Trait expr::scalar::func::LazyUnaryFunc[−][src]

trait LazyUnaryFunc {
    fn eval<'a>(
        &'a self, 
        datums: &[Datum<'a>], 
        temp_storage: &'a RowArena, 
        a: &'a MirScalarExpr
    ) -> Result<Datum<'a>, EvalError>;

    fn output_type(&self, input_type: ColumnType) -> ColumnType;

    fn propagates_nulls(&self) -> bool;

    fn introduces_nulls(&self) -> bool;

    fn preserves_uniqueness(&self) -> bool;
}
Expand description

A description of an SQL unary function that has the ability to lazy evaluate its arguments

Required methods

The output ColumnType of this function

Whether this function will produce NULL on NULL input

Whether this function will produce NULL on non-NULL input

Whether this function preserves uniqueness

Implementors