Buffer with string.pack/string.unpack

Buffer.lua

local function createReadBuffer(data)
	local index = 1

	local function readRaw(byteCount)
		local startIndex = index
		index = index + byteCount
		local endIndex = index - 1
		return string.byte(data, startIndex, endIndex)
	end

	local function process(...)
		index = select(-1, ...)
		return ...
	end
	local function read(formatString)
		return process(string.unpack(formatString, data, index))
	end

	return {
		read = read,
		readRaw = readRaw,
	}
end

local function createWriteBuffer()
	local chunks = {}

	local function writeRaw(string)
		table.insert(chunks, string)
	end

	local function write(...)
		table.insert(chunks, string.pack(...))
	end
	
	local function finish()
		return table.concat(chunks, "")
	end

	return {
		write = write,
		writeRaw = writeRaw,
		finish = finish,
	}
end

return {
	createReadBuffer = createReadBuffer,
	createWriteBuffer = createWriteBuffer,
}