Struct TriplePattern

Source

pub struct TriplePattern {
    pub subject: Option<NodeId>,
    pub predicate: Option<Predicate>,
    pub object: Option<Value>,
}

Expand description

A pattern for matching (Subject, Predicate, Object) triples.

A pattern specifies constraints on the components of a triple. Any component can be None, which acts as a wildcard that matches any value.

§Examples

Match all triples with a specific subject:

use aingle_graph::{TriplePattern, NodeId};

let pattern = TriplePattern::subject(NodeId::named("user:alice"));

Match triples with specific subject and predicate:

use aingle_graph::{TriplePattern, NodeId, Predicate};

let pattern = TriplePattern::subject(NodeId::named("user:alice"))
    .with_predicate(Predicate::named("has_name"));

Match all triples (wildcard pattern):

use aingle_graph::TriplePattern;

let pattern = TriplePattern::any();
assert!(pattern.is_wildcard());

Fields§

§subject: Option<NodeId>

An optional constraint on the triple’s subject.

§predicate: Option<Predicate>

An optional constraint on the triple’s predicate.

§object: Option<Value>

An optional constraint on the triple’s object.

Implementations§

Source §

impl TriplePattern

Source

pub fn any() -> Self

Creates a new pattern that matches any triple.

This is equivalent to a wildcard pattern with no constraints.

§Examples

use aingle_graph::TriplePattern;

let pattern = TriplePattern::any();
assert!(pattern.is_wildcard());

Source

pub fn subject(subject: NodeId) -> Self

Creates a new pattern that matches a specific subject.

§Examples

use aingle_graph::{TriplePattern, NodeId};

let pattern = TriplePattern::subject(NodeId::named("user:alice"));

Source

pub fn predicate(predicate: Predicate) -> Self

Creates a new pattern that matches a specific predicate.

Source

pub fn object(object: Value) -> Self

Creates a new pattern that matches a specific object.

Source

pub fn with_subject(self, subject: NodeId) -> Self

Adds a subject constraint to the pattern.

Source

pub fn with_predicate(self, predicate: Predicate) -> Self

Adds a predicate constraint to the pattern.

Source

pub fn with_object(self, object: Value) -> Self

Adds an object constraint to the pattern.

Source

pub fn matches(&self, triple: &Triple) -> bool

Returns true if the given Triple matches this pattern.

A triple matches the pattern if all non-None constraints are satisfied.

§Examples

use aingle_graph::{Triple, TriplePattern, NodeId, Predicate, Value};

let triple = Triple::new(
    NodeId::named("user:alice"),
    Predicate::named("has_name"),
    Value::literal("Alice"),
);

let pattern = TriplePattern::subject(NodeId::named("user:alice"));
assert!(pattern.matches(&triple));

let wrong_pattern = TriplePattern::subject(NodeId::named("user:bob"));
assert!(!wrong_pattern.matches(&triple));