getlines.lua

-- A simple decoder that pulls out line separated values
local function getLine(chunk)
  local s, e = string.find(chunk, "[\r\n]+")
  if not s then return end
  return string.sub(chunk, 1, s), string.sub(chunk, e + 1)
end

-- A generic adapter for applying decoders to emitter callbacks
local function applyDecoder(decoder, emit)
  local buffer = ""
  return function (chunk)
    buffer = buffer .. chunk
    repeat
      local event, more = getLine(buffer)
      if event then
        buffer = more
        emit(event)
      end
    until not more
  end
end

-- Sample emitter with decoder applied inline to emitter callback.
-- This will emit whole lines instead of raw chunks now.
stream:on("data", applyDecoder(getLine, function (line)
  print(line)
end))