pub enum ExpressionKind {
Show 16 variants Lit(Literal), Ident(Ident), StreamAccess(Box<Expression>, StreamAccessKind), Default(Box<Expression>, Box<Expression>), Offset(Box<Expression>, Offset), DiscreteWindowAggregation { expr: Box<Expression>, duration: Box<Expression>, wait: bool, aggregation: WindowOperation, }, SlidingWindowAggregation { expr: Box<Expression>, duration: Box<Expression>, wait: bool, aggregation: WindowOperation, }, Binary(BinOpBox<Expression>, Box<Expression>), Unary(UnOpBox<Expression>), Ite(Box<Expression>, Box<Expression>, Box<Expression>), ParenthesizedExpression(Option<Box<Parenthesis>>, Box<Expression>, Option<Box<Parenthesis>>), MissingExpression, Tuple(Vec<Expression>), Field(Box<Expression>, Ident), Method(Box<Expression>, FunctionNameVec<Type>, Vec<Expression>), Function(FunctionNameVec<Type>, Vec<Expression>),
}
Expand description

The Ast representation of a single expression

Variants

Lit(Literal)

A literal, e.g., 1, "foo"

Ident(Ident)

An identifier, e.g., foo

StreamAccess(Box<Expression>, StreamAccessKind)

Accessing a stream

Default(Box<Expression>, Box<Expression>)

A default expression, e.g., a.defaults(to: 0)

Offset(Box<Expression>, Offset)

An offset expression, e.g., a.offset(by: -1)

DiscreteWindowAggregation

Fields

expr: Box<Expression>

The accesses stream

duration: Box<Expression>

The duration of the window

wait: bool

Flag to mark that the window returns only a value if the complete duration has passed

aggregation: WindowOperation

The aggregation function

A discrete window with a duration duration as an integer constant and aggregation function aggregation

SlidingWindowAggregation

Fields

expr: Box<Expression>

The accesses stream

duration: Box<Expression>

The duration of the window

wait: bool

Flag to mark that the window returns only a value if the complete duration has passed

aggregation: WindowOperation

The aggregation function

A sliding window with duration duration and aggregation function aggregation

Binary(BinOpBox<Expression>, Box<Expression>)

A binary operation (For example: a + b, a * b)

Unary(UnOpBox<Expression>)

A unary operation (For example: !x, *x)

Ite(Box<Expression>, Box<Expression>, Box<Expression>)

An if-then-else expression

ParenthesizedExpression(Option<Box<Parenthesis>>, Box<Expression>, Option<Box<Parenthesis>>)

An expression enveloped in parentheses

MissingExpression

An expression was expected, e.g., after an operator like *

Tuple(Vec<Expression>)

A tuple expression

Field(Box<Expression>, Ident)

Access of a named (obj.foo) or unnamed (obj.0) struct field

Method(Box<Expression>, FunctionNameVec<Type>, Vec<Expression>)

A method call, e.g., foo.bar(-1)

Function(FunctionNameVec<Type>, Vec<Expression>)

A function call

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.