| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell98 |
Opaleye.Internal.Column
- newtype Column a = Column PrimExpr
- data Nullable a = Nullable
- unColumn :: Column a -> PrimExpr
- unsafeCoerce :: Column a -> Column b
- constant :: ShowConstant a => a -> Column a
- binOp :: BinOp -> Column a -> Column b -> Column c
- unOp :: UnOp -> Column a -> Column b
- case_ :: [(Column Bool, Column a)] -> Column a -> Column a
- ifThenElse :: Column Bool -> Column a -> Column a -> Column a
- (.>) :: Column a -> Column a -> Column Bool
- (.==) :: Column a -> Column a -> Column Bool
Documentation
The Num and Fractional instances for Column a are too
general. For example, they allow you to add two Column
Strings. This will be fixed in a subsequent release.
Instances
| Default ViewColumnMaker String (Column a) | |
| Default QueryRunnerColumn a b => Default QueryRunner (Column a) b | |
| Default Binaryspec (Column a) (Column a) | |
| Default Unpackspec (Column a) (Column a) | |
| Default Valuesspec (Column Int) (Column Int) | |
| Default NullMaker (Column a) (Column (Nullable a)) | |
| Default NullMaker (Column (Nullable a)) (Column (Nullable a)) | |
| Default ColumnMaker (Column a) (Column a) | |
| Default Distinctspec (Column a) (Column a) | |
| (ShowConstant a, Fractional a) => Fractional (Column a) | |
| (ShowConstant a, Num a) => Num (Column a) | |
| Show (Column a) |
Constructors
| Nullable |
unsafeCoerce :: Column a -> Column b Source
constant :: ShowConstant a => a -> Column a Source