Struct LambdaVariable 

pub struct LambdaVariable {
    pub name: String,
    pub field: Option<FieldRef>,
    pub spans: Spans,
}

A named reference to a lambda parameter which includes it’s own FieldRef, which is used to implement ExprSchemable, for example. It is an option only to make easier for expr_api users to construct lambda variables, but any expression tree or LogicalPlan containing unresolved variables must be resolved before usage with either Expr::resolve_lambda_variables or LogicalPlan::resolve_lambda_variables. The default SQL planner produces already resolved variables and no further resolving is required.

After resolving, if any argument from the lambda function which this variables originates from have it’s field changed (type, nullability, metadata, etc), the resolved variable may became outdated and must be resolved again.

Fields

name: String

field: Option<FieldRef>

spans: Spans

Implementations

impl LambdaVariable

pub fn new(name: String, field: Option<FieldRef>) -> Self

Create a lambda variable from a name and an optional field. If the field is none, the expression tree or LogicalPlan which owns this variable must be resolved before usage with either Expr::resolve_lambda_variables or LogicalPlan::resolve_lambda_variables.

pub fn spans_mut(&mut self) -> &mut Spans

Trait Implementations

impl Clone for LambdaVariable

fn clone(&self) -> LambdaVariable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LambdaVariable

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

Formats the value using the given formatter.

impl Eq for LambdaVariable

impl Hash for LambdaVariable

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 LambdaVariable

fn eq(&self, other: &LambdaVariable) -> 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 LambdaVariable

fn partial_cmp(&self, other: &LambdaVariable) -> 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 LambdaVariable