Struct datafusion_expr::Signature

pub struct Signature {
    pub type_signature: TypeSignature,
    pub volatility: Volatility,
}

The Signature of a function defines its supported input types as well as its volatility.

Fields

type_signature: TypeSignature

type_signature - The types that the function accepts. See TypeSignature for more information.

volatility: Volatility

volatility - The volatility of the function. See Volatility for more information.

Implementations

impl Signature

pub fn new(type_signature: TypeSignature, volatility: Volatility) -> Self

new - Creates a new Signature from any type signature and the volatility.

pub fn variadic(common_types: Vec<DataType>, volatility: Volatility) -> Self

variadic - Creates a variadic signature that represents an arbitrary number of arguments all from a type in common_types.

pub fn variadic_equal(volatility: Volatility) -> Self

variadic_equal - Creates a variadic signature that represents an arbitrary number of arguments of the same type.

pub fn uniform(
    arg_count: usize,
    valid_types: Vec<DataType>,
    volatility: Volatility
) -> Self

uniform - Creates a function with a fixed number of arguments of the same type, which must be from valid_types.

pub fn exact(exact_types: Vec<DataType>, volatility: Volatility) -> Self

exact - Creates a signature which must match the types in exact_types in order.

pub fn any(arg_count: usize, volatility: Volatility) -> Self

any - Creates a signature which can a be made of any type but of a specified number

pub fn one_of(
    type_signatures: Vec<TypeSignature>,
    volatility: Volatility
) -> Self

one_of Creates a signature which can match any of the TypeSignatures which are passed in.

Trait Implementations

impl Clone for Signature

fn clone(&self) -> Signature

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Signature

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

Formats the value using the given formatter.

impl Hash for Signature

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<Signature> for Signature

fn eq(&self, other: &Signature) -> 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 StructuralPartialEq for Signature