Lua:registerCustomTypeLua

<> Lua API Reference

function registerCustomTypeLua(typename, bytecount, bytestovaluefunction, valuetobytesfunction, isFloat) : CustomType

Registers a custom type based on Lua functions.

The bytes-to-value function is used to convert raw bytes into a value. It should be defined as a function that receives the bytes as separate parameters and returns an integer value.

The value-to-bytes function is used to convert a value back into bytes. It should be defined as a function that receives the value and returns the bytes that should be written.

Function Parameters

Parameter	Type	Description
typename	String	The name of the custom type to register.
bytecount	Integer	The number of bytes used by this custom type.
bytestovaluefunction	Function	The function that converts the raw bytes into a value.
valuetobytesfunction	Function	The function that converts a value into the bytes that should be written.
isFloat	Boolean	If true, the custom type is treated as a floating-point type.

Returns

CustomType — The registered Custom Type object.

Bytes To Value Function

Function	Return Type	Description
function bytestovalue(b1, b2, b3, b4)	Integer	Receives the bytes of the custom type and returns the interpreted value.

Value To Bytes Function

Function	Return Type	Description
function valuetobytes(value)	Integer values	Receives a value and returns the bytes that should be written.

Examples

 1 local function bytesToValue(b1, b2, b3, b4)
 2   return b1 + (b2 * 0x100) + (b3 * 0x10000) + (b4 * 0x1000000)
 3 end
 4 
 5 local function valueToBytes(value)
 6   local b1 = value % 0x100
 7   local b2 = math.floor(value / 0x100) % 0x100
 8   local b3 = math.floor(value / 0x10000) % 0x100
 9   local b4 = math.floor(value / 0x1000000) % 0x100
10 
11   return b1, b2, b3, b4
12 end
13 
14 local customType = registerCustomTypeLua(
15   "Lua Integer Example",
16   4,
17   bytesToValue,
18   valueToBytes,
19   false
20 )
21 
22 print("Registered custom type: " .. tostring(customType.name))

 1 local function encryptedBytesToValue(b1, b2, b3, b4)
 2   local value = b1 + (b2 * 0x100) + (b3 * 0x10000) + (b4 * 0x1000000)
 3 
 4   return value ~ 0x12345678
 5 end
 6 
 7 local function valueToEncryptedBytes(value)
 8   local encrypted = value ~ 0x12345678
 9 
10   local b1 = encrypted % 0x100
11   local b2 = math.floor(encrypted / 0x100) % 0x100
12   local b3 = math.floor(encrypted / 0x10000) % 0x100
13   local b4 = math.floor(encrypted / 0x1000000) % 0x100
14 
15   return b1, b2, b3, b4
16 end
17 
18 registerCustomTypeLua(
19   "Lua XOR Integer",
20   4,
21   encryptedBytesToValue,
22   valueToEncryptedBytes,
23   false
24 )

Main Pages

Core Lua documentation entry points

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