Merge branch 'main' into all-contributors/add-Arif812

src/libs.py

@@ -1,5 +1,205 @@
 # This file includes Lua snippets
 
+struct = """
+local struct = {}
+
+function struct.pack(format: string, size: number?, ...)
+	local predictedSize = size or 2048
+	local vars = {...}
+
+	local stream = buffer.create(predictedSize)
+	local endianness = true
+
+	local ind = 0
+
+	for i = 1, format:len() do
+		local opt = (format:sub(i, i) :: string)
+
+		if opt == '<' then
+			endianness = true
+		elseif opt == '>' then
+			endianness = false
+		elseif opt:find('[bBhHiIlL]') then
+			local n = opt:find('[hH]') and 2 or opt:find('[iI]') and 4 or opt:find('[lL]') and 8 or 1
+			local val = (tonumber(table.remove(vars, 1)) :: number)
+
+			local bytes = {}
+			for j = 1, n do
+				table.insert(bytes, string.char(val % (2 ^ 8)))
+				val = math.floor(val / (2 ^ 8))
+			end
+			local data
+			if not endianness then
+				data = string.reverse(table.concat(bytes))
+			else
+				data = table.concat(bytes)
+			end
+			buffer.writestring(stream, ind, data)
+			ind += #data
+		elseif opt:find('[fd]') then
+			local val = (tonumber(table.remove(vars, 1))  :: number)
+			local sign = 0
+
+			if val < 0 then
+				sign = 1
+				val = (-val :: number)
+			end
+
+			local mantissa, exponent = math.frexp(val)
+			if val == 0 then
+				mantissa = 0
+				exponent = 0
+			else
+				mantissa = (mantissa * 2 - 1) * math.ldexp(0.5, (opt == 'd') and 53 or 24)
+				exponent = exponent + ((opt == 'd') and 1022 or 126)
+			end
+
+			local bytes = {}
+			if opt == 'd' then
+				val = mantissa
+				for i = 1, 6 do
+					table.insert(bytes, string.char(math.floor(val) % (2 ^ 8)))
+					val = math.floor(val / (2 ^ 8))
+				end
+			else
+				table.insert(bytes, string.char(math.floor(mantissa) % (2 ^ 8)))
+				val = math.floor(mantissa / (2 ^ 8))
+				table.insert(bytes, string.char(math.floor(val) % (2 ^ 8)))
+				val = math.floor(val / (2 ^ 8))
+			end
+
+			table.insert(bytes, string.char(math.floor(exponent * ((opt == 'd') and 16 or 128) + val) % (2 ^ 8)))
+			val = math.floor((exponent * ((opt == 'd') and 16 or 128) + val) / (2 ^ 8))
+			table.insert(bytes, string.char(math.floor(sign * 128 + val) % (2 ^ 8)))
+			val = math.floor((sign * 128 + val) / (2 ^ 8))
+
+			local data
+			if not endianness then
+				data = string.reverse(table.concat(bytes))
+			else
+				data = table.concat(bytes)
+			end
+			buffer.writestring(stream, ind, data)
+			ind += #data
+		elseif opt == 's' then
+			local data = tostring(table.remove(vars, 1))
+
+			buffer.writestring(stream, ind, data)
+			ind += #data
+			buffer.writestring(stream, ind, string.char(0))
+			ind += 1
+		elseif opt == 'c' then
+			local n = format:sub(i + 1):match('%d+')
+			local str = tostring(table.remove(vars, 1))
+			local len = (tonumber(n) :: number)
+			if len <= 0 then
+				len = str:len()
+			end
+			if len - str:len() > 0 then
+				str = str .. string.rep(' ', len - str:len())
+			end
+			local data = str:sub(1, len)
+			buffer.writestring(stream, ind, data)
+			ind += #data
+			i = i + (n :: string):len()
+		end
+	end
+
+	return buffer.tostring(stream)
+end
+
+function struct.unpack(format: string, stream: string, pos: number?)
+        local stream = buffer.fromstring(stream)
+	local vars = {}
+	local iterator = pos or 1
+	local endianness = true
+
+	for i = 1, format:len() do
+		local opt: string = format:sub(i, i)
+
+		if opt == '<' then
+			endianness = true
+		elseif opt == '>' then
+			endianness = false
+		elseif opt:find('[bBhHiIlL]') then
+			local n = opt:find('[hH]') and 2 or opt:find('[iI]') and 4 or opt:find('[lL]') and 8 or 1
+			local signed = opt:lower() == opt
+
+			local val = 0
+			for j = 1, n do
+				local byte = buffer.readi8(stream, iterator)
+				if endianness then
+					val = val + byte * (2 ^ ((j - 1) * 8))
+				else
+					val = val + byte * (2 ^ ((n - j) * 8))
+				end
+				iterator = iterator + 1
+			end
+
+			if signed and val >= 2 ^ (n * 8 - 1) then
+				val = val - 2 ^ (n * 8)
+			end
+
+			table.insert(vars, math.floor(val))
+		elseif opt:find('[fd]') then
+			local n = if (opt == 'd') then 8 else 4
+			local x = --[[stream:sub(iterator, iterator + n - 1)]] buffer.readstring(stream, iterator, n)
+			iterator = iterator + n
+
+			if not endianness then
+				x = string.reverse(x)
+			end
+
+			local sign = 1
+			local mantissa = string.byte(x, (opt == 'd') and 7 or 3) % ((opt == 'd') and 16 or 128)
+			for i = n - 2, 1, -1 do
+				mantissa = mantissa * (2 ^ 8) + string.byte(x, i)
+			end
+
+			if string.byte(x, n) > 127 then
+				sign = -1
+			end
+
+			local exponent = (string.byte(x, n) % 128) * ((opt == 'd') and 16 or 2) + math.floor(string.byte(x, n - 1) / ((opt == 'd') and 16 or 128))
+			if exponent == 0 then
+				table.insert(vars, 0.0)
+			else
+				mantissa = (math.ldexp(mantissa, (opt == 'd') and -52 or -23) + 1) * sign
+				table.insert(vars, math.ldexp(mantissa, exponent - ((opt == 'd') and 1023 or 127)))
+			end
+		elseif opt == 's' then
+			local bytes = {}
+			for j = iterator, buffer.len(stream) do
+				local val = buffer.readstring(stream, j, 1)
+				if val == string.char(0) or val == '' then
+					break
+				end
+
+				table.insert(bytes, val)
+			end
+
+			local str = table.concat(bytes)
+			iterator = iterator + str:len() + 1
+			table.insert(vars, str)
+		elseif opt == 'c' then
+			local val = buffer.readstring(stream, i + 1, 1)
+			local n: string = (val:match('%d+') :: string)
+			local len = (tonumber(n) :: number)
+			if len <= 0 then
+				len = (table.remove(vars) :: number)
+			end
+
+			val = buffer.readstring(stream, iterator, len)
+			table.insert(vars, val)
+			iterator = iterator + len
+			i = i + n:len()
+		end
+	end
+
+	return unpack(vars)
+end
+"""
+
 json = """local json = {}
 function json.loads(t)
     return game.HttpService:JSONEncode(t)
@@ -717,4 +917,4 @@
 
 TUPLE = """\n\nfunction tuple(t)
 	return list(t,false)
-end"""
+end"""