eyeling

A compact Notation3 (N3) reasoner in JavaScript.

- Single self-contained bundle (eyeling.js), no external runtime deps
- Forward (=>) + backward (<=) chaining over Horn-style rules
- Outputs only newly derived forward facts (optionally with compact proof comments)
- Works in Node.js and fully client-side (browser/worker)

Links

- Handbook: https://eyereasoner.github.io/eyeling/HANDBOOK
- Semantics: https://eyereasoner.github.io/eyeling/SEMANTICS
- Playground: https://eyereasoner.github.io/eyeling/demo
- Notation3 test suite: https://codeberg.org/phochste/notation3tests
- Eyeling conformance report: https://codeberg.org/phochste/notation3tests/src/branch/main/reports/report.md

Eyeling is regularly checked against the community Notation3 test suite; the report above tracks current pass/fail results.

If you want to understand how the parser, unifier, proof search, skolemization, scoped closure, and builtins are implemented, start with the handbook.

Quick start

$3

- Node.js >= 18

$3

``bash
npm i eyeling
`

$3

Run on a file:

`bash
npx eyeling examples/socrates.n3
`

See all options:

`bash
npx eyeling --help
`

$3

CommonJS:

`js
const { reason } = require('eyeling');

const input =
@prefix rdfs: .
@prefix : .

:Socrates a :Human.
:Human rdfs:subClassOf :Mortal.

{ ?S a ?A. ?A rdfs:subClassOf ?B } => { ?S a ?B }.
;

console.log(reason({ proofComments: false }, input));
`

ESM:

`js
import eyeling from 'eyeling';
console.log(eyeling.reason({ proofComments: false }, input));
`

Streaming / in-process reasoning (browser/worker, direct eyeling.js):

`js
const { closureN3 } = eyeling.reasonStream(input, {
proof: false,
onDerived: ({ triple }) => console.log(triple),
});
`

> Note: the npm reason() helper shells out to the bundled eyeling.js CLI for simplicity and robustness.

Builtins

Builtins are defined in eyeling-builtins.ttl and described in the HANDBOOK.

Testing (repo checkout)

`bash
npm test
``

License

MIT (see LICENSE).