Ejemplo n.º 1
0
  private Constraint createAttributeConstraint(AttributeConstraint attributeConstraint) {
    Constraint result = null;

    Constraint constraint = null;
    AttributeOperand leftOperand = attributeConstraint.getLeftOperand();
    IntegerVariable leftOperandVariable = getVariableForAttributeOperand(leftOperand);

    AttributeOperand rightOperand = attributeConstraint.getRightOperand();
    IntegerVariable rightOperandVariable = getVariableForAttributeOperand(rightOperand);

    Relop operator = attributeConstraint.getOperator();
    switch (operator) {
      case EQUAL:
        constraint = Choco.eq(leftOperandVariable, rightOperandVariable);
        break;
      case GREATER_THAN:
        constraint = Choco.gt(leftOperandVariable, rightOperandVariable);
        break;
      case GREATER_THAN_OR_EQUAL:
        constraint = Choco.geq(leftOperandVariable, rightOperandVariable);
        break;
      case LESS_THAN:
        constraint = Choco.lt(leftOperandVariable, rightOperandVariable);
        break;
      case LESS_THAN_OR_EQUAL:
        constraint = Choco.leq(leftOperandVariable, rightOperandVariable);
        break;
      case UNEQUAL:
        constraint = Choco.neq(leftOperandVariable, rightOperandVariable);
        break;
      default:
        break;
    }

    IntegerVariable leftFeatureVariable = getFeatureVariableForOperand(leftOperand);
    IntegerVariable rightFeatureVariable = getFeatureVariableForOperand(rightOperand);
    // if both are features and both are selected, then the attribute constraint must be evaluated
    if (leftFeatureVariable != null && rightFeatureVariable != null) {
      Constraint leftFeatureSelected = Choco.eq(leftFeatureVariable, 1);
      Constraint rightFeatureSelected = Choco.eq(rightFeatureVariable, 1);
      Constraint and = Choco.and(leftFeatureSelected, rightFeatureSelected);
      result = Choco.implies(and, constraint);
    } else {
      // if one of the two operand is a constant,the constraint will be evaluated if the host
      // feature is selected
      if (leftFeatureVariable != null) {
        result = getFeatureAttributeValueConstraint(leftFeatureVariable, constraint);
      } else if (rightFeatureVariable != null) {
        result = getFeatureAttributeValueConstraint(rightFeatureVariable, constraint);
      }
    }

    return result;
  }
Ejemplo n.º 2
0
  private void createGroupConstraint(Group group) {
    // group with cardinality {n,m} represented as
    // ifThen(ParentFeature>0;sum(ChildFeature A, ChildFeature
    // B) in {n,m};)
    // if group cardinality is n=m, then
    // ifThen(ParentFeature>0;sum(ChildFeature A, ChildFeature B) = n)
    log.debug("Create constraint for group " + group);
    IntegerVariable parentFeatureVariable = getOrCreateVariable((Feature) group.eContainer());

    IntegerExpressionVariable childFeatureSum = createChildFeatureVariable(group);
    int minCardinality = getMinChocoCardinality(group);
    int maxCardinality = getMaxChocoCardinality(group);

    Constraint ifConstraint = Choco.gt(parentFeatureVariable, 0);

    Constraint greaterThan = Choco.geq(childFeatureSum, minCardinality);
    Constraint smallerThan = Choco.leq(childFeatureSum, maxCardinality);

    Constraint thenConstraint = Choco.and(greaterThan, smallerThan);

    Constraint groupCardinalityConstraint = Choco.implies(ifConstraint, thenConstraint);
    getModel().addConstraint(groupCardinalityConstraint);
  }
Ejemplo n.º 3
0
  private void createFeatureConstraint(Feature feature) {
    IntegerVariable childVariable = getOrCreateVariable(feature);

    int minCardinality = 0;
    int maxCardinality = 1;

    Constraint greaterThan = Choco.geq(childVariable, minCardinality);
    Constraint smallerThan = Choco.leq(childVariable, maxCardinality);
    Constraint thenConstraint = Choco.and(greaterThan, smallerThan);

    EObject featureContainer = feature.eContainer();
    if (featureContainer instanceof Group) {
      Group parentGroup = (Group) featureContainer;

      EObject groupContainer = parentGroup.eContainer();
      if (groupContainer instanceof Feature) {
        Feature parentFeature = (Feature) groupContainer;

        IntegerVariable parentVariable = getOrCreateVariable(parentFeature);

        // feature value must be in feature cardinality boundaries
        Constraint parentSelected = Choco.gt(parentVariable, 0);
        Constraint parentSelectedAndChildCardinality =
            Choco.implies(parentSelected, thenConstraint);
        getModel().addConstraint(parentSelectedAndChildCardinality);

        Constraint childSelected = Choco.gt(childVariable, 0);
        Constraint impliesConstraint = Choco.implies(childSelected, parentSelected);
        getModel().addConstraint(impliesConstraint);
      }

    } else {
      // handle rootgroup
      Constraint greater = Choco.gt(childVariable, minCardinality);
      getModel().addConstraint(greater);
    }
  }