Chapter 18: Functionslinear-chapter18

1 files changed, 10 insertions, 26 deletions

diff --git a/src/main/java/com/seaofnodes/simple/Ary.java b/src/main/java/com/seaofnodes/simple/Ary.java
index 8654d41e..b5184948 100644
--- a/src/main/java/com/seaofnodes/simple/Ary.java
+++ b/src/main/java/com/seaofnodes/simple/Ary.java
@@ -57,18 +57,6 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return true;
     }
 
-    ///** Slow, linear-time, element insert.  Preserves order.
-    // *  @param i index to insert at, between 0 and _len inclusive.
-    // *  @param e Element to insert
-    // */
-    //public void insert( int i, E e ) {
-    //    if( i < 0 || i>_len )
-    //        throw new ArrayIndexOutOfBoundsException(""+i+" >= "+_len);
-    //    if( _len >= _es.length ) _es = Arrays.copyOf(_es,Math.max(1,_es.length<<1));
-    //    System.arraycopy(_es,i,_es,i+1,(_len++)-i);
-    //    _es[i] = e;
-    //}
-
     /** Fast, constant-time, element removal.  Does not preserve order
      *  @param i element to be removed
      *  @return element removed */
@@ -79,20 +67,6 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return tmp;
     }
 
-    ///** Element removal, using '=='.  Does not preserve order.
-    // *  @param e element to be removed
-    // *  @return element removed */
-    //public E del( E e ) {
-    //    for( int i=0; i<_len; i++ ) {
-    //        E tmp = _es[i];
-    //        if( tmp==e ) {
-    //            _es[i]=_es[--_len];
-    //            return tmp;
-    //        }
-    //    }
-    //    return null;
-    //}
-
     /** Slow, linear-time, element removal.  Preserves order.
      *  @param i element to be removed
      *  @return element removed */
@@ -129,6 +103,16 @@ public class Ary<E> extends AbstractList<E> implements List<E> {
         return this;
     }
 
+    public void swap( int i, int j ) {
+        range_check(i);
+        range_check(j);
+        if( i==j ) return;
+        E tmp = _es[i];
+        _es[i] = _es[j];
+        _es[j] = tmp;
+    }
+
+
     /** @param c Collection to be added */
     public boolean addAll( Collection<? extends E> c ) {
         if( c==null ) return false;