src/Rel8/Schema/Field.hs · rel8

on 11bcbbb help sign in

34 lines 1.1 kB history raw

1{-# language DataKinds #-}

2{-# language StandaloneKindSignatures #-}

3{-# language TypeFamilies #-}

5module Rel8.Schema.Field

6 ( Field

7 )

8where

10-- base

11import Data.Functor.Identity ( Identity )

12import Data.Kind ( Type )

13import Prelude

15-- rel8

16import Rel8.Aggregate ( Aggregate )

17import Rel8.Expr ( Expr )

18import Rel8.Kind.Labels ( Labels )

19import Rel8.Kind.Necessity ( Necessity( Required, Optional ) )

20import Rel8.Schema.Insert ( Insert )

21import qualified Rel8.Schema.Kind as K

22import Rel8.Schema.Spec ( Spec( Spec ) )

23import Rel8.Schema.Structure ( Structure, Shape( Column ), Shape1 )

26type Field :: K.Context -> Labels -> Necessity -> Type -> Type

27type family Field labels context necessity a where

28 Field Identity _labels _necessity a = a

29 Field Expr _labels _necessity a = Expr a

30 Field Insert _labels 'Required a = Expr a

31 Field Insert _labels 'Optional a = Maybe (Expr a)

32 Field Aggregate _labels _necessity a = Aggregate (Expr a)

33 Field Structure labels necessity a = Shape1 'Column ('Spec labels necessity a)

34 Field context _labels _necessity a = context a