Rename to BPlusTree.

pkg/analysis_server/lib/src/index/b_plus_tree.dart

 // Copyright (c) 2014, 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.
 
-library index.btree;
+library index.b_plus_tree;
 
 
 /**
- * A simple B+Tree implementation.
+ * A simple B+ tree (http://en.wikipedia.org/wiki/B+_tree) implementation.
  */
-class BTree<K, V> {
+class BPlusTree<K, V> {
   /**
    * The [Comparator] to compare keys.
    */
   final Comparator<K> _comparator;
 
   /**
    * The maximum number of keys in an index node.
    */
   final int _maxIndexKeys;
 
   /**
    * The maximum number of keys in a leaf node.
    */
   final int _maxLeafKeys;
 
   /**
    * The root node.
    */
   _Node<K, V> _root;
 
-  BTree(this._maxIndexKeys, this._maxLeafKeys, this._comparator) {
+  BPlusTree(this._maxIndexKeys, this._maxLeafKeys, this._comparator) {
     _root = new _LeafNode(_maxLeafKeys, _comparator);
   }
 
   /**
    * Returns the value for [key] or `null` if [key] is not in the tree.
    */
   V find(K key) {
     return _root.find(key);
   }
 
@@ skipping 415 matching lines @@
 
 /**
  * A container with information about split during insert.
  */
 class _Split<K, V> {
   final K key;
   final _Node<K, V> left;
   final _Node<K, V> right;
   _Split(this.key, this.left, this.right);
 }