Hello, On Thursday 19 Jan 2006 1:29 am, John Meacham wrote:

is there a function floating around for _efficiently_ sorting a list of lists that will not evaluate any more of the lists than is needed to sort them properly and does not re-compare the common prefix of said lists?

as in, sortLists :: Ord a => [[a]] -> [[a]] sortLists = ...

if it proves faster in the general case than 'sort', then a RULES pragma might be in order to use it instead when sorting lists. a very common case being sorting strings.

Well I think you could produce this with tries :-) I have a small implementation for String(Maps) here.. http://homepages.nildram.co.uk/~ahey/HLibs/Data.StringMap/ But I can't remember if I made it lazy enough for what you want. I was thinking I should generalise this for Sets and Maps of Lists once a common API has been agreed. But I'm not going to have much time to work on any of this for a couple of weeks now. Regards -- Adrian Hey