use utf8;

+{
	v5.004 => {
		release => '1997-05-15',
		distro => {
			debian => '2.0', # hamm 1998-07 to potato 2000-08 eol 2003-06
		},
		unstable => 0,
	},

	v5.005 => {
		new => [
			['<code>lock</code>', 'obsolete <code>Thread</code> implementation, including a keyword to place advisory locks on shared variables', {experimental => 0, stable => 0, removed => v5.10}],
			['<code>B::…</code>', 'backend hooks'],
			['<code>qr//</code>' => 'overhauled regular expression engine: precompile operator, lookahead/behind, code, conditions, localised flags'],
			['<code>… foreach</code>' => '<code>for(each)</code> as statement modifier, with large ranges optimised as counting loops'],
			['<code>…::</code>' => 'implicitly quoted package name'],
			['<code>ref $@</code>' => '<code>die</code> passes reference values to exception handlers'],
			['<code>INIT {}</code>', 'subs run just before the perl runtime begins execution'],
			['<code>tie @…</code>' => 'base class for <code>TIEARRAY</code> implementations, and generally improved supported of tied handlers'],
			['<code>substr …,…,…,$replace</code>', 'replacement string in 4th argument'],
			['<code>splice …,…,-$length</code>', 'negative length indicates elements to keep at the end of an array'],
			['<code>$/</code>', 'integer or scalar separator makes <code>&lt;&gt;</code> read records instead of lines'],
		],
		modules => [
			['Data::Dumper' => 'stringify data structures'],
			['Errno' => 'system <code>errno.h</code> constants'],
			['File::Spec'],
			['Fatal'],
			['Test'],
		],
		release => '1998-07-22',
		unstable => 0,
	},

	v5.6 => {
		new => [
			['<code>use warnings</code>', 'pragma to enable warnings in lexical scope', {name => 'warnings'}],
			['<code>use utf8</code>', 'experimental unicode semantics <small>(completed in <a href="#utf8_data">v5.8</a>)</small>', {name => 'utf8', experimental => 0, stable => v5.8}],
			['<code>use charnames</code>', 'string escape <code>\N{}</code> to insert named character'],
			['<code>our</code>', 'declare global variables'],
			['<code>v1.2.3</code>', q"represent strings as vector of ordinals, useful in version numbers (<code>printf '%vd'</code> to display)"],
			['<code>0b0</code>', q"binary numbers in literals, <code>printf '%b'</code>, and <code>oct</code>"],
			['<code>sub :lvalue</code>', 'subroutine attribute to return a modifiable value', {name => 'sub_lvalue', experimental => 0, stable => v5.20}],
#			['<code>sub :locked :method</code>', 'syntax to declare subroutine attributes'], # can be inferred from :lvalue support
			['<code>open my $fh, $mode, $expr</code>', 'file handles in scoped scalars, third argument for unambiguous file name'],
			[q"<code>pack 'q'</code>", '64-bit integer support (also large files &gt;2GiB)', {experimental => 0, stable => v5.8.1}],
			['<code>sort $coderef ()</code>', 'comparison function can be a subroutine reference; prototype <code>($$)</code> to pass elements as normal <code>@_</code>'],
			['<code>CHECK {}</code>', 'special block called at end of compilation'],
			['<code>/[[:…:]]/</code>', 'POSIX character class syntax such as <code>/[[:alpha:]]/</code>'],
			# quite a lot more, but leave it at this
		],
		release => '2000-03-23',
		distro => {
			debian => '3.0', # woody 2002-07 eol 2006-06
			rhel => '2', # v5.6.0; also in red hat 7.0
			solaris => '9', # v5.6.1; 2002-05 eol 2014-10
			aix => '5.1', # 2001-05 eol 2006-04
			opensuse => '7.1', # 2001-01
		},
		versum => 'start of modern compatibility',
		unicode => '3.0.1',
	},

	v5.8 => {
		new => [
			[q"<code>no utf8</code>", 'full unicode support, <code>utf8</code> pragma only for script encoding', {name => 'utf8_data'}],
			[q"<code>use open</code>", 'file handle behaviour altered by PerlIO layers', {name => 'perlio', eg => 'binmode $fh, ":bytes"'}],
			[q"<code>open $fh, '-|', @cmd</code>", 'open list to fork a command without spawning a shell'],
			[q"<code>open $fh, '>', \$var</code>", 'perl scalars as virtual files'],
			[q"<code>printf '%1$s', @args</code>", 'syntax to use parameters out of order'],
			[q"<code>1_2_3 == 123</code>", 'underscores between digits allowed in numeric constants'],
		],
		modules => [
			[bignum => 'transparent big number support', 'length 1e100 == 101'],
			[if => 'conditional module inclusion', 'no if $] >= 5.022, "warnings", "redundant"'],
			[sort => 'override sort() algorithm', {dropped => v5.28, eg => 'sort::current eq "stable"'}],
			[Digest => 'calculate various message digests (data hashes)', '$hash = sha256_hex($data)'],
			[Encode => 'character set conversion', 'encode("utf8", decode("iso-8859-1", $octets))'],
			['File::Temp' => 'create a temporary file or directory safely', '$fh = tempfile();'],
			['List::Util' => 'general-utility list subroutines', '@cards = shuffle 0..51'],
			['Locale::Maketext' => 'various localization and internationalization in <code>Locale::*</code> and <code>L18N::*</code>'],
			['Memoize' => 'remember function results, trading space for time', 'memoize "stat"'],
			['MIME::Base64' => 'base64 encoded strings as in email attachments'],
			['Test::More' => 'modern framework for unit testing', 'is $got, $expected'],
			['Time::HiRes' => 'high resolution timers', '$μs = [gettimeofday]; sleep .1; $elapsed = tv_interval $μs'],
		],
		release => '2002-07-18',
		distro => {
			debian => '3.1', # sarge 2005-06 eol 2008-03, v5.8.8 in etch 2007-04 eol 2010-02
			rhel => '3', # v5.8.0; v5.8.8 in RHEL6 (2007-2014)
			solaris => '10', # v5.8.4; 2005-01 eol 2021-01
			centos => '3-5', # v5.8.0 in v3 (2004-03); v5.8.8 in v5 (eol 2017-03)
			ubuntu => '4.10', # v5.8.4 (2004-10); v5.8.7 in 6.06 LTS (2006-06); v5.8.8 in 8.04 LTS (2008-04)
			aix => '5.2', # v5.8.0; v5.8.2 in 5.3 and 6.1 (eol 2017-04-30)
			freebsd => '4-6',
			opensuse => '8.1', # 2002-09 eol (SLES8 2002-10 eol 2007-12 ltss 2009-12)
		},
		distrosum => "RHEL 3, SLES 8, AIX 5/6 until 2017, Solaris 10 until 2021",
		versum => 'stable minimum during 20[01]\d',
		support => '2021-01', # solaris
		unicode => '3.2.0',
	},

	v5.10 => {
		new => [
			['<code>//</code>', 'defined-or operator'],
			['<code>~~</code>', 'smart-match operator to compare different data types <small>(updated in v5.10.1)</small>', {experimental => 'smartmatch'}],
			['<code>say</code>', 'print with newline, equivalent to <code>print @_, "\n"</code>', {feature => 'say'}],
			['<code>given</code>', 'switch statement to smart-match with <code>when</code>/<code>default</code>', {name => 'switch', feature => 'switch', experimental => 'smartmatch'}],
			['<code>/(?&lt;name>)/</code>', 'named capture buffers into <code>%+</code>'],
			['<code>/(?1)/</code>', 'recursive regular expression patterns'],
			['<code>/(?|)/</code>', 'resets capture numbering for each contained branch'],
			['<code>/.++/</code>', 'possessive quantifiers <code>?+</code>, <code>*+</code>, <code>++</code> to match greedily'],
			['<code>s/keep\K//</code>', 'floating positive lookbehind, efficient alternative for <code>s/(keep)/$1/</code>'],
			['<code>/p</code>', 'optionally preserve <code>${^MATCH}</code> variables (avoiding <code>$&</code> penalty until COW in v5.20)'],
			['<code>/\v/, /\h/</code>', 'vertical and horizontal whitespace escapes (<code>\V</code> <code>\H</code> to invert); also <code>/\R/</code> for newlines'],
			['<code>my $_</code>', 'lexically scoped version of the default variable', {experimental => 'lexical_topic', dropped => v5.23.4}],
			['<code>state</code>', 'persistent <code>my</code> variables (scalars only until <a href="#state_ext">5.28</a>)', {feature => 'state'}],
		],
		modules => [
			[autodie => 'replace builtin functions to throw exceptions instead of returning failure', 'eval {open ...} or $@->matches("open") || die'],
			# overloading
			['IO::Compress::Zip' => 'various file compression standards', 'zip IO::Uncompress::Gunzip->new("test.gz") => "recompressed.zip"'],
			['Time::Piece' => 'timestamps as objects', 'localtime->year > 1900'],
			['File::Fetch' => 'generic data retrieval/download', 'File::Fetch->new(uri => "http://localhost/")->fetch(to => \$slurp)'],
		],
		release => '2007-12-18',
		distro => {
			debian => '5.0', # lenny 2009-02 eol 2012-02
			rhel => '6', # v5.10.1 (-6.9 2017-03 eol 2020-11 TuxCare els 2024-12)
			centos => '6', # v5.10.1 (2011-07 eol 2020-11 TuxCare els 2024-11)
			ubuntu => '8.10', # v5.10.1 in 10.04 LTS 2010-04 eol 2013-05
			aix => '7.1', # v5.10.1 (2010-09 eol 2023-04)
			opensuse => '11.0', # 2008-06 (SLES11 2009-03 eol 2019-03 ltss 2022-03)
		},
		distrosum => "SLES 11 until 2022, RHEL 6 until 2020 or commercially 2024, AIX 7.1 until 2023",
		versum => "supported commercially until 2024",
		support => '2024-11', # aix
		unicode => '5.0.0',
	},

	v5.12 => {
		new => [
			['<code>package</code> version', '<code>package</code> NAME VERSION shorthand for <code>our $VERSION</code>'],
			['<code>...</code>', 'yada-yada operator: code placeholder'],
			['<code>use 5.012</code>', 'implicit <code>strict</code> if use VERSION >= v5.12'],
			['<code>… when</code>', '<code>when</code> is now allowed to be used as a statement modifier'],
			[q"<code>use overload 'qr'</code>", 'customisable conversion to regular expressions'],
			['<code>/\N/</code>', 'inverse \n to match any character except newline regardless of <code>/s</code>', {experimental => 0, stable => v5.18}],
			['<code>each $ref</code> e.a.', 'array and hash container functions accept references', {experimental => 'autoderef', dropped => v5.23.1}],
		],
		release => '2010-04-12',
		unicode => '5.2',
		distro => {
			solaris => '11', # also v5.8.4; 2010-11; v11.3 eol 2024-01
			ubuntu => '11.10',
			freebsd => '7',
			opensuse => '11.3', # 2010-07
		},
		support => '2024-01', # solaris
	},

	v5.14 => {
		new => [
			['<code>s///r</code>', 'non-destructive substitution'],
			['<code>/(?{ m() })/</code>', 'regular expressions can be nested in <code>/(?{})/</code> and <code>/(??{})/</code>', {experimental => 0, stable => v5.20}],
			['<code>/dalu</code>', 'regexp modifiers to restrict character classes: either <strong>d</strong>efault, <strong>a</strong>scii, <strong>l</strong>ocale, or <strong>u</strong>nicode semantics.'],
			[q"<code>use re '/flags'</code>", 'customise default modifiers'],
			['<code>/(?^)/</code>', 'construct to reset to default modifiers'],
			['<code>FH->method</code>', 'filehandle method calls load IO::File on demand (eg. <code>STDOUT->flush</code>)'],
			['<code>\o{}</code>', 'escape sequence for octal values beyond \777'],
		],
		modules => [
			[JSON => 'interface with data in JavaScript Object Notation', 'decode_json <>'],
			['HTTP::Tiny' => 'minimal HTTP/1.1 client without <code>LWP::UserAgent</code> overhead'],
			# Unicode::Collate::Locale
		],
		release => '2011-05-14',
		distro => {
			debian => '7', # wheezy 2013-05 eol 2018-05 elts 2020-06
			ubuntu => '12.04',
			opensuse => '12.1', # 2011-11 (SLES12 2014-10 eol 2024-10 ltss 2027-10)
		},
		distrosum => "Debian 7 until 2020, Ubuntu 12.04, SLES 12 until 2027",
		support => '2027-10', # suse
		unicode => '6.0+#8',
	},

	v5.16 => {
		new => [
			['<code>__SUB__</code>', 'current subroutine reference', {feature => 'current_sub'}],
			['<code>fc, "\F"</code>', 'unicode foldcase to compare case-insensitively', {feature => 'fc'}],
			['<code>"\N{}"</code>', 'automatic <code>use charnames qw( :full :short )</code>'],
		],
		release => '2012-05-20',
		distro => {
			rhel => '7', # v5.16.3 (-7.9 2020-09 eol 2024-06)
			centos => '7', # v5.16.3 (2014-07 eol 2024-06 TuxCare els 2028-06)
			freebsd => '9',
			opensuse => '12.2', # 2012-09
		},
		unicode => '6.1',
	},

	v5.18 => {
		new => [
			['<code>${^LAST_FH}</code>', 'last read filehandle (used by <code>$.</code>)'],
			['<code>/(?[ a + b ])/</code>', 'regex set operations (character subtraction <code>-</code>, union <code>+</code>, intersection <code>&amp;</code>, xor <code>^</code>)', {experimental => 'regex_sets', stable => v5.36}],
			['<code>my sub</code>', 'lexical subroutines (also <code>state</code>, <code>our</code>); buggy before v5.22', {experimental => 'lexical_subs', stable => v5.26}],
			['<code>next $expression</code>', 'loop controls allow runtime expressions'],
			[q"<code>no warnings 'experimental::…'</code>", 'mechanism for experimental features, as of now required for <em>smartmatch</em>'],
		],
		release => '2013-05-18',
		distro => {
			ubuntu => '14.04 LTS', # trusty
			opensuse => '13.1', # 2013-11 eol 2016-01
		},
		unicode => '6.2',
	},

	v5.20 => {
		new => [
			['<code>sub ($var)</code>', 'subroutine signatures', {feature => 'signatures', experimental => 'signatures', stable => v5.36}],
			['<code>%hash{…}</code>', 'hash slices return key+value pairs'],
			['<code>[]->@*</code>', 'postfix dereferencing (also e.g. <code>$scalar->$*</code> for <code>$$scalar</code>)', {feature => 'postderef, postderef_qq', experimental => 'postderef', stable => v5.23.1}],
			[q"<code>use warnings 'once'; $a</code>", 'variables $a and $b are exempt from <em>used once</em> warnings'],
		],
		unicode => '6.3',
		release => '2014-05-27',
		distro => {
			debian => '8', # jessie 2015-04 eol 2018-06 lts 2020-06 elts 2025-06
			ubuntu => '14.10', # utopic
			aix => '7.2', # 2015-12 eol 2028?
			opensuse => '13.2', # 2014-11 eol 2017-01
		},
		distrosum => "Debian 8 until 2025, Ubuntu 14.10, openSUSE 13.2, AIX 7.2",
		versum => "extended vendor support 202X",
	},

	v5.22 => {
		new => [
			['<code>\$alias =</code>', 'aliasing via reference (scoped as of v5.25.3)', {experimental => 'refaliasing'}],
			['<code>&lt;&lt;>></code>', 'safe <code>readline</code> ignoring open flags in arguments'],
			['<code>/()/n</code>', 'flag to disable numbered capturing, turning <code>()</code> into <code>(?:)</code>'],
			['<code>/\b{}/</code>', 'boundary types: <em>gcb</em> (grapheme cluster), <em>sb</em> (sentence), <em>wb</em> (word)'],
			['<code>&.</code>', '<code>& | ^ ~</code> consistently numeric, dotted operators for strings', {feature => 'bitwise', experimental => 'bitwise', stable => v5.28}],
			[q"<code>use re 'strict'</code>", 'apply stricter syntax rules to regular expression patterns', {experimental => 're_strict'}],
			['<code>0x.beep+0</code>', q"hexadecimal floating point notation with binary power; <code>printf '%a'</code> to display"],
			['<code><s>??</s></code>', 'single match shorthand (deprecated since v5.14) requires the operator <code><em>m</em>?PATTERN?</code>'],
		],
		unicode => '7.0',
		release => '2015-06-01',
		distro => {
			ubuntu => '16.04 LTS', # xenial 2016-04 eol 2021-04 TuxCare els 2025-04
		},
	},

	v5.24 => {
		new => [
			[q"<code>printf '%.*2$x'</code>", 'reordered precision arguments'],
			['<code>/\b{lb}/</code>', 'line break boundary type (position suitable for hyphenation)'],
			['<code>/faster/</code>', 'various significant speedups, notably matching fixed substrings, <code>/i</code> on caseless languages, 64-bit arithmetic, scope overhead'],
		],
		unicode => '8.0',
		release => '2016-05-09',
		distro => {
			debian => '9', # stretch 2017-06 eol 2020-07 lts 2022-06 elts 2027-06
			ubuntu => '17.04', # zesty 2017-04 eol 2018-01
			freebsd => '10',
		},
		support => '2027-06',
	},

	v5.26 => {
		new => [
			['<code>&lt;&lt;~EOT</code>', 'indented here-docs, strips same whitespace before delimiter in each line'],
			['<code>@{^CAPTURE}</code>', q"array of last match's captures, so <code>${^CAPTURE}[0]</code> is <code>$1</code>"],
			['<code>//xx</code>', 'extended modifier to also ignore whitespace in bracketed character classes'],
		],
		modules => [
			['Test2::V0' => 'generic testing framework to replace <code>Test::*</code> and <code>TAP::*</code>'],
		],
		unicode => '9.0', # also Script_Extensions/scx in "\p{script}"
		release => '2017-05-30',
		distro => {
			ubuntu => '17.10', # artful 2017-10; 18.04 LTS 2018-04 eol 2023-04
			opensuse => '15.0', # 2018-05 eol 2019-11; same in 15.4 2022-06
			centos => '8', # 2019-09 eol 2021-12 TuxCare els 2026-01
		},
		distrosum => "stable servers such as Ubuntu 17.10+ (Debian &gt;9), CentOS 8, openSUSE 15.0",
		support => '2023-04',
	},

	v5.28 => {
		new => [
			['<code>delete %hash{…}</code>', 'hash slices can be deleted with key+value pairs'],
			['<code>/(*…)/</code>', 'alphabetic synonyms for assertions, e.g. <code>(*atomic:…)</code> for <code>(?&gt;…)</code> and <code>(*nlb:…)</code> for <code>(?&lt;!…)</code>', {experimental => 'alpha_assertions', stable => v5.31.6}],
			['<code>/(*script_run:)/</code>', 'enforces all characters to be from the same script', {experimental => 'script_run', stable => v5.31.6}],
			['<code>state @a</code>', 'persistent lexical array or hash variables (in addition to <a href="#state">scalars</a>)', {name => 'state_ext'}],
			['perl<code> -i -pe die</code>', 'safe in-place editing: files are replaced only after successful completion'],
			['<code>${^SAFE_LOCALES}</code>', 'locales are thread-safe on supported systems, indicated by this variable'],
		],
		unicode => '10.0',
		release => '2018-06-22',
		distro => {
			debian => '10', # buster 2019-07
			ubuntu => '19.04', # disco 2019-04 eol 2020-01
			freebsd => '11', # eol 2021-09
		},
		distrosum => "stable systems such as Debian 10, Ubuntu 19.04, FreeBSD 11",
	},

	v5.30 => {
		new => [
			['<code>/(?<=var+)</code>', 'variable length lookbehind assertions', {experimental => 'vlb', stable => v5.36}],
			['<code>m(\p{nv=/.*/})</code>', 'match unicode properties by regular expressions', {experimental => 'uniprop_wildcards'}],
			['<code><s>my $state if 0</s></code>', 'workaround for <code><a href="#state">state</a></code> (deprecated since v5.10!) is now prohibited'],
			[q"<code>qr'\N'</code>", 'Delimiters must be graphemes; unescaped <code>{</code> illegal; <code>\N</code> in single quotes'],
		],
		unicode => '12.1',
		release => '2019-05-22',
		distro => {
			ubuntu => '20.04', # focal LTS 2020-04 eol 2025-04
		},
	},

	v5.32 => {
		new => [
			['<code>isa</code>', 'infix operator to check class instance', {feature => 'isa', experimental => 'isa', stable => v5.36}],
			['<code>$min &lt; $_ &lt;= $max</code>', 'chained comparison repeats inner part as <code>$min &lt; $_ and $_ &lt;= $max</code>'],
			['<code>/\p{Name=$var}/</code>', 'match Unicode Name property like <code>\N{}</code> but with interpolation and subpatterns'],
			[q"<code>open F, '+&gt;&gt;', undef</code>", 'respect append mode on temporary files with mixed access'],
			["<code>no feature 'indirect'</code>", 'disable indirect object notation such as <code>new Class</code> instead of <code>Class-&gt;new</code>'],
			['streamzip', 'program distributed with core IO::Compress::Base to compress stdin into a zip container'],
		],
		unicode => '13.0',
		release => '2020-06-20',
		details => 'https://www.effectiveperlprogramming.com/2020/01/perl-v5-32-new-features/',
		distro => {
			debian => '11', # bullseye 2021-08
			ubuntu => '21.04', # hirsute 2021-04 eol 2022-01
			rhel => '8', # -8.7 and -9.1 2022-11
			solaris => '11.4', # 2018-08 eol 2034-11 (SRU 38 removes 5.22, 5.26)
		},
		distrosum => "stable systems such as Debian 11, Ubuntu 21.04, RHEL 8, Solaris 11.4, AIX 7.3",
		support => '2034-11', # solaris
	},

	v5.34 => {
		new => [
			['<code>try {} catch</code>', 'exception handling similar to eval blocks', {feature => 'try', experimental => 'try'}],
			['<code>/{,<i>n</i>}/</code>', 'empty lower bound quantifier is accepted as shorthand for 0'],
			['<code>\x{ … }</code>', 'insignificant space within curly braces, also for <code>\b{}</code>, <code>\g{}</code>, <code>\k{}</code>, <code>\N{}</code>, <code>\o{}</code> as well as <code>/{m,n}/</code> quantifiers'],
			['<code>0o0</code>', 'octal prefix <code>0o</code> alternative to <code>0…</code> and <code>oct</code>'],
			['<code>re::optimization(qr//)</code>', 'debug regular expression optimization information discovered at compile time'],
			['<code>no feature …</code>', 'disable discouraged practices of <code>bareword_filehandles</code> and <code>multidimensional</code> array emulation'],
		],
		release => '2021-05-20',
		distro => {
			ubuntu => '22.04', # jammy LTS 2022-04 eol 2027-04
			aix => '7.3', # 2021-12 eol 2035?
		},
	},

	v5.36 => {
		new => [
			['<code>use v5.36</code>', "use <code>warnings</code>; use feature qw'<code>signatures isa</code>'; no feature qw'<code>indirect multidimensional switch</code>'"],
			['<code>use builtin</code>', 'namespace for interpreter functions, such as <code>weaken</code> and <code>blessed</code> from <code>Scalar::Util</code>, <code>ceil</code>/<code>floor</code> from <code>POSIX</code>, and <code>trim</code> like <code>String::Util</code>', {experimental => 'builtin'}],
			['<code>is_bool(!0)</code>', 'distinguish scalar variable types (by <code>builtin</code> functions) for data interoperability', {name => 'is_bool'}],
			['<code>for my ($k, $v) (%hash)</code>', 'iterate over multiple values at a time (including <code>builtin::indexed</code> for arrays)', {experimental => 'for_list', feature => 'for_list'}],
			['<code>defer {}</code>', 'queue code to be executed when going out of scope', {feature => 'defer', experimental => 'defer'}],
			['<code>try {} finally {}</code>', 'run code at the end of a <code><a href="#try">try</a></code> construct regardless of failure', {name => 'finally', feature => 'try', experimental => 'try'}],
			['<code>q«…»</code>', 'unicode delimiters for quoting operators', {experimental => 'extra_paired_delimiters'}],
			['<code>sub ($var) {!<s>pop</s>}</code>', '<a href="#signatures">signature</a>d subs are stable, but mixing with the arguments array <code>@_</code> remains experimental', {feature => 'signatures', experimental => 'args_array_with_signatures'}],
			['<code>$SIG{FPE}</code>', 'floating-point exceptions no longer deferred but delivered immediately like other signals', {name => 'sig_fpe'}],
			['perl<code> -g</code>', 'disable input record separator (slurp mode), alias for <code>-0777</code>'],
		],
		unicode => '14.0',
		release => '2022-05-28',
		distro => {
			debian => '12', # bookworm 2023 upcoming
			ubuntu => '23.04', # lunar upcoming
		},
	},
}
