[Haskell-beginners] sorting by elements in a tuple

Ryan Temple ryantemple145 at googlemail.com
Thu Oct 15 19:19:34 EDT 2009


I am wanting to sort a list of tuples by the first and then the second item
in the tuple. So [(1,2),(4,2),(2,5)] would become [(1,2),(2,5),(4,2)]  I am
attempting to use the Sorty function but don't seem to be having much luck

tuplesort :: [(a,b)] -> [(a,b)]
tuplesort [(_,_)] = sortBy (comparing fst)  -- this is an attempt to
organise by the first element in the tuple

Any help would be much appreciated
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