4 title => 'perl version cheat sheet',
7 perl version feature features comparison
8 sheet cheat overview summary
10 stylesheet => [qw'light dark red'],
11 data => ['perl.inc.pl'],
15 <h1>Perl release summary</h1>
17 <p>The most significant features introduced for recent versions of the Perl
20 my $info = Data('perl');
22 use feature 'signatures';
24 return sprintf 'v%d%03d', unpack 'C*', $v;
26 sub linkversion ($v) {
27 return showlink(sprintf('%vd', $v), '#'.vname($v));
31 use List::Util 'first';
35 my $now = Time::Piece->new;
36 if (my $ts = $get{at}) {
37 $now = $now->strptime($ts, '%Y-%m-%d');
38 say "Compatibility details emulated for <em>$ts</em>.";
40 my $ts = $now->strftime('%F');
41 my @versions = sort grep { $info->{$_}{release} le $ts } keys %{$info};
43 # perlpolicy: «We "officially" support the two most recent stable release
44 # series. [...] we will attempt to fix critical issues»
45 $info->{ $versions[-2] }{versum} //= "active core support";
46 $info->{ $versions[-1] }{versum} //= "latest stable release";
48 # perlpolicy: «we will attempt to fix critical issues in the two most
49 # recent stable 5.x release series»
50 my $coreeol = ($now - ONE_YEAR * 3)->strftime('%F');
51 my $vcore = first { $info->{$_}{release} ge $coreeol } @versions;
52 print "<p>Core security support is provided for 3 years";
53 print ", so typical users should run at least ", linkversion($_)
56 $info->{$vcore}{versum} //= "official security patches";
58 # «We encourage vendors to ship the most recent supported release of Perl
59 # at the time of their code freeze» with debian&ubuntu having 5 years LTS
60 my $vendoreol = ($now - ONE_YEAR * 5)->strftime('%F');
62 $info->{$_}{release} ge $vendoreol && $info->{$_}{distro}{debian}
64 say sprintf "Stable distributions such as Debian %s maintain %s+.",
65 $info->{$_}{distro}{debian}, linkversion($_) for $vdebian // ();
66 $info->{$vdebian}{versum} //= "still maintained by common vendors";
68 # extended support given at random
69 my $nowcmp = $now->strftime('%F');
70 my $vdino = first { $info->{$_}{support} ge $nowcmp } @versions;
71 say "Enterprise platforms retain versions up to $_."
72 for map { linkversion($_) } $vdino // ();
74 } or Alert('Missing version recommendations', $@);
77 for my $vernum (reverse sort keys %{$info}) {
78 my $verrow = $info->{$vernum};
79 defined $verrow->{unstable} and next unless exists $get{v};
81 say sprintf '<div class="section" id="%s">', vname($vernum);
82 my $title = $verrow->{release} // '?';
83 $title .= ": $_" for $verrow->{versum} // ();
84 say sprintf '<h2>%vd <small>%s</small></h2>', $vernum, $title;
86 for (@{ $verrow->{new} }) {
87 my ($topic, $desc, $attr) = @{$_};
88 $desc .= featattrs($attr);
89 my $ref = defined $attr->{name} && sprintf ' id="%s"', $attr->{name};
90 say sprintf '<dt%s>%s<dd>%s', $ref, $topic, $desc || '<br/>';
92 if (my $mods = $verrow->{modules}) {
94 my ($name, $desc, $attr) = @{$_};
95 my $ref = lc $name =~ s/::/_/gr;
96 $desc .= featattrs($attr);
97 printf '<dt id="%s"><code>use %s</code>', $ref, $name;
101 say sprintf '<dt>Unicode</dt><dd>v%s', $_ for $verrow->{unicode} || ();
106 sub featattrs ($attr) {
108 ref $attr or $attr = {eg => $attr};
110 if (defined $attr->{experimental}) {
111 $title = 'experimental';
113 if (defined $attr->{dropped}) {
114 return '' unless exists $get{v};
115 $title = sprintf 'removed in %vd', $_ for $attr->{dropped} || ();
117 elsif ($attr->{stable}) {
118 $title .= sprintf ' until %vd', $attr->{stable};
120 if ($attr->{experimental}) {
121 $title = sprintf '<span title="experimental::%s">%s</span>',
122 $attr->{experimental}, $title;
123 $attr->{name} //= $attr->{experimental};
125 if ($attr->{feature}) {
126 my $prefix = sprintf '<span title="%s">feature</span>',
128 $title = join ', ', $prefix, $title // ();
129 $attr->{name} //= $attr->{feature};
131 $title = $title ? sprintf ' <em class="ex">(%s)</em>', $title : '';
133 if (my $eg = $attr->{eg}) {
134 my $pre = sprintf ' <small>{<code>%s</code>}</small>', Entity($eg);
135 $title = $pre . $title;