Re: [Ocaml-lib-devel] BitSet

[Brian H. <bh...@sp...>]

On Fri, 19 Mar 2004, Nicolas Cannasse wrote:

> Concerning the usage of int, OCaml runtime representation is 31 bits. They
> are unboxed and shifted by 1 and the lowest bit is set to 1 so it can't be
> mistaken with an address since all addresses are always aligned on 2 bytes
> (even 4 on most of 32-bits architectures) . So we could use ints as 31 bits
> but we would then need to div/mod to get the correct integer. Another nice
> thing about strings is that their contents are not scanned by the GC while
> Array of ints are.
> 

Having looked at implementing bitset myself, I came to the following 
conclusions:

1) bitset and big int support should be combined, much like an int can be 
viewed both as a small integer and as a small bitset, depending.

2) Both should be built on top of gmp.

3) GMP doesn't do everything I want bitset to be able to do yet.  Most 
everything, but not everything (bitblit doesn't exist).

4) I'm on-again off-again trying to get gmp to accept patches to let it 
do what I want it to, but I'm getting push-back.

I'm tempted to just provide the wrappers for the existing gmp 
functionality, and support the rest when it shows up.  Thoughts?

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Brian