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 ( Nullability( Nullable, NonNullable )

26 , Sql, nullabilization

27 )

28import Rel8.Type ( DBType, typeInformation )

29import Rel8.Type.Information ( TypeInformation(..) )

32litExpr :: Sql DBType a => a -> Expr a

33litExpr = slitExpr nullabilization typeInformation

36slitExpr :: Nullability db a -> TypeInformation db -> a -> Expr a

37slitExpr nullable info@TypeInformation {encode} =

38 scastExpr nullable info . Expr . encoder

39 where

40 encoder = case nullable of

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

42 NonNullable -> encode

45sparseValue :: Nullability db a -> TypeInformation db -> Hasql.Row a

46sparseValue nullability TypeInformation {decode, out} = case nullability of

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

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