| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Rel8.Internal.Table.Null
Synopsis
- newtype NullTable (context :: Context) a = NullTable (Nullify context a)
- nullableTable :: (Table Expr a, Table Expr b) => b -> (a -> b) -> NullTable Expr a -> b
- nullTable :: Table Expr a => NullTable Expr a
- nullifyTable :: a -> NullTable Expr a
- unsafeUnnullifyTable :: NullTable Expr a -> a
- isNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
- isNonNullTable :: Table Expr a => NullTable Expr a -> Expr Bool
- nameNullTable :: a -> NullTable Name a
- toMaybeTable :: Table Expr a => NullTable Expr a -> MaybeTable Expr a
- toNullTable :: Table Expr a => MaybeTable Expr a -> NullTable Expr a
Documentation
newtype NullTable (context :: Context) a Source #
NullTable t is the table t, but where all the columns in t have the
possibility of being null. This is very similar to
MaybeTable, except that it does not use an extra tag field, so it
cannot distinguish between Nothing and Just Nothing if nested. In other
words, if all of the columns of the t passed to NullTable are already
nullable, then NullTable has no effect.
Instances
nullableTable :: (Table Expr a, Table Expr b) => b -> (a -> b) -> NullTable Expr a -> b Source #
Like nullable.
unsafeUnnullifyTable :: NullTable Expr a -> a Source #
Assume that a NullTable is non-null. Like unsafeUnnullify.
isNonNullTable :: Table Expr a => NullTable Expr a -> Expr Bool Source #
The inverse of isNullTable.
nameNullTable :: a -> NullTable Name a Source #
toMaybeTable :: Table Expr a => NullTable Expr a -> MaybeTable Expr a Source #
Convert a NullTable to a MaybeTable.
toNullTable :: Table Expr a => MaybeTable Expr a -> NullTable Expr a Source #
Convert a MaybeTable to a NullTable. Note that if the underlying a
has no non-nullable fields, this is a lossy conversion.