JavaRule.java

Rules.This example shows how to use rule operations. Its source code is under the samples/java directory.

import cogitant.base.Environment;
import cogitant.base.IOHandler;
import cogitant.base.EnvironmentObject;
import cogitant.base.Graph;
import cogitant.base.Rule;
import cogitant.base.Projection;
import cogitant.base.ObserverMessage;
import cogitant.base.ObserverMessage.*;
import java.io.FileInputStream;
import java.util.Collection;

class SimpleObserver implements cogitant.base.Observer
{
    public void messageAttached()
    {}
    public void messageDetached()
    {}
    
    public void message(ObserverMessage msg)
    {
        System.out.println("Message: " + msg.toString());
    }
    public boolean wantsMessage(ObserverMessage.Type mt)
    {
        return true;
    }
};

public class JavaRule
{
    public static void runClosure(String prefix) throws Exception
    {
        Environment environment = new cogitant.jni.Environment();
        environment.loadSupport(new FileInputStream(prefix + "/bcgct/sisyphus/sisyphus.bcs"), IOHandler.Format.BCGCT);
        Collection<EnvironmentObject> loadedgraphs = environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/locals.bcg"), IOHandler.Format.BCGCT);
        Graph g = loadedgraphs.iterator().next().asGraph();
        environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/near_1.bcr"), IOHandler.Format.BCGCT);
        environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/near_2.bcr"), IOHandler.Format.BCGCT);
        environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/near_3.bcr"), IOHandler.Format.BCGCT);
        System.out.println(g.size());
        // At most 2 applications.
        environment.rulesClosure(g, null, 2, 0);
        System.out.println(g.size());
        // At most 1 pass.
        environment.rulesClosure(g, null, 0, 1);
        System.out.println(g.size());
        // A real closure.
        environment.rulesClosure(g, null, 0, 0);
        System.out.println(g.size());
    }

    public static void runLowLevelOperations(String prefix) throws Exception
    {
        Environment environment = new cogitant.jni.Environment();
        environment.loadSupport(new FileInputStream(prefix + "/bcgct/sisyphus/sisyphus.bcs"), IOHandler.Format.BCGCT);
        Collection<EnvironmentObject> loadedgraphs = environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/locals.bcg"), IOHandler.Format.BCGCT);
        Graph g = loadedgraphs.iterator().next().asGraph();
        Rule[] rules = new Rule[3];
        SimpleObserver s = new SimpleObserver();
        g.attachObserver(s);
        for (int i=0; i<3; i++)
        {
            Collection<EnvironmentObject> loadedrules = environment.loadObjects(new FileInputStream(prefix + "/bcgct/sisyphus/near_"+(i+1)+".bcr"), IOHandler.Format.BCGCT);
            rules[i] = loadedrules.iterator().next().asRule();
        }
        boolean onemore = true;
        System.out.println(g.size());
        while (onemore)
        {
            onemore = false;
            for (int i=0; i<3; i++)
            {
                Collection<Projection> cp = environment.ruleApplications(g, rules[i], true);
                for (Projection p:cp)
                    onemore |= environment.ruleApply(g, rules[i], p, true);
                System.out.println("after rule near_" + (i+1) + ":" + g.size());
            }
        }
        g.detachObserver(s);
    }

    public static void main(String args[]) throws Exception
    {
        String prefix = "..";
        if (args.length == 1)
            prefix = args[0];
        System.out.println("prefix: " + prefix);
        System.out.println("rulesClosure");
        runClosure(prefix);
        System.out.println("ruleApplications and ruleApply");
        runLowLevelOperations(prefix);
    }
}