Struct datafusion_expr::ScalarUDF

pub struct ScalarUDF {
    pub name: String,
    pub signature: Signature,
    pub return_type: ReturnTypeFunction,
    pub fun: ScalarFunctionImplementation,
}

Logical representation of a UDF.

Fields

name: String

name

signature: Signature

signature

return_type: ReturnTypeFunction

Return type

fun: ScalarFunctionImplementation

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: &ReturnTypeFunction,
    fun: &ScalarFunctionImplementation
) -> Self

Create a new ScalarUDF

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

Formats the value using the given formatter.

impl Hash for ScalarUDF

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, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<ScalarUDF> for ScalarUDF

fn eq(&self, other: &Self) -> 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 !=.