edu.cmu.cs.coral.icf.plan_based.planners.pip
Class TailPlan

java.lang.Object
  |
  +--edu.cmu.cs.coral.icf.plan_based.planners.pip.TailPlan

public class TailPlan

extends java.lang.Object

Represents the part of the plan generated by backward chaining from the goal.

Since:

ICF 0.0

Version:

$Id$

Field Summary

private java.util.Set	applicableOps the actions in the plan that can be applied, i.e.
private java.util.Set	expandableNodes the nodes that have yet to be expanded (used for expanding nodes)
private java.util.Map	literalToGoalNodeMap mapping from literals to goal node that considers them (used for repeated goal detection, updating the set of applicable ops, and updating maintainance goals)
private java.util.Set	maintainanceGoals the goals that have been achieved that are preconditions of operators in the tail plan that haven't been applied yet (used for noticing when replanning to achieve preconditions is necessary)
private PlanDAG	planDAG The graph representing the operators and goals in the tail plan.

Constructor Summary

TailPlan()
Construct an empty tail plan.

Method Summary

boolean	applyOp(ActionNode action_node, ChangeTracker change_tracker) Apply the action specified to the current state.
boolean	expandGoalNode(GoalNode goal_node, PlannerActionSchema op, ChangeTracker change_tracker) Expand the goal node with the given operator.
boolean	expandOpNode(OpNode op_node, Binding binding, ChangeTracker change_tracker) Expand the op node with the given binding.
java.util.Map	getLiteralToGoalNodeMap() Gets the mapping from literals to goal nodes
void	initialize(GoalNode goal) Initialize the tail plan with the given goal acting as the root.

Methods inherited from class java.lang.Object

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

Field Detail

planDAG

private PlanDAG planDAG

The graph representing the operators and goals in the tail plan.

Since:

ICF 0.0

expandableNodes

private java.util.Set expandableNodes

the nodes that have yet to be expanded (used for expanding nodes)

Since:

ICF 0.0

maintainanceGoals

private java.util.Set maintainanceGoals

the goals that have been achieved that are preconditions of operators in the tail plan that haven't been applied yet (used for noticing when replanning to achieve preconditions is necessary)

Since:

ICF 0.0

literalToGoalNodeMap

private java.util.Map literalToGoalNodeMap

mapping from literals to goal node that considers them (used for repeated goal detection, updating the set of applicable ops, and updating maintainance goals)

Since:

ICF 0.0

applicableOps

private java.util.Set applicableOps

the actions in the plan that can be applied, i.e. the set of action nodes in the plan for which all precondition goals have been achieved. A goal is considered achieved when it is removed from the set of expandable nodes.

Since:

ICF 0.0

Constructor Detail

TailPlan

public TailPlan()

Construct an empty tail plan.

Since:

ICF 0.0

Method Detail

initialize

public void initialize(GoalNode goal)

Initialize the tail plan with the given goal acting as the root.

Parameters:

goal - the goal to achieve

Since:

ICF 0.0

expandGoalNode

public boolean expandGoalNode(GoalNode goal_node,
                              PlannerActionSchema op,
                              ChangeTracker change_tracker)

Expand the goal node with the given operator.

Parameters:

goal_node - the node to expand

op - the operator to use

change_tracker - where to record the changes

Returns:

true if and only if the expansion was successful

Since:

ICF 0.0

expandOpNode

public boolean expandOpNode(OpNode op_node,
                            Binding binding,
                            ChangeTracker change_tracker)

Expand the op node with the given binding.

Parameters:

op_node - the operator node to expand

binding - the binding to use

change_tracker - where to track the changes

Returns:

true if and only if the expansion was successful

Since:

ICF 0.0

applyOp

public boolean applyOp(ActionNode action_node,
                       ChangeTracker change_tracker)

Apply the action specified to the current state.

Parameters:

action_node - the action to apply

change_tracker - where to track the changes

Returns:

true if and only if the application was successful

Since:

ICF 0.0

getLiteralToGoalNodeMap

public java.util.Map getLiteralToGoalNodeMap()

Gets the mapping from literals to goal nodes

Returns:

the mapping from literals to goal nodes

Since:

ICF 0.0