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41 lines
1.3 KiB
Haskell
41 lines
1.3 KiB
Haskell
module Data.List.Extended
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( duplicates
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, uniques
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, getDifference
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, getDifferenceOn
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, getOverlapWith
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, hasNoDuplicates
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, module L
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) where
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import Data.Function (on)
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import Data.Hashable (Hashable)
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import Prelude
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import qualified Data.HashMap.Strict.Extended as Map
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import qualified Data.HashSet as Set
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import qualified Data.List as L
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import qualified Data.List.NonEmpty as NE
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duplicates :: (Eq a, Hashable a) => [a] -> Set.HashSet a
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duplicates =
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Set.fromList . Map.keys . Map.filter (> 1) . Map.fromListWith (+) . map (,1::Int)
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uniques :: Eq a => [a] -> [a]
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uniques = map NE.head . NE.group
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getDifference :: (Eq a, Hashable a) => [a] -> [a] -> Set.HashSet a
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getDifference = Set.difference `on` Set.fromList
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getDifferenceOn :: (Eq k, Hashable k) => (v -> k) -> [v] -> [v] -> [v]
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getDifferenceOn f l = Map.elems . Map.differenceOn f l
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getOverlapWith :: (Eq k, Hashable k) => (v -> k) -> [v] -> [v] -> [(v, v)]
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getOverlapWith getKey left right =
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Map.elems $ Map.intersectionWith (,) (mkMap left) (mkMap right)
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where
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mkMap = Map.fromList . map (\v -> (getKey v, v))
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hasNoDuplicates :: (Eq a, Hashable a) => [a] -> Bool
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hasNoDuplicates xs = Set.size (Set.fromList xs) == length xs
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