src/Rel8/Expr/Serialize.hs · rel8

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rel8/src/Rel8/Expr/Serialize.hs

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1{-# language FlexibleContexts #-}

2{-# language NamedFieldPuns #-}

3{-# language TypeFamilies #-}

5module Rel8.Expr.Serialize

6 ( litExpr

7 , slitExpr

8 , sparseValue

9 )

10where

12-- base

13import Prelude

15-- hasql

16import qualified Hasql.Decoders as Hasql

18-- opaleye

19import qualified Opaleye.Internal.HaskellDB.PrimQuery as Opaleye

21-- rel8

22import {-# SOURCE #-} Rel8.Expr ( Expr( Expr ) )

23import Rel8.Expr.Opaleye ( scastExpr )

24import Rel8.Schema.Nullability

25 ( Unnullify

26 , Nullability( Nullable, NonNullable )

27 , Sql, nullabilization

28 )

29import Rel8.Type ( DBType, typeInformation )

30import Rel8.Type.Information ( TypeInformation(..) )

33litExpr :: Sql DBType a => a -> Expr a

34litExpr = slitExpr nullabilization typeInformation

37slitExpr :: Nullability a -> TypeInformation (Unnullify a) -> a -> Expr a

38slitExpr nullability info@TypeInformation {encode} =

39 scastExpr info . Expr . encoder

40 where

41 encoder = case nullability of

42 Nullable -> maybe (Opaleye.ConstExpr Opaleye.NullLit) encode

43 NonNullable -> encode

46sparseValue :: Nullability a -> TypeInformation (Unnullify a) -> Hasql.Row a

47sparseValue nullability TypeInformation {decode, out} = case nullability of

48 Nullable -> Hasql.column $ Hasql.nullable $ out <$> decode

49 NonNullable -> Hasql.column $ Hasql.nonNullable $ out <$> decode