Perl 5 version 24.3 documentation

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

  • our can now have an experimental optional attribute unique

    Introduced in Perl 5.8.0

    Deprecated in Perl 5.10.0

    The ticket for this feature is [perl #119313].

  • 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 #119317].

  • Pluggable keywords

    The ticket for this feature is [perl #119455].

    See PL_keyword_plugin in perlapi for the mechanism.

    Introduced in Perl 5.11.2

  • Lexical subroutines

    Introduced in Perl 5.18

    See also: Lexical Subroutines in perlsub

    Using this feature triggers warnings in the category experimental::lexical_subs .

    The ticket for this feature is [perl #120085].

  • Regular Expression Set Operations

    Introduced in Perl 5.18

    The ticket for this feature is [perl #119451].

    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 #121481].

  • 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 #122947].

    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 #123630].

    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 .

    See 'strict' mode in re

  • String- and number-specific bitwise operators

    Introduced in Perl 5.22.0

    See also: Bitwise String Operators in perlop

    Using this feature triggers warnings in the category experimental::bitwise .

    The ticket for this feature is [perl #123707].

  • The <:win32> IO pseudolayer

    The ticket for this feature is [perl #119453].

    See also perlrun

  • There is an installhtml target in the Makefile.

    The ticket for this feature is [perl #116487].

  • Unicode in Perl on EBCDIC

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.

  • -bit support

    Introduced in Perl 5.005

  • die accepts a reference

    Introduced in Perl 5.005

  • DB module

    Introduced in Perl 5.6.0

    See also perldebug, perldebtut

  • Weak references

    Introduced in Perl 5.6.0

  • Internal file glob

    Introduced in Perl 5.6.0

  • fork() emulation

    Introduced in Perl 5.6.1

    See also perlfork

  • -Dusemultiplicity -Duseithreads

    Introduced in Perl 5.6.0

    Accepted in Perl 5.8.0

  • Support for long doubles

    Introduced in Perl 5.6.0

    Accepted in Perl 5.8.1

  • The \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

  • Linux abstract Unix domain sockets

    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

  • Lvalue subroutines

    Introduced in Perl 5.6.0

    Accepted in Perl 5.20.0

    See also perlsub

  • Backtracking control verbs

    (*ACCEPT)

    Introduced in Perl 5.10

    Accepted in Perl 5.20.0

  • The <:pop> IO pseudolayer

    See also perlrun

    Accepted in Perl 5.20.0

  • \s in regexp matches vertical tab

    Accepted in Perl 5.22.0

  • Postfix dereference syntax

    Introduced in Perl 5.20.0

    Accepted in Perl 5.24.0

  • 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).

  • 005-style threading

    Introduced in Perl 5.005

    Removed in Perl 5.10

  • perlcc

    Introduced in Perl 5.005

    Moved from Perl 5.9.0 to CPAN

  • The pseudo-hash data type

    Introduced in Perl 5.6.0

    Removed in Perl 5.9.0

  • GetOpt::Long Options can now take multiple values at once (experimental)

    Getopt::Long upgraded to version 2.35

    Removed in Perl 5.8.8

  • Assertions

    The -A command line switch

    Introduced in Perl 5.9.0

    Removed in Perl 5.9.5

  • Test::Harness::Straps

    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

  • Lexical $_

    Using this feature triggered warnings in the category experimental::lexical_topic .

    Introduced in Perl 5.10.0

    Removed in Perl 5.24.0

  • Array and hash container functions accept references

    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

  • 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.