Edison RC3

Robert Dockins robdockins at fastmail.fm
Wed Apr 5 12:14:37 EDT 2006

On Apr 5, 2006, at 11:33 AM, Christian Maeder wrote:

> Robert Dockins wrote:
>> Major changes in 1.2rc3 are:
> [..]
>>   * add Eq instances for concrete associated collections
> Why not also Ord instances i.e. for UnbalancedSet

That's a good idea.  However, I'm not sure what the "right" total  
order would be.  The obvious thing that comes to me is the  
lexicographic order on the ascending listing of elements.  Another  
attractive option is to extend the partial order defined by 'subset'  
into a total order in some way (any ideas)?

<looks at standard lib docs>
I see Data.Set has an Ord instance.  I suppose to be practical I  
should adopt the ordering used by Data.Set.

<looks some more>
Ohh! So does Data.Map.

I guess I should browse the source to see how those orders are defined.

I think its a bit irritating that Haddock doesn't pay attention to  
docs attached to instances.  It is sometimes nice to add a few  
sentences about how an instance is implemented.

> Cheers Christian


Rob Dockins

Speak softly and drive a Sherman tank.
Laugh hard; it's a long way to the bank.
           -- TMBG

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