Re: [Ocaml-lib-devel] Map with set operations over the keys

[Nicolas C. <war...@fr...>]

>> After a second though I think it's little overweighted to make the user
>> specify a merge function. Why not simply specify that in such cases, the
>> item of the first map is selected ? That seems more reasonable.
>>
>
>No, you can for instance implement multiset as map to natural ... and
>the merge function is then addition.
>
>Your merge function should even raise the exception Remove when you want
>to say that the result should be removed from the map ... (For insance,
>if you have Map to integer and want to say that 0 should be removed from
>the map).

I would say it's bad API design to use a "merge" function in order to remove
elements.
A more specific function should be provided.

Nicolas