Refactor removeRange.

runtime/lib/growable_array.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class _GrowableObjectArray<T> implements List<T> {
   factory _GrowableObjectArray._uninstantiable() {
     throw new UnsupportedError(
         "GrowableObjectArray can only be allocated by the VM");
   }
 
@@ skipping 59 matching lines @@
   }
 
   Iterable<T> getRange(int start, int end) {
     return IterableMixinWorkaround.getRangeList(this, start, end);
   }
 
   void setRange(int start, int end, List<T> from, [int startFrom = 0]) {
     IterableMixinWorkaround.setRangeList(this, start, end, from, startFrom);
   }
 
-  void removeRange(int start, int length) {
-    if (length == 0) {
-      return;
-    }
-    Arrays.rangeCheck(this, start, length);
+  void removeRange(int start, int end) {
+    Arrays.indicesCheck(this, start, end);
     Arrays.copy(this,
-                start + length,
+                end,
                 this,
                 start,
-                this.length - length - start);
-    this.length = this.length - length;
+                this.length - end);
+    this.length = this.length - (end - start);
   }
 
   void insertRange(int start, int length, [T initialValue = null]) {
     if (length == 0) {
       return;
     }
     if ((length < 0) || (length is! int)) {
       throw new ArgumentError("invalid length specified $length");
     }
     if (start < 0 || start > this.length) {
@@ skipping 248 matching lines @@
   }
 
   Set<T> toSet() {
     return new Set<T>.from(this);
   }
 
   Map<int, T> asMap() {
     return IterableMixinWorkaround.asMapList(this);
   }
 }