From: Daniel Fischer

Am Montag 19 April 2010 14:37:33 schrieb John Lato:

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Is it really necessary to use Strings?  I think a packed type, e.g. Vector or ByteString, would be much more efficient here.

Not very much if the strings are fairly short (and the list isn't too long, so there's not a big difference in cache-friendliness). If eight-bit characters aren't enough, packing the strings into UArray Int Char gives performance quite close to ByteStrings.

I agree, provided that the Strings are used only once. I missed the first part of this thread, so there may be context I don't have, but if Strings are retained and the Hamming distance calculated for multiple pairings, I think it would be a noticeable difference. Although probably not as much as reducing the number of calls to Hamming as you and H. Apfelmus suggest. John