Integers as bit arrays

[Roberto Bagnara]

Brian Hurt wrote:
> The basic functionality I was thinking of implementing was:
> - get, set (to 1), clear (to 0), invert individual bits
> - get, set, clear, invert ranges of bits
> - bitwise operators- and, or, xor, negation
> - shifts (already implemented), rotates.

It is in fact very useful to use GMP integers as sets of naturals
(i.e., the set of their positions containing a bit set to one).
For this, the following functionality is desirable:

- searching 0 or 1 bits scanning towards less significant bits;
- efficiently deciding whether a set of naturals is a (proper
   or non proper) subset of another.

You can look at our code for doing that at

   http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/~checkout~/ppl/src/SatRow.cc?rev=1.20&content-type=text/plain&cvsroot=ppl

Cheers

     Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara@cs.unipr.it