Struct ForeignScalarUDF 

pub struct ForeignScalarUDF { /* private fields */ }

This struct is used to access an UDF provided by a foreign library across a FFI boundary.

The ForeignScalarUDF is to be used by the caller of the UDF, so it has no knowledge or access to the private data. All interaction with the UDF must occur through the functions defined in FFI_ScalarUDF.

Trait Implementations

impl Debug for ForeignScalarUDF

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for ForeignScalarUDF

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ForeignScalarUDF

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl ScalarUDFImpl for ForeignScalarUDF

fn as_any(&self) -> &dyn Any

Returns this object as an Any trait object

fn name(&self) -> &str

Returns this function’s name

fn signature(&self) -> &Signature

Returns a Signature describing the argument types for which this function has an implementation, and the function’s Volatility.

fn return_type(&self, arg_types: &[DataType]) -> Result<DataType>

DataType returned by this function, given the types of the arguments.

fn return_field_from_args(&self, args: ReturnFieldArgs<'_>) -> Result<FieldRef>

What type will be returned by this function, given the arguments?

fn invoke_with_args( &self, invoke_args: ScalarFunctionArgs, ) -> Result<ColumnarValue>

Invoke the function returning the appropriate result.

fn aliases(&self) -> &[String]

Returns any aliases (alternate names) for this function.

fn short_circuits(&self) -> bool

Returns true if some of this exprs subexpressions may not be evaluated and thus any side effects (like divide by zero) may not be encountered.

fn coerce_types(&self, arg_types: &[DataType]) -> Result<Vec<DataType>>

Coerce arguments of a function call to types that the function can evaluate.

fn display_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

👎Deprecated since 50.0.0: This method is unused and will be removed in a future release

Returns the user-defined display name of function, given the arguments

fn schema_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

Returns the name of the column this expression would create

fn is_nullable(&self, _args: &[Expr], _schema: &dyn ExprSchema) -> bool

👎Deprecated since 45.0.0: Use return_field_from_args instead. if you use is_nullable that returns non-nullable with return_type, you would need to switch to return_field_from_args, you might have error

fn simplify( &self, args: Vec<Expr>, _info: &dyn SimplifyInfo, ) -> Result<ExprSimplifyResult, DataFusionError>

Optionally apply per-UDF simplification / rewrite rules.

fn evaluate_bounds( &self, _input: &[&Interval], ) -> Result<Interval, DataFusionError>

Computes the output Interval for a ScalarUDFImpl, given the input intervals.

fn propagate_constraints( &self, _interval: &Interval, _inputs: &[&Interval], ) -> Result<Option<Vec<Interval>>, DataFusionError>

Updates bounds for child expressions, given a known Intervals for this function.

fn output_ordering( &self, inputs: &[ExprProperties], ) -> Result<SortProperties, DataFusionError>

Calculates the SortProperties of this function based on its children’s properties.

fn preserves_lex_ordering( &self, _inputs: &[ExprProperties], ) -> Result<bool, DataFusionError>

Returns true if the function preserves lexicographical ordering based on the input ordering.

fn documentation(&self) -> Option<&Documentation>

Returns the documentation for this Scalar UDF.

impl TryFrom<&FFI_ScalarUDF> for ForeignScalarUDF

type Error = DataFusionError

The type returned in the event of a conversion error.

fn try_from(udf: &FFI_ScalarUDF) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for ForeignScalarUDF

impl Send for ForeignScalarUDF

impl Sync for ForeignScalarUDF