Re: [Ocaml-lib-devel] a bug in BitSet?

[Janne H. <ja...@hy...>]

> Looks like all intersect, unite, and friends have serious flaws.
> They have been posted on this list by some people, and I added them without
> checking. Next time I will ;)

Yep, that's what I figured as well.  But decided I will point my 
finger at only the ones that I have a tester ready :)

I am not yet 100% sure, but it also seems that BitSet.compare is broken. 
According to the docs, it is not absolutely clear how the comparison 
should be interpreted, but to me a sensible compare would work the same 
way as forming a bignum of the bitset and comparing the bignums.

Currently this does not appear to be the case.

> The functions themselves are not designed correctly, I would like to change
> them from :
>
> val intersect : t -> t -> unit
>
> to :
>
> val intersect : t -> t -> t
>
> which will produce a new bitset. Sounds more logical to me in Ocaml world.
> Any volunteer for implementation ?

Yes, this is one nitpick that I had in mind.  Is it possible to just go 
and change the API on these?

I also think that "union" would be a nicer name "unite" and "difference" 
(or "subtract") instead of "differentiate".  In my mind differentiate 
associates to calculating derivatives.

I might have a little time during the next couple of weeks.  So if there's 
no hurry, perhaps I could volunteer for making these changes.

ciao,
janne