perldelta - what is new for perl v5.29.9
This document describes differences between the 5.29.8 release and the 5.29.9 release.
If you are upgrading from an earlier release such as 5.29.7, first read perl5298delta, which describes differences between 5.29.7 and 5.29.8.
You can now do something like this in a regular expression pattern
qr! \p{nv= /(?x) \A [0-5] \z / }!
which matches all Unicode code points which have numeric value is between 0 and 5 inclusive.
This marks another step in implementing the regular expression features the Unicode Consortium suggests.
Most properties are supported, with the remainder planned for 5.32. Details are in "Wildcards in Property Values" in perlunicode.
Previously it was an error to evaluate a named character \N{...} within a single quoted regular expression pattern (whose evaluation is deferred from the normal place). This restriction is now removed.
\N{...}
For details, see https://www.unicode.org/versions/Unicode12.0.0/.
Because of a change in Unicode release cycles, Perl jumps from Unicode 10.0 in Perl 5.28 to Unicode 12.0 in Perl 5.30.
Previously, these calls were only used when the perl was compiled to be multi-threaded. To always enable them, add
-Accflags='-DUSE_THREAD_SAFE_LOCALE'
to your Configure flags.
Using a lookbehind assertion (like (?<=foo) or (?<!bar) previously would generate an error and refuse to compile. Now it compiles (if the maximum lookbehind is at most 255 characters), but raises a warning in the new experimental::vlb warnings category. This is to caution you that the precise behavior is subject to change based on feedback from use in the field.
(?<=foo)
(?<!bar)
experimental::vlb
See "(?<=pattern)" in perlre and "(?<!pattern)" in perlre.
pack()
It croaks if it would otherwise return a UTF-8 string that contains malformed UTF-8. This protects agains potential security threats. This is considered a bug fix as well ([perl #131642]).
There are several sets of digits in the Common script. [0-9] is the most familiar. But there are also [\x{FF10}-\x{FF19}] (FULLWIDTH DIGIT ZERO - FULLWIDTH DIGIT NINE), and several sets for use in mathematical notation, such as the MATHEMATICAL DOUBLE-STRUCK DIGITs. Any of these sets should be able to appear in script runs of, say, Greek. But the design of 5.30 overlooked all but the ASCII digits [0-9], so the design was flawed. This has been fixed, so is both a bug fix and an incompatibility. [perl #133547]
[0-9]
[\x{FF10}-\x{FF19}]
All digits in a run still have to come from the same set of ten digits.
Devel::PPPort has been upgraded from version 3.44 to 3.45.
Encode has been upgraded from version 3.00 to 3.01.
ExtUtils::Manifest has been upgraded from version 1.71 to 1.72.
JSON::PP has been upgraded from version 4.00 to 4.02.
Module::CoreList has been upgraded from version 5.20190220 to 5.20190320.
perl5db.pl has been upgraded from version 1.54 to 1.55.
Debugging threaded code no longer deadlocks in DB::sub nor DB::lsub.
DB::sub
DB::lsub
PerlIO::encoding has been upgraded from version 0.26 to 0.27.
Warnings enabled by setting the WARN_ON_ERR flag in $PerlIO::encoding::fallback are now only produced if warnings are enabled with use warnings "utf8"; or setting $^W.
WARN_ON_ERR
$PerlIO::encoding::fallback
use warnings "utf8";
$^W
threads::shared has been upgraded from version 1.59 to 1.60.
Added support for extra tracing of locking, this requires a -DDEBUGGING and extra compilation flags.
-DDEBUGGING
utf8 has been upgraded from version 1.21 to 1.22.
warnings has been upgraded from version 1.43 to 1.44.
The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, see perldiag.
Specifying \o{} without anything between the braces now yields the fatal error message "Empty \o{}". Previously it was "Number with no digits". This means the same wording is used for this kind of error as with similar constructs such as \p{}.
\o{}
\p{}
Within the scope of the experimental feature use re 'strict', specifying \x{} without anything between the braces now yields the fatal error message "Empty \x{}". Previously it was "Number with no digits". This means the same wording is used for this kind of error as with similar constructs such as \p{}. It is legal, though not wise to have an empty \x outside of re 'strict'; it silently generates a NUL character.
use re 'strict'
\x{}
\x
re 'strict'
Added newSVsv_nomg() to copy a SV without processing get magic on the source. [perl #132964]
newSVsv_nomg()
pack() no longer can return malformed UTF-8. It croaks if it would otherwise return a UTF-8 string that contains malformed UTF-8. This protects agains potential security threats. [perl #131642]
See "Any set of digits in the Common script are legal in a script run of another script".
Perl 5.29.9 represents approximately 4 weeks of development since Perl 5.29.8 and contains approximately 47,000 lines of changes across 210 files from 11 authors.
Excluding auto-generated files, documentation and release tools, there were approximately 38,000 lines of changes to 71 .pm, .t, .c and .h files.
Perl continues to flourish into its fourth decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.29.9:
Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Kogai, David Mitchell, Karen Etheridge, Karl Williamson, Nicolas R., Pali, Tony Cook, Unicode Consortium.
The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.
Many of the changes included in this version originated in the CPAN modules included in Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.
For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.
If you find what you think is a bug, you might check the perl bug database at https://rt.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 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 perl -V, will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
perl -V
If the bug you are reporting has security implications which make it inappropriate to send to a publicly archived mailing list, then see "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec for details of how to report the issue.
If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by running the perlthanks program:
perlthanks
This will send an email to the Perl 5 Porters list with your show of thanks.
The Changes file for an explanation of how to view exhaustive details on what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.
To install vars, copy and paste the appropriate command in to your terminal.
cpanm
cpanm vars
CPAN shell
perl -MCPAN -e shell install vars
For more information on module installation, please visit the detailed CPAN module installation guide.