Struct Expression

pub struct Expression {
    pub kind: ExpressionKind,
    pub id: NodeId,
    pub span: Span,
}

The Ast representation of a stream expression

Fields

kind: ExpressionKind

The kind of the root expression, e.g., stream access

id: NodeId

The id of the node in the Ast

span: Span

The span in the specification declaring the extend declaration

Implementations

impl Expression

pub fn parse_discrete_duration(&self) -> Result<u64, String>

Parses an expression into a duration for a discrete window ExpressionKind::DiscreteWindowAggregation

pub fn parse_frequency(&self) -> Result<UOM_Frequency, String>

Parses an expression into a frequency. Expression must be a positive numeric value with Hz unit.

pub fn parse_freqspec(&self) -> Result<UOM_Frequency, String>

Parses a frequency annotation. Expression must either be a frequency or a duration representing the period

Trait Implementations

impl Clone for Expression

fn clone(&self) -> Expression

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Expression

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

Formats the value using the given formatter.

impl Display for Expression

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

Formats the value using the given formatter.

impl Hash for Expression

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 Ord for Expression

fn cmp(&self, other: &Expression) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Expression

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

fn partial_cmp(&self, other: &Expression) -> 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 Eq for Expression

impl StructuralPartialEq for Expression