[Haskell] RFC: DData in hierarchical libraries
maeder at tzi.de
Thu Mar 11 15:21:24 EST 2004
>> Set.toAscList is not really necessary as it is the same as Set.toList.
> Not necessarily: the lists from Set.toList will be equal for equal
> Set's, but may be unordered. Use "toAscList" or "toDescList" if you
> want an ordered variant.
That really surprises me. I think that toList must return a sorted list
(to properly abstract the Set data type), and anything unsorted should
only be for debugging purposes.
>> The functions Set.fromAscList and Set.fromAscDistinctList should be
>> marked as "unsafe"
> I think so too, although I like "unchecked" better?
Good, I agree.
>> Map.keySet = Set.fromDistinctAscList . Map.keys
> Yes, we could do that -- but the circular dependency is terrible, and a
> wrapper module
> would need to look at the internal representation of Map/Set :-(
I don't see the circular dependency. Map imports Set (but not vice
versa?). In any case, I would prefer a wrapper (possible revealing some
more "unchecked" functions).
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