List now implements various forms of add()

classpath/java/util/ArrayList.java

@@ -67,6 +67,13 @@ public class ArrayList<T> implements List<T> {
     return false;
   }
 
+  public void add(int index, T element) {
+    size = Math.max(size+1, index+1);
+    grow();
+    System.arraycopy(array, index, array, index+1, size-index);
+    array[index] = element;
+  }
+
   public boolean add(T element) {
     ++ size;
     grow();

classpath/java/util/Arrays.java

@@ -25,6 +25,10 @@ public class Arrays {
         throw new UnsupportedOperationException();
       }
 
+      public void add(int index, T element) {
+        throw new UnsupportedOperationException();
+      }
+
       public boolean contains(T element) {
         for (int i = 0; i < array.length; ++i) {
           if (equal(element, array[i])) {

classpath/java/util/LinkedList.java

@@ -107,6 +107,16 @@ public class LinkedList<T> implements List<T> {
     return true;
   }
 
+  public void add(int index, T element) {
+    if (index == 0) {
+      addFirst(element);
+    } else {
+      Cell<T> cell = find(index);
+      Cell<T> newCell = new Cell<T>(element, cell.prev, cell);
+      cell.prev.next = newCell;
+    }
+  }
+
   public void addFirst(T element) {
     addFirst(new Cell(element, null, null));
   }

classpath/java/util/List.java

@@ -5,6 +5,10 @@ public interface List<T> extends Collection<T> {
 
   public T remove(int index);
 
+  public boolean add(T element);
+
+  public void add(int index, T element);
+
   public boolean isEmpty();
 
   public <S> S[] toArray(S[] a);

classpath/java/util/Vector.java

@@ -26,6 +26,10 @@ public class Vector<T> implements List<T> {
     return list.contains(element);
   }
 
+  public synchronized void add(int index, T element) {
+    list.add(index, element);
+  }
+
   public synchronized boolean add(T element) {
     return list.add(element);
   }