| // Copyright 2006 The Closure Library Authors. All Rights Reserved. |
| // |
| // 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 for fast string concatenation. |
| */ |
| |
| goog.provide('goog.string.StringBuffer'); |
| |
| |
| |
| /** |
| * Utility class to facilitate string concatenation. |
| * |
| * @param {*=} opt_a1 Optional first initial item to append. |
| * @param {...*} var_args Other initial items to |
| * append, e.g., new goog.string.StringBuffer('foo', 'bar'). |
| * @constructor |
| */ |
| goog.string.StringBuffer = function(opt_a1, var_args) { |
| if (opt_a1 != null) { |
| this.append.apply(this, arguments); |
| } |
| }; |
| |
| |
| /** |
| * Internal buffer for the string to be concatenated. |
| * @type {string} |
| * @private |
| */ |
| goog.string.StringBuffer.prototype.buffer_ = ''; |
| |
| |
| /** |
| * Sets the contents of the string buffer object, replacing what's currently |
| * there. |
| * |
| * @param {*} s String to set. |
| */ |
| goog.string.StringBuffer.prototype.set = function(s) { |
| this.buffer_ = '' + s; |
| }; |
| |
| |
| /** |
| * Appends one or more items to the buffer. |
| * |
| * Calling this with null, undefined, or empty arguments is an error. |
| * |
| * @param {*} a1 Required first string. |
| * @param {*=} opt_a2 Optional second string. |
| * @param {...?} var_args Other items to append, |
| * e.g., sb.append('foo', 'bar', 'baz'). |
| * @return {!goog.string.StringBuffer} This same StringBuffer object. |
| * @suppress {duplicate} |
| */ |
| goog.string.StringBuffer.prototype.append = function(a1, opt_a2, var_args) { |
| // Use a1 directly to avoid arguments instantiation for single-arg case. |
| this.buffer_ += String(a1); |
| if (opt_a2 != null) { // second argument is undefined (null == undefined) |
| for (var i = 1; i < arguments.length; i++) { |
| this.buffer_ += arguments[i]; |
| } |
| } |
| return this; |
| }; |
| |
| |
| /** |
| * Clears the internal buffer. |
| */ |
| goog.string.StringBuffer.prototype.clear = function() { |
| this.buffer_ = ''; |
| }; |
| |
| |
| /** |
| * @return {number} the length of the current contents of the buffer. |
| */ |
| goog.string.StringBuffer.prototype.getLength = function() { |
| return this.buffer_.length; |
| }; |
| |
| |
| /** |
| * @return {string} The concatenated string. |
| * @override |
| */ |
| goog.string.StringBuffer.prototype.toString = function() { |
| return this.buffer_; |
| }; |