Package edu.uky.ai.planning.ss

Class BackwardNode

java.lang.Object
edu.uky.ai.planning.ss.BackwardNode
All Implemented Interfaces:
StateSpaceNode
Direct Known Subclasses:
BackwardRoot
public class BackwardNode extends Object implements StateSpaceNode
Represents a node in a backward state space search graph, where a node is a goal and a plan to achieve the problem goal if the node's goal can be achieved.
Author:
Stephen G. Ware

  • Field Details

    • goal

      public final Conjunction goal
      The goal to be achieve that will allow the plan to succeed

    • plan

      public final BackwardPlan plan
      The plan to reach the goal

    • parent

      public final BackwardNode parent
      This node's parent node (i.e. the rest of the plan after the first step)

  • Method Details

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getPlan

      public Plan getPlan()
      Description copied from interface: StateSpaceNode
      Returns the plan this node represents.
      Specified by:
      getPlan in interface StateSpaceNode
      Returns:
      the plan

    • getRoot

      public final BackwardRoot getRoot()
      Description copied from interface: StateSpaceNode
      Returns the root node of the search space.
      Specified by:
      getRoot in interface StateSpaceNode
      Returns:
      the root

    • expand

      public BackwardNode expand(Conjunction goal, Step step)
      Expands the child node that would be generated if the given step were the first one to be taken. If the parent has not yet been visited, the parent is marked as visited.
      Parameters:
      goal - the goal that must be achieved to take the given step
      step - the first step to take
      Returns:
      a node for the resulting goal