Struct rtlola_parser::ast::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.

Examples found in repository

src/ast/conversion.rs (line 147)

    pub fn parse_freqspec(&self) -> Result<UOM_Frequency, String> {
        if let Ok(freq) = self.parse_frequency() {
            Ok(freq)
        } else if let Ok(period) = self.parse_duration() {
            let seconds = period.get::<second>();
            if seconds.is_positive() {
                Ok(UOM_Frequency::new::<hertz>(seconds.inv()))
            } else {
                Err(format!(
                    "duration of periodic stream specification must be positive, found `{:#?}`",
                    period
                ))
            }
        } else {
            Err(format!("expected frequency or duration, found `{}`", self))
        }
    }

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 copy 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 PartialEq<Expression> for Expression

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

impl StructuralEq for Expression

impl StructuralPartialEq for Expression