Enum Expression 

#[repr(C)]
pub enum Expression {
    Variable(VariableId),
    Literal(u64),
    Iri(u64),
    UnaryOp {
        op: UnaryOp,
        expr: ExpressionId,
    },
    BinaryOp {
        op: BinaryOp,
        left: ExpressionId,
        right: ExpressionId,
    },
    Function {
        func: Function,
        args_start: u16,
        args_len: u16,
    },
    Subquery {
        query_id: u16,
    },
    EmbeddedTriple {
        subject: u64,
        predicate: u64,
        object: u64,
    },
    Exists {
        pattern: PatternId,
        negated: bool,
    },
}

Expression - uses ExpressionId for nested expressions

Variants

Variable(VariableId)

Variable reference

Literal(u64)

Literal value (index into literal table)

Iri(u64)

IRI reference

UnaryOp

Unary operation

Fields

op: UnaryOp

expr: ExpressionId

BinaryOp

Binary operation

Fields

op: BinaryOp

left: ExpressionId

right: ExpressionId

Function

Function call

Fields

func: Function

args_start: u16

args_len: u16

Subquery

Subquery

Fields

query_id: u16

EmbeddedTriple

Embedded triple (RDF-Star)

Fields

subject: u64

predicate: u64

object: u64

Exists

EXISTS { … } / NOT EXISTS { … } — true iff the inner group graph pattern has ≥1 solution when the current row’s bindings are substituted in. negated flips the result (NOT EXISTS). Evaluated by the executor (it needs graph access), not the pure value evaluator; it is only valid in a FILTER/HAVING boolean position.

Fields

pattern: PatternId

negated: bool

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 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 Copy for Expression

impl Eq for Expression

impl StructuralPartialEq for Expression