Enum Expression 

pub enum Expression {
    Literal(Value),
    Variable(String),
    Binary {
        left: Box<Expression>,
        op: BinaryOperator,
        right: Box<Expression>,
    },
    Unary {
        op: UnaryOperator,
        expr: Box<Expression>,
    },
    Function {
        name: String,
        args: Vec<Expression>,
    },
}

A conditional expression.

Variants

Literal(Value)

Literal value.

Variable(String)

Variable reference.

Binary

Binary operation.

Fields

left: Box<Expression>

Left operand.

op: BinaryOperator

Binary operator.

right: Box<Expression>

Right operand.

Unary

Unary operation.

Fields

op: UnaryOperator

Unary operator.

expr: Box<Expression>

Expression to apply operator to.

Function

Function call.

Fields

name: String

Function name.

args: Vec<Expression>

Function arguments.

Implementations

impl Expression

pub fn literal(value: Value) -> Self

Create a literal expression.

pub fn variable<S: Into<String>>(name: S) -> Self

Create a variable reference expression.

pub fn binary(left: Expression, op: BinaryOperator, right: Expression) -> Self

Create a binary expression.

pub fn eq(left: Expression, right: Expression) -> Self

Create an equality expression.

pub fn and(left: Expression, right: Expression) -> Self

Create a logical AND expression.

pub fn or(left: Expression, right: Expression) -> Self

Create a logical OR expression.

pub fn logical_not(expr: Expression) -> Self

Create a NOT expression.

pub fn evaluate(&self, context: &ExpressionContext) -> Result<Value>

Evaluate the expression.

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<'de> Deserialize<'de> for Expression

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Expression

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.