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diff --git a/src/blockly/core/names.js b/src/blockly/core/names.js
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+/**
+ * @license
+ * Visual Blocks Editor
+ *
+ * Copyright 2012 Google Inc.
+ * https://developers.google.com/blockly/
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Utility functions for handling variables and procedure names.
+ * @author fraser@google.com (Neil Fraser)
+ */
+'use strict';
+
+goog.provide('Blockly.Names');
+
+
+/**
+ * Class for a database of entity names (variables, functions, etc).
+ * @param {string} reservedWords A comma-separated string of words that are
+ *     illegal for use as names in a language (e.g. 'new,if,this,...').
+ * @param {string=} opt_variablePrefix Some languages need a '$' or a namespace
+ *     before all variable names.
+ * @constructor
+ */
+Blockly.Names = function(reservedWords, opt_variablePrefix) {
+  this.variablePrefix_ = opt_variablePrefix || '';
+  this.reservedDict_ = Object.create(null);
+  if (reservedWords) {
+    var splitWords = reservedWords.split(',');
+    for (var i = 0; i < splitWords.length; i++) {
+      this.reservedDict_[splitWords[i]] = true;
+    }
+  }
+  this.reset();
+};
+
+/**
+ * When JavaScript (or most other languages) is generated, variable 'foo' and
+ * procedure 'foo' would collide.  However, Blockly has no such problems since
+ * variable get 'foo' and procedure call 'foo' are unambiguous.
+ * Therefore, Blockly keeps a separate type name to disambiguate.
+ * getName('foo', 'variable') -> 'foo'
+ * getName('foo', 'procedure') -> 'foo2'
+ */
+
+/**
+ * Empty the database and start from scratch.  The reserved words are kept.
+ */
+Blockly.Names.prototype.reset = function() {
+  this.db_ = Object.create(null);
+  this.dbReverse_ = Object.create(null);
+};
+
+/**
+ * Convert a Blockly entity name to a legal exportable entity name.
+ * @param {string} name The Blockly entity name (no constraints).
+ * @param {string} type The type of entity in Blockly
+ *     ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).
+ * @return {string} An entity name legal for the exported language.
+ */
+Blockly.Names.prototype.getName = function(name, type) {
+  var normalized = name.toLowerCase() + '_' + type;
+  var prefix = (type == Blockly.Variables.NAME_TYPE) ?
+      this.variablePrefix_ : '';
+  if (normalized in this.db_) {
+    return prefix + this.db_[normalized];
+  }
+  var safeName = this.getDistinctName(name, type);
+  this.db_[normalized] = safeName.substr(prefix.length);
+  return safeName;
+};
+
+/**
+ * Convert a Blockly entity name to a legal exportable entity name.
+ * Ensure that this is a new name not overlapping any previously defined name.
+ * Also check against list of reserved words for the current language and
+ * ensure name doesn't collide.
+ * @param {string} name The Blockly entity name (no constraints).
+ * @param {string} type The type of entity in Blockly
+ *     ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).
+ * @return {string} An entity name legal for the exported language.
+ */
+Blockly.Names.prototype.getDistinctName = function(name, type) {
+  var safeName = this.safeName_(name);
+  var i = '';
+  while (this.dbReverse_[safeName + i] ||
+         (safeName + i) in this.reservedDict_) {
+    // Collision with existing name.  Create a unique name.
+    i = i ? i + 1 : 2;
+  }
+  safeName += i;
+  this.dbReverse_[safeName] = true;
+  var prefix = (type == Blockly.Variables.NAME_TYPE) ?
+      this.variablePrefix_ : '';
+  return prefix + safeName;
+};
+
+/**
+ * Given a proposed entity name, generate a name that conforms to the
+ * [_A-Za-z][_A-Za-z0-9]* format that most languages consider legal for
+ * variables.
+ * @param {string} name Potentially illegal entity name.
+ * @return {string} Safe entity name.
+ * @private
+ */
+Blockly.Names.prototype.safeName_ = function(name) {
+  if (!name) {
+    name = 'unnamed';
+  } else {
+    // Unfortunately names in non-latin characters will look like
+    // _E9_9F_B3_E4_B9_90 which is pretty meaningless.
+    name = encodeURI(name.replace(/ /g, '_')).replace(/[^\w]/g, '_');
+    // Most languages don't allow names with leading numbers.
+    if ('0123456789'.indexOf(name[0]) != -1) {
+      name = 'my_' + name;
+    }
+  }
+  return name;
+};
+
+/**
+ * Do the given two entity names refer to the same entity?
+ * Blockly names are case-insensitive.
+ * @param {string} name1 First name.
+ * @param {string} name2 Second name.
+ * @return {boolean} True if names are the same.
+ */
+Blockly.Names.equals = function(name1, name2) {
+  return name1.toLowerCase() == name2.toLowerCase();
+};