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a1886b3729
### Description This PR is one further step towards remote joins from remote schemas. It introduces a custom partial AST to represent queries to remote schemas in the IR: we now need to augment what used to be a straightforward GraphQL AST with additional information for remote join fields. This PR does the minimal amount of work to adjust the rest of the code accordingly, using `Void` in all places that expect a type representing remote relationships. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3794 GitOrigin-RevId: 33fc317731aace71f82ad158a1951ea93350d6cc
55 lines
1.6 KiB
Haskell
55 lines
1.6 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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longestCommonPrefix,
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module L,
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)
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where
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import Data.Function (on)
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import Data.HashMap.Strict.Extended qualified as Map
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import Data.HashSet qualified as Set
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import Data.Hashable (Hashable)
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import Data.List qualified as L
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import Data.List.NonEmpty qualified as NE
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import Prelude
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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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-- | Returns the longest prefix common to all given lists. Returns an empty list on an empty list.
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--
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-- >>> longestCommonPrefix ["abcd", "abce", "abgh"]
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-- "ab"
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--
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-- >>> longestCommonPrefix []
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-- []
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longestCommonPrefix :: Eq a => [[a]] -> [a]
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longestCommonPrefix [] = []
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longestCommonPrefix (x : xs) = foldr prefix x xs
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where
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prefix l1 l2 = map fst $ takeWhile (uncurry (==)) $ zip l1 l2
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