[Haskell] RFC: DData in hierarchical libraries

Tomasz Zielonka t.zielonka at students.mimuw.edu.pl
Mon Mar 8 12:07:42 EST 2004


On Mon, Mar 08, 2004 at 12:32:21PM +0100, Christian Maeder wrote:
> Yes, I support this proposal.

So do I.

> Maybe the documentation to the "0rdered lists" section can be improved.
> 
> Set.toAscList is not really necessary as it is the same as Set.toList. 
> In order to be a proper function, the result of Set.tolist must return a 
> sorted list without duplicates, since equal sets should yield equal 
> lists, if converted by Set.toList.

It is still a proper function this way, you only don't get some nice
axioms.

> Returning a descending list is not necessary, because this can simply
> be achieved by reversing, if needed.

If the descending list is built lazily, you can get M highest elements
of N element Set in O(M log N) time, which is nice. Using reverse, you
would pay O(N log N).

Best regards,
Tom

-- 
.signature: Too many levels of symbolic links


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