+ distro => {
+ rhel => '7', # v5.16.3
+ centos => '7', # v5.16.3 (2014-07 eol 2024-06)
+ freebsd => '9',
+ opensuse => '12.2',
+ },
+ 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 substraction <code>-</code>, unions <code>&</code>)', {experimental => 'regex_sets'}],
+ ['<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 $expression</code>', 'loop controls allow runtime expressions'],
+ [q"<code>no warnings 'experimental::…'</code>", 'mechanism for experimental features, as of now required for <em>smartmatch</em>'],
+ ],
+ release => '2013-05-18',
+ distro => {
+ ubuntu => '14.04 LTS', # trusty
+ opensuse => '13.1',
+ },
+ unicode => '6.2',
+ },
+
+ v5.20 => {
+ new => [
+ ['<code>sub ($var)</code>', 'subroutine signatures', {feature => 'signatures', experimental => 'signatures'}],
+ ['<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 $b are exempt from <em>used once</em> warnings'],
+ ],
+ unicode => '6.3',
+ release => '2014-05-27',
+ distro => {
+ debian => '8', # jessie 2015-04 eol 2020-05
+ ubuntu => '14.10', # utopic
+ aix => '7.2',
+ opensuse => '13.2', # 2014-11 eol 2017-01
+ },
+ distrosum => "stable servers such as Debian 8 (oldstable), Ubuntu 14.10, FreeBSD 10, openSUSE 13.2",
+ },
+
+ v5.22 => {
+ new => [
+ ['<code>\$alias =</code>', 'aliasing via reference (scoped as of v5.25.3)', {experimental => 'refaliasing'}],
+ ['<code><<>></code>', 'safe <code>readline</code> ignoring open flags in arguments'],
+ ['<code>/()/n</code>', 'flag to disable numbered capturing, turning <code>()</code> into <code>(?:)</code>'],
+ ['<code>/\b{}/</code>', 'boundary types: <em>gcb</em> (grapheme cluster), <em>sb</em> (sentence), <em>wb</em> (word)'],
+ ['<code>&.</code>', '<code>& | ^ ~</code> consistently numeric, dotted operators for strings', {feature => 'bitwise', experimental => 'bitwise', stable => v5.28}],
+ [q"<code>use re 'strict'</code>", 'apply stricter syntax rules to regular expression patterns', {experimental => 're_strict'}],
+ ['<code>0x.beep+0</code>', q"hexadecimal floating point notation with binary power; <code>printf '%a'</code> to display"],
+ ['<code><s>??</s></code>', 'single match shorthand (deprecated since v5.14) requires the operator <code><em>m</em>?PATTERN?</code>'],
+ ],
+ unicode => '7.0',
+ release => '2015-06-01',
+ distro => {
+ ubuntu => '16.04 LTS', # xenial
+ },
+ },
+
+ v5.24 => {
+ new => [
+ [q"<code>printf '%.*2$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
+ ubuntu => '17.04', # zesty
+ freebsd => '10',
+ },
+ },
+
+ v5.26 => {
+ new => [
+ ['<code><<~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>$1</code>"],
+ ['<code>//xx</code>', 'extended modifier to also ignore whitespace in bracketed character classes'],
+ ],
+ unicode => '9.0', # also Script_Extensions/scx in "\p{script}"
+ release => '2017-05-30',
+ distro => {
+ ubuntu => '17.10', # artful
+ },
+ },
+
+ v5.28 => {
+ new => [
+ ['<code>delete %hash{…}</code>', 'hash slices can be deleted with key+value pairs'],
+ ['<code>/(*…)/</code>', 'alphabetic synonyms for assertions, e.g. <code>(*atomic:…)</code> for <code>(?>…)</code> and <code>(*nlb:…)</code> for <code>(?<!…)</code>', {experimental => 'alpha_assertions', stable => v5.31.6}],
+ ['<code>/(*script_run:)/</code>', 'enforces all characters to be from the same script', {experimental => 'script_run', stable => v5.31.6}],
+ ['<code>state @a</code>', 'persistent lexical array or hash variables'],
+ ['<code>perl -i -pe die</code>', 'safe in-place editing: files are replaced only after successful completion'],
+ ['<code>${^SAFE_LOCALES}</code>', 'locales are thread-safe on supported systems, indicated by this variable'],
+ ],
+ unicode => '10.0',
+ release => '2018-06-22',
+ distro => {
+ },
+ },
+
+ v5.30 => {
+ new => [
+ ['<code>/(?<=var+)</code>', 'variable length lookbehind assertions', {experimental => 'vlb'}],
+ ['<code>m(\p{nv=/.*/})</code>', 'match unicode properties by regular expressions', {experimental => 'uniprop_wildcards'}],
+ ['<code><s>my $state if 0</s></code>', 'workaround for <code>state</code> (deprecated since v5.10!) is now prohibited'],
+ [q"<code>qr'\N'</code>", 'Delimiters must be graphemes; unescaped { illegal; \N in single quotes'],
+ ],
+ unicode => '12.1',
+ release => '2019-05-22',
+ },
+
+ v5.32 => {
+ new => [
+ ['<code>isa</code>', 'infix operator to check class instance'],
+ ['<code>$min < $_ <= $max</code>', 'chained comparison repeats inner part as <code>$min < $_ and $_ <= $max</code>'],
+ ['<code>/\p{Name=$var}/</code>', 'match Unicode Name property like \N{} but with interpolation and subpatterns'],
+ [q"<code>open F, '+>>', 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->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/',
+ },
+
+ v5.34 => {
+ new => [
+ ['<code>try {} catch</code>', 'exception handling similar to eval blocks', {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'],
+ ],
+ release => '2021-05-20',