rm
perl591delta.pod	11173	0644	edit dl rm
perl592delta.pod	10954	0644	edit dl rm
perl593delta.pod	17034	0644	edit dl rm
perl594delta.pod	12661	0644	edit dl rm
perl595delta.pod	18934	0644	edit dl rm
perl5004delta.pod	56240	0644	edit dl rm
perl5005delta.pod	34285	0644	edit dl rm
perl5100delta.pod	53922	0644	edit dl rm
perl5101delta.pod	43877	0644	edit dl rm
perlaix.pod	18128	0644	edit dl rm
perlamiga.pod	7031	0644	edit dl rm
perlapi.pod	169428	0644	edit dl rm
perlapio.pod	19332	0644	edit dl rm
perlapollo.pod	829	0644	edit dl rm
perlartistic.pod	6802	0644	edit dl rm
perlbeos.pod	2939	0644	edit dl rm
perlbook.pod	663	0644	edit dl rm
perlboot.pod	28355	0644	edit dl rm
perlbot.pod	11675	0644	edit dl rm
perlbs2000.pod	7929	0644	edit dl rm
perlcall.pod	55173	0644	edit dl rm
perlce.pod	9257	0644	edit dl rm
perlcheat.pod	4153	0644	edit dl rm
perlclib.pod	7684	0644	edit dl rm
perlcn.pod	4915	0644	edit dl rm
perlcommunity.pod	6398	0644	edit dl rm
perlcompile.pod	9516	0644	edit dl rm
perlcygwin.pod	28183	0644	edit dl rm
perldata.pod	36879	0644	edit dl rm
perldbmfilter.pod	4987	0644	edit dl rm
perldebguts.pod	31887	0644	edit dl rm
perldebtut.pod	21304	0644	edit dl rm
perldebug.pod	37535	0644	edit dl rm
perldelta.pod	43877	0644	edit dl rm
perldgux.pod	2821	0644	edit dl rm
perldiag.pod	183151	0644	edit dl rm
perldoc.pod	7310	0644	edit dl rm
perldos.pod	10853	0644	edit dl rm
perldsc.pod	25447	0644	edit dl rm
perlebcdic.pod	66607	0644	edit dl rm
perlembed.pod	38033	0644	edit dl rm
perlepoc.pod	3779	0644	edit dl rm
perlfaq.pod	24841	0644	edit dl rm
perlfaq1.pod	17762	0644	edit dl rm
perlfaq2.pod	21614	0644	edit dl rm
perlfaq3.pod	38534	0644	edit dl rm
perlfaq4.pod	81412	0644	edit dl rm
perlfaq5.pod	49201	0644	edit dl rm
perlfaq6.pod	38538	0644	edit dl rm
perlfaq7.pod	37588	0644	edit dl rm
perlfaq8.pod	46128	0644	edit dl rm
perlfaq9.pod	24191	0644	edit dl rm
perlfilter.pod	21140	0644	edit dl rm
perlfork.pod	11440	0644	edit dl rm
perlform.pod	16894	0644	edit dl rm
perlfreebsd.pod	1950	0644	edit dl rm
perlfunc.pod	291909	0644	edit dl rm
perlglossary.pod	112139	0644	edit dl rm
perlgpl.pod	18806	0644	edit dl rm
perlguts.pod	105182	0644	edit dl rm
perlhack.pod	121512	0644	edit dl rm
perlhaiku.pod	1504	0644	edit dl rm
perlhist.pod	38766	0644	edit dl rm
perlhpux.pod	28650	0644	edit dl rm
perlhurd.pod	1990	0644	edit dl rm
perlintern.pod	26408	0644	edit dl rm
perlintro.pod	21491	0644	edit dl rm
perliol.pod	33755	0644	edit dl rm
perlipc.pod	67761	0644	edit dl rm
perlirix.pod	4397	0644	edit dl rm
perljp.pod	8070	0644	edit dl rm
perlko.pod	7892	0644	edit dl rm
perllexwarn.pod	14435	0644	edit dl rm
perllinux.pod	1492	0644	edit dl rm
perllocale.pod	41616	0644	edit dl rm
perllol.pod	8252	0644	edit dl rm
perlmachten.pod	4500	0644	edit dl rm
perlmacos.pod	2111	0644	edit dl rm
perlmacosx.pod	11322	0644	edit dl rm
perlmint.pod	9539	0644	edit dl rm
perlmod.pod	24494	0644	edit dl rm
perlmodinstall.pod	13929	0644	edit dl rm
perlmodlib.pod	77333	0644	edit dl rm
perlmodstyle.pod	21114	0644	edit dl rm
perlmpeix.pod	15087	0644	edit dl rm
perlmroapi.pod	2959	0644	edit dl rm
perlnetware.pod	6488	0644	edit dl rm
perlnewmod.pod	11214	0644	edit dl rm
perlnumber.pod	8352	0644	edit dl rm
perlobj.pod	21813	0644	edit dl rm
perlop.pod	96225	0644	edit dl rm
perlopenbsd.pod	1207	0644	edit dl rm
perlopentut.pod	37997	0644	edit dl rm
perlos2.pod	92783	0644	edit dl rm
perlos390.pod	16074	0644	edit dl rm
perlos400.pod	4618	0644	edit dl rm
perlothrtut.pod	40657	0644	edit dl rm
perlpacktut.pod	51047	0644	edit dl rm
perlperf.pod	51328	0644	edit dl rm
perlplan9.pod	5125	0644	edit dl rm
perlpod.pod	21626	0644	edit dl rm
perlpodspec.pod	67792	0644	edit dl rm
perlport.pod	86302	0644	edit dl rm
perlpragma.pod	4320	0644	edit dl rm
perlqnx.pod	4246	0644	edit dl rm
perlre.pod	82798	0644	edit dl rm
perlreapi.pod	25427	0644	edit dl rm
perlrebackslash.pod	20109	0644	edit dl rm
perlrecharclass.pod	21909	0644	edit dl rm
perlref.pod	26465	0644	edit dl rm
perlreftut.pod	18670	0644	edit dl rm
perlreguts.pod	36877	0644	edit dl rm
perlrepository.pod	23453	0644	edit dl rm
perlrequick.pod	17617	0644	edit dl rm
perlreref.pod	11996	0644	edit dl rm
perlretut.pod	115005	0644	edit dl rm
perlriscos.pod	1511	0644	edit dl rm
perlrun.pod	49928	0644	edit dl rm
perlsec.pod	23542	0644	edit dl rm
perlsolaris.pod	29131	0644	edit dl rm
perlstyle.pod	8618	0644	edit dl rm
perlsub.pod	54222	0644	edit dl rm
perlsymbian.pod	16222	0644	edit dl rm
perlsyn.pod	31090	0644	edit dl rm
perlthrtut.pod	46510	0644	edit dl rm
perltie.pod	36665	0644	edit dl rm
perltoc.pod	642987	0644	edit dl rm
perltodo.pod	48360	0644	edit dl rm
perltooc.pod	51425	0644	edit dl rm
perltoot.pod	68625	0644	edit dl rm
perltrap.pod	41151	0644	edit dl rm
perltru64.pod	7736	0644	edit dl rm
perltw.pod	5384	0644	edit dl rm
perlunicode.pod	56169	0644	edit dl rm
perlunifaq.pod	12878	0644	edit dl rm
perluniintro.pod	32973	0644	edit dl rm
perlunitut.pod	7907	0644	edit dl rm
perlutil.pod	9881	0644	edit dl rm
perluts.pod	3180	0644	edit dl rm
perlvar.pod	59133	0644	edit dl rm
perlvmesa.pod	3952	0644	edit dl rm
perlvms.pod	52545	0644	edit dl rm
perlvos.pod	5567	0644	edit dl rm
perlwin32.pod	40809	0644	edit dl rm
perlxs.pod	74194	0644	edit dl rm
perlxstut.pod	49670	0644	edit dl rm

Edit: /usr/share/perl5/pod/perl594delta.pod (12661B)

=head1 NAME

perl594delta - what is new for perl v5.9.4

=head1 DESCRIPTION

This document describes differences between the 5.9.3 and the 5.9.4
development releases. See L<perl590delta>, L<perl591delta>, L<perl592delta>
and L<perl593delta> for the differences between 5.8.0 and 5.9.3.

=head1 Incompatible Changes

=head2 chdir FOO

A bareword argument to chdir() is now recognized as a file handle.
Earlier releases interpreted the bareword as a directory name.
(Gisle Aas)

=head2 Handling of pmc files

An old feature of perl was that before C<require> or C<use> look for a
file with a F<.pm> extension, they will first look for a similar filename
with a F<.pmc> extension. If this file is found, it will be loaded in
place of any potentially existing file ending in a F<.pm> extension.

Previously, F<.pmc> files were loaded only if more recent than the
matching F<.pm> file. Starting with 5.9.4, they'll be always loaded if
they exist. (This trick is used by Pugs.)

=head2 @- and @+ in patterns

The special arrays C<@-> and C<@+> are no longer interpolated in regular
expressions. (Sadahiro Tomoyuki)

=head2 $AUTOLOAD can now be tainted

If you call a subroutine by a tainted name, and if it defers to an
AUTOLOAD function, then $AUTOLOAD will be (correctly) tainted.
(Rick Delaney)

=head1 Core Enhancements

=head2 state() variables

A new class of variables has been introduced. State variables are similar
to C<my> variables, but are declared with the C<state> keyword in place of
C<my>. They're visible only in their lexical scope, but their value is
persistent: unlike C<my> variables, they're not undefined at scope entry,
but retain their previous value. (Rafael Garcia-Suarez)

To use state variables, one needs to enable them by using

use feature "state";

or by using the C<-E> command-line switch in one-liners.

See L<perlsub/"Persistent variables via state()">.

=head2 UNIVERSAL::DOES()

The C<UNIVERSAL> class has a new method, C<DOES()>. It has been added to
solve semantic problems with the C<isa()> method. C<isa()> checks for
inheritance, while C<DOES()> has been designed to be overridden when
module authors use other types of relations between classes (in addition
to inheritance). (chromatic)

See L<< UNIVERSAL/"$obj->DOES( ROLE )" >>.

=head2 Exceptions in constant folding

The constant folding routine is now wrapped in an exception handler, and
if folding throws an exception (such as attempting to evaluate 0/0), perl
now retains the current optree, rather than aborting the whole program.
(Nicholas Clark, Dave Mitchell)

=head2 Source filters in @INC

It's possible to enhance the mechanism of subroutine hooks in @INC by
adding a source filter on top of the filehandle opened and returned by the
hook. This feature was planned a long time ago, but wasn't quite working
until now. See L<perlfunc/require> for details. (Nicholas Clark)

=head2 MAD

MAD, which stands for I<Misc Attribute Decoration>, is a
still-in-development work leading to a Perl 5 to Perl 6 converter. To
enable it, it's necessary to pass the argument C<-Dmad> to Configure. The
obtained perl isn't binary compatible with a regular perl 5.9.4, and has
space and speed penalties; moreover not all regression tests still pass
with it. (Larry Wall, Nicholas Clark)

=head1 Modules and Pragmas

=over 4

=item *

C<encoding::warnings> is now a lexical pragma. (Although on older perls,
which don't have support for lexical pragmas, it keeps its global
behaviour.) (Audrey Tang)

=item *

C<threads> is now a dual-life module, also available on CPAN. It has been
expanded in many ways. A kill() method is available for thread signalling.
One can get thread status, or the list of running or joinable threads.

A new C<< threads->exit() >> method is used to exit from the application
(this is the default for the main thread) or from the current thread only
(this is the default for all other threads). On the other hand, the exit()
built-in now always causes the whole application to terminate. (Jerry
D. Hedden)

=back

=head2 New Core Modules

=over 4

=item *

C<Hash::Util::FieldHash>, by Anno Siegel, has been added. This module
provides support for I<field hashes>: hashes that maintain an association
of a reference with a value, in a thread-safe garbage-collected way.
Such hashes are useful to implement inside-out objects.

=item *

C<Module::Build>, by Ken Williams, has been added. It's an alternative to
C<ExtUtils::MakeMaker> to build and install perl modules.

=item *

C<Module::Load>, by Jos Boumans, has been added. It provides a single
interface to load Perl modules and F<.pl> files.

=item *

C<Module::Loaded>, by Jos Boumans, has been added. It's used to mark
modules as loaded or unloaded.

=item *

C<Package::Constants>, by Jos Boumans, has been added. It's a simple
helper to list all constants declared in a given package.

=item *

C<Win32API::File>, by Tye McQueen, has been added (for Windows builds).
This module provides low-level access to Win32 system API calls for
files/dirs.

=back

=head1 Utility Changes

=head2 config_data

C<config_data> is a new utility that comes with C<Module::Build>. It
provides a command-line interface to the configuration of Perl modules
that use Module::Build's framework of configurability (that is,
C<*::ConfigData> modules that contain local configuration information for
their parent modules.)

=head1 Documentation

=head2 New manpage, perlpragma

The L<perlpragma> manpage documents how to write one's own lexical
pragmas in pure Perl (something that is possible starting with 5.9.4).

=head2 New manpage, perlreguts

The L<perlreguts> manpage, courtesy of Yves Orton, describes internals of the
Perl regular expression engine.

=head2 New manpage, perlunitut

The L<perlunitut> manpage is an tutorial for programming with Unicode and
string encodings in Perl, courtesy of Juerd Waalboer.

=head1 Performance Enhancements

=head2 Memory optimisations

Several internal data structures (typeglobs, GVs, CVs, formats) have been
restructured to use less memory. (Nicholas Clark)

=head2 UTF-8 cache optimisation

The UTF-8 caching code is now more efficient, and used more often.
(Nicholas Clark)

=head2 Regular expressions

=over 4

=item Engine de-recursivised

The regular expression engine is no longer recursive, meaning that
patterns that used to overflow the stack will either die with useful
explanations, or run to completion, which, since they were able to blow
the stack before, will likely take a very long time to happen. If you were
experiencing the occasional stack overflow (or segfault) and upgrade to
discover that now perl apparently hangs instead, look for a degenerate
regex. (Dave Mitchell)

=item Single char char-classes treated as literals

Classes of a single character are now treated the same as if the character
had been used as a literal, meaning that code that uses char-classes as an
escaping mechanism will see a speedup. (Yves Orton)

=item Trie optimisation of literal string alternations

Alternations, where possible, are optimised into more efficient matching
structures. String literal alternations are merged into a trie and are
matched simultaneously.  This means that instead of O(N) time for matching
N alternations at a given point the new code performs in O(1) time. (Yves
Orton)

B<Note:> Much code exists that works around perl's historic poor
performance on alternations. Often the tricks used to do so will disable
the new optimisations. Hopefully the utility modules used for this purpose
will be educated about these new optimisations by the time 5.10 is
released.

=item Aho-Corasick start-point optimisation

When a pattern starts with a trie-able alternation and there aren't
better optimisations available the regex engine will use Aho-Corasick
matching to find the start point. (Yves Orton)

=back

=head2 Sloppy stat on Windows

On Windows, perl's stat() function normally opens the file to determine
the link count and update attributes that may have been changed through
hard links. Setting ${^WIN32_SLOPPY_STAT} to a true value speeds up
stat() by not performing this operation. (Jan Dubois)

=head1 Installation and Configuration Improvements

=head2 Relocatable installations

There is now Configure support for creating a relocatable perl tree. If
you Configure with C<-Duserelocatableinc>, then the paths in @INC (and
everything else in %Config) can be optionally located via the path of the
perl executable.

That means that, if the string C<".../"> is found at the start of any
path, it's substituted with the directory of $^X. So, the relocation can
be configured on a per-directory basis, although the default with
C<-Duserelocatableinc> is that everything is relocated. The initial
install is done to the original configured prefix.

=head2 Ports

Many improvements have been made towards making Perl work correctly on
z/OS.

Perl has been reported to work on DragonFlyBSD.

=head2 Compilation improvements

All F<ppport.h> files in the XS modules bundled with perl are now
autogenerated at build time. (Marcus Holland-Moritz)

=head2 New probes

The configuration process now detects whether strlcat() and strlcpy() are
available.  When they are not available, perl's own version is used (from
Russ Allbery's public domain implementation).  Various places in the perl
interpreter now use them. (Steve Peters)

=head2 Windows build improvements

=over 4

=item Building XS extensions

Support for building XS extension modules with the free MinGW compiler has
been improved in the case where perl itself was built with the Microsoft
VC++ compiler. (ActiveState)

=item Support for 64-bit compiler

Support for building perl with Microsoft's 64-bit compiler has been
improved. (ActiveState)

=back

=head1 Selected Bug Fixes

=head2 PERL5SHELL and tainting

On Windows, the PERL5SHELL environment variable is now checked for
taintedness. (Rafael Garcia-Suarez)

=head2 Using *FILE{IO}

C<stat()> and C<-X> filetests now treat *FILE{IO} filehandles like *FILE
filehandles. (Steve Peters)

=head2 Overloading and reblessing

Overloading now works when references are reblessed into another class.
Internally, this has been implemented by moving the flag for "overloading"
from the reference to the referent, which logically is where it should
always have been. (Nicholas Clark)

=head2 Overloading and UTF-8

A few bugs related to UTF-8 handling with objects that have
stringification overloaded have been fixed. (Nicholas Clark)

=head2 eval memory leaks fixed

Traditionally, C<eval 'syntax error'> has leaked badly. Many (but not all)
of these leaks have now been eliminated or reduced. (Dave Mitchell)

=head2 Random device on Windows

In previous versions, perl would read the file F</dev/urandom> if it
existed when seeding its random number generator.  That file is unlikely
to exist on Windows, and if it did would probably not contain appropriate
data, so perl no longer tries to read it on Windows. (Alex Davies)

=head1 New or Changed Diagnostics

=over 4

=item State variable %s will be reinitialized

One can assign initial values to state variables, but not when they're
declared as a sub-part of a list assignment. See L<perldiag>.

=back

=head1 Changed Internals

A new file, F<mathoms.c>, contains functions that aren't used anymore in
the perl core, but remain around because modules out there might
still use them. They come from a factorization effort: for example, many
PP functions are now shared for several ops.

The implementation of the special variables $^H and %^H has changed, to
allow implementing lexical pragmas in pure perl.

=head1 Known Problems

One warning test (number 263 in F<lib/warnings.t>) fails under UTF-8
locales.

Bytecode tests fail under several platforms. We are considering removing
support for byteloader and compiler before the 5.10.0 release.

=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
bug database at http://rt.perl.org/rt3/ .  There may also be
information at http://www.perl.org/ , the Perl Home Page.

If you believe you have an unreported bug, please run the B<perlbug>
program included with your release.  Be sure to trim your bug down
to a tiny but sufficient test case.  Your bug report, along with the
output of C<perl -V>, will be sent off to perlbug@perl.org to be
analysed by the Perl porting team.

=head1 SEE ALSO

The F<Changes> file for exhaustive details on what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut

=head1 NAME perl594delta - what is new for perl v5.9.4 =head1 DESCRIPTION This document describes differences between the 5.9.3 and the 5.9.4 development releases. See L, L, L and L for the differences between 5.8.0 and 5.9.3. =head1 Incompatible Changes =head2 chdir FOO A bareword argument to chdir() is now recognized as a file handle. Earlier releases interpreted the bareword as a directory name. (Gisle Aas) =head2 Handling of pmc files An old feature of perl was that before C or C look for a file with a F<.pm> extension, they will first look for a similar filename with a F<.pmc> extension. If this file is found, it will be loaded in place of any potentially existing file ending in a F<.pm> extension. Previously, F<.pmc> files were loaded only if more recent than the matching F<.pm> file. Starting with 5.9.4, they'll be always loaded if they exist. (This trick is used by Pugs.) =head2 @- and @+ in patterns The special arrays C<@-> and C<@+> are no longer interpolated in regular expressions. (Sadahiro Tomoyuki) =head2 $AUTOLOAD can now be tainted If you call a subroutine by a tainted name, and if it defers to an AUTOLOAD function, then $AUTOLOAD will be (correctly) tainted. (Rick Delaney) =head1 Core Enhancements =head2 state() variables A new class of variables has been introduced. State variables are similar to C variables, but are declared with the C keyword in place of C. They're visible only in their lexical scope, but their value is persistent: unlike C variables, they're not undefined at scope entry, but retain their previous value. (Rafael Garcia-Suarez) To use state variables, one needs to enable them by using use feature "state"; or by using the C<-E> command-line switch in one-liners. See L. =head2 UNIVERSAL::DOES() The C class has a new method, C. It has been added to solve semantic problems with the C method. C checks for inheritance, while C has been designed to be overridden when module authors use other types of relations between classes (in addition to inheritance). (chromatic) See L<< UNIVERSAL/"$obj->DOES( ROLE )" >>. =head2 Exceptions in constant folding The constant folding routine is now wrapped in an exception handler, and if folding throws an exception (such as attempting to evaluate 0/0), perl now retains the current optree, rather than aborting the whole program. (Nicholas Clark, Dave Mitchell) =head2 Source filters in @INC It's possible to enhance the mechanism of subroutine hooks in @INC by adding a source filter on top of the filehandle opened and returned by the hook. This feature was planned a long time ago, but wasn't quite working until now. See L for details. (Nicholas Clark) =head2 MAD MAD, which stands for I, is a still-in-development work leading to a Perl 5 to Perl 6 converter. To enable it, it's necessary to pass the argument C<-Dmad> to Configure. The obtained perl isn't binary compatible with a regular perl 5.9.4, and has space and speed penalties; moreover not all regression tests still pass with it. (Larry Wall, Nicholas Clark) =head1 Modules and Pragmas =over 4 =item * C is now a lexical pragma. (Although on older perls, which don't have support for lexical pragmas, it keeps its global behaviour.) (Audrey Tang) =item * C is now a dual-life module, also available on CPAN. It has been expanded in many ways. A kill() method is available for thread signalling. One can get thread status, or the list of running or joinable threads. A new C<< threads->exit() >> method is used to exit from the application (this is the default for the main thread) or from the current thread only (this is the default for all other threads). On the other hand, the exit() built-in now always causes the whole application to terminate. (Jerry D. Hedden) =back =head2 New Core Modules =over 4 =item * C, by Anno Siegel, has been added. This module provides support for I: hashes that maintain an association of a reference with a value, in a thread-safe garbage-collected way. Such hashes are useful to implement inside-out objects. =item * C, by Ken Williams, has been added. It's an alternative to C to build and install perl modules. =item * C, by Jos Boumans, has been added. It provides a single interface to load Perl modules and F<.pl> files. =item * C, by Jos Boumans, has been added. It's used to mark modules as loaded or unloaded. =item * C, by Jos Boumans, has been added. It's a simple helper to list all constants declared in a given package. =item * C, by Tye McQueen, has been added (for Windows builds). This module provides low-level access to Win32 system API calls for files/dirs. =back =head1 Utility Changes =head2 config_data C is a new utility that comes with C. It provides a command-line interface to the configuration of Perl modules that use Module::Build's framework of configurability (that is, C<*::ConfigData> modules that contain local configuration information for their parent modules.) =head1 Documentation =head2 New manpage, perlpragma The L manpage documents how to write one's own lexical pragmas in pure Perl (something that is possible starting with 5.9.4). =head2 New manpage, perlreguts The L manpage, courtesy of Yves Orton, describes internals of the Perl regular expression engine. =head2 New manpage, perlunitut The L manpage is an tutorial for programming with Unicode and string encodings in Perl, courtesy of Juerd Waalboer. =head1 Performance Enhancements =head2 Memory optimisations Several internal data structures (typeglobs, GVs, CVs, formats) have been restructured to use less memory. (Nicholas Clark) =head2 UTF-8 cache optimisation The UTF-8 caching code is now more efficient, and used more often. (Nicholas Clark) =head2 Regular expressions =over 4 =item Engine de-recursivised The regular expression engine is no longer recursive, meaning that patterns that used to overflow the stack will either die with useful explanations, or run to completion, which, since they were able to blow the stack before, will likely take a very long time to happen. If you were experiencing the occasional stack overflow (or segfault) and upgrade to discover that now perl apparently hangs instead, look for a degenerate regex. (Dave Mitchell) =item Single char char-classes treated as literals Classes of a single character are now treated the same as if the character had been used as a literal, meaning that code that uses char-classes as an escaping mechanism will see a speedup. (Yves Orton) =item Trie optimisation of literal string alternations Alternations, where possible, are optimised into more efficient matching structures. String literal alternations are merged into a trie and are matched simultaneously. This means that instead of O(N) time for matching N alternations at a given point the new code performs in O(1) time. (Yves Orton) B Much code exists that works around perl's historic poor performance on alternations. Often the tricks used to do so will disable the new optimisations. Hopefully the utility modules used for this purpose will be educated about these new optimisations by the time 5.10 is released. =item Aho-Corasick start-point optimisation When a pattern starts with a trie-able alternation and there aren't better optimisations available the regex engine will use Aho-Corasick matching to find the start point. (Yves Orton) =back =head2 Sloppy stat on Windows On Windows, perl's stat() function normally opens the file to determine the link count and update attributes that may have been changed through hard links. Setting ${^WIN32_SLOPPY_STAT} to a true value speeds up stat() by not performing this operation. (Jan Dubois) =head1 Installation and Configuration Improvements =head2 Relocatable installations There is now Configure support for creating a relocatable perl tree. If you Configure with C<-Duserelocatableinc>, then the paths in @INC (and everything else in %Config) can be optionally located via the path of the perl executable. That means that, if the string C<".../"> is found at the start of any path, it's substituted with the directory of $^X. So, the relocation can be configured on a per-directory basis, although the default with C<-Duserelocatableinc> is that everything is relocated. The initial install is done to the original configured prefix. =head2 Ports Many improvements have been made towards making Perl work correctly on z/OS. Perl has been reported to work on DragonFlyBSD. =head2 Compilation improvements All F files in the XS modules bundled with perl are now autogenerated at build time. (Marcus Holland-Moritz) =head2 New probes The configuration process now detects whether strlcat() and strlcpy() are available. When they are not available, perl's own version is used (from Russ Allbery's public domain implementation). Various places in the perl interpreter now use them. (Steve Peters) =head2 Windows build improvements =over 4 =item Building XS extensions Support for building XS extension modules with the free MinGW compiler has been improved in the case where perl itself was built with the Microsoft VC++ compiler. (ActiveState) =item Support for 64-bit compiler Support for building perl with Microsoft's 64-bit compiler has been improved. (ActiveState) =back =head1 Selected Bug Fixes =head2 PERL5SHELL and tainting On Windows, the PERL5SHELL environment variable is now checked for taintedness. (Rafael Garcia-Suarez) =head2 Using *FILE{IO} C and C<-X> filetests now treat *FILE{IO} filehandles like *FILE filehandles. (Steve Peters) =head2 Overloading and reblessing Overloading now works when references are reblessed into another class. Internally, this has been implemented by moving the flag for "overloading" from the reference to the referent, which logically is where it should always have been. (Nicholas Clark) =head2 Overloading and UTF-8 A few bugs related to UTF-8 handling with objects that have stringification overloaded have been fixed. (Nicholas Clark) =head2 eval memory leaks fixed Traditionally, C has leaked badly. Many (but not all) of these leaks have now been eliminated or reduced. (Dave Mitchell) =head2 Random device on Windows In previous versions, perl would read the file F if it existed when seeding its random number generator. That file is unlikely to exist on Windows, and if it did would probably not contain appropriate data, so perl no longer tries to read it on Windows. (Alex Davies) =head1 New or Changed Diagnostics =over 4 =item State variable %s will be reinitialized One can assign initial values to state variables, but not when they're declared as a sub-part of a list assignment. See L. =back =head1 Changed Internals A new file, F, contains functions that aren't used anymore in the perl core, but remain around because modules out there might still use them. They come from a factorization effort: for example, many PP functions are now shared for several ops. The implementation of the special variables $^H and %^H has changed, to allow implementing lexical pragmas in pure perl. =head1 Known Problems One warning test (number 263 in F) fails under UTF-8 locales. Bytecode tests fail under several platforms. We are considering removing support for byteloader and compiler before the 5.10.0 release. =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 bug database at http://rt.perl.org/rt3/ . There may also be information at http://www.perl.org/ , the Perl Home Page. If you believe you have an unreported bug, please run the B program included with your release. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report, along with the output of C, will be sent off to perlbug@perl.org to be analysed by the Perl porting team. =head1 SEE ALSO The F file for exhaustive details on what changed. The F file for how to build Perl. The F file for general stuff. The F and F files for copyright information. =cut