signal finder [Factorio]

/c --[[ signal finder ]]
local function findme(signal_name)
  local out = ""
  for _,e in pairs(game.player.surface.find_entities_filtered{type = {"constant-combinator","arithmetic-combinator","decider-combinator"}}) do
    for k,v in pairs(e.get_control_behavior().parameters.parameters) do
      if type(v) == "table" and ((v.name == signal_name) or (v.signal and v.signal.name == signal_name)) then
        out = out .. "[gps=" .. e.position.x .. "," .. e.position.y .. "] "
        break
      end
    end
  end
  game.player.print(#out > 0 and out or "None found.")
end
findme "signal-S"