src/Rel8/Type/Information.hs · rel8

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rel8/src/Rel8/Type/Information.hs

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1{-# language NamedFieldPuns #-}

2{-# language StandaloneKindSignatures #-}

4module Rel8.Type.Information

5 ( TypeInformation(..)

6 , mapTypeInformation

7 , parseTypeInformation

8 )

9where

11-- base

12import Data.Bifunctor ( first )

13import Data.Kind ( Type )

14import Prelude

16-- hasql

17import qualified Hasql.Decoders as Hasql

19-- opaleye

20import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye

22-- text

23import qualified Data.Text as Text

26type TypeInformation :: Type -> Type

27data TypeInformation a = TypeInformation

28 { encode :: a -> Opaleye.PrimExpr

29 , decode :: Hasql.Value a

30 , typeName :: String

31 }

34mapTypeInformation :: ()

35 => (a -> b) -> (b -> a)

36 -> TypeInformation a -> TypeInformation b

37mapTypeInformation = parseTypeInformation . fmap pure

40parseTypeInformation :: ()

41 => (a -> Either String b) -> (b -> a)

42 -> TypeInformation a -> TypeInformation b

43parseTypeInformation to from TypeInformation {encode, decode, typeName} =

44 TypeInformation

45 { encode = encode . from

46 , decode = Hasql.refine (first Text.pack . to) decode

47 , typeName

48 }