private void addIfAllowed(AgentPosition position, ICollection <AgentPosition> positions)
{
if (allowedPositions.Contains(position))
{
positions.Add(position);
}
}
public override bool Equals(object obj)
{
if (obj != null && GetType() == obj.GetType())
{
AgentPosition other = (AgentPosition)obj;
return((getX() == other.getX()) && (getY() == other.getY()) &&
(orientation == other.getOrientation()));
}
return(false);
}
public ICollection <AgentPosition> getLocationsLinkedTo(AgentPosition fromLocation)
{
int x = fromLocation.getX();
int y = fromLocation.getY();
AgentPosition.Orientation orientation = fromLocation.getOrientation();
ICollection <AgentPosition> result = CollectionFactory.CreateQueue <AgentPosition>();
AgentPosition currentForwardNorth = new AgentPosition(x, y + 1,
AgentPosition.Orientation.FACING_NORTH);
AgentPosition currentForwardSouth = new AgentPosition(x, y - 1,
AgentPosition.Orientation.FACING_SOUTH);
AgentPosition currentForwardEast = new AgentPosition(x + 1, y,
AgentPosition.Orientation.FACING_EAST);
AgentPosition currentForwardWest = new AgentPosition(x - 1, y,
AgentPosition.Orientation.FACING_WEST);
AgentPosition currentNorth = new AgentPosition(x, y,
AgentPosition.Orientation.FACING_NORTH);
AgentPosition currentSouth = new AgentPosition(x, y,
AgentPosition.Orientation.FACING_SOUTH);
AgentPosition currentEast = new AgentPosition(x, y,
AgentPosition.Orientation.FACING_EAST);
AgentPosition currentWest = new AgentPosition(x, y,
AgentPosition.Orientation.FACING_WEST);
if (orientation.Equals(AgentPosition.Orientation.FACING_NORTH))
{
addIfAllowed(currentForwardNorth, result);
addIfAllowed(currentEast, result);
addIfAllowed(currentWest, result);
}
else if (orientation.Equals(AgentPosition.Orientation.FACING_SOUTH))
{
addIfAllowed(currentForwardSouth, result);
addIfAllowed(currentEast, result);
addIfAllowed(currentWest, result);
}
else if (orientation.Equals(AgentPosition.Orientation.FACING_EAST))
{
addIfAllowed(currentNorth, result);
addIfAllowed(currentSouth, result);
addIfAllowed(currentForwardEast, result);
}
else if (orientation.Equals(AgentPosition.Orientation.FACING_WEST))
{
addIfAllowed(currentNorth, result);
addIfAllowed(currentSouth, result);
addIfAllowed(currentForwardWest, result);
}
return(result);
}
public AgentPosition askCurrentPosition(int t)
{
int locX = -1, locY = -1;
for (int x = 1; x <= getCaveXDimension() && locX == -1; x++)
{
for (int y = 1; y <= getCaveYDimension() && locY == -1; y++)
{
if (ask(newSymbol(LOCATION, t, x, y)))
{
locX = x;
locY = y;
}
}
}
if (locX == -1 || locY == -1)
{
throw new IllegalStateException("Inconsistent KB, unable to determine current room position.");
}
AgentPosition current = null;
if (ask(newSymbol(FACING_NORTH, t)))
{
current = new AgentPosition(locX, locY, AgentPosition.Orientation.FACING_NORTH);
}
else if (ask(newSymbol(FACING_SOUTH, t)))
{
current = new AgentPosition(locX, locY, AgentPosition.Orientation.FACING_SOUTH);
}
else if (ask(newSymbol(FACING_EAST, t)))
{
current = new AgentPosition(locX, locY, AgentPosition.Orientation.FACING_EAST);
}
else if (ask(newSymbol(FACING_WEST, t)))
{
current = new AgentPosition(locX, locY, AgentPosition.Orientation.FACING_WEST);
}
else
{
throw new IllegalStateException("Inconsistent KB, unable to determine current room orientation.");
}
return(current);
}
private ICollection <IAction> plan = CollectionFactory.CreateFifoQueue <IAction>(); // FIFOQueue
/**
* function HYBRID-WUMPUS-AGENT(percept) returns an action<br>
*
* @param percept
* a list, [stench, breeze, glitter, bump, scream]
*
* @return an action the agent should take.
*/
public override IAction Execute(IPercept percept)
{
// TELL(KB, MAKE-PERCEPT-SENTENCE(percept, t))
kb.makePerceptSentence((AgentPercept)percept, t);
// TELL the KB the temporal "physics" sentences for time t
kb.tellTemporalPhysicsSentences(t);
AgentPosition current = kb.askCurrentPosition(t);
// safe <- {[x, y] : ASK(KB, OK<sup>t</sup><sub>x,y</sub>) = true}
ISet <Room> safe = kb.askSafeRooms(t);
// if ASK(KB, Glitter<sup>t</sup>) = true then
if (kb.askGlitter(t))
{
// plan <- [Grab] + PLAN-ROUTE(current, {[1,1]}, safe) + [Climb]
ISet <Room> goals = CollectionFactory.CreateSet <Room>();
goals.Add(new Room(1, 1));
plan.Add(new Grab());
plan.AddAll(planRoute(current, goals, safe));
plan.Add(new Climb());
}
// if plan is empty then
// unvisited <- {[x, y] : ASK(KB, L<sup>t'</sup><sub>x,y</sub>) = false
// for all t' ≤ t}
ISet <Room> unvisited = kb.askUnvisitedRooms(t);
if (plan.IsEmpty())
{
// plan <- PLAN-ROUTE(current, unvisited ∩ safe, safe)
plan.AddAll(planRoute(current, SetOps.intersection(unvisited, safe), safe));
}
// if plan is empty and ASK(KB, HaveArrow<sup>t</sup>) = true then
if (plan.IsEmpty() && kb.askHaveArrow(t))
{
// possible_wumpus <- {[x, y] : ASK(KB, ~W<sub>x,y</sub>) = false}
ISet <Room> possibleWumpus = kb.askPossibleWumpusRooms(t);
// plan <- PLAN-SHOT(current, possible_wumpus, safe)
plan.AddAll(planShot(current, possibleWumpus, safe));
}
// if plan is empty then //no choice but to take a risk
if (plan.IsEmpty())
{
// not_unsafe <- {[x, y] : ASK(KB, ~OK<sup>t</sup><sub>x,y</sub>) =
// false}
ISet <Room> notUnsafe = kb.askNotUnsafeRooms(t);
// plan <- PLAN-ROUTE(current, unvisited ∩ not_unsafe, safe)
plan.AddAll(planRoute(current, SetOps.intersection(unvisited, notUnsafe), safe));
}
// if plan is empty then
if (plan.IsEmpty())
{
// plan PLAN-ROUTE(current, {[1,1]}, safe) + [Climb]
ISet <Room> start = CollectionFactory.CreateSet <Room>();
start.Add(new Room(1, 1));
plan.AddAll(planRoute(current, start, safe));
plan.Add(new Climb());
}
// action <- POP(plan)
IAction action = plan.Pop();
// TELL(KB, MAKE-ACTION-SENTENCE(action, t))
kb.makeActionSentence(action, t);
// t <- t+1
t = t + 1;
// return action
return(action);
}
/**
*
* @param current
* the agent's current position
* @param possibleWumpus
* a set of squares where we don't know that there isn't the
* wumpus.
* @param allowed
* a set of squares that can form part of the route
*
* @return the sequence of actions to reach the nearest square that is in
* line with a possible wumpus position. The last action is a shot.
*/
public ICollection <IAction> planShot(AgentPosition current, ISet <Room> possibleWumpus, ISet <Room> allowed)
{
ISet <AgentPosition> shootingPositions = CollectionFactory.CreateSet <AgentPosition>();
foreach (Room p in possibleWumpus)
{
int x = p.getX();
int y = p.getY();
for (int i = 1; i <= kb.getCaveXDimension(); i++)
{
if (i < x)
{
shootingPositions.Add(new AgentPosition(i, y, AgentPosition.Orientation.FACING_EAST));
}
if (i > x)
{
shootingPositions.Add(new AgentPosition(i, y, AgentPosition.Orientation.FACING_WEST));
}
if (i < y)
{
shootingPositions.Add(new AgentPosition(x, i, AgentPosition.Orientation.FACING_NORTH));
}
if (i > y)
{
shootingPositions.Add(new AgentPosition(x, i, AgentPosition.Orientation.FACING_SOUTH));
}
}
}
// Can't have a shooting position from any of the rooms the wumpus could
// reside
foreach (Room p in possibleWumpus)
{
foreach (AgentPosition.Orientation orientation in AgentPosition.Orientation.values())
{
shootingPositions.Remove(new AgentPosition(p.getX(), p.getY(), orientation));
}
}
ISet <Room> shootingPositionsArray = CollectionFactory.CreateSet <Room>();
foreach (AgentPosition tmp in shootingPositions)
{
shootingPositionsArray.Add(new Room(tmp.getX(), tmp.getY()));
}
ICollection <IAction> actions = planRoute(current, shootingPositionsArray, allowed);
AgentPosition newPos = current;
if (actions.Size() > 0)
{
newPos = ((Forward)actions.Get(actions.Size() - 1)).getToPosition();
}
while (!shootingPositions.Contains(newPos))
{
TurnLeft tLeft = new TurnLeft(newPos.getOrientation());
newPos = new AgentPosition(newPos.getX(), newPos.getY(), tLeft.getToOrientation());
actions.Add(tLeft);
}
actions.Add(new Shoot());
return(actions);
}
/**
* Returns a sequence of actions using A* Search.
*
* @param current
* the agent's current position
* @param goals
* a set of squares; try to plan a route to one of them
* @param allowed
* a set of squares that can form part of the route
*
* @return the best sequence of actions that the agent have to do to reach a
* goal from the current position.
*/
public ICollection <IAction> planRoute(AgentPosition current, ISet <Room> goals, ISet <Room> allowed)
{
// Every square represent 4 possible positions for the agent, it could
// be in different orientations. For every square in allowed and goals
// sets we add 4 squares.
ISet <AgentPosition> allowedPositions = CollectionFactory.CreateSet <AgentPosition>();
foreach (Room allowedRoom in allowed)
{
int x = allowedRoom.getX();
int y = allowedRoom.getY();
allowedPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_WEST));
allowedPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_EAST));
allowedPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_NORTH));
allowedPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_SOUTH));
}
ISet <AgentPosition> goalPositions = CollectionFactory.CreateSet <AgentPosition>();
foreach (Room goalRoom in goals)
{
int x = goalRoom.getX();
int y = goalRoom.getY();
goalPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_WEST));
goalPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_EAST));
goalPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_NORTH));
goalPositions.Add(new AgentPosition(x, y, AgentPosition.Orientation.FACING_SOUTH));
}
WumpusCave cave = new WumpusCave(kb.getCaveXDimension(), kb.getCaveYDimension(), allowedPositions);
GoalTest <AgentPosition> goalTest = goalPositions.Contains;
IProblem <AgentPosition, IAction> problem = new GeneralProblem <AgentPosition, IAction>(current,
WumpusFunctionFunctions.createActionsFunction(cave),
WumpusFunctionFunctions.createResultFunction(), goalTest);
IToDoubleFunction <Node <AgentPosition, IAction> > h = new ManhattanHeuristicFunction(goals);
ISearchForActions <AgentPosition, IAction> search = new AStarSearch <AgentPosition, IAction>(
new GraphSearch <AgentPosition, IAction>(), h);
SearchAgent <AgentPosition, IAction> agent;
ICollection <IAction> actions = null;
try
{
agent = new SearchAgent <AgentPosition, IAction>(problem, search);
actions = agent.getActions();
// Search agent can return a NoOp if already at goal,
// in the context of this agent we will just return
// no actions.
if (actions.Size() == 1 && actions.Get(0).IsNoOp())
{
actions = CollectionFactory.CreateQueue <IAction>();
}
}
catch (Exception e)
{
throw e;
}
return(actions);
}
