Re: Ord instance for Data.Map?

On Wed, 18 Apr 2007, Isaac Dupree wrote:

And then what do you do with (set1 `union` set2) where they have different comparators? C++ collections have that think-o, I don't know about Java.... the problem being that the comparators are not statically required to be "the same", just the same *type*, so, what do you do with two different ones?

I expect that local instances of equal types provide equal method dictionaries, don't they? However I don't think that local instances solve the problem here. Locally used (<) for complex numbers should be regarded the same error like (<) for complex numbers everywhere.