=head1 DESCRIPTION
-This document describes differences between the 5.6.0 release and the
-5.8.0 release.
+This document describes differences between the 5.6.0 release
+and the 5.8.0 release.
+
+Many of the bug fixes in 5.8.0 were already seen in the 5.6.1
+maintenance release since the two releases were kept closely
+coordinated.
+
+If you are upgrading from Perl 5.005_03, you might also want
+to read L<perl56delta>.
+
+=head1 Highlights In 5.8.0
+
+=over 4
+
+=item *
+
+Better Unicode support
+
+=item *
+
+New Thread Implementation
+
+=item *
+
+Many New Modules
+
+=item *
+
+Better Numeric Accuracy
+
+=item *
+
+Safe Signals
+
+=item *
+
+More Extensive Regression Testing
+
+=back
=head1 Incompatible Changes
=head2 64-bit platforms and malloc
-If your pointers are 64 bits wide, the Perl malloc is no more being
-used because it simply does not work with 8-byte pointers. Also,
+If your pointers are 64 bits wide, the Perl malloc is no longer being
+used because it does not work well with 8-byte pointers. Also,
usually the system mallocs on such platforms are much better optimized
-for such large memory models than the Perl malloc. Such platforms
-include 64-bit Alpha, MIPS, HPPA, PPC, and Sparc.
+for such large memory models than the Perl malloc. Some memory-hungry
+Perl applications like the PDL don't work well with Perl's malloc.
+Finally, other applications than Perl (like modperl) tend to prefer
+the system malloc. Such platforms include Alpha and 64-bit HPPA,
+MIPS, PPC, and Sparc.
=head2 AIX Dynaloading
TCP/IP stacks of VMS: we do not know since we weren't able to test
Perl in such configurations.
+=head2 IEEE-format Floating Point Default on OpenVMS Alpha
+
+Perl now uses IEEE format (T_FLOAT) as the default internal floating
+point format on OpenVMS Alpha, potentially breaking binary compatibility
+with external libraries or existing data. G_FLOAT is still available as
+a configuration option. The default on VAX (D_FLOAT) has not changed.
+
=head2 Different Definition of the Unicode Character Classes \p{In...}
As suggested by the Unicode consortium, the Unicode character classes
Markov chain input and the few found crashes and lockups have been
fixed.
-=head2 Deprecations
+=head2 REF(...) Instead Of SCALAR(...)
-The current user-visible implementation of pseudo-hashes (the weird
-use of the first array element) is deprecated starting from Perl 5.8.0
-and will be removed in Perl 5.10.0, and the feature will be
-implemented differently. Not only is the current interface rather
-ugly, but the current implementation slows down normal array and hash
-use quite noticeably. The C<fields> pragma interface will remain
-available.
-
-The syntaxes C<@a->[...]> and C<@h->{...}> have now been deprecated.
-
-After years of trying the suidperl is considered to be too complex to
-ever be considered truly secure. The suidperl functionality is likely
-to be removed in a future release.
+A reference to a reference now stringifies as "REF(0x81485ec)" instead
+of "SCALAR(0x81485ec)" in order to be more consistent with the return
+value of ref().
-The C<package;> syntax (C<package> without an argument has been
-deprecated. Its semantics were never that clear and its
-implementation even less so. If you have used that feature to
-disallow all but fully qualified variables, C<use strict;> instead.
+=head2 Deprecations
=over 4
=item *
-A reference to a reference now stringify as "REF(0x81485ec)" instead
-of "SCALAR(0x81485ec)" in order to be more consistent with the return
-value of ref().
+The obsolete chat2 library that should never have been allowed
+to escape the laboratory has been decommissioned.
=item *
=item *
-The obsolete chat2 library that should never have been allowed
-to escape the laboratory has been decommissioned.
+The (bogus) escape sequences \8 and \9 now give an optional warning
+("Unrecognized escape passed through"). There is no need to \-escape
+any C<\w> character.
=item *
-The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
-recognised but now cause fatal errors. The previous behaviour of
-ignoring them by default and warning if requested was unacceptable
-since it, in a way, falsely promised that the features could be used.
+The list of filenames from glob() (or <...>) is now by default sorted
+alphabetically to be csh-compliant (which is what happened before
+in most UNIX platforms). (bsd_glob() does still sort platform
+natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
=item *
-The (bogus) escape sequences \8 and \9 now give an optional warning
-("Unrecognized escape passed through"). There is no need to \-escape
-any C<\w> character.
+Spurious syntax errors generated in certain situations, when glob()
+caused File::Glob to be loaded for the first time, have been fixed.
+
+=item *
+
+Although "you shouldn't do that", it was possible to write code that
+depends on Perl's hashed key order (Data::Dumper does this). The new
+algorithm "One-at-a-Time" produces a different hashed key order.
+More details are in L</"Performance Enhancements">.
=item *
=item *
-The long deprecated uppercase aliases for the string comparison
-operators (EQ, NE, LT, LE, GE, GT) have now been removed.
+The C<package;> syntax (C<package> without an argument) has been
+deprecated. Its semantics were never that clear and its
+implementation even less so. If you have used that feature to
+disallow all but fully qualified variables, C<use strict;> instead.
=item *
-The regular expression captured submatches ($1, $2, ...) are now
-more consistently unset if the match fails, instead of leaving false
-data lying around in them.
+The unimplemented POSIX regex features [[.cc.]] and [[=c=]] are still
+recognised but now cause fatal errors. The previous behaviour of
+ignoring them by default and warning if requested was unacceptable
+since it, in a way, falsely promised that the features could be used.
=item *
-The tr///C and tr///U features have been removed and will not return;
-the interface was a mistake. Sorry about that. For similar
-functionality, see pack('U0', ...) and pack('C0', ...).
+The current user-visible implementation of pseudo-hashes (the weird
+use of the first array element) is deprecated starting from Perl 5.8.0
+and will be removed in Perl 5.10.0, and the feature will be
+implemented differently. Not only is the current interface rather
+ugly, but the current implementation slows down normal array and hash
+use quite noticeably. The C<fields> pragma interface will remain
+available.
=item *
-Although "you shouldn't do that", it was possible to write code that
-depends on Perl's hashed key order (Data::Dumper does this). The new
-algorithm "One-at-a-Time" produces a different hashed key order.
-More details are in L</"Performance Enhancements">.
+The syntaxes C<< @a->[...] >> and C<< %h->{...} >> have now been deprecated.
=item *
-The list of filenames from glob() (or <...>) is now by default sorted
-alphabetically to be csh-compliant. (bsd_glob() does still sort platform
-natively, ASCII or EBCDIC, unless GLOB_ALPHASORT is specified.)
+After years of trying the suidperl is considered to be too complex to
+ever be considered truly secure. The suidperl functionality is likely
+to be removed in a future release.
-=back
+=item *
-=head1 Core Enhancements
+The long deprecated uppercase aliases for the string comparison
+operators (EQ, NE, LT, LE, GE, GT) have now been removed.
-=head2 AUTOLOAD Is Now Lvaluable
+=item *
-AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
-to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+The tr///C and tr///U features have been removed and will not return;
+the interface was a mistake. Sorry about that. For similar
+functionality, see pack('U0', ...) and pack('C0', ...).
+
+=back
+
+=head1 Core Enhancements
=head2 PerlIO is Now The Default
creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
the child process.
-=item *
-
-The following builtin functions are now overridable: chop(), chomp(),
-each(), keys(), pop(), push(), shift(), splice(), unshift().
-
-=item *
-
-Formats now support zero-padded decimal fields.
-
-=item *
+=back
-Perl now tries internally to use integer values in numeric conversions
-and basic arithmetics (+ - * /) if the arguments are integers, and
-tries also to keep the results stored internally as integers.
-This change leads into often slightly faster and always less lossy
-arithmetics. (Previously Perl always preferred floating point numbers
-in its math.)
+=head2 Signals Are Now Safe
-=item *
+Perl used to be fragile in that signals arriving at inopportune moments
+could corrupt Perl's internal state. Now Perl postpones handling of
+signals until it's safe.
-The printf() and sprintf() now support parameter reordering using the
-C<%\d+\$> and C<*\d+\$> syntaxes. For example
+=head2 Unicode Overhaul
- print "%2\$s %1\$s\n", "foo", "bar";
+Unicode in general should be now much more usable than in Perl 5.6.0
+(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
+regular expressions should work now, Unicode in tr/// should work now,
+Unicode in I/O should work now.
-will print "bar foo\n"; This feature helps in writing
-internationalised software.
+=over 4
=item *
-Unicode in general should be now much more usable. Unicode can be
-used in hash keys, Unicode in regular expressions should work now,
-Unicode in tr/// should work now (though tr/// seems to be a
-particularly tricky to get right, so you have been warned)
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.1.1. For more information, see http://www.unicode.org/.
=item *
-The Unicode Character Database coming with Perl has been upgraded
-to Unicode 3.1. For more information, see http://www.unicode.org/,
-and http://www.unicode.org/unicode/reports/tr27/
-
For developers interested in enhancing Perl's Unicode capabilities:
almost all the UCD files are included with the Perl distribution in
-the lib/unicode subdirectory. The most notable omission, for space
+the lib/unicore subdirectory. The most notable omission, for space
considerations, is the Unihan database.
=item *
=back
-=head2 Signals Are Now Safe
-
-Perl used to be fragile in that signals arriving at inopportune moments
-could corrupt Perl's internal state.
-
=head2 Understanding of Numbers
In general a lot of fixing has happened in the area of Perl's
and C<atof()> seem to have bugs, Perl tries to work around their
deficiencies. This results hopefully in more accurate numbers.
+Perl now tries internally to use integer values in numeric conversions
+and basic arithmetics (+ - * /) if the arguments are integers, and
+tries also to keep the results stored internally as integers.
+This change leads to often slightly faster and always less lossy
+arithmetics. (Previously Perl always preferred floating point numbers
+in its math.)
+
+=head2 Miscellaneous Enhancements
+
=over 4
=item *
+AUTOLOAD is now lvaluable, meaning that you can add the :lvalue attribute
+to AUTOLOAD subroutines and you can assign to the AUTOLOAD return value.
+
+=item *
+
C<perl -d:Module=arg,arg,arg> now works (previously one couldn't pass
in multiple arguments.)
=item *
-Lexicals I: lexicals outside an eval "" weren't resolved
-correctly inside a subroutine definition inside the eval "" if they
-were not already referenced in the top level of the eval""ed code.
-
-=item *
-
-Lexicals II: lexicals leaked at file scope into subroutines that
-were declared before the lexicals.
+Formats now support zero-padded decimal fields.
=item *
Lvalue subroutines can now return C<undef> in list context.
+However, the lvalue subroutine feature still remains experimental.
=item *
=item *
+The following builtin functions are now overridable: each(), keys(),
+pop(), push(), shift(), splice(), unshift().
+
+=item *
+
C<pack('U0a*', ...)> can now be used to force a string to UTF8.
=item *
=item *
-prototype(\&) is now available.
+The printf() and sprintf() now support parameter reordering using the
+C<%\d+\$> and C<*\d+\$> syntaxes. For example
+
+ print "%2\$s %1\$s\n", "foo", "bar";
+
+will print "bar foo\n". This feature helps in writing
+internationalised software, and in general when the order
+of the parameters can vary.
=item *
-Right-hand side magic (GMAGIC) could in many cases such as string
-concatenation be invoked too many times.
+prototype(\&) is now available.
=item *
-The rules for allowing underscores (underbars) in numeric constants
-have been relaxed and simplified: now you can have an underscore
-simply B<between digits>.
+prototype(\[$@%&]) is now available to implicitly create references
+(useful for example if you want to emulate the tie() interface).
=item *
-An UNTIE method is now available.
+untie() will now call an UNTIE() hook if it exists. See L<perltie>
+for details.
=item *
=item *
-C<eval "v200"> now works.
+The rules for allowing underscores (underbars) in numeric constants
+have been relaxed and simplified: now you can have an underscore
+simply B<between digits>.
=back
=head1 Modules and Pragmata
-=head2 New Modules
+=head2 New Modules and Pragmata
=over 4
=item *
+C<Devel::PPPort>, originally from Kenneth Albanowski and now
+maintained by Paul Marquess, has been added. It is primarily used
+by C<h2xs> to enhance portability of of XS modules between different
+versions of Perl.
+
+=item *
+
C<Digest>, frontend module for calculating digests (checksums), from
Gisle Aas, has been added. See L<Digest>.
print $digest, "\n"; # 01d19d9d2045e005c3f1b80e8b164de1
NOTE: the C<MD5> backward compatibility module is deliberately not
-included since its use is discouraged.
+included since its further use is discouraged.
=item *
=item *
C<I18N::LangTags> has functions for dealing with RFC3066-style
-language tags, by Sean Burke. See <I18N::LangTags>.
+language tags, by Sean Burke. See L<I18N::LangTags>.
=item *
=item *
C<List::Util> is a selection of general-utility list subroutines, like
-sum(), min(), first(), and shuffle(), by Graham barr. See L<List::Util>.
+sum(), min(), first(), and shuffle(), by Graham Barr. See L<List::Util>.
=item *
necessary to use it with PerlIO::Via as in :
use MIME::QuotedPrint;
- open($fh,">Via(MIME::QuotedPrint)",$path)
+ open($fh,">Via(MIME::QuotedPrint)",$path);
See L<MIME::QuotedPrint>.
=item *
+C<open> is a new pragma for setting the default I/O disciplines
+for open().
+
+=item *
+
C<PerlIO::Scalar> provides the implementation of IO to "in memory"
Perl scalars as discussed above, from Nick Ing-Simmons. It also
serves as an example of a loadable PerlIO layer. Other future
code), from Nick Ing-Simmons.
use MIME::QuotedPrint;
- open($fh,">Via(MIME::QuotedPrint)",$path)
+ open($fh,">Via(MIME::QuotedPrint)",$path);
This will automatically convert everything output to C<$fh>
to Quoted-Printable. See L<PerlIO::Via>.
=item *
+C<Pod::ParseLink>, by Russ Allbery, has been added,
+to parse L<> links in pods as described in the new
+perlpodspec.
+
+=item *
+
C<Pod::Text::Overstrike>, by Joe Smith, has been added.
It converts POD data to formatted overstrike text.
See L<Pod::Text::Overstrike>.
=item *
+C<sort> is a new pragma for controlling the behaviour of sort().
+
+=item *
+
C<Storable> gives persistence to Perl data structures by allowing the
storage and retrieval of Perl data to and from files in a fast and
compact binary format, from Raphael Manfredi. See L<Storable>.
=item *
-C<Test::Simple> has the- basic utilities for writing tests, by Michael
+C<Test::Simple> has basic utilities for writing tests, by Michael
Schwern. See L<Test::Simple>.
=item *
=item *
-C<threads> is an interface interpreter threads, by Arthur Bergman.
+C<threads> is an interface to interpreter threads, by Arthur Bergman.
Interpreter threads (ithreads) is the new thread model introduced in
-Perl 5.6 but then available only as an internal interface for
-extension writers. See L<threads>.
+Perl 5.6 but only available as an internal interface for extension
+writers (and for Win32 Perl for C<fork()> emulation). See L<threads>.
=item *
=item *
-AutoLoader can now be disabled with C<no AutoLoader;>,
+AutoLoader can now be disabled with C<no AutoLoader;>.
=item *
-Data::Dumper has now an option to sort hashes.
+B::Deparse has been significantly enhanced. It now can deparse almost
+all of the standard test suite (so that the tests still succeed).
+There is a make target "test.deparse" for trying this out.
=item *
-The English module can now be used without the infamous performance
-hit by saying
-
- use English '-no_performance_hit';
-
-(Assuming, of course, that one doesn't need the troublesome variables
-C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
-C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
+Class::Struct can now define the classes in compile time.
=item *
-File::Find now has pre- and post-processing callbacks. It also
-correctly changes directories when chasing symbolic links. Callbacks
-(naughtily) exiting with "next;" instead of "return;" now work.
+Class::Struct now assigns the array/hash element if the accessor
+is called with an array/hash element as the B<sole> argument.
=item *
-File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
-prototype mismatch with CORE::glob().
+Data::Dumper has now an option to sort hashes.
=item *
-IPC::Open3 now allows the use of numeric file descriptors.
+Data::Dumper has now an option to dump code references
+using B::Deparse.
=item *
-use lib now works identically to @INC. Removing directories
-with 'no lib' now works.
+DB_File now supports newer Berkeley DB versions, among
+other improvements.
=item *
-C<%INC> now localised in a Safe compartment so that use/require work.
+The English module can now be used without the infamous performance
+hit by saying
-=item *
+ use English '-no_performance_hit';
-The Shell module now has an OO interface.
+(Assuming, of course, that one doesn't need the troublesome variables
+C<$`>, C<$&>, or C<$'>.) Also, introduced C<@LAST_MATCH_START> and
+C<@LAST_MATCH_END> English aliases for C<@-> and C<@+>.
=item *
-B::Deparse has been significantly enhanced. It now can deparse almost
-all of the standard test suite (so that the tests still succeed).
-There is a make target "test.deparse" for trying this out.
+Fcntl, Socket, and Sys::Syslog have been rewritten to use the
+new-style constant dispatch section (see L<ExtUtils::Constant>).
+This means that they will be more robust and hopefully faster.
=item *
-Class::Struct can now define the classes in compile time.
+File::Find now chdir()s correctly when chasing symbolic links.
=item *
-Class::Struct now assigns the array/hash element if the accessor
-is called with an array/hash element as the B<sole> argument.
+File::Find now has pre- and post-processing callbacks. It also
+correctly changes directories when chasing symbolic links. Callbacks
+(naughtily) exiting with "next;" instead of "return;" now work.
=item *
-Fcntl, Socket, and Sys::Syslog have been rewritten to use the
-new-style constant dispatch section (see L<ExtUtils::Constant>).
+File::Find is now (again) reentrant. It also has been made
+more portable.
=item *
-File::Find is now (again) reentrant. It also has been made
-more portable.
+File::Glob::glob() renamed to File::Glob::bsd_glob() to avoid
+prototype mismatch with CORE::glob().
=item *
=item *
+IPC::Open3 now allows the use of numeric file descriptors.
+
+=item *
+
IO::Socket has now atmark() method, which returns true if the socket
is positioned at the out-of-band mark. The method is also exportable
as a sockatmark() function.
=item *
-Math::BigFloat and Math::BigInt have undergone much fixing,
-they are now magnitudes faster, and they support various
+use lib now works identically to @INC. Removing directories
+with 'no lib' now works.
+
+=item *
+
+Math::BigFloat and Math::BigInt have undergone a full rewrite.
+They are now magnitudes faster, and they support various
bignum libraries such as GMP and PARI as their backends.
=item *
-Net::Ping has been enhanced. There is now "external" protocol which
-uses Net::Ping::External module which runs external ping(1) and parses
-the output. An alpha version of Net::Ping::External is available in
-CPAN and in 5.7.2 the Net::Ping::External may be integrated to Perl.
+Math::Complex handles inf, NaN etc., better.
=item *
-The C<open> pragma allows layers other than ":raw" and ":crlf" when
-using PerlIO.
+Net::Ping has been enhanced. There is now "external" protocol which
+uses Net::Ping::External module which runs external ping(1) and parses
+the output. A version of Net::Ping::External is available in CPAN.
=item *
=item *
+In Safe the C<%INC> now localised in a Safe compartment so that
+use/require work.
+
+=item *
+
+In SDBM_File on dosish platforms, some keys went missing because of
+lack of support for files with "holes". A workaround for the problem
+has been added.
+
+=item *
+
+In Search::Dict one can now have a pre-processing hook for the
+lines being searched.
+
+=item *
+
+The Shell module now has an OO interface.
+
+=item *
+
The Test module has been significantly enhanced.
=item *
-The C<vars> pragma now supports declaring fully qualified variables.
+The vars pragma now supports declaring fully qualified variables.
(Something that C<our()> does not and will not support.)
=item *
=item *
-h2xs now produces a template README.
+C<h2ph> now supports C trigraphs.
+
+=item *
+
+C<h2xs> now produces a template README.
=item *
-L<h2ph> now supports C trigraphs.
+C<h2xs> now uses C<Devel::PPort> for better portability between
+different versions of Perl.
=item *
-L<h2xs> uses the new L<ExtUtils::Constant> module which will affect
+C<h2xs> uses the new L<ExtUtils::Constant> module which will affect
newly created extensions that define constants. Since the new code is
more correct (if you have two constants where the first one is a
prefix of the second one, the first constant B<never> gets defined),
=item *
-L<libnetcfg> has been added to configure the libnet.
+C<libnetcfg> has been added to configure the libnet.
=item *
-perlbug is now much more robust. It also sends the bug report to
+C<perlbug> is now much more robust. It also sends the bug report to
perl.org, not perl.com.
=item *
-perlcc has been rewritten and its user interface (that is,
+C<perlcc> has been rewritten and its user interface (that is,
command line) is much more like that of the UNIX C compiler, cc.
+(The perlbc tools has been removed. Use C<perlcc -B> instead.)
=item *
-perlivp is a new utility for doing Installation Verification
-Procedure after installing Perl.
+C<perlivp> is a new Installation Verification Procedure utility
+for running any time after installing Perl.
=item *
-pod2html now allows specifying a cache directory.
+C<pod2html> now allows specifying a cache directory.
=item *
-s2p has been completely rewritten in Perl. (It is in fact a full
-implementation of sed in Perl.)
+C<s2p> has been completely rewritten in Perl. (It is in fact a full
+implementation of sed in Perl: you can use the sed functionality by
+using the C<psed> utility.)
=item *
-xsubpp now understands POD documentation embedded in the *.xs files.
+C<xsubpp> now understands POD documentation embedded in the *.xs files.
=item *
-xsubpp now supports OUT keyword.
+C<xsubpp> now supports OUT keyword.
=back
=item *
perlebcdic contains considerations for running Perl on EBCDIC platforms.
-Note that unfortunately EBCDIC platforms that used to supported back in
-Perl 5.005 are still unsupported by Perl 5.7.0; the plan, however, is to
-bring them back to the fold.
=item *
=item *
+perlpacktut is a pack() tutorial.
+
+=item *
+
perlpod has been rewritten to be clearer and to record the best
practices gathered over the years.
=item *
-perlpodstyle is a more formal specification of the pod format,
+perlpodspec is a more formal specification of the pod format,
mainly of interest for writers of pod applications, not to
people writing in pod.
=item *
-perlposix-bc explains using Perl on the POSIX-BC platform
-(an EBCDIC mainframe platform).
-
-=item *
-
perlretut is a regular expression tutorial.
=item *
=item *
-map() that changes the size of the list should now work faster.
-
-=item *
-
-sort() has been changed to use mergesort internally as opposed to the
-earlier quicksort. For very small lists this may result in slightly
-slower sorting times, but in general the speedup should be at least
-20%. Additional bonuses are that the worst case behaviour of sort()
-is now better (in computer science terms it now runs in time O(N log N),
-as opposed to quicksort's Theta(N**2) worst-case run time behaviour),
-and that sort() is now stable (meaning that elements with identical
-keys will stay ordered as they were before the sort).
+map() could get pathologically slow when the result list it generates
+is larger than the source list. The performance has been improved for
+common scenarios.
+
+=item *
+
+sort() has been changed to use primarily mergesort internally as
+opposed to the earlier quicksort. For very small lists this may
+result in slightly slower sorting times, but in general the speedup
+should be at least 20%. Additional bonuses are that the worst case
+behaviour of sort() is now better (in computer science terms it now
+runs in time O(N log N), as opposed to quicksort's Theta(N**2)
+worst-case run time behaviour), and that sort() is now stable
+(meaning that elements with identical keys will stay ordered as they
+were before the sort). See the C<sort> pragma for information.
+
+The story in more detail: suppose you want to serve yourself a little
+slice of Pi.
+
+ @digits = ( 3,1,4,1,5,9 );
+
+A numerical sort of the digits will yield (1,1,3,4,5,9), as expected.
+Which C<1> comes first is hard to know, since one C<1> looks pretty
+much like any other. You can regard this as totally trivial,
+or somewhat profound. However, if you just want to sort the even
+digits ahead of the odd ones, then what will
+
+ sort { ($a % 2) <=> ($b % 2) } @digits;
+
+yield? The only even digit, C<4>, will come first. But how about
+the odd numbers, which all compare equal? With the quicksort algorithm
+used to implement Perl 5.6 and earlier, the order of ties is left up
+to the sort. So, as you add more and more digits of Pi, the order
+in which the sorted even and odd digits appear will change.
+and, for sufficiently large slices of Pi, the quicksort algorithm
+in Perl 5.8 won't return the same results even if reinvoked with the
+same input. The justification for this rests with quicksort's
+worst case behavior. If you run
+
+ sort { $a <=> $b } ( 1 .. $N , 1 .. $N );
+
+(something you might approximate if you wanted to merge two sorted
+arrays using sort), doubling $N doesn't just double the quicksort time,
+it I<quadruples> it. Quicksort has a worst case run time that can
+grow like N**2, so-called I<quadratic> behaviour, and it can happen
+on patterns that may well arise in normal use. You won't notice this
+for small arrays, but you I<will> notice it with larger arrays,
+and you may not live long enough for the sort to complete on arrays
+of a million elements. So the 5.8 quicksort scrambles large arrays
+before sorting them, as a statistical defence against quadratic behaviour.
+But that means if you sort the same large array twice, ties may be
+broken in different ways.
+
+Because of the unpredictability of tie-breaking order, and the quadratic
+worst-case behaviour, quicksort was I<almost> replaced completely with
+a stable mergesort. I<Stable> means that ties are broken to preserve
+the original order of appearance in the input array. So
+
+ sort { ($a % 2) <=> ($b % 2) } (3,1,4,1,5,9);
+
+will yield (4,3,1,1,5,9), guaranteed. The even and odd numbers
+appear in the output in the same order they appeared in the input.
+Mergesort has worst case O(NlogN) behaviour, the best value
+attainable. And, ironically, this mergesort does particularly
+well where quicksort goes quadratic: mergesort sorts (1..$N, 1..$N)
+in O(N) time. But quicksort was rescued at the last moment because
+it is faster than mergesort on certain inputs and platforms.
+For example, if you really I<don't> care about the order of even
+and odd digits, quicksort will run in O(N) time; it's very good
+at sorting many repetitions of a small number of distinct elements.
+The quicksort divide and conquer strategy works well on platforms
+with relatively small, very fast, caches. Eventually, the problem gets
+whittled down to one that fits in the cache, from which point it
+benefits from the increased memory speed.
+
+Quicksort was rescued by implementing a sort pragma to control aspects
+of the sort. The B<stable> subpragma forces stable behaviour,
+regardless of algorithm. The B<_quicksort> and B<_mergesort>
+subpragmas are heavy-handed ways to select the underlying implementation.
+The leading C<_> is a reminder that these subpragmas may not survive
+beyond 5.8. More appropriate mechanisms for selecting the implementation
+exist, but they wouldn't have arrived in time to save quicksort.
=item *
=item *
+Configure support for pdp11-style memory models has been removed due
+to obsolescence.
+
+=item *
+
configure.gnu now works with options with whitespace in them.
=item *
=item *
+If your file system supports symbolic links you can build Perl outside
+of the source directory by
+
+ mkdir /tmp/perl/build/directory
+ cd /tmp/perl/build/directory
+ sh /path/to/perl/source/Configure -Dmksymlinks ...
+
+This will create in /tmp/perl/build/directory a tree of symbolic links
+pointing to files in /path/to/perl/source. The original files are left
+unaffected. After Configure has finished you can just say
+
+ make all test
+
+and Perl will be built and tested, all in /tmp/perl/build/directory.
+
+=item *
+
For Perl developers several new make targets for profiling
and debugging have been added, see L<perlhack>.
=item *
-Amdahl UTS UNIX mainframe platform is now supported.
+NEC SUPER-UX is now supported.
+
+=item *
+
+Amdahl UTS UNIX mainframe platform is now supported.
+
+=item *
+
+WinCE is now supported. See L<perlce>.
+
+=item *
+
+z/OS (formerly known as OS/390, formerly known as MVS OE) has now
+support for dynamic loading. This is not selected by default,
+however, you must specify -Dusedl in the arguments of Configure.
+
+=back
+
+=head1 Selected Bug Fixes
+
+Numerous memory leaks and uninitialized memory accesses have been
+hunted down. Most importantly anonymous subs used to leak quite
+a bit.
+
+=over 4
+
+=item *
+
+The autouse pragma didn't work for Multi::Part::Function::Names.
+
+=item *
+
+caller() could cause core dumps in certain situations. Carp was sometimes
+affected by this problem.
=item *
-WinCE is now supported. See L<perlce>.
+chop(@list) in list context returned the characters chopped in
+reverse order. This has been reversed to be in the right order.
=item *
-z/OS (formerly known as OS/390, formerly known as MVS OE) has now
-support for dynamic loading. This is not selected by default,
-however, you must specify -Dusedl in the arguments of Configure.
+Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
+when building the Perl binary. The only exception to this is SunOS 4.x,
+which needs them.
-=back
+=item *
-=head1 Selected Bug Fixes
+The behaviour of non-decimal but numeric string constants such as
+"0x23" was platform-dependent: in some platforms that was seen as 35,
+in some as 0, in some as a floating point number (don't ask). This
+was caused by Perl using the operating system libraries in a situation
+where the result of the string to number conversion is undefined: now
+Perl consistently handles such strings as zero in numeric contexts.
-Numerous memory leaks and uninitialized memory accesses have been hunted down.
-Most importantly anonymous subs used to leak quite a bit.
+=item *
-=over 4
+The order of DESTROYs has been made more predictable.
=item *
Several debugger fixes: exit code now reflects the script exit code,
condition C<"0"> now treated correctly, the C<d> command now checks
-line number, the C<$.> no longer gets corrupted, all debugger output now
-goes correctly to the socket if RemotePort is set.
+line number, the C<$.> no longer gets corrupted, all debugger output
+now goes correctly to the socket if RemotePort is set.
=item *
-C<*foo{FORMAT}> now works.
+Perl 5.6.0 could emit spurious warnings about redefinition of dl_error()
+when statically building extensions into perl. This has been corrected.
=item *
-Lexical warnings now propagating correctly between scopes.
+L<dprofpp> -R didn't work.
=item *
-Line renumbering with eval and C<#line> now works.
-
+C<*foo{FORMAT}> now works.
=item *
-Fixed numerous memory leaks, especially in eval "".
+Infinity is now recognized as a number.
=item *
-Modulus of unsigned numbers now works (4063328477 % 65535 used to
-return 27406, instead of 27047).
+UNIVERSAL::isa no longer caches methods incorrectly. (This broke
+the Tk extension with 5.6.0.)
=item *
-Some "not a number" warnings introduced in 5.6.0 eliminated to be
-more compatible with 5.005. Infinity is now recognised as a number.
+Lexicals I: lexicals outside an eval "" weren't resolved
+correctly inside a subroutine definition inside the eval "" if they
+were not already referenced in the top level of the eval""ed code.
=item *
-our() variables will not cause "will not stay shared" warnings.
+Lexicals II: lexicals leaked at file scope into subroutines that
+were declared before the lexicals.
=item *
-pack "Z" now correctly terminates the string with "\0".
+Lexical warnings now propagating correctly between scopes
+and into C<eval "...">.
=item *
-Fix password routines which in some shadow password platforms
-(e.g. HP-UX) caused getpwent() to return every other entry.
+C<use warnings qw(FATAL all)> did not work as intended. This has been
+corrected.
=item *
-printf() no longer resets the numeric locale to "C".
+warnings::enabled() now reports the state of $^W correctly if the caller
+isn't using lexical warnings.
=item *
-C<q(a\\b)> now parses correctly as C<'a\\b'>.
+Line renumbering with eval and C<#line> now works.
=item *
-Printing quads (64-bit integers) with printf/sprintf now works
-without the q L ll prefixes (assuming you are on a quad-capable platform).
+Fixed numerous memory leaks, especially in eval "".
=item *
-Regular expressions on references and overloaded scalars now work.
+mkdir() now ignores trailing slashes in the directory name,
+as mandated by POSIX.
=item *
-scalar() now forces scalar context even when used in void context.
+Some versions of glibc have a broken modfl(). This affects builds
+with C<-Duselongdouble>. This version of Perl detects this brokenness
+and has a workaround for it. The glibc release 2.2.2 is known to have
+fixed the modfl() bug.
=item *
-sort() arguments are now compiled in the right wantarray context
-(they were accidentally using the context of the sort() itself).
+Modulus of unsigned numbers now works (4063328477 % 65535 used to
+return 27406, instead of 27047).
=item *
-Changed the POSIX character class C<[[:space:]]> to include the (very
-rare) vertical tab character. Added a new POSIX-ish character class
-C<[[:blank:]]> which stands for horizontal whitespace (currently,
-the space and the tab).
+Some "not a number" warnings introduced in 5.6.0 eliminated to be
+more compatible with 5.005. Infinity is now recognised as a number.
=item *
-$AUTOLOAD, sort(), lock(), and spawning subprocesses
-in multiple threads simultaneously are now thread-safe.
+Numeric conversions did not recognize changes in the string value
+properly in certain circumstances.
=item *
-Allow read-only string on left hand side of non-modifying tr///.
+Attributes (like :shared) didn't work with our().
=item *
-Several Unicode fixes (but still not perfect).
+our() variables will not cause "will not stay shared" warnings.
-=over 8
+=item *
+
+"our" variables of the same name declared in two sibling blocks
+resulted in bogus warnings about "redeclaration" of the variables.
+The problem has been corrected.
=item *
-BOMs (byte order marks) in the beginning of Perl files
-(scripts, modules) should now be transparently skipped.
-UTF-16 (UCS-2) encoded Perl files should now be read correctly.
+pack "Z" now correctly terminates the string with "\0".
=item *
-The character tables have been updated to Unicode 3.0.1.
+Fix password routines which in some shadow password platforms
+(e.g. HP-UX) caused getpwent() to return every other entry.
=item *
-chr() for values greater than 127 now create utf8 when under use
-utf8.
+The PERL5OPT environment variable (for passing command line arguments
+to Perl) didn't work for more than a single group of options.
=item *
-Comparing with utf8 data does not magically upgrade non-utf8 data into
-utf8.
+PERL5OPT with embedded spaces didn't work.
=item *
-C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
+printf() no longer resets the numeric locale to "C".
=item *
-Concatenation with the C<.> operator or via variable interpolation,
-C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
-substitution with C<s///>, single-quoted UTF8, should now work--in
-theory.
+C<qw(a\\b)> now parses correctly as C<'a\\b'>.
=item *
-The C<tr///> operator now works I<slightly> better but is still rather
-broken. Note that the C<tr///CU> functionality has been removed (but
-see pack('U0', ...)).
+pos() did not return the correct value within s///ge in earlier
+versions. This is now handled correctly.
=item *
-vec() now refuses to deal with characters >255.
+Printing quads (64-bit integers) with printf/sprintf now works
+without the q L ll prefixes (assuming you are on a quad-capable platform).
=item *
-Zero entries were missing from the Unicode classes like C<IsDigit>.
+Regular expressions on references and overloaded scalars now work.
=item *
-chop(@list) in list context returned the characters chopped in
-reverse order. This has been reversed to be in the right order.
+Right-hand side magic (GMAGIC) could in many cases such as string
+concatenation be invoked too many times.
=item *
-The order of DESTROYs has been made more predictable.
+scalar() now forces scalar context even when used in void context.
=item *
-mkdir() now ignores trailing slashes in the directory name,
-as mandated by POSIX.
+SOCKS support is now much more robust.
=item *
-Attributes (like :shared) didn't work with our().
+sort() arguments are now compiled in the right wantarray context
+(they were accidentally using the context of the sort() itself).
+The comparison block is now run in scalar context, and the arguments
+to be sorted are always provided list context.
=item *
-The PERL5OPT environment variable (for passing command line arguments
-to Perl) didn't work for more than a single group of options.
+Changed the POSIX character class C<[[:space:]]> to include the (very
+rarely used) vertical tab character. Added a new POSIX-ish character
+class C<[[:blank:]]> which stands for horizontal whitespace
+(currently, the space and the tab).
=item *
=item *
-All but the first argument of the IO syswrite() method are now optional.
+Some cases of inconsistent taint propagation (such as within hash
+values) have been fixed.
=item *
-Tie::ARRAY SPLICE method was broken.
+The RE engine found in Perl 5.6.0 accidentally pessimised certain kinds
+of simple pattern matches. These are now handled better.
=item *
-vec() now tries to work with characters <= 255 when possible, but it leaves
-higher character values in place. In that case, if vec() was used to modify
-the string, it is no longer considered to be utf8-encoded.
+Regular expression debug output (whether through C<use re 'debug'>
+or via C<-Dr>) now looks better.
=item *
-The autouse pragma didn't work for Multi::Part::Function::Names.
+Multi-line matches like C<"a\nxb\n" =~ /(?!\A)x/m> were flawed. The
+bug has been fixed.
=item *
-The behaviour of non-decimal but numeric string constants such as
-"0x23" was platform-dependent: in some platforms that was seen as 35,
-in some as 0, in some as a floating point number (don't ask). This
-was caused by Perl using the operating system libraries in a situation
-where the result of the string to number conversion is undefined: now
-Perl consistently handles such strings as zero in numeric contexts.
+Use of $& could trigger a core dump under some situations. This
+is now avoided.
=item *
-L<dprofpp> -R didn't work.
+The regular expression captured submatches ($1, $2, ...) are now
+more consistently unset if the match fails, instead of leaving false
+data lying around in them.
=item *
-PERL5OPT with embedded spaces didn't work.
+readline() on files opened in "slurp" mode could return an extra "" at
+the end in certain situations. This has been corrected.
=item *
-L<Sys::Syslog> ignored the C<LOG_AUTH> constant.
+Autovivification of symbolic references of special variables described
+in L<perlvar> (as in C<${$num}>) was accidentally disabled. This works
+again now.
=item *
-Some versions of glibc have a broken modfl(). This affects builds
-with C<-Duselongdouble>. This version of Perl detects this brokenness
-and has a workaround for it. The glibc release 2.2.2 is known to have
-fixed the modfl() bug.
+Sys::Syslog ignored the C<LOG_AUTH> constant.
=item *
-Linux previously had problems related to sockaddrlen when using
-accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+All but the first argument of the IO syswrite() method are now optional.
=item *
-Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+$AUTOLOAD, sort(), lock(), and spawning subprocesses
+in multiple threads simultaneously are now thread-safe.
=item *
-Windows
-
-=over 8
+Tie::ARRAY SPLICE method was broken.
=item *
-Borland C++ v5.5 is now a supported compiler that can build Perl.
-However, the generated binaries continue to be incompatible with those
-generated by the other supported compilers (GCC and Visual C++).
+Allow read-only string on left hand side of non-modifying tr///.
=item *
-Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
-Other bugs in chdir() and Cwd::cwd() have also been fixed.
+Several Unicode fixes.
+
+=over 8
=item *
-Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+BOMs (byte order marks) in the beginning of Perl files
+(scripts, modules) should now be transparently skipped.
+UTF-16 (UCS-2) encoded Perl files should now be read correctly.
=item *
-HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+The character tables have been updated to Unicode 3.1.1.
=item *
-The makefiles now provide a single switch to bulk-enable all the features
-enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
+Comparing with utf8 data does not magically upgrade non-utf8 data
+into utf8.
-=back
+=item *
-=back
+C<IsAlnum>, C<IsAlpha>, and C<IsWord> now match titlecase.
=item *
-UNIVERSAL::isa no longer caches methods incorrectly. (This broke
-the Tk extension with 5.6.0.)
+Concatenation with the C<.> operator or via variable interpolation,
+C<eq>, C<substr>, C<reverse>, C<quotemeta>, the C<x> operator,
+substitution with C<s///>, single-quoted UTF8, should now work.
=item *
-Configure no longer includes the DBM libraries (dbm, gdbm, db, ndbm)
-when building the Perl binary. The only exception to this is SunOS 4.x,
-which needs them.
+The C<tr///> operator now works. Note that the C<tr///CU>
+functionality has been removed (but see pack('U0', ...)).
=item *
-SOCKS support is now much more robust.
+C<eval "v200"> now works.
=item *
-If your file system supports symbolic links you can build Perl outside
-of the source directory by
+Perl 5.6.0 parsed m/\x{ab}/ incorrectly, leading to spurious warnings.
+This has been corrected.
- mkdir /tmp/perl/build/directory
- cd /tmp/perl/build/directory
- sh /path/to/perl/source/Configure -Dmksymlinks ...
+=item *
-This will create in /tmp/perl/build/directory a tree of symbolic links
-pointing to files in /path/to/perl/source. The original files are left
-unaffected. After Configure has finished you can just say
+Zero entries were missing from the Unicode classes like C<IsDigit>.
- make all test
+=back
-and Perl will be built and tested, all in /tmp/perl/build/directory.
+=item *
+
+Large unsigned numbers (those above 2**31) could sometimes lose their
+unsignedness, causing bogus results in arithmetic operations.
=back
All BSDs
-Setting C<$0> now works (as much as possible; see perlvar for details).
+Setting C<$0> now works (as much as possible; see L<perlvar> for details).
=item *
=item *
+Previously DYNIX/ptx had problems in its Configure probe for non-blocking I/O.
+
+=item *
+
EPOC
EPOC update after Perl 5.6.0. See README.epoc.
Linux
+=over 8
+
+=item *
+
Long doubles should now work (see INSTALL).
=item *
+Linux previously had problems related to sockaddrlen when using
+accept(), revcfrom() (in Perl: recv()), getpeername(), and getsockname().
+
+=back
+
+=item *
+
MacOS Classic
Compilation of the standard Perl distribution in MacOS Classic should
chdir() now works better despite a CRT bug; now works with MULTIPLICITY
(see INSTALL); now works with Perl's malloc.
+The tainting of C<%ENV> elements via C<keys> or C<values> was previously
+unimplemented. It now works as documented.
+
+The C<waitpid> emulation has been improved. The worst bug (now fixed)
+was that a pid of -1 would cause a wildcard search of all processes on
+the system. The most significant enhancement is that we can now
+usually get the completion status of a terminated process.
+
+POSIX-style signals are now emulated much better on VMS versions prior
+to 7.0.
+
+The C<system> function and backticks operator have improved
+functionality and better error handling.
+
=item *
Windows
=item *
+Borland C++ v5.5 is now a supported compiler that can build Perl.
+However, the generated binaries continue to be incompatible with those
+generated by the other supported compilers (GCC and Visual C++).
+
+=item *
+
Better chdir() return value for a non-existent directory.
=item *
+Duping socket handles with open(F, ">&MYSOCK") now works under Windows 9x.
+
+=item *
+
New %ENV entries now propagate to subprocesses.
=item *
+Current directory entries in %ENV are now correctly propagated to child
+processes.
+
+=item *
+
$ENV{LIB} now used to search for libs under Visual C.
=item *
+fork() emulation has been improved in various ways, but still continues
+to be experimental. See L<perlfork> for known bugs and caveats.
+
+=item *
+
A failed (pseudo)fork now returns undef and sets errno to EAGAIN.
=item *
+Win32::GetCwd() correctly returns C:\ instead of C: when at the drive root.
+Other bugs in chdir() and Cwd::cwd() have also been fixed.
+
+=item *
+
+HTML files will be installed in c:\perl\html instead of c:\perl\lib\pod\html
+
+=item *
+
+The makefiles now provide a single switch to bulk-enable all the features
+enabled in ActiveState ActivePerl (a popular Win32 binary distribution).
+
+=item *
+
Allow REG_EXPAND_SZ keys in the registry.
=item *
=item *
+%SIG has been enabled under USE_ITHREADS, but its use is completely
+unsupported under all configurations.
+
+=item *
+
Less stack reserved per thread so that more threads can run
concurrently. (Still 16M per thread.)
=item *
-C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
+C<File::Spec->tmpdir()> now prefers C:/temp over /tmp
(works better when perl is running as service).
=item *
=item *
-wait() and waitpid() now work much better.
+wait(), waitpid() and backticks now return the correct exit status under
+Windows 9x.
=item *
The various "opened only for", "on closed", "never opened" warnings
drop the C<main::> prefix for filehandles in the C<main> package,
-for example C<STDIN> instead of <main::STDIN>.
+for example C<STDIN> instead of C<main::STDIN>.
=item *
=item *
-Using arrays or hashes as references (e.g. C<%foo->{bar}> has been
-deprecated for a while. Now you will get an optional warning.
+Using arrays or hashes as references (e.g. C<< %foo->{bar} >>
+has been deprecated for a while. Now you will get an optional warning.
=back
=item *
-Added rsignal(), whichsig(), do_join() to the publicised API.
+Added rsignal(), whichsig(), do_join(), op_clear, op_null,
+ptr_table_clear(), ptr_table_free(), sv_setref_uv(), and several UTF-8
+interfaces to the publicised API. For the full list of the available
+APIs see L<perlapi>.
=item *
=item *
-Added is_utf8_char(), is_utf8_string(), bytes_to_utf8(), and utf8_to_bytes().
-
-=item *
-
Now xsubs can have attributes just like subs.
=item *
-Some new APIs: ptr_table_clear(), ptr_table_free(), sv_setref_uv().
-For the full list of the available APIs see L<perlapi>.
-
-=item *
-
dTHR and djSP have been obsoleted; the former removed (because it's
a no-op) and the latter replaced with dSP.
=item *
-There are now several profiling make targets
-
-=item *
-
-The C<op_clear> and C<op_null> are now exported.
+There are now several profiling make targets.
=back
=head1 New Tests
-Several new tests have been added, especially for the F<lib> subsection.
+Several new tests have been added, especially for the F<lib>
+subsection. There are now about 34 000 individual tests (spread over
+about 530 test scripts), in the regression suite (5.6.1 has about
+11700 tests, in 258 test scripts) Many of the new tests are introduced
+by the new modules, but still in general Perl is now more thoroughly
+tested.
+
+Because of the large number of tests, running the regression suite
+will take considerably longer time than it used to: expect the suite
+to take up to 4-5 times longer to run than in perl 5.6. In a really
+fast machine you can hope to finish the suite in about 5 minutes
+(wallclock time).
The tests are now reported in a different order than in earlier Perls.
(This happens because the test scripts from under t/lib have been moved
=head1 Known Problems
-Note that unlike other sections in this document (which describe
-changes since 5.7.0) this section is cumulative containing known
-problems for all the 5.7 releases.
-
=head2 AIX
=over 4
=head2 Amiga Perl Invoking Mystery
One cannot call Perl using the C<volume:> syntax, that is, C<perl -v>
-works, but for example C<bin:perl -v> doesn't. The exact reason is
+works, but for example C<bin:perl -v> doesn't. The exact reason isn't
known but the current suspect is the F<ixemul> library.
=head2 lib/ftmp-security tests warn 'system possibly insecure'
No known fix.
+=head2 Mac OS X
+
+The following tests are known to fail:
+
+ Failed Test Stat Wstat Total Fail Failed List of Failed
+ -------------------------------------------------------------------------
+ ../ext/DB_File/t/db-btree.t 0 11 ?? ?? % ??
+ ../ext/DB_File/t/db-recno.t 149 3 2.01% 61 63 65
+ ../ext/POSIX/t/posix.t 31 1 3.23% 10
+ ../lib/warnings.t 450 1 0.22% 316
+
=head2 OS/390
OS/390 has rather many test failures but the situation is actually
=head2 Failure of Thread tests
-B<Note that support for 5.005-style threading remains experimental.>
+B<Note that support for 5.005-style threading remains experimental
+and practically unsupported.>
The following tests are known to fail due to fundamental problems in
the 5.005 threading implementation. These are not new failures--Perl
5.005_0x has the same bugs, but didn't have these tests.
- lib/autouse.t 4
- t/lib/thr5005.t 19-20
+ ext/List/Util/t/first 2
+ lib/autouse 4
+ ext/Thread/thr5005 19-20
+
+These failures are unlikely to get fixed.
=head2 UNICOS
=head2 VMS
-Rather many tests are failing in VMS but that actually more tests
-succeed in VMS than they used to, it's just that there are many,
-many more tests than there used to be.
-
-Here are the known failures from some compiler/platform combinations.
-
-DEC C V5.3-006 on OpenVMS VAX V6.2
-
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.ext.posix]sigaction..................FAILED on test 7
- [-.ext.time.hires]hires.................FAILED on test 14
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- [.op]sprintf............................FAILED on test 12
- Failed 8/399 tests, 91.23% okay.
-
-DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and
-Compaq C V6.2-008 on OpenVMS Alpha V7.1
-
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- Failed 4/399 tests, 92.48% okay.
-
-Compaq C V6.4-005 on OpenVMS Alpha 7.2.1
-
- [-.ext.b]showlex........................FAILED on test 1
- [-.ext.list.util.t]tainted..............FAILED on test 3
- [-.lib.file.find]taint..................FAILED on test 17
- [-.lib.test.simple.t]exit...............FAILED on test 1
- [.lib]vmsish............................FAILED on test 13
- [.op]misc...............................FAILED on test 49
- Failed 6/401 tests, 92.77% okay.
-
+There is one known test failure with a default configuration:
+
+ [.run]switches..........................FAILED on test 1
+
=head2 Win32
In multi-CPU boxes there are some problems with the I/O buffering:
Code like the above is known to leak memory every time the local()
is executed.
+=head2 Localising Tied Arrays and Hashes Is Broken
+
+ local %tied_array;
+
+doesn't work as one would expect: the old value is restored
+incorrectly.
+
=head2 Self-tying of Arrays and Hashes Is Forbidden
Self-tying of arrays and hashes is broken in rather deep and
This limitation will hopefully be fixed in future. (Subroutine
attributes work fine for tieing, see L<Attribute::Handlers>).
+One way to run into this limitation is to have a loop variable with
+attributes within a loop: the tie is called only once, not for each
+iteration of the loop.
+
=head2 Building Extensions Can Fail Because Of Largefiles
Some extensions like mod_perl are known to have issues with
all binaries with different ideas about file offsets, all this is
platform-dependent.
+=head2 Unicode Support on EBCDIC Still Spotty
+
+Though mostly working, Unicode support still has problem spots on
+EBCDIC platforms. One such known spot are the C<\p{}> and C<\P{}>
+regular expression constructs for code points less than 256: the
+pP are testing for Unicode code points, not knowing about EBCDIC.
+
=head2 The Compiler Suite Is Still Experimental
-The compiler suite is slowly getting better but is nowhere near
-working order yet.
+The compiler suite is slowly getting better but it continues to be
+highly experimental. Use in production environments is discouraged.
=head2 The Long Double Support is Still Experimental