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lib/Bio/Phylo/Util/CONSTANT.pm  view on Meta::CPAN

# for tree drawing
sub _PI_ () { 4 * atan2(1,1) }

# this is a drop in replacement for Scalar::Util's function
my $looks_like_number;
{
    eval { Scalar::Util::looks_like_number(0) };
    if ($@) {
        my $LOOKS_LIKE_NUMBER_RE =
          qr/^([-+]?\d+(\.\d+)?([eE][-+]\d+)?|Inf|NaN)$/;
        $looks_like_number = sub {
            my $num = shift;
            if ( defined $num and $num =~ $LOOKS_LIKE_NUMBER_RE ) {
                return 1;
            }
            else {
                return;
            }
          }
    }