28 lines
789 B
Haskell
28 lines
789 B
Haskell
{-# OPTIONS_GHC -fno-warn-orphans #-}
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module Data.Universe.Instances.Reverse.JSON
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(
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) where
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import ClassyPrelude
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import Data.Aeson
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import Data.Aeson.Types (Parser)
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import qualified Data.HashSet as HashSet
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import qualified Data.HashMap.Strict as HashMap
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import Data.HashMap.Strict ((!))
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import Data.Universe
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instance (Eq a, Hashable a, Finite a, ToJSON b, ToJSONKey a) => ToJSON (a -> b) where
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toJSON f = toJSON $ HashMap.fromList [(k, f k) | k <- universeF]
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instance (Eq a, Hashable a, Finite a, FromJSON b, FromJSONKey a) => FromJSON (a -> b) where
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parseJSON val = do
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vMap <- parseJSON val :: Parser (HashMap a b)
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unless (HashSet.fromMap (HashMap.map (const ()) vMap) == HashSet.fromList universeF) $
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fail "Not all required keys found"
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return $ (vMap !)
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