6 ['<code>use warnings</code>', 'pragma to enable warnings in lexical scope'],
7 ['<code>use utf8</code>', 'experimental unicode semantics <small>(completed in v5.8)</small>'],
8 ['<code>use charnames</code>', 'string escape <code>\N{}</code> to insert named character'],
9 ['<code>our</code>', 'declare global variables'],
10 ['<code>v1.2.3</code>', q`represent strings as vector of ordinals, useful in version numbers (<code>printf '%vd'</code> to display)`],
11 ['<code>0b0</code>', q`binary numbers in literals, <code>printf '%b'</code>, and <code>oct</code>`],
12 ['<code>sub :lvalue</code>', 'subroutine attribute to return a modifiable value'],
13 # ['<code>sub :locked :method</code>', 'syntax to declare subroutine attributes'], # can be inferred from :lvalue support
14 ['<code>open my $fh, $mode, $expr</code>', 'file handles in scoped scalars, third argument for unambiguous file name'],
15 [q`<code>pack 'q'</code>`, '64-bit integer support (also large files >2GiB)'],
16 ['<code>sort $coderef ()</code>', 'comparison function can be a subroutine reference; prototype <code>($$)</code> to pass elements as normal <code>@_</code>'],
17 ['<code>CHECK {}</code>', 'special block called at end of compilation'],
18 ['<code>/[[:…:]]/</code>', 'POSIX character class syntax such as <code>[[:alpha:]]/</code>'],
19 # quite a lot more, but leave it at this
21 release => '2000-03-23',
25 solaris => '9', # 2002-05 eol 2014-10
32 [q`<code>no utf8</code>`, 'full unicode support, <code>utf8</code> pragma only for script encoding'],
33 [q`<code>binmode $fh, ':perlio'</code>`, 'file handle behaviour altered by PerlIO layers'],
34 [q`<code>open $fh, '-|', @cmd</code>`, 'open list to fork a command without spawning a shell'],
35 [q`<code>open $fh, '>', \$var</code>`, 'perl scalars as virtual files'],
36 [q`<code>printf '%1$s', @args</code>`, 'syntax to use parameters out of order'],
37 [q`<code>1_2_3 == 123</code>`, 'underscores between digits allowed in numeric constants'],
38 # [q`<code>use if</code>`, 'conditional module inclusion'], # also installable in earlier versions
40 release => '2002-07-18',
44 solaris => '10', # v5.8.4; 2005-01 eol 2021-01
51 ['<code>//</code>', 'defined-or operator'],
52 ['<code>~~</code>', 'smart-match operator to compare different data types <small>(updated in v5.10.1)</small>'],
53 ['<code>given</code>', 'switch statement to smart-match with <code>when</code>/<code>default</code>'],
54 ['<code>/(?<name>)/</code>', 'named capture buffers into <code>%+</code>'],
55 ['<code>s/keep\K//</code>', 'floating positive lookbehind, efficient alternative for <code>s/(keep)/$1/</code>'],
56 ['<code>/\v/, /\h/</code>', 'vertical and horizontal whitespace escapes'],
57 ['<code>my $_</code>', 'lexically scoped version of the default variable'],
59 release => '2007-12-18',
69 ['<code>package version</code>', '<code>package</code> NAME VERSION shorthand for <code>our $VERSION</code>'],
70 ['<code>...</code>', 'yada-yada operator: code placeholder'],
71 ['<code>use 5.012</code>', 'Implicit <code>strict</code> if use VERSION >= v5.12'],
72 ['<code>… when</code>', '<code>when</code> is now allowed to be used as a statement modifier'],
73 [q(<code>use overload 'qr'</code>), 'customisable conversion to regular expressions'],
74 ['<code>/\N/</code>', 'inverse \n to match any character except newline regardless of <code>/s</code>'],
76 release => '2010-04-12',
79 solaris => '11', # also v5.8.4; 2010-11 eol 2024-11
85 ['<code>s///r</code>', 'non-destructive substitution'],
86 ['<code>/(?^)/</code>', 'construct to reset to default modifiers'],
87 ['<code>/(?{ m// })/</code>', 'regular expressions can be nested in <code>/(?{})/</code> and <code>/(??{})/</code>'],
88 ["<code>use re '/flags'</code>", 'customize default modifiers'],
89 ['<code>each $ref</code> e.a.', 'array and hash container functions accept references'],
90 ['<code>FH->method</code>', 'filehandle method calls load IO::File on demand (eg. <code>STDOUT->flush</code>)'],
92 release => '2011-05-14',
101 ['<code>__SUB__</code>', 'current subroutine reference'],
102 ['<code>fc, "\F"</code>', 'unicode foldcase to compare case-insensitively'],
103 ['<code>"\N{}"</code>', 'automatic <code>use charnames qw( :full :short )</code>'],
105 release => '2012-05-20',
114 ['<code>${^LAST_FH}</code>', 'last read filehandle (used by <code>$.</code>)'],
115 ['<code>/(?[ a + b ])/</code>', 'regex set operations (character substraction <code>-</code>, unions <code>&</code>)'],
116 ['<code>my sub foo</code>', 'lexical subroutines (also state, our)'],
117 ['<code>next $expression</code>', 'loop controls allow runtime expressions'],
118 [q(<code>no warnings 'experimental::…'</code>), 'mechanism for experimental features, as of now required for smartmatch'],
120 release => '2013-05-18',
126 ['<code>sub ($var)</code>', 'subroutine signatures'],
127 ['<code>%hash{…}</code>', 'hash slices return key+value pairs'],
128 ['<code>[]->@*</code>', 'postfix dereferencing (also e.g. <code>$scalar->$*</code> for <code>$$scalar</code>)'],
129 [q(<code>use warnings 'once'; $a</code>), 'variables $a and $b are exempt from <em>used once</em> warnings'],
132 release => '2014-05-27',