Struct FunctionSignature 

pub struct FunctionSignature {
    pub name: String,
    pub parameters: Vec<FunctionParameter>,
    pub return_type: SqlType,
    pub is_aggregate: bool,
    pub is_window: bool,
    pub is_deterministic: bool,
    pub min_args: usize,
    pub max_args: Option<usize>,
}

Function signature for built-in and user-defined functions.

Fields

name: String

Function name (uppercase).

parameters: Vec<FunctionParameter>

Parameter types (None means any type is accepted).

return_type: SqlType

Return type.

is_aggregate: bool

Whether this is an aggregate function.

is_window: bool

Whether this is a window function.

is_deterministic: bool

Whether the function is deterministic.

min_args: usize

Minimum number of arguments.

max_args: Option<usize>

Maximum number of arguments (None = unlimited).

Implementations

impl FunctionSignature

pub fn scalar(name: impl Into<String>, return_type: SqlType) -> Self

Create a scalar function signature.

pub fn aggregate(name: impl Into<String>, return_type: SqlType) -> Self

Create an aggregate function signature.

pub fn window(name: impl Into<String>, return_type: SqlType) -> Self

Create a window function signature.

pub fn with_min_args(self, min: usize) -> Self

Set minimum number of arguments.

pub fn with_max_args(self, max: usize) -> Self

Set maximum number of arguments.

pub fn with_args(self, count: usize) -> Self

Set exact number of arguments.

pub fn with_param(self, param: FunctionParameter) -> Self

Add a parameter.

pub fn non_deterministic(self) -> Self

Mark as non-deterministic.

pub fn accepts_arg_count(&self, count: usize) -> bool

Check if the given number of arguments is valid.

pub fn can_be_window(&self) -> bool

Check if the function can be used in a window context.

Trait Implementations

impl Clone for FunctionSignature

fn clone(&self) -> FunctionSignature

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FunctionSignature

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

Formats the value using the given formatter.

impl PartialEq for FunctionSignature

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