Help language development. Donate to The Perl Foundation

Bits cpan:ELIZABETH last updated on 2020-07-12



Bits - provide bit related functions for arbitrarily large integers


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


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.



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

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


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

Takes a 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.


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

Takes a 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.


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.


Elizabeth Mattijsen [email protected]

Source can be located at: . Comments and Pull Requests are welcome.


Copyright 2019-2020 Elizabeth Mattijsen

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