Enum HigherOrderTypeSignature 

pub enum HigherOrderTypeSignature {
    UserDefined,
    VariadicAny,
    Any(usize),
    Exact(Vec<ValueOrLambda<(), ()>>),
}

The types of arguments for which a function has implementations.

HigherOrderTypeSignature DOES NOT define the types that a user query could call the function with. DataFusion will automatically coerce (cast) argument types to one of the supported function signatures, if possible.

Overview

Functions typically provide implementations for a small number of different argument DataTypes, rather than all possible combinations. If a user calls a function with arguments that do not match any of the declared types, DataFusion will attempt to automatically coerce (add casts to) function arguments so they match the HigherOrderTypeSignature. See the type_coercion module for more details

Variants

UserDefined

The acceptable signature and coercions rules are special for this function.

If this signature is specified, DataFusion will call HigherOrderUDFImpl::coerce_value_types to prepare argument types.

VariadicAny

One or more lambdas or arguments with arbitrary types

Any(usize)

The specified number of lambdas or arguments with arbitrary types.

Exact(Vec<ValueOrLambda<(), ()>>)

Exactly the specified arguments in the given order, with arbitrary types. DataFusion will call HigherOrderUDFImpl::coerce_value_types to prepare the value argument types.

Trait Implementations

impl Clone for HigherOrderTypeSignature

fn clone(&self) -> HigherOrderTypeSignature

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HigherOrderTypeSignature

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

Formats the value using the given formatter.

impl Eq for HigherOrderTypeSignature

impl Hash for HigherOrderTypeSignature

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 HigherOrderTypeSignature

fn eq(&self, other: &HigherOrderTypeSignature) -> 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 PartialOrd for HigherOrderTypeSignature

fn partial_cmp(&self, other: &HigherOrderTypeSignature) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for HigherOrderTypeSignature