Add hasTransitionRewards() method to explicit Reward interface.

Currently, the main use is to determinie whether a MDPRewards has
any transition rewards.


git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@10579 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/explicit/rewards/MCRewardsFromMDPRewards.java

@@ -64,4 +64,11 @@ public class MCRewardsFromMDPRewards implements MCRewards
 	{
 		throw new UnsupportedOperationException();
 	}
+
+	@Override
+	public boolean hasTransitionRewards()
+	{
+		// only state rewards
+		return false;
+	}
 }

prism/src/explicit/rewards/MDPRewards.java

@@ -46,4 +46,7 @@ public interface MDPRewards extends Rewards
 
 	@Override
 	public MDPRewards liftFromModel(Product<? extends Model> product);
+
+	/** Returns true if this reward structure has transition rewards */
+	public boolean hasTransitionRewards();
 }

prism/src/explicit/rewards/MDPRewardsSimple.java

@@ -216,4 +216,10 @@ public class MDPRewardsSimple implements MDPRewards
 	{
 		return "st: " + this.stateRewards + "; tr:" + this.transRewards;
 	}
+
+	@Override
+	public boolean hasTransitionRewards()
+	{
+		return transRewards != null;
+	}
 }

prism/src/explicit/rewards/Rewards.java

@@ -40,4 +40,7 @@ public interface Rewards
 	 * model that is a product of the one that this reward structure is defined over. 
 	 */
 	public Rewards liftFromModel(Product<? extends Model> product);
+
+	/** Returns true if this reward structure has transition rewards */
+	public boolean hasTransitionRewards();
 }

prism/src/explicit/rewards/StateRewards.java

@@ -64,4 +64,11 @@ public abstract class StateRewards implements MCRewards, MDPRewards, STPGRewards
 	 * Perform a deep copy.
 	 */
 	public abstract StateRewards deepCopy();
+
+	@Override
+	public boolean hasTransitionRewards()
+	{
+		// only state rewards
+		return false;
+	}
 }