[Haskell-cafe] cost of List.// for Ord types?
fjh007 at galois.com
Tue Sep 7 15:07:43 EDT 2004
On 03-Sep-2004, David Roundy <droundy at droundy.dyndns.org> wrote:
> I was wondering if the list diff operator \\ takes advantage of situations
> where the list data type is in class Ord, besides being in Eq.
No, it cannot, at least not in the general case.
The interface for "\\" says that it only depends on the Eq class;
calling Ord member functions would not have the right semantics.
> Basically, I'm wondering if I should avoid using the standard library \\,
If efficiency is a significant concern, and the lists involved may be long,
yes, you should.
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Galois Connections, Inc. | of excellence is a lethal habit"
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