[Haskell] duplicate elements in Data.Set

[Jean-Philippe Bernardy]

I'd say your compare function isn't transitive.

If you can tell it's well behaved, and if you can send me even your
complicated example, I'll look into it.

Cheers,
JP.

On 1/21/06, Walter Moreira <gwallter at gmail.com> wrote:
> Hello list. Are there situations where a set can contain duplicate
> elements?
>
> I have a newtype and it is an instance of 'Eq' via the 'compare' method,
> and it is also an instance of 'Ord'. After some Data.Set operations
> with sets of that type I get a set which contains two elements which
> compare equal. What am I doing wrong?
>
> The function 'Set.valid' returns 'False' when applied to the set. I
> use the function 'Set.fromList' sometimes. Is it supposed to always
> yield a valid set? or it may depend on the order or equality?
>
> Sorry the question is a little vague. When I try to construct small
> examples the problem disappear.
>
> Thanks,
> Walter
> _______________________________________________
> Haskell mailing list
> Haskell at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell
>