[Haskell-cafe] Follow up on 'GroupBy behavior'

Hans van Thiel hthiel.char at zonnet.nl
Sat Apr 28 15:15:55 EDT 2007

Thanks again for the help, and, to follow up, this now does what I

-- partitions a list according to an equivalence relation

partition1 :: (a -> a -> Bool) -> [a] -> ([a],[a])
partition1 eq ls = partition ((head ls) `eq`) ls 
partitionBy :: (a -> a -> Bool) -> [a] -> [[a]]
partitionBy eq [] = []
partitionBy eq ls = 
    (fst x):(partitionBy eq (snd x))  where
                             x =  partition1 eq ls


Hans van Thiel

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