Html({
title => 'perl version cheat sheet',
- version => '1.3',
+ version => '1.4',
keywords => [qw'
perl version feature features comparison
sheet cheat overview summary
<p>The most significant features introduced for recent versions of the Perl
scripting language.
<:
-my $info = do 'perl.inc.pl' or die $@ // $!;
+my $info = Data('perl');
-say "Depending on desired compatibility you'll want to support a minimum of";
-say join(' or ', map {
- sprintf '<span title="on %s">v%vd</span>', $info->{$_}->{distrosum}, $_
-} v5.8, v5.20), '.';
+use feature 'signatures';
+sub vname ($v) {
+ return sprintf 'v%d%03d', unpack 'C*', $v;
+}
+sub linkversion ($v) {
+ return showlink(sprintf('%vd', $v), '#'.vname($v));
+}
+
+eval {
+ use List::Util 'first';
+ use Time::Piece;
+ use Time::Seconds;
+
+ my $now = Time::Piece->new;
+ if (my $ts = $get{at}) {
+ $now = $now->strptime($ts, '%Y-%m-%d');
+ say "Compatibility details emulated for <em>$ts</em>.";
+ }
+ my $ts = $now->strftime('%F');
+ my @versions = sort grep { $info->{$_}{release} le $ts } keys %{$info};
+
+ # perlpolicy: «We "officially" support the two most recent stable release
+ # series. [...] we will attempt to fix critical issues»
+ $info->{ $versions[-2] }{versum} //= "active core support";
+ $info->{ $versions[-1] }{versum} //= "latest stable release";
+
+ # perlpolicy: «we will attempt to fix critical issues in the two most
+ # recent stable 5.x release series»
+ my $coreeol = ($now - ONE_YEAR * 3)->strftime('%F');
+ my $vcore = first { $info->{$_}{release} ge $coreeol } @versions;
+ print "<p>Core security support is provided for 3 years";
+ print ", so typical users should run at least ", linkversion($_)
+ for $vcore // ();
+ say '.';
+ $info->{$vcore}{versum} //= "official security patches";
+
+ # «We encourage vendors to ship the most recent supported release of Perl
+ # at the time of their code freeze» with debian&ubuntu having 5 years LTS
+ my $vendoreol = ($now - ONE_YEAR * 5)->strftime('%F');
+ my $vdebian = first {
+ $info->{$_}{release} ge $vendoreol && $info->{$_}{distro}{debian}
+ } @versions;
+ say sprintf "Stable distributions such as Debian %s maintain %s+.",
+ $info->{$_}{distro}{debian}, linkversion($_) for $vdebian // ();
+ $info->{$vdebian}{versum} //= "still maintained by common vendors";
+
+ # extended support given at random
+ my $nowcmp = $now->strftime('%F');
+ my $vdino = first { $info->{$_}{support} ge $nowcmp } @versions;
+ say "Enterprise platforms retain versions up to $_."
+ for map { linkversion($_) } $vdino // ();
+ return 1;
+} or Alert('Missing version recommendations', $@);
say '</p>';
for my $vernum (reverse sort keys %{$info}) {
my $verrow = $info->{$vernum};
defined $verrow->{unstable} and next unless exists $get{v};
- say '<div class="section">';
- say sprintf '<h2>%vd <small>%s</small></h2>', $vernum, $verrow->{release};
+ say sprintf '<div class="section" id="%s">', vname($vernum);
+ my $title = $verrow->{release} // '?';
+ $title .= ": $_" for $verrow->{versum} // ();
+ say sprintf '<h2>%vd <small>%s</small></h2>', $vernum, $title;
say '<dl>';
for (@{ $verrow->{new} }) {
my ($topic, $desc, $attr) = @{$_};
if ($attr->{feature}) {
my $prefix = sprintf '<span title="%s">feature</span>',
$attr->{feature};
- my $title = join ', ', $prefix, $title // ();
+ $title = join ', ', $prefix, $title // ();
}
$desc .= sprintf ' <em class="ex">(%s)</em>', $title;
}