# method calls

main->routine("foo");
main->$ref   ("foo");
$pkg->routine("foo");
$pkg->$ref   ("foo");
$obj->routine("foo");
$obj->$ref   ("foo");
# or even
(join'',map{chr}(109,97,105,110))->routine("foo");
__PACKAGE__->$ref("foo");
(bless \my $x)->$ref("foo");

# function calls

routine ('main', "foo");
$ref -> ('main', "foo");
routine ($pkg,   "foo");
$ref -> ($pkg,   "foo");
&$ref   ($pkg,   "foo");

routine ($obj,   "foo");
# etc.