Skip to content

Classify in five minutes (Rust)

Run OWL classification from crates.io — no repository clone. Uses ontologos-facade::classify.

The one rule for Rust integrators

Reasoner holds config and ontology state. Always call ontologos_facade::classify(&mut reasoner) — never reasoner.classify(). See Rust integration contract.

Prerequisites

  • Rust 1.88+ (rustc --version must be >= 1.88.0)
  • OntoLogos crates — see Release status for published v1.0.0 pins
curl -L -o family.owl \
  https://raw.githubusercontent.com/eddiethedean/ontologos/main/benchmarks/data/family.owl
cargo new ontologos-classify-demo && cd ontologos-classify-demo

Cargo.toml

[dependencies]
ontologos-core = "1.0.0"
ontologos-parser = "1.0.0"
ontologos-facade = "1.0.0"

Classify with profile auto

use ontologos_core::{Profile, Reasoner};
use ontologos_facade::ClassifyOutcome;
use ontologos_parser::load_ontology;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let ontology = load_ontology(std::path::Path::new("family.owl"))?;
    let mut reasoner = Reasoner::builder()
        .profile(Profile::Auto)
        .build(ontology)?;
    match ontologos_facade::classify(&mut reasoner)? {
        ClassifyOutcome::Taxonomy(t) => {
            println!("subsumptions: {}", t.subsumption_count());
        }
        ClassifyOutcome::Rdfs(r) => {
            println!("inferred: {}", r.inferred_total());
        }
        ClassifyOutcome::Rl(r) => {
            println!("inferred: {}", r.inferred_total());
        }
    }
    Ok(())
}

Profile::Auto detects RL for Family and runs saturation. Expected: inferred > 0; ~57 mapped axioms (normal for Family — not Protégé totals). See Protégé axiom counts.

For EL taxonomies, use Profile::El with an EL-shaped ontology (in-memory builder below, or Pizza after clone + ./benchmarks/scripts/download.sh).

Classify with a profile crate directly

For EL without the facade, use an in-memory EL ontology (Family.owl is RL-shaped — do not use it for EL demos):

# Add to Cargo.toml
ontologos-el = "1.0.0"

use ontologos_core::Ontology;
use ontologos_el::ElClassifier;

fn main() -> Result<(), ontologos_core::Error> {
    let ontology = Ontology::builder()
        .class("http://example.org/Food")?
        .class("http://example.org/Pizza")?
        .subclass_of("http://example.org/Pizza", "http://example.org/Food")?
        .build()?;
    let taxonomy = ElClassifier::new().classify(&ontology)?;
    println!("subsumptions: {}", taxonomy.subsumption_count());
    Ok(())
}

For Pizza EL file-based demos, clone the repo and run ./benchmarks/scripts/download.sh. See OWL EL classification.

Do not use

// WRONG — deprecated; returns NotImplemented / delegate hints
ontologos_core::Reasoner::classify(&mut reasoner)?;

See Choosing an API.

Next steps