cl-prolog

A small, dependency-free Prolog engine for Common Lisp. Rulebases are plain data, proof search is continuation-passing, and the builtin goal set is extensible. The public package is cl-prolog.

Quick Start

(require :asdf)
(asdf:load-asd (truename "cl-prolog.asd")) ; run from the repository root
(asdf:load-system :cl-prolog)

(in-package #:cl-prolog)

(define-rulebase *family*
  ((parent tom bob))
  ((parent bob alice))
  ((ancestor ?x ?y) (parent ?x ?y))
  ((ancestor ?x ?y) (parent ?x ?z) (ancestor ?z ?y)))

(query-prolog *family* '(ancestor tom ?who))
;; => (((?WHO . BOB)) ((?WHO . ALICE)))

Prolog source text works too:

(query-prolog (consult-prolog #p"family.pl") (read-prolog-term "ancestor(tom, Who)"))

Install

cl-prolog is not on Quicklisp. Clone it and load its ASDF definition, or put the checkout on your ASDF source registry:

git clone https://github.com/nerima-lisp/cl-prolog.git

With Nix, nix run github:nerima-lisp/cl-prolog runs the regression suite, and as a flake input:

# flake.nix
inputs.cl-prolog = {
  url = "github:nerima-lisp/cl-prolog/v1.0.1";
  inputs.nixpkgs.follows = "nixpkgs";
};

Note the pinned tag. A bare github:nerima-lisp/cl-prolog follows this repository's default branch, so a push here would break your build without warning.

Documentation

Full documentation is published at https://nerima-lisp.github.io/cl-prolog/. The source for that site lives in docs/src/.

• Installation
• Quick Start
• API Reference
• Architecture

Development

nix develop          # SBCL with CL_SOURCE_REGISTRY already set
nix run .#test       # run the test suite
nix flake check      # tests + formatting + docs, the same gate CI uses
nix fmt              # format Nix sources (treefmt)

Tests live in t/ and run under cl-weave, the org's test framework. Without Nix, sbcl --script run-tests.lisp runs the same suite, provided cl-weave is on CL_SOURCE_REGISTRY.

Contributing

See the org-wide CONTRIBUTING guide and the package standard. Release history is in CHANGELOG.md.

Support

See SUPPORT.

License

MIT — see LICENSE.