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 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 the function’s Signature for information about what input types are accepted and the function’s Volatility.

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

What DataType will be returned by this function, given the types of 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 Setting this to true prevents certain optimizations such as common subexpression elimination

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>

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 return_type_from_exprs( &self, _args: &[Expr], _schema: &dyn ExprSchema, arg_types: &[DataType], ) -> Result<DataType, DataFusionError>

👎Deprecated since 45.0.0: Use return_type_from_args instead

fn return_type_from_args( &self, args: ReturnTypeArgs<'_>, ) -> Result<ReturnInfo, DataFusionError>

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

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

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

fn invoke( &self, _args: &[ColumnarValue], ) -> Result<ColumnarValue, DataFusionError>

👎Deprecated since 42.1.0: Use invoke_with_args instead

Invoke the function on args, returning the appropriate result

fn invoke_batch( &self, args: &[ColumnarValue], number_rows: usize, ) -> Result<ColumnarValue, DataFusionError>

Invoke the function with args and the number of rows, returning the appropriate result.

fn invoke_no_args( &self, _number_rows: usize, ) -> Result<ColumnarValue, DataFusionError>

👎Deprecated since 42.1.0: Use invoke_with_args instead

Invoke the function without args, instead the number of rows are provided, returning the appropriate result.

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 interval for this function. This is used to propagate constraints down through an expression tree.

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>

Whether the function preserves lexicographical ordering based on the input ordering

fn equals(&self, other: &dyn ScalarUDFImpl) -> bool

Return true if this scalar UDF is equal to the other.

fn hash_value(&self) -> u64

Returns a hash value for this scalar UDF.

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 Send for ForeignScalarUDF

impl Sync for ForeignScalarUDF