Eyelang

Eyelang is a small logic programming language for rules, goals, answers, and proofs. Its source syntax is a deliberately small subset of ordinary Prolog term and Horn-clause syntax. It grew out of logic-language experiments in the EYE/N3 reasoning tradition, but is packaged here as its own project.

Install and run

Eyelang has no runtime npm dependencies and no build step. From a source checkout, run the CLI directly with Node.js 18 or newer:

node bin/eyelang.js examples/ancestor.pl
node bin/eyelang.js --proof examples/socrates.pl
printf 'works(stdin, true) :- eq(ok, ok).\n' | node bin/eyelang.js -

For one-off local CLI use from the checkout, npm can run the package bin without a manual symlink:

npm exec -- eyelang --version
npm exec -- eyelang examples/ancestor.pl

To install the checkout's eyelang command on your PATH, use npm's package link:

npm link
eyelang --version

JavaScript API

import { run, Program, Solver } from 'eyelang';

const result = run(`
materialize(answer, 1).
answer(ok) :- eq(ok, ok).
`);
console.log(result.stdout);

Documentation

• Guide
• Language reference

Tests

npm test
npm run test:conformance
npm run test:examples
npm run test:regression