sub new {
    my $proto = shift;
    my $class = CORE::ref $proto || $proto; # yes, I know what I'm doing
    return $class->_new_var unless @_;
    if (2 == @_) { # more common (performance)
        return _new_from_functor_and_arity($class, @_) unless 'ARRAY' eq CORE::ref $_[1];
    }
    elsif (1 == @_) {
        my $arg = shift;
        return _new_with_id($class, $arg)     if ! CORE::ref $arg && $arg =~ /^[[:digit:]]+$/;
        return _new_from_string($class, $arg) if ! CORE::ref $arg;
        return $arg->_term($class)            if   CORE::ref $arg && $arg->isa(Parser);
    }
    require Carp;
    Carp::croak("Unknown arguments to Term->new");
}