diff options
Diffstat (limited to 'chromium/third_party/cygwin/lib/perl5/5.10/pods/perl591delta.pod')
| -rw-r--r-- | chromium/third_party/cygwin/lib/perl5/5.10/pods/perl591delta.pod | 323 |
1 files changed, 0 insertions, 323 deletions
diff --git a/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl591delta.pod b/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl591delta.pod deleted file mode 100644 index 349c49a40f2..00000000000 --- a/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl591delta.pod +++ /dev/null @@ -1,323 +0,0 @@ -=head1 NAME - -perl591delta - what is new for perl v5.9.1 - -=head1 DESCRIPTION - -This document describes differences between the 5.9.0 and the 5.9.1 -development releases. See L<perl590delta> for the differences between -5.8.0 and 5.9.0. - -=head1 Incompatible Changes - -=head2 substr() lvalues are no longer fixed-length - -The lvalues returned by the three argument form of substr() used to be a -"fixed length window" on the original string. In some cases this could -cause surprising action at distance or other undefined behaviour. Now the -length of the window adjusts itself to the length of the string assigned to -it. - -=head2 The C<:unique> attribute is only meaningful for globals - -Now applying C<:unique> to lexical variables and to subroutines will -result in a compilation error. - -=head1 Core Enhancements - -=head2 Lexical C<$_> - -The default variable C<$_> can now be lexicalized, by declaring it like -any other lexical variable, with a simple - - my $_; - -The operations that default on C<$_> will use the lexically-scoped -version of C<$_> when it exists, instead of the global C<$_>. - -In a C<map> or a C<grep> block, if C<$_> was previously my'ed, then the -C<$_> inside the block is lexical as well (and scoped to the block). - -In a scope where C<$_> has been lexicalized, you can still have access to -the global version of C<$_> by using C<$::_>, or, more simply, by -overriding the lexical declaration with C<our $_>. - -=head2 Tied hashes in scalar context - -As of perl 5.8.2/5.9.0, tied hashes did not return anything useful in -scalar context, for example when used as boolean tests: - - if (%tied_hash) { ... } - -The old nonsensical behaviour was always to return false, -regardless of whether the hash is empty or has elements. - -There is now an interface for the implementors of tied hashes to implement -the behaviour of a hash in scalar context, via the SCALAR method (see -L<perltie>). Without a SCALAR method, perl will try to guess whether -the hash is empty, by testing if it's inside an iteration (in this case -it can't be empty) or by calling FIRSTKEY. - -=head2 Formats - -Formats were improved in several ways. A new field, C<^*>, can be used for -variable-width, one-line-at-a-time text. Null characters are now handled -correctly in picture lines. Using C<@#> and C<~~> together will now -produce a compile-time error, as those format fields are incompatible. -L<perlform> has been improved, and miscellaneous bugs fixed. - -=head2 Stacked filetest operators - -As a new form of syntactic sugar, it's now possible to stack up filetest -operators. You can now write C<-f -w -x $file> in a row to mean -C<-x $file && -w _ && -f _>. See L<perlfunc/-X>. - -=head1 Modules and Pragmata - -=over 4 - -=item Benchmark - -In C<Benchmark>, cmpthese() and timestr() now use the time statistics of -children instead of parent when the selected style is 'nop'. - -=item Carp - -The error messages produced by C<Carp> now include spaces between the -arguments in function argument lists: this makes long error messages -appear more nicely in browsers and other tools. - -=item Exporter - -C<Exporter> will now recognize grouping tags (such as C<:name>) anywhere -in the import list, not only at the beginning. - -=item FindBin - -A function C<again> is provided to resolve problems where modules in different -directories wish to use FindBin. - -=item List::Util - -You can now weaken references to read only values. - -=item threads::shared - -C<cond_wait> has a new two argument form. C<cond_timedwait> has been added. - -=back - -=head1 Utility Changes - -C<find2perl> now assumes C<-print> as a default action. Previously, it -needed to be specified explicitly. - -A new utility, C<prove>, makes it easy to run an individual regression test -at the command line. C<prove> is part of Test::Harness, which users of earlier -Perl versions can install from CPAN. - -The perl debugger now supports a C<save> command, to save the current -history to a file, and an C<i> command, which prints the inheritance tree -of its argument (if the C<Class::ISA> module is installed.) - -=head1 Documentation - -The documentation has been revised in places to produce more standard manpages. - -The long-existing feature of C</(?{...})/> regexps setting C<$_> and pos() -is now documented. - -=head1 Performance Enhancements - -Sorting arrays in place (C<@a = sort @a>) is now optimized to avoid -making a temporary copy of the array. - -The operations involving case mapping on UTF-8 strings (uc(), lc(), -C<//i>, etc.) have been greatly speeded up. - -Access to elements of lexical arrays via a numeric constant between 0 and -255 is now faster. (This used to be only the case for global arrays.) - -=head1 Selected Bug Fixes - -=head2 UTF-8 bugs - -Using substr() on a UTF-8 string could cause subsequent accesses on that -string to return garbage. This was due to incorrect UTF-8 offsets being -cached, and is now fixed. - -join() could return garbage when the same join() statement was used to -process 8 bit data having earlier processed UTF-8 data, due to the flags -on that statement's temporary workspace not being reset correctly. This -is now fixed. - -Using Unicode keys with tied hashes should now work correctly. - -chop() and chomp() used to mangle UTF-8 strings. This has been fixed. - -sprintf() used to misbehave when the format string was in UTF-8. This is -now fixed. - -=head2 Threading bugs - -Hashes with the C<:unique> attribute weren't made read-only in new -threads. They are now. - -=head2 More bugs - -C<$a .. $b> will now work as expected when either $a or $b is C<undef>. - -Reading $^E now preserves $!. Previously, the C code implementing $^E -did not preserve C<errno>, so reading $^E could cause C<errno> and therefore -C<$!> to change unexpectedly. - -C<strict> wasn't in effect in regexp-eval blocks (C</(?{...})/>). - -=head1 New or Changed Diagnostics - -A new deprecation warning, I<Deprecated use of my() in false conditional>, -has been added, to warn against the use of the dubious and deprecated -construct - - my $x if 0; - -See L<perldiag>. - -The fatal error I<DESTROY created new reference to dead object> is now -documented in L<perldiag>. - -A new error, I<%ENV is aliased to %s>, is produced when taint checks are -enabled and when C<*ENV> has been aliased (and thus doesn't reflect the -program's environment anymore.) - -=head1 Changed Internals - -These news matter to you only if you either write XS code or like to -know about or hack Perl internals (using Devel::Peek or any of the -C<B::> modules counts), or like to run Perl with the C<-D> option. - -=head2 Reordering of SVt_* constants - -The relative ordering of constants that define the various types of C<SV> -have changed; in particular, C<SVt_PVGV> has been moved before C<SVt_PVLV>, -C<SVt_PVAV>, C<SVt_PVHV> and C<SVt_PVCV>. This is unlikely to make any -difference unless you have code that explicitly makes assumptions about that -ordering. (The inheritance hierarchy of C<B::*> objects has been changed -to reflect this.) - -=head2 Removal of CPP symbols - -The C preprocessor symbols C<PERL_PM_APIVERSION> and -C<PERL_XS_APIVERSION>, which were supposed to give the version number of -the oldest perl binary-compatible (resp. source-compatible) with the -present one, were not used, and sometimes had misleading values. They have -been removed. - -=head2 Less space is used by ops - -The C<BASEOP> structure now uses less space. The C<op_seq> field has been -removed and replaced by two one-bit fields, C<op_opt> and C<op_static>. -C<opt_type> is now 9 bits long. (Consequently, the C<B::OP> class doesn't -provide an C<seq> method anymore.) - -=head2 New parser - -perl's parser is now generated by bison (it used to be generated by -byacc.) As a result, it seems to be a bit more robust. - -=head1 Configuration and Building - -C<Configure> now invokes callbacks regardless of the value of the variable -they are called for. Previously callbacks were only invoked in the -C<case $variable $define)> branch. This change should only affect platform -maintainers writing configuration hints files. - -The portability and cleanliness of the Win32 makefiles has been improved. - -=head1 Known Problems - -There are still a couple of problems in the implementation of the lexical -C<$_>: it doesn't work inside C</(?{...})/> blocks and with regard to the -reverse() built-in used without arguments. (See the TODO tests in -F<t/op/mydef.t>.) - -=head2 Platform Specific Problems - -The test F<ext/IPC/SysV/t/ipcsysv.t> may fail on OpenBSD. This hasn't been -diagnosed yet. - -On some configurations on AIX 5, one test in F<lib/Time/Local.t> fails. -When configured with long doubles, perl may fail tests 224-236 in -F<t/op/pow.t> on the same platform. - -For threaded builds, F<ext/threads/shared/t/wait.t> has been reported to -fail some tests on HP-UX 10.20. - -=head1 To-do for perl 5.10.0 - -This is a non-exhaustive, non-ordered, non-contractual and non-definitive -list of things to do (or nice to have) for perl 5.10.0 : - -Clean up and finish support for assertions. See L<assertions>. - -Reimplement the mechanism of lexical pragmas to be more extensible. Fix -current pragmas that don't work well (or at all) with lexical scopes or in -run-time eval(STRING) (C<sort>, C<re>, C<encoding> for example). MJD has a -preliminary patch that implements this. - -Fix (or rewrite) the implementation of the C</(?{...})/> closures. - -Conversions from byte strings to UTF-8 currently map high bit characters -to Unicode without translation (or, depending on how you look at it, by -implicitly assuming that the byte strings are in Latin-1). As perl assumes -the C locale by default, upgrading a string to UTF-8 may change the -meaning of its contents regarding character classes, case mapping, etc. -This should probably emit a warning (at least). - -Introduce a new special block, UNITCHECK, which is run at the end of a -compilation unit (module, file, eval(STRING) block). This will correspond to -the Perl 6 CHECK. Perl 5's CHECK cannot be changed or removed because the -O.pm/B.pm backend framework depends on it. - -Study the possibility of adding a new prototype character, C<_>, meaning -"this argument defaults to $_". - -Make the peephole optimizer optional. - -Allow lexical aliases (maybe via the syntax C<my \$alias = \$foo>. - -Fix the bugs revealed by running the test suite with the C<-t> switch (via -C<make test.taintwarn>). - -Make threads more robust. - -Make C<no 6> and C<no v6> work (opposite of C<use 5.005>, etc.). - -A test suite for the B module would be nice. - -A ponie. - -=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://bugs.perl.org/ . 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 |