src/Rel8/Schema/Column.hs · rel8

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rel8/src/Rel8/Schema/Column.hs

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1{-# language DataKinds #-}

2{-# language TypeFamilies #-}

3{-# language StandaloneKindSignatures #-}

5module Rel8.Schema.Column

6 ( Column, Default

7 )

8where

10-- base

11import Data.Kind ( Type )

12import Prelude ()

14-- rel8

15import Rel8.Kind.Necessity ( Necessity( Required, Optional ) )

16import Rel8.Schema.Field ( Field )

17import qualified Rel8.Schema.Kind as K

20-- | The @Column@ type family should be used to indicate which fields of your

21-- data types are single columns in queries. This type family has special

22-- support when a query is executed, allowing you to use a single data type for

23-- both query data and rows decoded to Haskell.

24type Column :: K.Context -> Type -> Type

25type Column context a = Field context 'Required a

28type Default :: K.Context -> Type -> Type

29type Default context a = Field context 'Optional a