Exemple #1
0
  /** Unify goal: pred1(X,[1|Z]|Z) rule: pred1(V,[1,2,3,4],2,3|U):-pred2(V|U). */
  @Test
  public void unifyNonEmptyListTest() {
    ProvaKnowledgeBase kb = new ProvaKnowledgeBaseImpl();

    ProvaConstant c1 = ProvaConstantImpl.create(1);
    ProvaVariable z = ProvaVariableImpl.create("Z");
    ProvaList l1 = ProvaListImpl.create(new ProvaObject[] {c1}, z);
    ProvaVariable x = ProvaVariableImpl.create("X");
    ProvaList l2 = ProvaListImpl.create(new ProvaObject[] {x, l1}, z);
    ProvaLiteral query = kb.generateLiteral("pred1", l2);
    ProvaRule goal = kb.generateGoal(new ProvaLiteral[] {query});

    ProvaConstant c2 = ProvaConstantImpl.create(2);
    ProvaConstant c3 = ProvaConstantImpl.create(3);
    ProvaConstant c4 = ProvaConstantImpl.create(4);
    ProvaList l3 = ProvaListImpl.create(new ProvaObject[] {c1, c2, c3, c4});
    ProvaVariable v = ProvaVariableImpl.create("V");
    ProvaVariable u = ProvaVariableImpl.create("U");
    ProvaList l4 = ProvaListImpl.create(new ProvaObject[] {v, l3, c2, c3}, u);
    ProvaLiteral lit1 = kb.generateLiteral("pred1", l4);
    ProvaList l5 = ProvaListImpl.create(new ProvaObject[] {v}, u);
    ProvaLiteral lit2 = kb.generateLiteral("pred2", l5);
    ProvaRule rule = kb.generateRule(lit1, new ProvaLiteral[] {lit2});

    ProvaUnificationImpl unification = new ProvaUnificationImpl(goal, rule);
    boolean result = unification.unify();

    org.junit.Assert.assertTrue(result);

    int countSourceSubstitutions = 0;
    for (ProvaVariable var : unification.getSourceVariables()) {
      ProvaObject to = var.getRecursivelyAssigned();
      if (to != var) {
        countSourceSubstitutions++;
      }
    }
    org.junit.Assert.assertEquals(countSourceSubstitutions, 1);

    int countTargetSubstitutions = 0;
    for (ProvaVariable var : unification.getTargetVariables()) {
      ProvaObject to = var.getRecursivelyAssigned();
      if (to != var) {
        countTargetSubstitutions++;
      }
    }
    org.junit.Assert.assertEquals(countTargetSubstitutions, 2);

    // Recover actual substitutions resulting from the unification
    ProvaLiteral[] newGoals = unification.rebuildNewGoals();

    org.junit.Assert.assertNotNull(newGoals);
    // There is one actual goal: pred2(X,4)
    org.junit.Assert.assertEquals(newGoals.length, 1);
    // The goal literal has fixed arity of 2
    org.junit.Assert.assertEquals(newGoals[0].getTerms().computeSize(), 2);
    // The "fixed" part of the goal literal has length equal to 2
    org.junit.Assert.assertEquals(newGoals[0].getTerms().getFixed().length, 2);
  }
Exemple #2
0
  /** Unify goal: pred1(X,[2|A]|Z) rule: pred1(V,Y,3,Y,U):-pred2(V|Y). */
  @Test
  public void unifyTest2() {
    ProvaKnowledgeBase kb = new ProvaKnowledgeBaseImpl();

    ProvaConstant c2 = ProvaConstantImpl.create(2);
    ProvaVariable a = ProvaVariableImpl.create("A");
    ProvaList l1 = ProvaListImpl.create(new ProvaObject[] {c2}, a);
    ProvaVariable x = ProvaVariableImpl.create("X");
    ProvaVariable z = ProvaVariableImpl.create("Z");
    ProvaList l2 = ProvaListImpl.create(new ProvaObject[] {x, l1}, z);
    ProvaLiteral query = kb.generateLiteral("pred1", l2);
    ProvaRule goal = kb.generateGoal(new ProvaLiteral[] {query});

    ProvaVariable v = ProvaVariableImpl.create("V");
    ProvaVariable y = ProvaVariableImpl.create("Y");
    ProvaConstant c4 = ProvaConstantImpl.create(3);
    ProvaVariable u = ProvaVariableImpl.create("U");
    ProvaList l3 = ProvaListImpl.create(new ProvaObject[] {v, y, c4, y, u});
    ProvaLiteral lit1 = kb.generateLiteral("pred1", l3);
    ProvaList l4 = ProvaListImpl.create(new ProvaObject[] {v}, y);
    ProvaLiteral lit3 = kb.generateLiteral("pred2", l4);
    ProvaRule rule = kb.generateRule(lit1, new ProvaLiteral[] {lit3});

    ProvaUnificationImpl unification = new ProvaUnificationImpl(goal, rule);
    boolean result = unification.unify();

    org.junit.Assert.assertTrue(result);

    int countSourceSubstitutions = 0;
    for (ProvaVariable var : unification.getSourceVariables()) {
      ProvaObject to = var.getRecursivelyAssigned();
      if (to != var) {
        countSourceSubstitutions++;
      }
    }
    org.junit.Assert.assertEquals(countSourceSubstitutions, 1);

    int countTargetSubstitutions = 0;
    for (ProvaVariable var : unification.getTargetVariables()) {
      ProvaObject to = var.getRecursivelyAssigned();
      if (to != var) {
        countTargetSubstitutions++;
      }
    }
    org.junit.Assert.assertEquals(countTargetSubstitutions, 2);

    // Recover actual substitutions resulting from the unification
    ProvaLiteral[] newGoals = unification.rebuildNewGoals();

    org.junit.Assert.assertNotNull(newGoals);
    // There is one actual goal: pred2(X,2|A)
    org.junit.Assert.assertEquals(newGoals.length, 1);
    // The goal literal has variable arity
    org.junit.Assert.assertEquals(newGoals[0].getTerms().computeSize(), -1);
    // The second argument "2" is added to the "fixed" part of the goal literal
    org.junit.Assert.assertEquals(newGoals[0].getTerms().getFixed().length, 2);
  }
 @Override
 // TODO: recursive expressions as operands
 public boolean process(
     ProvaReagent prova,
     ProvaDerivationNode node,
     ProvaGoal goal,
     List<ProvaLiteral> newLiterals,
     ProvaRule query) {
   ProvaLiteral literal = goal.getGoal();
   List<ProvaVariable> variables = query.getVariables();
   ProvaList terms = (ProvaList) literal.getTerms().cloneWithVariables(variables);
   ProvaObject[] data = terms.getFixed();
   if (data.length != 3) return false;
   ProvaObject lt = data[0];
   if (lt instanceof ProvaVariablePtr) {
     ProvaVariablePtr varPtr = (ProvaVariablePtr) lt;
     lt = variables.get(varPtr.getIndex()).getRecursivelyAssigned();
   }
   if (!((lt instanceof ProvaVariable) || (lt instanceof ProvaConstant))) return false;
   ProvaObject a1 = data[1];
   if (a1 instanceof ProvaVariablePtr) {
     ProvaVariablePtr varPtr = (ProvaVariablePtr) a1;
     a1 = variables.get(varPtr.getIndex()).getRecursivelyAssigned();
   }
   if (!(a1 instanceof ProvaConstant)) return false;
   Object oa1 = ((ProvaConstant) a1).getObject();
   if (!(oa1 instanceof Number)) return false;
   ProvaObject a2 = data[2];
   if (a2 instanceof ProvaVariablePtr) {
     ProvaVariablePtr varPtr = (ProvaVariablePtr) a2;
     a2 = variables.get(varPtr.getIndex()).getRecursivelyAssigned();
   }
   if (!(a2 instanceof ProvaConstant)) return false;
   Object oa2 = ((ProvaConstant) a2).getObject();
   if (!(oa2 instanceof Number)) return false;
   Number na1 = (Number) oa1;
   Number na2 = (Number) oa2;
   Number result;
   if (na1 instanceof Double || na2 instanceof Double)
     result = na1.doubleValue() * na2.doubleValue();
   else if (na1 instanceof Float || na2 instanceof Float)
     result = na1.floatValue() * na2.floatValue();
   else if (na1 instanceof Long || na2 instanceof Long) result = na1.longValue() * na2.longValue();
   else if (na1 instanceof Integer || na2 instanceof Integer)
     result = na1.intValue() * na2.intValue();
   else result = na1.byteValue() * na2.byteValue();
   if (lt instanceof ProvaConstant) return ((ProvaConstant) lt).getObject() == result;
   ((ProvaVariable) lt).setAssigned(ProvaConstantImpl.create(result));
   return true;
 }