Trait expr::scalar::func::EagerUnaryFunc [−][src]
trait EagerUnaryFunc<'a> {
type Input: DatumType<'a, EvalError>;
type Output: DatumType<'a, EvalError>;
fn call(&self, input: Self::Input) -> Self::Output;
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 operates on eagerly evaluated expressions
Associated Types
Required methods
fn output_type(&self, input_type: ColumnType) -> ColumnType
fn output_type(&self, input_type: ColumnType) -> ColumnType
The output ColumnType of this function
Provided methods
fn propagates_nulls(&self) -> bool
fn propagates_nulls(&self) -> bool
Whether this function will produce NULL on NULL input
fn introduces_nulls(&self) -> bool
fn introduces_nulls(&self) -> bool
Whether this function will produce NULL on non-NULL input
fn preserves_uniqueness(&self) -> bool
fn preserves_uniqueness(&self) -> bool
Whether this function preserves uniqueness