Java Annotation Framework for tuProlog

Java Annotation Framework for tuProlog

Example: Permutation

Requirements

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]

Contacts

Mirko Viroli

2P