Bitfield

Packed bit manipulation types with network byte order support.

import core.bitfield

Types

Four bitfield sizes are available:

Type	Bits	Range
`Bitfield8`	8	0-255
`Bitfield16`	16	0-65535
`Bitfield32`	32	0-4294967295
`Bitfield64`	64	0-2^64-1

Construction

let bf = Bitfield8.new(0xFF)
let bf = Bitfield8.zero()
let bf = Bitfield8.fromBits(1, 0, 1, 1, 0, 0, 1, 0)

Convenience constructors:

let bf = bitfield8(42)
let bf = bitfield16(1024)
let bf = bitfield32(0xDEADBEEF)
let bf = bitfield64(0)

Bit Operations

All types share the same methods:

Method	Return	Description
`getBit(index: Int)`	`Int`	Get bit at position (0 or 1)
`setBit(index: Int, value: Int)`	`Bitfield*`	Set bit, return new
`getField(start: Int, length: Int)`	`Int`	Extract bit field
`setField(start: Int, length: Int, value: Int)`	`Bitfield*`	Set bit field, return new

Bitwise Operations

Method	Return	Description
`bitwiseAnd(other: Bitfield*)`	`Bitfield*`	AND
`bitwiseOr(other: Bitfield*)`	`Bitfield*`	OR
`bitwiseXor(other: Bitfield*)`	`Bitfield*`	XOR
`bitwiseNot()`	`Bitfield*`	NOT
`shiftLeft(amount: Int)`	`Bitfield*`	Left shift
`shiftRight(amount: Int)`	`Bitfield*`	Right shift

Bit Counting

Method	Return	Description
`countOnes()`	`Int`	Population count
`countZeros()`	`Int`	Zero count
`leadingZeros()`	`Int`	Leading zero count
`trailingZeros()`	`Int`	Trailing zero count

Conversion

Method	Return	Description
`toInt()`	`Int`	Convert to integer
`toUnsigned()`	`Int`	Convert to unsigned integer
`toBinaryString()`	`String`	Binary representation
`toHexString()`	`String`	Hexadecimal representation
`toString()`	`String`	String representation

Endianness Conversion

Method	Return	Description
`toBigEndian()`	`Bitfield*`	Convert to big endian
`toLittleEndian()`	`Bitfield*`	Convert to little endian

Network Byte Order Functions

Function	Description
`htons(value)`	Host to network short (16-bit)
`htonl(value)`	Host to network long (32-bit)
`htonll(value)`	Host to network long long (64-bit)
`ntohs(value)`	Network to host short
`ntohl(value)`	Network to host long
`ntohll(value)`	Network to host long long

Utility

fun pow2(n: Int) r: Int  // 2^n

Example

let flags = Bitfield8.zero()
let flags = flags.setBit(0, 1)  // set bit 0
let flags = flags.setBit(3, 1)  // set bit 3
println(flags.toBinaryString()) // "00001001"
println("Bit 0: {flags.getBit(0)}")  // 1
println("Ones: {flags.countOnes()}")  // 2

// Network packet header
let header = bitfield32(0)
let header = header.setField(0, 4, 6)   // version = 6
let header = header.setField(4, 8, 128) // traffic class
let network = header.toBigEndian()