Assume a version with undefined support value will be the same as either its
predecessor or unsupported successor.
my $compare = (
!defined $ver ? undef : # last column if nameless
ref $data ne 'HASH' ? 'u' : # unsupported if no support hash
- $data->{$ver} # known
- || 'u' # unsure unless oldest is unsupported
+ $data->{$ver} // $prev # known or inherit from predecessor
+ // (grep { defined } @{$data}{ @{ $versions{$browser} } })[0]
+ ~~ 'n' && 'n' # first known version is unsupported
+ || 'u' # unsure
);
unless (!defined $prev or $prev ~~ $compare) {
my $usage = sum(map { $canihas->{$browser}->{$_} } @span);