Package ptolemy.domains.modal.kernel

Class RelationList

  • public class RelationList
extends java.lang.Object
    A RelationList object contains a list of relations of a guard expression. Relations are comparison operations, for example "x ≥ 10", where x is a variable. This class provides facilities for measuring how far the expression is from the threshold; for example, if x = 7, then the distance to the threshold is 3. Moreover, it provides a mechanism for recording the current distance (via a "commit") and then later accessing that distance and comparing it against the current distance. The information includes relation type and the difference information. (See ParseTreeEvaluatorForGuardExpression for the detailed explanation of relation type and difference.) This attribute is non-persistent and will not be exported into MoML.

    This class is designed to be used with ParseTreeEvaluatorForGuardExpression. The common usage would be like:

    Construct a relation list for a transition with the first argument of the constructor as that transition. 

     _relationList = new RelationList();

    Associate the relation list with the an object of ParseTreeEvaluatorForGuardExpression 

     _parseTreeEvaluator =
 new ParseTreeEvaluatorForGuardExpression(_relationList, getErrorTolerance());

    See Transition for the detailed usage.

    Since:
    Ptolemy II 8.0
    Version:
    $Id$
    Author:
    Haiyang Zheng
    Pt.AcceptedRating:
    Red (hyzheng)
    Pt.ProposedRating:
    Yellow (hyzheng)

    • Constructor Summary

      Constructors 
      Constructor Description
      RelationList()
      Construct a relation list.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addRelation​(int type, double difference)
      Construct a relation node with the given type and difference information of a relation, and add it to the end of the relation list.
      void commitRelationValues()
      Record the current relation values so that when getPreviousMaximumDistance() is called, these recorded values are used.
      void destroy()
      Destroy the relation list by deleting all the contained elements.
      double getMaximumDifference()
      Return the maximum current difference of all the relations by iterating the relation list.
      double getPreviousMaximumDistance()
      Return the previous difference of the relation that has the maximum current difference.
      boolean hasEvent()
      Return true if there exists an event caused by the type change of any relation.
      boolean isEmpty()
      Return true if the relation list is empty.
      int length()
      Return the number of relations in the relation list.
      void resetRelationList()
      Reset the relation list by resetting each relation node.
      void setRelation​(int relationIndex, int type, double difference)
      Update the relation in the relation list referred by the relation index argument with the given type and difference information.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • RelationList

        public RelationList()
        Construct a relation list.

    • Method Detail

      • addRelation

        public void addRelation​(int type,
                        double difference)
        Construct a relation node with the given type and difference information of a relation, and add it to the end of the relation list.
        Parameters:
        type - The relation type of the relation.
        difference - The difference of the relation.

      • resetRelationList

        public void resetRelationList()
        Reset the relation list by resetting each relation node.

      • commitRelationValues

        public void commitRelationValues()
        Record the current relation values so that when getPreviousMaximumDistance() is called, these recorded values are used.
        See Also:
        getPreviousMaximumDistance()

      • destroy

        public void destroy()
        Destroy the relation list by deleting all the contained elements.

      • getPreviousMaximumDistance

        public double getPreviousMaximumDistance()
        Return the previous difference of the relation that has the maximum current difference. This is the value as of the last call to commitRelationValues().
        Returns:
        The previous distance of a relation.
        See Also:
        commitRelationValues()

      • hasEvent

        public boolean hasEvent()
        Return true if there exists an event caused by the type change of any relation.
        Returns:
        True If there exits an event.

      • isEmpty

        public boolean isEmpty()
        Return true if the relation list is empty.
        Returns:
        True If the relation list is empty.

      • length

        public int length()
        Return the number of relations in the relation list.
        Returns:
        the number of relations in the relation list.

      • getMaximumDifference

        public double getMaximumDifference()
        Return the maximum current difference of all the relations by iterating the relation list.
        Returns:
        maximumDistance The maximum current distance.

      • setRelation

        public void setRelation​(int relationIndex,
                        int type,
                        double difference)
        Update the relation in the relation list referred by the relation index argument with the given type and difference information.
        Parameters:
        relationIndex - The position of the relation in the relation list.
        type - The current type of the relation.
        difference - The current difference of the relation.