About

Clara is a forward-chaining rules engine written in Clojure(Script) with Java interoperability. It aims to simplify code with a developer-centric approach to expert systems. See clara-rules.org for more.

NOTE: this fork only supports the JVM/Clojure, and not ClojureScript.

Usage

Here's a simple example. Complete documentation is at clara-rules.org.

(ns clara.support-example
  (:require [clara.rules :refer :all]
            [futurama.core :refer [!<!!]))

(defrecord SupportRequest [client level])

(defrecord ClientRepresentative [name client])

(defrule is-important
  "Find important support requests."
  [SupportRequest (= :high level)]
  =>
  (println "High support requested!"))

(defrule notify-client-rep
  "Find the client representative and send a notification of a support request."
  [SupportRequest (= ?client client)]
  [ClientRepresentative (= ?client client) (= ?name name)] ; Join via the ?client binding.
  =>
  (println "Notify" ?name "that"  ?client "has a new support request!"))

;; We can just use Clojure's threading macro to wire things up below.

;; Run the rules!
(-> (mk-session)
    (insert (->ClientRepresentative "Alice" "Acme")
            (->SupportRequest "Acme" :high))
    (fire-rules))

;; Run the rules asynchronously!
(!<!! (-> (mk-session)
          (insert (->ClientRepresentative "Alice" "Acme")
                  (->SupportRequest "Acme" :high))
          (fire-rules-async {:parallel-batch-size 50})))

;;;; Prints this:

;; High support requested!
;; Notify Alice that Acme has a new support request!

Building

Clara is built, tested, and deployed using Clojure Tools Deps.

GNU Make is used to simplify invocation of some commands.

Availability

Clara releases for this project are on Clojars. Simply add the following to your project:

Communication

• Questions about Clara rules can be posted to the Clara Rules Google Group or the Slack channel.
• For any other questions or issues about this Clara rules fork specifically feel free to browse or open a Github Issue.

Contributing

See CONTRIBUTING.md

YourKit

YourKit supports open source projects with innovative and intelligent tools for monitoring and profiling Java and .NET applications. YourKit is the creator of YourKit Java Profiler, YourKit .NET Profiler, and YourKit YouMonitor.

LICENSE

Copyright 2023 Jose Gomez

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.