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use anyhow::Result;
use oxigraph::model::{GraphName, NamedNode, Quad, Subject, Term};
use oxigraph::store::Store;
#[derive(Debug, PartialEq, Eq, Hash, Clone)]
pub enum ReasoningStrategy {
None,
RDFS,
OWLRL,
}
pub struct SynapseReasoner {
pub strategy: ReasoningStrategy,
}
impl SynapseReasoner {
pub fn new(strategy: ReasoningStrategy) -> Self {
Self { strategy }
}
/// Apply reasoning to a store and return inferred triples (without inserting)
pub fn apply(&self, store: &Store) -> Result<Vec<(String, String, String)>> {
let mut inferred = Vec::new();
match self.strategy {
ReasoningStrategy::None => {}
ReasoningStrategy::RDFS => {
// RDFS: SubClassOf Transitivity
// If A subClassOf B, and B subClassOf C -> A subClassOf C
let subclass_prop =
NamedNode::new("http://www.w3.org/2000/01/rdf-schema#subClassOf")?;
for q1 in store
.quads_for_pattern(None, Some(subclass_prop.as_ref()), None, None)
.flatten()
{
if let Subject::NamedNode(a) = q1.subject {
if let Term::NamedNode(b) = q1.object {
for q2 in store
.quads_for_pattern(
Some(b.as_ref().into()),
Some(subclass_prop.as_ref()),
None,
None,
)
.flatten()
{
if let Term::NamedNode(c) = q2.object {
inferred.push((
a.as_str().to_string(),
subclass_prop.as_str().to_string(),
c.as_str().to_string(),
));
}
}
}
}
}
}
ReasoningStrategy::OWLRL => {
// OWL-RL: TransitiveProperty
// If p is TransitiveProperty, and x p y, y p z -> x p z
let type_prop = NamedNode::new("http://www.w3.org/1999/02/22-rdf-syntax-ns#type")?;
let transitive_class =
NamedNode::new("http://www.w3.org/2002/07/owl#TransitiveProperty")?;
// Find all transitive properties
for q in store
.quads_for_pattern(
None,
Some(type_prop.as_ref()),
Some(transitive_class.as_ref().into()),
None,
)
.flatten()
{
if let Subject::NamedNode(p_node) = q.subject {
let p_ref = p_node.as_ref();
// Naive transitive: x p y ("xy")
for xy_quad in store
.quads_for_pattern(None, Some(p_ref), None, None)
.flatten()
{
if let Subject::NamedNode(x) = xy_quad.subject {
if let Term::NamedNode(y) = xy_quad.object {
// Find y p z ("yz")
for yz_quad in store
.quads_for_pattern(
Some(y.as_ref().into()),
Some(p_ref),
None,
None,
)
.flatten()
{
if let Term::NamedNode(z) = yz_quad.object {
inferred.push((
x.as_str().to_string(),
p_node.as_str().to_string(),
z.as_str().to_string(),
));
}
}
}
}
}
}
}
// OWL-RL: SymmetricProperty
// If p is SymmetricProperty, and x p y -> y p x
let symmetric_class =
NamedNode::new("http://www.w3.org/2002/07/owl#SymmetricProperty")?;
for q in store
.quads_for_pattern(
None,
Some(type_prop.as_ref()),
Some(symmetric_class.as_ref().into()),
None,
)
.flatten()
{
if let Subject::NamedNode(p_node) = q.subject {
let p_ref = p_node.as_ref();
for e in store
.quads_for_pattern(None, Some(p_ref), None, None)
.flatten()
{
// Infer: y p x
if let Subject::NamedNode(s_node) = e.subject {
if let Term::NamedNode(obj_node) = e.object {
inferred.push((
obj_node.as_str().to_string(),
p_node.as_str().to_string(),
s_node.as_str().to_string(),
));
}
}
}
}
}
// OWL-RL: inverseOf
// If p1 inverseOf p2, and x p1 y -> y p2 x
let inverse_prop = NamedNode::new("http://www.w3.org/2002/07/owl#inverseOf")?;
for q in store
.quads_for_pattern(None, Some(inverse_prop.as_ref()), None, None)
.flatten()
{
if let Subject::NamedNode(p1_node) = q.subject {
let p1_ref = p1_node.as_ref();
if let Term::NamedNode(p2_node) = q.object {
// p1 inverseOf p2. For every x p1 y, infer y p2 x
for e in store
.quads_for_pattern(None, Some(p1_ref), None, None)
.flatten()
{
if let Subject::NamedNode(x) = e.subject {
if let Term::NamedNode(y) = e.object {
inferred.push((
y.as_str().to_string(),
p2_node.as_str().to_string(),
x.as_str().to_string(),
));
}
}
}
}
}
}
}
}
Ok(inferred)
}
/// Apply reasoning and persist inferred triples
pub fn materialize(&self, store: &Store) -> Result<usize> {
let mut total_inferred = 0;
// Fixed-point iteration loop
loop {
let inferred = self.apply(store)?;
if inferred.is_empty() {
break;
}
let mut new_triples = 0;
for (s, p, o) in inferred {
let s_node = NamedNode::new(s)?;
let p_node = NamedNode::new(p)?;
let o_node = NamedNode::new(o)?;
let quad = Quad::new(s_node, p_node, o_node, GraphName::DefaultGraph);
// Only count if actually new
// Note: store.contains checks exact match including graph name.
// We insert into DefaultGraph.
if !store.contains(&quad)? {
store.insert(&quad)?;
new_triples += 1;
}
}
if new_triples == 0 {
break;
}
total_inferred += new_triples;
}
Ok(total_inferred)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_rdfs_transitivity() -> Result<()> {
let store = Store::new()?;
let reasoner = SynapseReasoner::new(ReasoningStrategy::RDFS);
let a = NamedNode::new("http://example.org/A")?;
let b = NamedNode::new("http://example.org/B")?;
let c = NamedNode::new("http://example.org/C")?;
let sub_class_of = NamedNode::new("http://www.w3.org/2000/01/rdf-schema#subClassOf")?;
store.insert(&Quad::new(
a.clone(),
sub_class_of.clone(),
b.clone(),
GraphName::DefaultGraph,
))?;
store.insert(&Quad::new(
b.clone(),
sub_class_of.clone(),
c.clone(),
GraphName::DefaultGraph,
))?;
let inferred = reasoner.apply(&store)?;
assert!(!inferred.is_empty());
assert!(inferred.contains(&(
a.as_str().to_string(),
sub_class_of.as_str().to_string(),
c.as_str().to_string()
)));
Ok(())
}
#[test]
fn test_owl_transitive_property() -> Result<()> {
let store = Store::new()?;
let reasoner = SynapseReasoner::new(ReasoningStrategy::OWLRL);
let p = NamedNode::new("http://example.org/ancestorOf")?;
let type_prop = NamedNode::new("http://www.w3.org/1999/02/22-rdf-syntax-ns#type")?;
let trans_class = NamedNode::new("http://www.w3.org/2002/07/owl#TransitiveProperty")?;
// p a TransitiveProperty
store.insert(&Quad::new(
p.clone(),
type_prop,
trans_class,
GraphName::DefaultGraph,
))?;
let x = NamedNode::new("http://example.org/grandparent")?;
let y = NamedNode::new("http://example.org/parent")?;
let z = NamedNode::new("http://example.org/child")?;
// x p y
store.insert(&Quad::new(
x.clone(),
p.clone(),
y.clone(),
GraphName::DefaultGraph,
))?;
// y p z
store.insert(&Quad::new(
y.clone(),
p.clone(),
z.clone(),
GraphName::DefaultGraph,
))?;
let inferred = reasoner.apply(&store)?;
assert!(inferred.contains(&(
x.as_str().to_string(),
p.as_str().to_string(),
z.as_str().to_string()
)));
Ok(())
}
}