3 [ Any text flagged as XXX needs to be processed before release. ]
5 perldelta - what is new for perl v5.11.2
9 This document describes differences between the 5.11.1 release and
14 XXX Unlikely to need this section.
16 =head1 Incompatible Changes
18 =head2 Use of C<:=> to mean an empty attribute list is now deprecated.
20 An accident of Perl's parser means that these constructions are all equivalent:
26 with the C<:> being treated as the start of an attribute list, which ends
27 before the C<=>. As whitespace is not significant here, all are parsed as an
28 empty attribute list, hence all the above are equivalent to, and better written
33 because no attribute processing is done for an empty list.
35 As is, this means that C<:=> cannot be used as a new token, without silently
36 changing the meaning of existing code. Hence that particular form is now
37 deprecated, and will become a syntax error. If it is absolutely necessary to
38 have empty attribute lists (for example, because of a code generator) the
39 avoid the warning by adding a space before the C<=>.
41 =head1 Core Enhancements
43 XXX New core language features go here. Summarise user-visible core language
44 enhancements. Particularly prominent performance optimisations could go
45 here, but most should go in the L</Performance Enhancements> section.
49 It is now possible to overload the C<qr//> operator, that is, conversion
50 to regexp, like it was already possible to overload conversion to
51 boolean, string or number of objects. It is invoked when an object
52 appears on the right hand side of the C<=~> operator, or when it is
53 interpolated into a regexp. See L<overload>.
55 =head2 Pluggable keywords
57 Extension modules can now cleanly hook into the Perl parser to define new
58 kinds of keyword-headed expression and compound statement. The syntax
59 following the keyword is defined entirely by the extension. This allow
60 a completely non-Perl sublanguage to be parsed inline, with the right
61 ops cleanly generated.
63 This feature is currently considered experimental, and using it to do
64 anything interesting is difficult. Many necessary supporting facilities,
65 such as the lexer and the pad system, can only be accessed through
66 unsupported internal interfaces. It is intended that the Perl 5.13
67 development cycle will see the addition of clean, supported interfaces
68 for many of these functions. In Perl 5.12 most uses of pluggable keywords
69 will be via L<Devel::Declare>.
71 See L<perlapi/PL_keyword_plugin> for the mechanism. The Perl core source
72 distribution also includes a new module L<XS::APItest::KeywordRPN>, which
73 implements reverse Polish notation arithmetic via pluggable keywords.
74 This module is mainly used for test purposes, and is not normally
75 installed, but also serves as an example of how to use the new mechanism.
79 XXX List any platforms that this version of perl compiles on, that previous
80 versions did not. These will either be enabled by new files in the F<hints/>
81 directories, or new subdirectories and F<README> files at the top level of the
84 =head1 Modules and Pragmata
86 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
87 go here, in a list ordered by distribution name. Minimally it should be the
88 module version, but it's more useful to the end user to give a paragraph's
89 summary of the module's changes. In an ideal world, dual-life modules would
90 have a F<Changes> file that could be cribbed.
92 =head2 New Modules and Pragmata
102 =head2 Pragmata Changes
112 =head2 Updated Modules
122 =head1 Utility Changes
124 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
125 here. Most of these are built within the directories F<utils> and F<x2p>.
135 =head1 New Documentation
137 XXX Changes which create B<new> files in F<pod/> go here.
147 =head1 Changes to Existing Documentation
149 XXX Changes which significantly change existing files in F<pod/> go here.
150 Any changes to F<pod/perldiag.pod> should go in L</New or Changed Diagnostics>.
153 =head1 Performance Enhancements
155 XXX Changes which enhance performance without changing behaviour go here. There
156 may well be none in a stable release.
166 =head1 Installation and Configuration Improvements
168 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
171 =head2 Configuration improvements
175 =head2 Compilation improvements
179 =head2 Platform Specific Changes
183 =item XXX-some-platform
189 =head1 Selected Bug Fixes
191 XXX Important bug fixes in the core language are summarised here.
192 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
193 L</Modules and Pragmata>.
203 =head1 New or Changed Diagnostics
205 XXX New or changed warnings emitted by the core's C<C> code go here.
215 =head1 Changed Internals
221 C<Perl_pmflag> has been removed from the public API. Calling it now generates
222 a deprecation warning, and it will be removed in a future release. Although
223 listed as part of the API, it was never documented, and only ever used in
224 F<toke.c>, and prior to 5.10, F<regcomp.c>. In core, it has been replaced by a
231 XXX Changes which create B<new> files in F<t/> go here. Changes to
232 existing files in F<t/> aren't worth summarising, although the bugs that
233 they represent may be.
243 =head1 Known Problems
245 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
246 tests that had to be C<TODO>ed for the release would be noted here, unless
247 they were specific to a particular platform (see below).
249 This is a list of some significant unfixed bugs, which are regressions
250 from either 5.10.1 or 5.11.1.
262 XXX Add any new known deprecations here.
264 The following items are now deprecated.
274 =head1 Platform Specific Notes
276 XXX Any changes specific to a particular platform. VMS and Win32 are the usual
277 stars here. It's probably best to group changes under the same section layout
278 as the main perldelta
282 XXX If any significant core contributor has died, we've added a short obituary
285 =head1 Acknowledgements
287 XXX The list of people to thank goes here.
290 =head1 Reporting Bugs
292 If you find what you think is a bug, you might check the articles
293 recently posted to the comp.lang.perl.misc newsgroup and the perl
294 bug database at http://rt.perl.org/perlbug/ . There may also be
295 information at http://www.perl.org/ , the Perl Home Page.
297 If you believe you have an unreported bug, please run the B<perlbug>
298 program included with your release. Be sure to trim your bug down
299 to a tiny but sufficient test case. Your bug report, along with the
300 output of C<perl -V>, will be sent off to perlbug@perl.org to be
301 analysed by the Perl porting team.
303 If the bug you are reporting has security implications, which make it
304 inappropriate to send to a publicly archived mailing list, then please send
305 it to perl5-security-report@perl.org. This points to a closed subscription
306 unarchived mailing list, which includes all the core committers, who be able
307 to help assess the impact of issues, figure out a resolution, and help
308 co-ordinate the release of patches to mitigate or fix the problem across all
309 platforms on which Perl is supported. Please only use this address for
310 security issues in the Perl core, not for modules independently
315 The F<Changes> file for an explanation of how to view exhaustive details
318 The F<INSTALL> file for how to build Perl.
320 The F<README> file for general stuff.
322 The F<Artistic> and F<Copying> files for copyright information.