Enum Scalar 

pub enum Scalar {
    Field(FieldRef),
    Literal(Cell),
    Param(ParameterName),
    Call(ScalarOp, Vec<Scalar>),
    Case {
        branches: Vec<(Scalar, Scalar)>,
        otherwise: Option<Box<Scalar>>,
    },
    Exists(Box<Rel>),
    InQuery {
        value: Box<Scalar>,
        query: Box<Rel>,
    },
    ScalarQuery(Box<Rel>),
}

A scalar expression. Subqueries retain lexical access to their outer scope.

Variants

Field(FieldRef)

Bound field.

Literal(Cell)

Typed literal.

Param(ParameterName)

Declared parameter.

Call(ScalarOp, Vec<Scalar>)

Portable operator call.

Case

Conditional expression.

Fields

branches: Vec<(Scalar, Scalar)>

Ordered predicate/value branches.

otherwise: Option<Box<Scalar>>

Optional else expression.

Exists(Box<Rel>)

Existence subquery.

InQuery

Membership subquery.

Fields

value: Box<Scalar>

Compared expression.

query: Box<Rel>

Single-column query.

ScalarQuery(Box<Rel>)

Single-value subquery.

Trait Implementations

impl Clone for Scalar

fn clone(&self) -> Scalar

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Scalar

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

Formats the value using the given formatter.

impl Eq for Scalar

impl PartialEq for Scalar

fn eq(&self, other: &Scalar) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Scalar