Ruby in S-Expressions?

Since parenthesis are optional in function application, why not do (foo a, b, c) Instead of foo(a, b, c)?

def send(f, o, *args, &block)
  o.public_send(f, *args, &block)
end

(puts (send :join,
            (send :map,
                  (send :push, (Array 1), 2),
                  &(->(n) { send :*, n, n })),
            ", "))

Not quite there…