src/Rel8/Schema/Spec.hs · rel8

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1{-# language DataKinds #-}

2{-# language FlexibleContexts #-}

3{-# language GADTs #-}

4{-# language StandaloneKindSignatures #-}

5{-# language UndecidableInstances #-}

7module Rel8.Schema.Spec

8 ( Spec( Spec )

9 , SSpec( SSpec, labels, info, nullity )

10 , KnownSpec( specSing )

11 )

12where

14-- base

15import Data.Kind ( Constraint, Type )

16import Prelude ()

18-- rel8

19import Rel8.Kind.Labels ( Labels, SLabels, KnownLabels, labelsSing )

20import Rel8.Schema.Null ( Nullity, Sql, Unnullify, nullable )

21import Rel8.Type ( DBType, typeInformation )

22import Rel8.Type.Information ( TypeInformation )

25type Spec :: Type

26data Spec = Spec Labels Type

29type SSpec :: Spec -> Type

30data SSpec spec where

31 SSpec ::

32 { labels :: SLabels labels

33 , info :: TypeInformation (Unnullify a)

34 , nullity :: Nullity a

35 }

36 -> SSpec ('Spec labels a)

39type KnownSpec :: Spec -> Constraint

40class KnownSpec spec where

41 specSing :: SSpec spec

44instance

45 ( KnownLabels labels

46 , Sql DBType a

47 )

48 => KnownSpec ('Spec labels a)

49 where

50 specSing = SSpec

51 { labels = labelsSing

52 , info = typeInformation

53 , nullity = nullable

54 }