Struct datafusion_physical_expr::udf::ScalarUDF

pub struct ScalarUDF {
    pub name: String,
    pub signature: Signature,
    pub return_type: Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType, Global>, DataFusionError> + Send + Sync, Global>,
    pub fun: Arc<dyn Fn(&[ColumnarValue]) -> Result<ColumnarValue, DataFusionError> + Send + Sync, Global>,
}

Logical representation of a UDF.

Fields

name: String

name

signature: Signature

signature

return_type: Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType, Global>, DataFusionError> + Send + Sync, Global>

Return type

fun: Arc<dyn Fn(&[ColumnarValue]) -> Result<ColumnarValue, DataFusionError> + Send + Sync, Global>

actual implementation

The fn param is the wrapped function but be aware that the function will be passed with the slice / vec of columnar values (either scalar or array) with the exception of zero param function, where a singular element vec will be passed. In that case the single element is a null array to indicate the batch’s row count (so that the generative zero-argument function can know the result array size).

Implementations

impl ScalarUDF

pub fn new( name: &str, signature: &Signature, return_type: &Arc<dyn Fn(&[DataType]) -> Result<Arc<DataType, Global>, DataFusionError> + Send + Sync, Global>, fun: &Arc<dyn Fn(&[ColumnarValue]) -> Result<ColumnarValue, DataFusionError> + Send + Sync, Global> ) -> ScalarUDF

Create a new ScalarUDF

pub fn call(&self, args: Vec<Expr, Global>) -> Expr

creates a logical expression with a call of the UDF This utility allows using the UDF without requiring access to the registry.

Trait Implementations

impl Clone for ScalarUDF

fn clone(&self) -> ScalarUDF

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScalarUDF

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

Formats the value using the given formatter.

impl Hash for ScalarUDF

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

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<ScalarUDF> for ScalarUDF

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl Eq for ScalarUDF