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

(?{code}) and (??{ code })

Introduced in Perl 5.6.0

See also perlre

Lvalue subroutines

Introduced in Perl 5.6.0

See also perlsub

our can now have an experimental optional attribute unique

Introduced in Perl 5.8.0

Deprecated in Perl 5.10.0

Linux abstract Unix domain sockets

Introduced in Perl 5.9.2

See also Socket

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.

Lexical $_

Introduced in Perl 5.10.0

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

Backtracking control verbs

(*ACCEPT)

Introduced in: Perl 5.10

Pluggable keywords

See "PL_keyword_plugin" in perlapi for the mechanism.

Introduced in: Perl 5.11.2

Array and hash container functions accept references

Introduced in Perl 5.14.0

Lexical subroutines

Introduced in: Perl 5.18

See also: "Lexical Subroutines" in perlsub

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

Regular Expression Set Operations

Introduced in: Perl 5.18

See also: "Extended Bracketed Character Classes" in perlrecharclass

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

\s in regexp matches vertical tab

Introduced in Perl 5.18

The <:pop> IO pseudolayer

See also perlrun

The <:win32> IO pseudolayer

See also perlrun

MLDBM

See also perldsc

internal functions with M flag

See also perlguts

lex_start API

Introduced in Perl 5.13.7

internal API for %^H

Introduced in Perl 5.13.7

See also cophh_ in perlapi.

alloccopstash

Introduced in Perl 5.18.0

av_create_and_push

av_create_and_unshift_one

av_create_and_unshift_one

cop_store_label

Introduced in Perl 5.16.0

PL_keyword_plugin

gv_fetchmethod_*_flags

Introduced in Perl 5.16.0

hv_iternext_flags

lex_bufutf8

lex_discard_to

lex_grow_linestr

lex_next_chunk

lex_peek_unichar

lex_read_space

lex_read_to

lex_read_unichar

lex_stuff_pv

lex_stuff_pvn

lex_stuff_pvs

lex_stuff_sv

lex_unstuff

op_scope

op_lvalue

parse_fullstmt

parse_stmtseq

PL_parser->bufend

PL_parser->bufptr

PL_parser->linestart

PL_parser->linestr

Perl_signbit

pad_findmy

sv_utf8_decode

sv_utf8_downgrade

bytes_from_utf8

bytes_to_utf8

utf8_to_bytes

There is an installhtml target in the Makefile.

Unicode in Perl on EBCDIC

See also: "Special Backtracking Control Verbs" in perlre

Code expressions, conditional expressions, and independent expressions in regexes

gv_try_downgrade

See also perlintern

Experimental Support for Sun Studio Compilers for Linux OS

See also perllinux

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.

64-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.

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).

5.005-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: 5.11.2

Removed in: 5.11.3

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.