Drools forward enhanced chaining example knowledge base with roots from wikipedia definition example / published by https://github.com/dacr/code-examples-manager #d374f076-7ea4-4e8b-9b6b-696cc8dd1120/93ec4797d67cbfd713ee27f16e55f04fc7f4a3df

drools-kb-reasoning-forward-chaining-enhanced.sc

// summary : Drools forward enhanced chaining example knowledge base with roots from wikipedia definition example
// keywords : scala, drools, mvel, scalatest, ai, knowledgebase, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : d374f076-7ea4-4e8b-9b6b-696cc8dd1120
// created-on : 2019-10-21T22:04:56+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.5.1"
//> using dep "fr.janalyse::drools-scripting:1.2.0"
//> using dep "org.scalatest::scalatest:3.2.19"
// ---------------------

import fr.janalyse.droolscripting.*, org.scalatest.*, flatspec.*, matchers.*, OptionValues.*

object KbTest extends AnyFlatSpec with should.Matchers {
  override def suiteName: String = "KBTest"
  /*  https://en.wikipedia.org/wiki/Forward_chaining
    If X croaks and X eats flies - Then X is a frog
    If X chirps and X sings - Then X is a canary
    If X is a frog - Then X is green
    If X is a canary - Then X is yellow
   */
  val drl =
    """package test
      |dialect "mvel"
      |
      |declare ItCroaks    x:String end
      |declare ItEatsFlies x:String end
      |declare ItChirps    x:String end
      |declare ItSings     x:String end
      |
      |declare IsGreen     x:String end
      |declare IsYellow    x:String end
      |
      |declare IsFrog      x:String end
      |declare IsCanary    x:String end
      |
      |rule "frog"   when ItCroaks($xItCroaks:x) ItEatsFlies(x == $xItCroaks) then insert(new IsFrog($xItCroaks)) end
      |rule "canary" when ItChirps($x:x) ItSings(x == $x)     then insert(new IsCanary($x)) end
      |
      |rule "all frogs are green"     when IsFrog($x:x)   then insert(new IsGreen($x)) end
      |rule "all canaries are yellow" when IsCanary($x:x) then insert(new IsYellow($x)) end
      |""".stripMargin

  "Forward chaining KB" should "work" in {
    val engine = DroolsEngine(drl)
    val facts = List(
      ("""{"x":"milou"}""", "test.ItCroaks"),
      ("""{"x":"milou"}""", "test.ItEatsFlies"),
      ("""{"x":"milou"}""", "test.ItSings"),
    )
    //facts.foreach{case (kind, json) => engine.insertJson(json, kind)}
    for { (json, declareType) <- facts } {
      engine.insertJson(json, declareType)
    }
    engine.getModelInstances("test.IsFrog").size shouldBe 0
    engine.fireAllRules()
    //engine.getObjects.foreach(x => println(x))
    engine.getModelInstances("test.IsFrog").size shouldBe 1
    engine.getModelInstances("test.IsCanary").size shouldBe 0
  }
}

KbTest.execute()