return function (self, sel, atoms)
  self.inlets = 3
  function self:in_1_float(f)  pd.post("float: "  .. f) end
  function self:in_2_symbol(s) pd.post("symbol: " .. s) end
  function self:in_3_foo(atoms)
    pd.post("foo(")
    for i,v in ipairs(atoms) do
      pd.post("  " .. i .. " = " .. v)
    end
    pd.post(")")
  end
  return true
end