wnsrc/addons/sam-master/lua/sam/libs/message_pack/sh_messagepack.lua

--[[
| This file was obtained through the combined efforts
| of Madbluntz & Plymouth Antiquarian Society.
|
| Credits: lifestorm, Gregory Wayne Rossel JR.,
| 	Maloy, DrPepper10 @ RIP, Atle!
|
| Visit for more: https://plymouth.thetwilightzone.ru/
--]]

if SAM_LOADED then return end
--
-- lua-MessagePack : <https://fperrad.frama.io/lua-MessagePack/>
--
local SIZEOF_NUMBER = string.pack and #string.pack('n', 0.0) or 8
local maxinteger
local mininteger
local assert = assert
local error = error
local pairs = pairs
local pcall = pcall
local setmetatable = setmetatable
local tostring = tostring
local char = string.char
local format = string.format
local floor = math.floor
local tointeger = floor
local frexp = math.frexp
local ldexp = math.ldexp
local huge = math.huge
local tconcat = table.concat
local type = sam.type
local isnumber = sam.isnumber
local _ENV = nil
local m = {}

--[[ debug only
local function hexadump (s)
	return (s:gsub('.', function (c) return format('%02X ', c:byte()) end))
end
m.hexadump = hexadump
--]]
local function argerror(caller, narg, extramsg)
	error("bad argument #" .. tostring(narg) .. " to " .. caller .. " (" .. extramsg .. ")")
end

local function typeerror(caller, narg, arg, tname)
	argerror(caller, narg, tname .. " expected, got " .. type(arg))
end

local function checktype(caller, narg, arg, tname)
	if type(arg) ~= tname then
		typeerror(caller, narg, arg, tname)
	end
end

local packers = setmetatable({}, {
	__index = function(t, k)
		if k == 1 then return end -- allows ipairs
		error("pack '" .. k .. "' is unimplemented")
	end
})

m.packers = packers

packers["nil"] = function(buffer)
	buffer[#buffer + 1] = char(0xC0) -- nil
end

packers["boolean"] = function(buffer, bool)
	if bool then
		buffer[#buffer + 1] = char(0xC3) -- true
	else
		buffer[#buffer + 1] = char(0xC2) -- false
	end
end

packers["string_compat"] = function(buffer, str)
	local n = #str

	if n <= 0x1F then
		buffer[#buffer + 1] = char(0xA0 + n) -- fixstr
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xDA, floor(n / 0x100), n % 0x100) -- str16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xDB, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- str32
	else
		error"overflow in pack 'string_compat'"
	end

	buffer[#buffer + 1] = str
end

packers["_string"] = function(buffer, str)
	local n = #str

	if n <= 0x1F then
		buffer[#buffer + 1] = char(0xA0 + n) -- fixstr
	elseif n <= 0xFF then
		buffer[#buffer + 1] = char(0xD9, n) -- str8
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xDA, floor(n / 0x100), n % 0x100) -- str16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xDB, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- str32
	else
		error("overflow in pack 'string'")
	end

	buffer[#buffer + 1] = str
end

packers["binary"] = function(buffer, str)
	local n = #str

	if n <= 0xFF then
		buffer[#buffer + 1] = char(0xC4, n) -- bin8
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xC5, floor(n / 0x100), n % 0x100) -- bin16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xC6, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- bin32
	else
		error("overflow in pack 'binary'")
	end

	buffer[#buffer + 1] = str
end

local set_string = function(str)
	if str == "string_compat" then
		packers["string"] = packers["string_compat"]
	elseif str == "string" then
		packers["string"] = packers["_string"]
	elseif str == "binary" then
		packers["string"] = packers["binary"]
	else
		argerror("set_string", 1, "invalid option '" .. str .. "'")
	end
end

m.set_string = set_string

packers["map"] = function(buffer, tbl, n)
	if n <= 0x0F then
		buffer[#buffer + 1] = char(0x80 + n) -- fixmap
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xDE, floor(n / 0x100), n % 0x100) -- map16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xDF, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- map32
	else
		error("overflow in pack 'map'")
	end

	for k, v in pairs(tbl) do
		packers[type(k)](buffer, k)
		packers[type(v)](buffer, v)
	end
end

packers["array"] = function(buffer, tbl, n)
	if n <= 0x0F then
		buffer[#buffer + 1] = char(0x90 + n) -- fixarray
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xDC, floor(n / 0x100), n % 0x100) -- array16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xDD, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- array32
	else
		error("overflow in pack 'array'")
	end

	for i = 1, n do
		local v = tbl[i]
		packers[type(v)](buffer, v)
	end
end

local set_array = function(array)
	if array == "without_hole" then
		packers["_table"] = function(buffer, tbl)
			local is_map, n, max = false, 0, 0

			for k in pairs(tbl) do
				if isnumber(k) and k > 0 then
					if k > max then
						max = k
					end
				else
					is_map = true
				end

				n = n + 1
			end

			-- there are holes
			if max ~= n then
				is_map = true
			end

			if is_map then
				packers["map"](buffer, tbl, n)
			else
				packers["array"](buffer, tbl, n)
			end
		end
	elseif array == "with_hole" then
		packers["_table"] = function(buffer, tbl)
			local is_map, n, max = false, 0, 0

			for k in pairs(tbl) do
				if isnumber(k) and k > 0 then
					if k > max then
						max = k
					end
				else
					is_map = true
				end

				n = n + 1
			end

			if is_map then
				packers["map"](buffer, tbl, n)
			else
				packers["array"](buffer, tbl, max)
			end
		end
	elseif array == "always_as_map" then
		packers["_table"] = function(buffer, tbl)
			local n = 0

			for k in pairs(tbl) do
				n = n + 1
			end

			packers["map"](buffer, tbl, n)
		end
	else
		argerror("set_array", 1, "invalid option '" .. array .. "'")
	end
end

m.set_array = set_array

packers["table"] = function(buffer, tbl)
	packers["_table"](buffer, tbl)
end

packers["unsigned"] = function(buffer, n)
	if n >= 0 then
		if n <= 0x7F then
			buffer[#buffer + 1] = char(n) -- fixnum_pos
		elseif n <= 0xFF then
			buffer[#buffer + 1] = char(0xCC, n) -- uint8
		elseif n <= 0xFFFF then
			buffer[#buffer + 1] = char(0xCD, floor(n / 0x100), n % 0x100) -- uint16
		elseif n <= 4294967295.0 then
			buffer[#buffer + 1] = char(0xCE, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- uint32
		else
			buffer[#buffer + 1] = char(0xCF, 0, floor(n / 0x1000000000000) % 0x100, floor(n / 0x10000000000) % 0x100, floor(n / 0x100000000) % 0x100, floor(n / 0x1000000) % 0x100, floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- uint64 -- only 53 bits from double
		end
	else
		if n >= -0x20 then
			buffer[#buffer + 1] = char(0x100 + n) -- fixnum_neg
		elseif n >= -0x80 then
			buffer[#buffer + 1] = char(0xD0, 0x100 + n) -- int8
		elseif n >= -0x8000 then
			n = 0x10000 + n
			buffer[#buffer + 1] = char(0xD1, floor(n / 0x100), n % 0x100) -- int16
		elseif n >= -0x80000000 then
			n = 4294967296.0 + n
			buffer[#buffer + 1] = char(0xD2, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int32
		else
			buffer[#buffer + 1] = char(0xD3, 0xFF, floor(n / 0x1000000000000) % 0x100, floor(n / 0x10000000000) % 0x100, floor(n / 0x100000000) % 0x100, floor(n / 0x1000000) % 0x100, floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int64 -- only 53 bits from double
		end
	end
end

packers["signed"] = function(buffer, n)
	if n >= 0 then
		if n <= 0x7F then
			buffer[#buffer + 1] = char(n) -- fixnum_pos
		elseif n <= 0x7FFF then
			buffer[#buffer + 1] = char(0xD1, floor(n / 0x100), n % 0x100) -- int16
		elseif n <= 0x7FFFFFFF then
			buffer[#buffer + 1] = char(0xD2, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int32
		else
			buffer[#buffer + 1] = char(0xD3, 0, floor(n / 0x1000000000000) % 0x100, floor(n / 0x10000000000) % 0x100, floor(n / 0x100000000) % 0x100, floor(n / 0x1000000) % 0x100, floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int64 -- only 53 bits from double
		end
	else
		if n >= -0x20 then
			buffer[#buffer + 1] = char(0xE0 + 0x20 + n) -- fixnum_neg
		elseif n >= -0x80 then
			buffer[#buffer + 1] = char(0xD0, 0x100 + n) -- int8
		elseif n >= -0x8000 then
			n = 0x10000 + n
			buffer[#buffer + 1] = char(0xD1, floor(n / 0x100), n % 0x100) -- int16
		elseif n >= -0x80000000 then
			n = 4294967296.0 + n
			buffer[#buffer + 1] = char(0xD2, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int32
		else
			buffer[#buffer + 1] = char(0xD3, 0xFF, floor(n / 0x1000000000000) % 0x100, floor(n / 0x10000000000) % 0x100, floor(n / 0x100000000) % 0x100, floor(n / 0x1000000) % 0x100, floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100) -- int64 -- only 53 bits from double
		end
	end
end

local set_integer = function(integer)
	if integer == "unsigned" then
		packers["integer"] = packers["unsigned"]
	elseif integer == "signed" then
		packers["integer"] = packers["signed"]
	else
		argerror("set_integer", 1, "invalid option '" .. integer .. "'")
	end
end

m.set_integer = set_integer

packers["float"] = function(buffer, n)
	local sign = 0

	if n < 0.0 then
		sign = 0x80
		n = -n
	end

	local mant, expo = frexp(n)

	if mant ~= mant then
		buffer[#buffer + 1] = char(0xCA, 0xFF, 0x88, 0x00, 0x00) -- nan
	elseif mant == huge or expo > 0x80 then
		if sign == 0 then
			buffer[#buffer + 1] = char(0xCA, 0x7F, 0x80, 0x00, 0x00) -- inf
		else
			buffer[#buffer + 1] = char(0xCA, 0xFF, 0x80, 0x00, 0x00) -- -inf
		end
	elseif (mant == 0.0 and expo == 0) or expo < -0x7E then
		buffer[#buffer + 1] = char(0xCA, sign, 0x00, 0x00, 0x00) -- zero
	else
		expo = expo + 0x7E
		mant = floor((mant * 2.0 - 1.0) * ldexp(0.5, 24))
		buffer[#buffer + 1] = char(0xCA, sign + floor(expo / 0x2), (expo % 0x2) * 0x80 + floor(mant / 0x10000), floor(mant / 0x100) % 0x100, mant % 0x100)
	end
end

packers["double"] = function(buffer, n)
	local sign = 0

	if n < 0.0 then
		sign = 0x80
		n = -n
	end

	local mant, expo = frexp(n)

	if mant ~= mant then
		buffer[#buffer + 1] = char(0xCB, 0xFF, 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) -- nan
	elseif mant == huge or expo > 0x400 then
		if sign == 0 then
			buffer[#buffer + 1] = char(0xCB, 0x7F, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) -- inf
		else
			buffer[#buffer + 1] = char(0xCB, 0xFF, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) -- -inf
		end
	elseif (mant == 0.0 and expo == 0) or expo < -0x3FE then
		buffer[#buffer + 1] = char(0xCB, sign, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) -- zero
	else
		expo = expo + 0x3FE
		mant = floor((mant * 2.0 - 1.0) * ldexp(0.5, 53))
		buffer[#buffer + 1] = char(0xCB, sign + floor(expo / 0x10), (expo % 0x10) * 0x10 + floor(mant / 0x1000000000000), floor(mant / 0x10000000000) % 0x100, floor(mant / 0x100000000) % 0x100, floor(mant / 0x1000000) % 0x100, floor(mant / 0x10000) % 0x100, floor(mant / 0x100) % 0x100, mant % 0x100)
	end
end

local set_number = function(number)
	if number == "float" then
		packers["number"] = function(buffer, n)
			if floor(n) == n and n < maxinteger and n > mininteger then
				packers["integer"](buffer, n)
			else
				packers["float"](buffer, n)
			end
		end
	elseif number == "double" then
		packers["number"] = function(buffer, n)
			if floor(n) == n and n < maxinteger and n > mininteger then
				packers["integer"](buffer, n)
			else
				packers["double"](buffer, n)
			end
		end
	else
		argerror("set_number", 1, "invalid option '" .. number .. "'")
	end
end

m.set_number = set_number

for k = 0, 4 do
	local n = tointeger(2 ^ k)
	local fixext = 0xD4 + k

	packers["fixext" .. tostring(n)] = function(buffer, tag, data)
		assert(#data == n, "bad length for fixext" .. tostring(n))
		buffer[#buffer + 1] = char(fixext, tag < 0 and tag + 0x100 or tag)
		buffer[#buffer + 1] = data
	end
end

packers["ext"] = function(buffer, tag, data)
	local n = #data

	if n <= 0xFF then
		buffer[#buffer + 1] = char(0xC7, n, tag < 0 and tag + 0x100 or tag) -- ext8
	elseif n <= 0xFFFF then
		buffer[#buffer + 1] = char(0xC8, floor(n / 0x100), n % 0x100, tag < 0 and tag + 0x100 or tag) -- ext16
	elseif n <= 4294967295.0 then
		buffer[#buffer + 1] = char(0xC9, floor(n / 0x1000000), floor(n / 0x10000) % 0x100, floor(n / 0x100) % 0x100, n % 0x100, tag < 0 and tag + 0x100 or tag) -- ext&32
	else
		error("overflow in pack 'ext'")
	end

	buffer[#buffer + 1] = data
end

function m.pack(data)
	local buffer = {}
	packers[type(data)](buffer, data)

	return tconcat(buffer)
end

local unpackers -- forward declaration

local function unpack_cursor(c)
	local s, i, j = c.s, c.i, c.j

	if i > j then
		c:underflow(i)
		s, i, j = c.s, c.i, c.j
	end

	local val = s:byte(i)
	c.i = i + 1

	return unpackers[val](c, val)
end

m.unpack_cursor = unpack_cursor

local function unpack_str(c, n)
	local s, i, j = c.s, c.i, c.j
	local e = i + n - 1

	if e > j or n < 0 then
		c:underflow(e)
		s, i, j = c.s, c.i, c.j
		e = i + n - 1
	end

	c.i = i + n

	return s:sub(i, e)
end

local function unpack_array(c, n)
	local t = {}

	for i = 1, n do
		t[i] = unpack_cursor(c)
	end

	return t
end

local function unpack_map(c, n)
	local t = {}

	for i = 1, n do
		local k = unpack_cursor(c)
		local val = unpack_cursor(c)

		if k == nil or k ~= k then
			k = m.sentinel
		end

		if k ~= nil then
			t[k] = val
		end
	end

	return t
end

local function unpack_float(c)
	local s, i, j = c.s, c.i, c.j

	if i + 3 > j then
		c:underflow(i + 3)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4 = s:byte(i, i + 3)
	local sign = b1 > 0x7F
	local expo = (b1 % 0x80) * 0x2 + floor(b2 / 0x80)
	local mant = ((b2 % 0x80) * 0x100 + b3) * 0x100 + b4

	if sign then
		sign = -1
	else
		sign = 1
	end

	local n

	if mant == 0 and expo == 0 then
		n = sign * 0.0
	elseif expo == 0xFF then
		if mant == 0 then
			n = sign * huge
		else
			n = 0.0 / 0.0
		end
	else
		n = sign * ldexp(1.0 + mant / 0x800000, expo - 0x7F)
	end

	c.i = i + 4

	return n
end

local function unpack_double(c)
	local s, i, j = c.s, c.i, c.j

	if i + 7 > j then
		c:underflow(i + 7)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4, b5, b6, b7, b8 = s:byte(i, i + 7)
	local sign = b1 > 0x7F
	local expo = (b1 % 0x80) * 0x10 + floor(b2 / 0x10)
	local mant = ((((((b2 % 0x10) * 0x100 + b3) * 0x100 + b4) * 0x100 + b5) * 0x100 + b6) * 0x100 + b7) * 0x100 + b8

	if sign then
		sign = -1
	else
		sign = 1
	end

	local n

	if mant == 0 and expo == 0 then
		n = sign * 0.0
	elseif expo == 0x7FF then
		if mant == 0 then
			n = sign * huge
		else
			n = 0.0 / 0.0
		end
	else
		n = sign * ldexp(1.0 + mant / 4503599627370496.0, expo - 0x3FF)
	end

	c.i = i + 8

	return n
end

local function unpack_uint8(c)
	local s, i, j = c.s, c.i, c.j

	if i > j then
		c:underflow(i)
		s, i, j = c.s, c.i, c.j
	end

	local b1 = s:byte(i)
	c.i = i + 1

	return b1
end

local function unpack_uint16(c)
	local s, i, j = c.s, c.i, c.j

	if i + 1 > j then
		c:underflow(i + 1)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2 = s:byte(i, i + 1)
	c.i = i + 2

	return b1 * 0x100 + b2
end

local function unpack_uint32(c)
	local s, i, j = c.s, c.i, c.j

	if i + 3 > j then
		c:underflow(i + 3)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4 = s:byte(i, i + 3)
	c.i = i + 4

	return ((b1 * 0x100 + b2) * 0x100 + b3) * 0x100 + b4
end

local function unpack_uint64(c)
	local s, i, j = c.s, c.i, c.j

	if i + 7 > j then
		c:underflow(i + 7)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4, b5, b6, b7, b8 = s:byte(i, i + 7)
	c.i = i + 8

	return ((((((b1 * 0x100 + b2) * 0x100 + b3) * 0x100 + b4) * 0x100 + b5) * 0x100 + b6) * 0x100 + b7) * 0x100 + b8
end

local function unpack_int8(c)
	local s, i, j = c.s, c.i, c.j

	if i > j then
		c:underflow(i)
		s, i, j = c.s, c.i, c.j
	end

	local b1 = s:byte(i)
	c.i = i + 1

	if b1 < 0x80 then
		return b1
	else
		return b1 - 0x100
	end
end

local function unpack_int16(c)
	local s, i, j = c.s, c.i, c.j

	if i + 1 > j then
		c:underflow(i + 1)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2 = s:byte(i, i + 1)
	c.i = i + 2

	if b1 < 0x80 then
		return b1 * 0x100 + b2
	else
		return ((b1 - 0xFF) * 0x100 + (b2 - 0xFF)) - 1
	end
end

local function unpack_int32(c)
	local s, i, j = c.s, c.i, c.j

	if i + 3 > j then
		c:underflow(i + 3)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4 = s:byte(i, i + 3)
	c.i = i + 4

	if b1 < 0x80 then
		return ((b1 * 0x100 + b2) * 0x100 + b3) * 0x100 + b4
	else
		return ((((b1 - 0xFF) * 0x100 + (b2 - 0xFF)) * 0x100 + (b3 - 0xFF)) * 0x100 + (b4 - 0xFF)) - 1
	end
end

local function unpack_int64(c)
	local s, i, j = c.s, c.i, c.j

	if i + 7 > j then
		c:underflow(i + 7)
		s, i, j = c.s, c.i, c.j
	end

	local b1, b2, b3, b4, b5, b6, b7, b8 = s:byte(i, i + 7)
	c.i = i + 8

	if b1 < 0x80 then
		return ((((((b1 * 0x100 + b2) * 0x100 + b3) * 0x100 + b4) * 0x100 + b5) * 0x100 + b6) * 0x100 + b7) * 0x100 + b8
	else
		return ((((((((b1 - 0xFF) * 0x100 + (b2 - 0xFF)) * 0x100 + (b3 - 0xFF)) * 0x100 + (b4 - 0xFF)) * 0x100 + (b5 - 0xFF)) * 0x100 + (b6 - 0xFF)) * 0x100 + (b7 - 0xFF)) * 0x100 + (b8 - 0xFF)) - 1
	end
end

function m.build_ext(tag, data)
	return nil
end

local function unpack_ext(c, n, tag)
	local s, i, j = c.s, c.i, c.j
	local e = i + n - 1

	if e > j or n < 0 then
		c:underflow(e)
		s, i, j = c.s, c.i, c.j
		e = i + n - 1
	end

	c.i = i + n

	return m.build_ext(tag, s:sub(i, e))
end

local fn_1 = function(c, val) return val end
local fn_2 = function(c, val) return unpack_map(c, val % 0x10) end
local fn_3 = function(c, val) return unpack_array(c, val % 0x10) end
local fn_4 = function(c, val) return unpack_str(c, val % 0x20) end
local fn_5 = function(c, val) return val - 0x100 end

unpackers = setmetatable({
	[0xC0] = function() return nil end,
	[0xC2] = function() return false end,
	[0xC3] = function() return true end,
	[0xC4] = function(c) return unpack_str(c, unpack_uint8(c)) end, -- bin8
	[0xC5] = function(c) return unpack_str(c, unpack_uint16(c)) end, -- bin16
	[0xC6] = function(c) return unpack_str(c, unpack_uint32(c)) end, -- bin32
	[0xC7] = function(c) return unpack_ext(c, unpack_uint8(c), unpack_int8(c)) end,
	[0xC8] = function(c) return unpack_ext(c, unpack_uint16(c), unpack_int8(c)) end,
	[0xC9] = function(c) return unpack_ext(c, unpack_uint32(c), unpack_int8(c)) end,
	[0xCA] = unpack_float,
	[0xCB] = unpack_double,
	[0xCC] = unpack_uint8,
	[0xCD] = unpack_uint16,
	[0xCE] = unpack_uint32,
	[0xCF] = unpack_uint64,
	[0xD0] = unpack_int8,
	[0xD1] = unpack_int16,
	[0xD2] = unpack_int32,
	[0xD3] = unpack_int64,
	[0xD4] = function(c) return unpack_ext(c, 1, unpack_int8(c)) end,
	[0xD5] = function(c) return unpack_ext(c, 2, unpack_int8(c)) end,
	[0xD6] = function(c) return unpack_ext(c, 4, unpack_int8(c)) end,
	[0xD7] = function(c) return unpack_ext(c, 8, unpack_int8(c)) end,
	[0xD8] = function(c) return unpack_ext(c, 16, unpack_int8(c)) end,
	[0xD9] = function(c) return unpack_str(c, unpack_uint8(c)) end,
	[0xDA] = function(c) return unpack_str(c, unpack_uint16(c)) end,
	[0xDB] = function(c) return unpack_str(c, unpack_uint32(c)) end,
	[0xDC] = function(c) return unpack_array(c, unpack_uint16(c)) end,
	[0xDD] = function(c) return unpack_array(c, unpack_uint32(c)) end,
	[0xDE] = function(c) return unpack_map(c, unpack_uint16(c)) end,
	[0xDF] = function(c) return unpack_map(c, unpack_uint32(c)) end
}, {
	__index = function(t, k)
		if k < 0xC0 then
			if k < 0x80 then
				return fn_1
			elseif k < 0x90 then
				return fn_2
			elseif k < 0xA0 then
				return fn_3
			else
				return fn_4
			end
		elseif k > 0xDF then
			return fn_5
		else
			return function()
				error("unpack '" .. format("%#x", k) .. "' is unimplemented")
			end
		end
	end
})

local function cursor_string(str)
	return {
		s = str,
		i = 1,
		j = #str,
		underflow = function()
			error"missing bytes"
		end
	}
end

local function cursor_loader(ld)
	return {
		s = '',
		i = 1,
		j = 0,
		underflow = function(self, e)
			self.s = self.s:sub(self.i)
			e = e - self.i + 1
			self.i = 1
			self.j = 0

			while e > self.j do
				local chunk = ld()

				if not chunk then
					error"missing bytes"
				end

				self.s = self.s .. chunk
				self.j = #self.s
			end
		end
	}
end

function m.unpack(s)
	checktype("unpack", 1, s, "string")
	local cursor = cursor_string(s)
	local data = unpack_cursor(cursor)

	if cursor.i <= cursor.j then
		error("extra bytes")
	end

	return data
end

function m.unpacker(src)
	if type(src) == "string" then
		local cursor = cursor_string(src)

		return function()
			if cursor.i <= cursor.j then return cursor.i, unpack_cursor(cursor) end
		end
	elseif type(src) == "function" then
		local cursor = cursor_loader(src)

		return function()
			if cursor.i > cursor.j then
				pcall(cursor.underflow, cursor, cursor.i)
			end

			if cursor.i <= cursor.j then return true, unpack_cursor(cursor) end
		end
	else
		argerror("unpacker", 1, "string or function expected, got " .. type(src))
	end
end

set_string("string")
set_integer("unsigned")

if SIZEOF_NUMBER == 4 then
	maxinteger = 16777215
	mininteger = -maxinteger
	m.small_lua = true
	unpackers[0xCB] = nil -- double
	unpackers[0xCF] = nil -- uint64
	unpackers[0xD3] = nil -- int64
	set_number("float")
else
	maxinteger = 9007199254740991
	mininteger = -maxinteger
	set_number("double")

	if SIZEOF_NUMBER > 8 then
		m.long_double = true
	end
end

set_array("always_as_map")
m._VERSION = "0.5.2"
m._DESCRIPTION = "lua-MessagePack : a pure Lua implementation"
m._COPYRIGHT = "Copyright (c) 2012-2019 Francois Perrad"

return m
--
-- This library is licensed under the terms of the MIT/X11 license,
-- like Lua itself.
--