NAME

Bits - provide bit related functions for arbitrarily large integers

SYNOPSIS

use Bits;  # exports "bit", "bits", "bitcnt", "bitswap"

say bit(8, 3);    # 1000 -> True
say bit(7, 3);    # 0111 -> False

say bits(8);      # 1000 -> (3,).Seq
say bits(7);      # 0111 -> (0,1,2).Seq

say bitcnt(8);    # 1000 -> 1
say bitcnt(7);    # 0111 -> 3

say bitswap(1);   # 0001 -> 1110
say bitswap(-1);  # 1111 -> 0000

DESCRIPTION

This module exports a number of function to handle significant bits in arbitrarily large integer values, aka bitmaps. If the specified value is zero or positive, then the on-bits will be considered significant. If the specified value is negative, then the off-bits in the value will be considered significant.

SUBROUTINES

bit

sub bit(Int:D value, UInt:D bit --> Bool:D)

Takes an integer value and a bit number and returns whether that bit is significant (1 for positive values, 0 for negative values).

bits

sub bits(Int:D value --> Seq:D)

Takes an integer value and returns a Sequence of the bit numbers that are significant in the value. For negative values, these are the bits that are 0.

bitcnt

sub bitcnt(Int:D value --> Int:D)

Takes an integer value and returns the number of significant bits that are set in the value. For negative values, this is the number of bits that are 0.

bitswap

sub bitswap(Int:D value --> Int:D)

Takes an integer value and returns an integer value with all of the 1-bits turned to 0-bits and vice-versa.

AUTHOR

Elizabeth Mattijsen [email protected]

Source can be located at: https://github.com/lizmat/Bits . Comments and Pull Requests are welcome.

COPYRIGHT AND LICENSE

Copyright 2019, 2020, 2021 Elizabeth Mattijsen

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.