V:\>perl -MO=Deparse -e "sub foo {}; sub bar {};$x = bar foo 7, 9"
sub foo { }
sub bar { }
$x = bar(foo(7, 9));
-e syntax OK
V:\>perl -MO=Deparse -e "sub foo ($) {}; sub bar {};$x = bar foo 7, 9"
sub foo ($) { }
sub bar { }
$x = bar(foo(7), 9);
-e syntax OK