JDDVars: add mergeVarsFrom(), sortByIndex() and removeVar() methods

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11822 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/jdd/JDDVars.java

@@ -26,6 +26,8 @@
 
 package jdd;
 
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.Iterator;
 import java.util.Vector;
 
@@ -133,6 +135,29 @@ public class JDDVars implements Iterable<JDDNode>
 		return result;
 	}
 
+
+	/**
+	 * Copy JDDNodes from another JDDVars, merge into the existing variables,
+	 * sorting by the variable indices. Afterwards, this JDDVars container
+	 * is fully sorted by variable indices, i.e., the existing variables are
+	 * sorted as well.
+	 * @param ddv the new variables
+	 */
+	public void mergeVarsFrom(JDDVars ddv) {
+		copyVarsFrom(ddv);
+		sortByIndex();
+	}
+
+	/**
+	 * Remove variable v from container. Does not decrease the refcount.
+	 */
+	public void removeVar(JDDNode v)
+	{
+		vars.remove(v);
+		if (arrayBuilt) DDV_FreeArray(array);
+		arrayBuilt = false;
+	}
+
 	/**
 	 * Removes the JDDNodes contained in ddv from this JDDVars container.
 	 * Does not decrease the refcount!
@@ -346,6 +371,21 @@ public class JDDVars implements Iterable<JDDNode>
 		}
 		return result;
 	}
+
+	/** Sort the variables in this container by their variable index. */
+	public void sortByIndex()
+	{
+		if (arrayBuilt) DDV_FreeArray(array);
+		arrayBuilt = false;
+
+		Collections.sort(vars, new Comparator<JDDNode>() {
+			@Override
+			public int compare(JDDNode a, JDDNode b)
+			{
+				return new Integer(a.getIndex()).compareTo(b.getIndex());
+			}
+		});
+	}
 }
 
 //------------------------------------------------------------------------------