function tileSonar(sonar)
  return function()
    val = sonarReading(sonar)
    if val < 30 then
       return 0
    else
       return 1
    end
  end
end

sensors = {tileSonar(1), tileSonar(2), tileSonar(3)}

function makeKey(sensorList) 
  local key = ""
  for i,func in ipairs(sensorList) do
    key = key .. func() .. " "
  end
  return key
end

cls()
repeat
  k = makeKey(sensors)
  write(k)
until isPressed(ESCAPE)