Java Annotation Framework for tuProlog

Check Integrating Java and Prolog through Generic Methods and Type Inference for more information on this feature

Example: Permutation

Requirements

Download tuProlog (version 2.3.0 or greather) from previous page
Download JBoss's javassist library

Code

import alice.tuprologx.pj.engine.*;
import alice.tuprologx.pj.model.*;
import alice.tuprologx.pj.annotations.*;

public abstract class PermutationUtility {

   @PrologMethod ( clauses = {
       "permutation([],[]).",
       "permutation(U,[X|V]):-remove(U,X,Z),permutation(Z,V).",
       "remove([X|T],X,T).",
       "remove([X|U],E,[X|V]):-remove(U,E,V)."
   })

   public abstract <$X extends List<Int>, $Y extends List<Int>> Iterable<$Y> permutation($X l);

   public static void main(String[] args) throws Exception{
        PermutationUtility pu = PJ.newInstance(PermutationUtility.class);
        java.util.Collection<Integer> l=java.util.Arrays.<Integer>asList(new Integer[]{1,2,3});
       for (List<Int> p : pu.permutation(new List<Int>(l))) {
            System.out.println(p.toJava());
       }
   }
}

Compilation

To compile the sample code you should add all required libraries in the classpath
In this example we assume the libraries are in the same folder of sample code
Use the command below to execute

javac -classpath javassist.jar:2p-3.0-alpha.jar PermutationUtility.java

Execution

To execute the sample code you should add all required libraries in the classpath
In the same way as for compilation, we assume the libraries are in the same folder of sample code
Use the command below to execute

java -classpath javassist.jar:2p-3.0-alpha.jar PermutationUtility

Expected Result

If you have done all steps correcly now you should see an output like this:

[1, 2, 3]
[1, 3, 2]
[2, 1, 3]
[2, 3, 1]
[3, 1, 2]
[3, 2, 1]