src/Rel8/Table/Undefined.hs · rel8

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rel8/src/Rel8/Table/Undefined.hs

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1{-# language FlexibleContexts #-}

2{-# language NamedFieldPuns #-}

3{-# language TypeFamilies #-}

5module Rel8.Table.Undefined

6 ( undefined

7 )

8where

10-- base

11import Prelude hiding ( undefined )

13-- rel8

14import Rel8.Expr ( Expr )

15import Rel8.Expr.Null ( snull, unsafeUnnullify )

16import Rel8.Schema.Context ( Col(..) )

17import Rel8.Schema.HTable ( htabulate, hfield, hspecs )

18import Rel8.Schema.Nullability ( Nullability( Nullable, NonNullable ) )

19import Rel8.Schema.Spec ( SSpec(..) )

20import Rel8.Table ( Table, fromColumns )

23undefined :: Table Expr a => a

24undefined = fromColumns $ htabulate $ \field -> case hfield hspecs field of

25 SSpec {nullability, info} -> case nullability of

26 Nullable -> DB (snull Nullable info)

27 NonNullable -> DB (unsafeUnnullify (snull Nullable info))