Percept generation of MapEnvironment extended with possible action information.

Author: Ruediger.Lunde

src/aima/search/map/DynAttributeNames.java

@@ -15,29 +15,32 @@
 public class DynAttributeNames {
 	/**
 	 * Name of a dynamic attribute, which contains the current location of the
-	 * agent.
+	 * agent. Expected value type: String.
 	 */
 	public static final String AGENT_LOCATION = "location";
 	/**
 	 * Name of a dynamic attribute, which maintains the total traveling distance
-	 * of the agent since birth. Should be of type Integer.
+	 * of the agent since birth. Expected value type: Integer.
 	 */
 	public static final String AGENT_TRAVEL_DISTANCE = "travelDistance";
 	/**
 	 * Name of a dynamic attribute, which indicates the current status of the
-	 * agent, such as traveling, completed or aborted.
+	 * agent, such as traveling, completed or aborted. Expected value type:
+	 * String.
 	 */
 	public static final String AGENT_STATUS = "status";
 
 	/**
-	 * Name of a dynamic attribute, which tells the agent where it is.
+	 * Name of a dynamic attribute, which tells the agent where it is. Expected
+	 * value type: String.
 	 */
 	public static final String PERCEPT_IN = "In";
 	/**
 	 * Name of a dynamic attribute, which tells the agent which actions are
-	 * possible at the current location of the agent.
+	 * possible at the current location of the agent. Expected value type: List
+	 * of alternating Strings and Integers.
 	 */
-	public static final String PERCEPT_POSSIBLE_ACTIONS = "Signpost";
+	public static final String PERCEPT_POSSIBLE_ACTIONS = "PossibleActions";
 	/**
 	 * Name of a dynamic attribute. It provides access to informations which are
 	 * available at the current location of the agent.

src/aima/search/map/MapEnvironment.java

@@ -1,5 +1,8 @@
 package aima.search.map;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import aima.basic.Agent;
 import aima.basic.Environment;
 import aima.basic.Percept;
@@ -43,8 +46,15 @@ public void executeAction(Agent a, String act) {
 
 	@Override
 	public Percept getPerceptSeenBy(Agent anAgent) {
-		return new Percept(DynAttributeNames.PERCEPT_IN, anAgent
-				.getAttribute(DynAttributeNames.AGENT_LOCATION));
+		String currLoc = (String) anAgent.getAttribute(
+				DynAttributeNames.AGENT_LOCATION);
+		List<Object> possibleActions = new ArrayList<Object>();
+		for (String a : aMap.getLocationsLinkedTo(currLoc)) {
+			possibleActions.add(a);
+			possibleActions.add(new Integer(aMap.getDistance(currLoc, a)));
+		}
+		return new Percept(DynAttributeNames.PERCEPT_IN, currLoc,
+				DynAttributeNames.PERCEPT_POSSIBLE_ACTIONS, possibleActions);
 	}
 
 	public Map getMap() {