perlexperiment
NAME
perlexperiment - A listing of experimental features in Perl
DESCRIPTION
This document lists the current and past experimental features in the perl core. Although all of these are documented with their appropriate topics, this succinct listing gives you an overview and basic facts about their status.
So far we've merely tried to find and list the experimental features and infer their inception, versions, etc. There's a lot of speculation here.
Current experiments
- Smart match (
~~)Introduced in Perl 5.10.0
Modified in Perl 5.10.1, 5.12.0
Using this feature triggers warnings in the category
experimental::smartmatch.The ticket for this feature is [perl #13173].
- Pluggable keywords
The ticket for this feature is [perl #13199].
See PL_keyword_plugin in perlapi for the mechanism.
Introduced in Perl 5.11.2
- Regular Expression Set Operations
Introduced in Perl 5.18
The ticket for this feature is [perl #13197].
See also: Extended Bracketed Character Classes in perlrecharclass
Using this feature triggers warnings in the category
experimental::regex_sets. - Subroutine signatures
Introduced in Perl 5.20.0
Using this feature triggers warnings in the category
experimental::signatures.The ticket for this feature is [perl #13681].
- Aliasing via reference
Introduced in Perl 5.22.0
Using this feature triggers warnings in the category
experimental::refaliasing.The ticket for this feature is [perl #14150].
See also: Assigning to References in perlref
- The "const" attribute
Introduced in Perl 5.22.0
Using this feature triggers warnings in the category
experimental::const_attr.The ticket for this feature is [perl #14428].
See also: Constant Functions in perlsub
- use re 'strict';
Introduced in Perl 5.22.0
Using this feature triggers warnings in the category
experimental::re_strict. - The <:win32> IO pseudolayer
The ticket for this feature is [perl #13198].
See also PERLIO in perlrun
- Declaring a reference to a variable
Introduced in Perl 5.26.0
Using this feature triggers warnings in the category
experimental::declared_refs.The ticket for this feature is [perl #15458].
- There is an
installhtmltarget in the Makefile.The ticket for this feature is [perl #12726].
- (Limited) Variable-length look-behind
Introduced in Perl 5.30.0. Variability of up to 255 characters is handled.
Using this feature triggers warnings in the category
experimental::vlb.See also: (*positive_lookbehind:pattern) in perlre and (*negative_lookbehind:pattern) in perlre
Accepted features
These features were so wildly successful and played so well with others that we decided to remove their experimental status and admit them as full, stable features in the world of Perl, lavishing all the benefits and luxuries thereof. They are also awarded +5 Stability and +3 Charisma.
Introduced in Perl 5.005
Introduced in Perl 5.005
Introduced in Perl 5.6.0
See also perldebug, perldebtut
Introduced in Perl 5.6.0
Introduced in Perl 5.6.0
Introduced in Perl 5.6.1
See also perlfork
Introduced in Perl 5.6.0
Accepted in Perl 5.8.0
Introduced in Perl 5.6.0
Accepted in Perl 5.8.1
\N
regex character class
The \N
character class, not to be confused with the named character
sequence \N{NAME}
, denotes any non-newline character in a regular
expression.
Introduced in Perl 5.12
Exact version of acceptance unclear, but no later than Perl 5.18.
(?{code}) and (??{ code })
Introduced in Perl 5.6.0
Accepted in Perl 5.20.0
See also perlre
Introduced in Perl 5.9.2
Accepted before Perl 5.20.0. The Socket library is now primarily maintained on CPAN, rather than in the perl core.
See also Socket
Introduced in Perl 5.6.0
Accepted in Perl 5.20.0
See also perlsub
(*ACCEPT)
Introduced in Perl 5.10
Accepted in Perl 5.20.0
See also PERLIO in perlrun
Accepted in Perl 5.20.0
\s in regexp matches vertical tab
Accepted in Perl 5.22.0
Introduced in Perl 5.20.0
Accepted in Perl 5.24.0
Introduced in Perl 5.18.0
Accepted in Perl 5.26.0
Introduced in Perl 5.22.0
Accepted in Perl 5.28.0
Introduced in Perl 5.28.0
Accepted in Perl 5.32.0
Introduced in Perl 5.28.0
Accepted in Perl 5.32.0
Removed features
These features are no longer considered experimental and their functionality has disappeared. It's your own fault if you wrote production programs using these features after we explicitly told you not to (see perlpolicy).
Introduced in Perl 5.005
Removed in Perl 5.10
Introduced in Perl 5.005
Moved from Perl 5.9.0 to CPAN
Introduced in Perl 5.6.0
Removed in Perl 5.9.0
Getopt::Long
upgraded to version 2.35
Removed in Perl 5.8.8
The -A
command line switch
Introduced in Perl 5.9.0
Removed in Perl 5.9.5
Moved from Perl 5.10.1 to CPAN
legacy
The experimental legacy
pragma was swallowed by the feature
pragma.
Introduced in Perl 5.11.2
Removed in Perl 5.11.3
$_
Using this feature triggered warnings in the category
experimental::lexical_topic
.
Introduced in Perl 5.10.0
Removed in Perl 5.24.0
Using this feature triggered warnings in the category
experimental::autoderef
.
Superseded by Postfix dereference syntax.
Introduced in Perl 5.14.0
Removed in Perl 5.24.0
our can have an experimental optional attribute unique
Introduced in Perl 5.8.0
Deprecated in Perl 5.10.0
Removed in Perl 5.28.0
SEE ALSO
For a complete list of features check feature.
AUTHORS
brian d foy <brian.d.foy@gmail.com>
Sébastien Aperghis-Tramoni <saper@cpan.org>
COPYRIGHT
Copyright 2010, brian d foy <brian.d.foy@gmail.com>
LICENSE
You can use and redistribute this document under the same terms as Perl itself.