Module

pooka/bit

src/pooka/bit.pooka

Bits are tiny lamps; each one has a numbered switch.

Use arbitrary-width integer bitwise operations. Checked shifts and bit positions reject negative counts. Right shift is arithmetic, so negative integers keep their sign.

import pooka/bit

assert bit.set(0, 3) == Ok(8)

API reference

enumBitError
functionand
functionor
functionxor
functionnot
functionshift_left
functionshift_right
functionis_set
functionset
functionclear

enum

BitError

src/pooka/bit.pooka:17

enum BitError

variant

NegativeCount

src/pooka/bit.pooka:18

BitError.NegativeCount

variant

NegativePosition

src/pooka/bit.pooka:19

BitError.NegativePosition

function

and

src/pooka/bit.pooka:43

and(a: Int, b: Int) -> Int

INFERREDfn(Int, Int) -> Int

Keep the bit positions set in both integers.

import pooka/bit

assert bit.and(6, 3) == 2

function

or

src/pooka/bit.pooka:54

or(a: Int, b: Int) -> Int

INFERREDfn(Int, Int) -> Int

Keep the bit positions set in either integer.

import pooka/bit

assert bit.or(4, 2) == 6

function

xor

src/pooka/bit.pooka:65

xor(a: Int, b: Int) -> Int

INFERREDfn(Int, Int) -> Int

Keep the bit positions set in exactly one integer.

import pooka/bit

assert bit.xor(6, 3) == 5

function

not

src/pooka/bit.pooka:76

not(value: Int) -> Int

INFERREDfn(Int) -> Int

Complement the integer's bits using Erlang integer bit semantics.

import pooka/bit

assert bit.not(0) == -1

function

shift_left

src/pooka/bit.pooka:87

shift_left(value: Int, count: Int) -> Result(Int, BitError)

INFERREDfn(Int, Int) -> Result(Int, pooka/bit.BitError)

Shift left by a nonnegative count, or return NegativeCount.

import pooka/bit

assert bit.shift_left(1, 3) == Ok(8)

function

shift_right

src/pooka/bit.pooka:101

shift_right(value: Int, count: Int) -> Result(Int, BitError)

INFERREDfn(Int, Int) -> Result(Int, pooka/bit.BitError)

Arithmetic-shift right by a nonnegative count, preserving the sign.

import pooka/bit

assert bit.shift_right(-8, 1) == Ok(-4)

function

is_set

src/pooka/bit.pooka:124

is_set(value: Int, position: Int) -> Result(Bool, BitError)

INFERREDfn(Int, Int) -> Result(Bool, pooka/bit.BitError)

Check a zero-based bit position. Negative positions return NegativePosition.

import pooka/bit

assert bit.is_set(8, 3) == Ok(True)

function

set

src/pooka/bit.pooka:136

set(value: Int, position: Int) -> Result(Int, BitError)

INFERREDfn(Int, Int) -> Result(Int, pooka/bit.BitError)

Switch on one zero-based bit, returning a new integer.

import pooka/bit

assert bit.set(0, 3) == Ok(8)

function

clear

src/pooka/bit.pooka:148

clear(value: Int, position: Int) -> Result(Int, BitError)

INFERREDfn(Int, Int) -> Result(Int, pooka/bit.BitError)

Switch off one zero-based bit, returning a new integer.

import pooka/bit

assert bit.clear(10, 1) == Ok(8)