perl5112delta
(1)
名称
perl5112delta - what is new for perl v5.11.2
用法概要
Please see following description for synopsis
描述
Perl Programmers Reference Guide PERL5112DELTA(1)
NAME
perl5112delta - what is new for perl v5.11.2
DESCRIPTION
This document describes differences between the 5.11.1
release and the 5.11.2 release.
Core Enhancements
qr overloading
It is now possible to overload the "qr//" operator, that is,
conversion to regexp, like it was already possible to
overload conversion to boolean, string or number of objects.
It is invoked when an object appears on the right hand side
of the "=~" operator, or when it is interpolated into a
regexp. See overload.
Pluggable keywords
Extension modules can now cleanly hook into the Perl parser
to define new kinds of keyword-headed expression and
compound statement. The syntax following the keyword is
defined entirely by the extension. This allow a completely
non-Perl sublanguage to be parsed inline, with the right ops
cleanly generated. This feature is currently considered
experimental.
See "PL_keyword_plugin" in perlapi for the mechanism. The
Perl core source distribution also includes a new module
XS::APItest::KeywordRPN, which implements reverse Polish
notation arithmetic via pluggable keywords. This module is
mainly used for test purposes, and is not normally
installed, but also serves as an example of how to use the
new mechanism.
APIs for more internals
The lowest layers of the lexer and parts of the pad system
now have C APIs available to XS extensions. These are
necessary to support proper use of pluggable keywords, but
have other uses too. The new APIs are experimental, and only
cover a small proportion of what would be necessary to take
full advantage of the core's facilities in these areas. It
is intended that the Perl 5.13 development cycle will see
the addition of a full range of clean, supported interfaces.
Overridable function lookup
Where an extension module hooks the creation of rv2cv ops to
modify the subroutine lookup process, this now works
correctly for bareword subroutine calls. This means that
prototypes on subroutines referenced this way will be
processed correctly. (Previously bareword subroutine names
were initially looked up, for parsing purposes, by an
unhookable mechanism, so extensions could only properly
influence subroutine names that appeared with an "&" sigil.)
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Modules and Pragmata
New Modules and Pragmata
"legacy"
Preserves legacy behaviors or enable new non-default
behaviors. Currently the only behaviour concerns
semantics for the 128 characters on ASCII systems that
have the 8th bit set.
Pragmata Changes
"diagnostics"
Supports %.0f formatting internally.
"overload"
Allow overloading of 'qr'.
Updated Modules
"B::Concise"
Optimize reversing an array in-place, avoid using
defined %hash in core code and tests.
"B::Deparse"
Teach B::Deparse about in-place reverse.
"Carp"
Refine Carp caller() fix and add tests.
"Compress::Zlib"
Updated to 2.022.
"CPANPLUS"
Updated to 0.89_09.
"Encode"
Updated to 2.38.
"ExtUtils::CBuilder"
Updated to 0.27.
"Env"
Add EXISTS and DELETE methods to Env.pm.
"File::Fetch"
Updated to 0.22.
"I8N::Langinfo"
Correctly document export of I18N::Langinfo.
"I8N::LangTags"
In I18N::LangTags::Detect, avoid using defined @array
and defined %hash.
"IO::Compress"
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Updated to 2.022.
"IPC::Cmd"
Updated to 0.54.
"List::Util"
Updated to 1.22.
"Locale::Maketext"
In Locale::Maketext, avoid using defined @array and
defined %hash. Convert the odd Locale::Maketext test
out from Test to Test::More.
"Module::Build"
Updated to 0.35_08.
"Module::CoreList"
Implemented is_deprecated().
"Pod::Simple"
Updated to 3.10.
"Scalar::Util"
Updated to 1.22.
"Switch"
Updated to 2.16.
Utility Changes
a2p Fixed bugs with the match() operator in list context,
remove mention of $[.
Performance Enhancements
o Reversing an array to itself (as in "@a = reverse @a")
in void context now happens in-place and is several
orders of magnitude faster than it used to be. It will
also preserve non-existent elements whenever possible,
i.e. for non magical arrays or tied arrays with "EXISTS"
and "DELETE" methods.
New or Changed Diagnostics
Several new diagnostics, see perldiag for details.
"Bad plugin affecting keyword '%s'"
"gmtime(%.0f) too large"
Latin-1 input"
"Lexing code attempted to stuff non-Latin-1 character into
"Lexing code internal error (%s)"
"localtime(%.0f) too large"
"Overloaded dereference did not return a reference"
"Overloaded qr did not return a REGEXP"
API"
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"Perl_pmflag() is deprecated, and will be removed from the
XS
One diagnostic has been removed:
"Runaway format"
Changed Internals
o "Perl_pmflag" has been removed from the public API.
Calling it now generates a deprecation warning, and it
will be removed in a future release. Although listed as
part of the API, it was never documented, and only ever
used in toke.c, and prior to 5.10, regcomp.c. In core,
it has been replaced by a static function.
New Tests
t/op/while_readdir.t
Test that a bare readdir in while loop sets $_.
Known Problems
Known test failures on VMS
Perl 5.11.2 fails a small set of core and CPAN tests as
of this release. With luck, that'll be sorted out for
5.11.3.
Deprecations
The following items are now deprecated.
Use of ":=" to mean an empty attribute list is now deprecated.
An accident of Perl's parser meant that these constructions
were all equivalent:
my $pi := 4;
my $pi : = 4;
my $pi : = 4;
with the ":" being treated as the start of an attribute
list, which ends before the "=". As whitespace is not
significant here, all are parsed as an empty attribute list,
hence all the above are equivalent to, and better written as
my $pi = 4;
because no attribute processing is done for an empty list.
As is, this meant that ":=" cannot be used as a new token,
without silently changing the meaning of existing code.
Hence that particular form is now deprecated, and will
become a syntax error. If it is absolutely necessary to have
empty attribute lists (for example, because of a code
generator) then avoid the warning by adding a space before
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the "=".
Acknowledgements
Perl 5.11.2 represents approximately 3 weeks development
since Perl 5.11.1 and contains 29,992 lines of changes
across 458 files from 38 authors and committers:
Abhijit Menon-Sen, Abigail, Ben Morrow, Bo Borgerson, Brad
Gilbert, Bram, Chris Williams, Craig A. Berry, Daniel
Frederick Crisman, Dave Rolsky, David E. Wheeler, David
Golden, Eric Brine, Father Chrysostomos, Frank Wiegand,
Gerard Goossen, Gisle Aas, Graham Barr, Harmen, H.Merijn
Brand, Jan Dubois, Jerry D. Hedden, Jesse Vincent, Karl
Williamson, Kevin Ryde, Leon Brocard, Nicholas Clark, Paul
Marquess, Philippe Bruhat, Rafael Garcia-Suarez, Sisyphus,
Steffen Mueller, Steve Hay, Steve Peters, Vincent Pit, Yuval
Kogman, Yves Orton, and Zefram.
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.
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/perlbug/ . 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.
If the bug you are reporting has security implications,
which make it inappropriate to send to a publicly archived
mailing list, then please send it to
perl5-security-report@perl.org. This points to a closed
subscription unarchived mailing list, which includes all the
core committers, who be able to help assess the impact of
issues, figure out a resolution, and help co-ordinate the
release of patches to mitigate or fix the problem across all
platforms on which Perl is supported. Please only use this
address for security issues in the Perl core, not for
modules independently distributed on CPAN.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
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+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | runtime/perl-512 |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
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.
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://www.cpan.org/src/5.0/perl-5.12.5.tar.bz2
Further information about this software can be found on the
open source community website at http://www.perl.org/.
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