Load an OWL File¶

Load OWL and RDF serializations into the core ontology model via ontologos-parser.

Important: OntoLogos maps a subset of OWL axioms into its core model. axiom_count() reflects mapped axioms, not Protégé's total. See Known limitations and Supported constructs.

owl:imports behavior

Import handling is format-dependent. load_ontology() merges local RDF/XML imports (merge_imports: true). ParseLimits::default() has merge_imports: false. Turtle and OWL Functional do not merge imports. Remote URLs are never fetched.

See OWL imports reference.

Prerequisites¶

Rust 1.88+
A sample file (download below) or a clone for benchmark corpora

Supported formats¶

Extension	Format
`.owl`	OWL/XML or RDF/XML (content sniffed)
`.rdf`, `.xml`	RDF/XML
`.ttl`, `.turtle`	Turtle
`.ofn`, `.func`	OWL Functional Syntax

CLI¶

./benchmarks/scripts/download.sh
cargo build -p ontologos-cli --release
./target/release/ontologos profile benchmarks/data/pizza.owl

Expected output for Pizza (abbreviated):

detected profile: Dl
diagnostics:
  - InverseObjectProperties: construct is outside OWL 2 EL (mapped axiom rules out OWL 2 EL)
  - SubClassOfExistential: construct is outside OWL 2 RL (mapped axiom rules out OWL 2 RL)
  ...

Family ontology typically reports detected profile: Rl.

Library¶

Path convention

Crates.io quick start: download family.owl to the current directory (see Getting started) and use family.owl.

Repository clone: use benchmarks/data/family.owl after ./benchmarks/scripts/download.sh.

Add dependencies:

[dependencies]
ontologos-core = "1.1.4"
ontologos-parser = "1.1.4"

Load and inspect:

use ontologos_parser::load_ontology;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let path = std::path::Path::new("family.owl");
    let ontology = load_ontology(path)?;

    println!("entities: {}", ontology.entity_count());
    println!("axioms (mapped): {}", ontology.axiom_count());

    if let Some(meta) = ontology.parse_meta() {
        println!("mapped: {}", meta.mapped_axiom_count);
        println!("skipped: {}", meta.skipped_axiom_count);
        for warning in &meta.warnings {
            println!("warning: {warning}");
        }
    }

    Ok(())
}

Run the repository example:

./benchmarks/scripts/download.sh
cargo run -p ontologos-parser --example load_and_profile

Parse metadata¶

After loading, ontology.parse_meta() contains:

Field	Meaning
`constructs`	All OWL constructs observed in the source
`profile_constructs`	Constructs from successfully mapped axioms
`mapped_axiom_count`	Axioms stored in core (equals `axiom_count()`)
`skipped_axiom_count`	Logical components not mapped
`logical_axiom_count`	`mapped + skipped`
`warnings`	Skipped shapes and mapping messages

Not every construct in the file becomes a core axiom. See Supported constructs.

OWL imports¶

See OWL imports reference for the full format matrix.

RDF/XML: local owl:imports are merged by default. Disable with ParseLimits { merge_imports: false, .. }.

Turtle / OWL Functional: imports are not merged — use a single bundle file or merge upstream (e.g. ROBOT).

Remote import IRIs: never fetched over the network.

Untrusted files¶

Use custom limits for uploads:

use ontologos_parser::{load_ontology_with_limits, ParseLimits};

let limits = ParseLimits {
    max_file_bytes: 1_048_576, // 1 MiB
    ..ParseLimits::default()
};
let ontology = load_ontology_with_limits(path, limits)?;

See Security.

Why not `Ontology::from_file`?¶

ontologos-core deliberately does not depend on the parser. Ontology::from_file returns Error::ParseNotAvailable. Always use ontologos_parser::load_ontology.