text: /**
   * @license
   * Copyright The Closure Library Authors.
   * SPDX-License-Identifier: Apache-2.0
   */
  
  /**
   * @fileoverview Protocol buffer serializer.
   */
  
  
  // TODO(arv): Serialize booleans as 0 and 1
  
  
  goog.provide('goog.proto.Serializer');
  
  
  goog.require('goog.json.Serializer');
  goog.require('goog.string');
  
  
  
  /**
   * Object that can serialize objects or values to a protocol buffer string.
   * @constructor
   * @extends {goog.json.Serializer}
   * @final
   */
  goog.proto.Serializer = function() {
    'use strict';
    goog.json.Serializer.call(this);
  };
  goog.inherits(goog.proto.Serializer, goog.json.Serializer);
  
  
  /**
   * Serializes an array to a protocol buffer string. This overrides the JSON
   * method to don't output trailing null or undefined.
   * @param {Array<*>} arr The array to serialize.
   * @param {Array<string>} sb Array used as a string builder.
   * @override
   */
  goog.proto.Serializer.prototype.serializeArray = function(arr, sb) {
    'use strict';
    var l = arr.length;
    sb.push('[');
    var emptySlots = 0;
    var sep = '';
    for (var i = 0; i < l; i++) {
      if (arr[i] == null) {  // catches undefined as well
        emptySlots++;
      } else {
        sb.push(sep);
        if (emptySlots > 0) {
          sb.push(goog.string.repeat('null,', emptySlots));
          emptySlots = 0;
        }
        this.serializeInternal(arr[i], sb);
        sep = ',';
      }
    }
    sb.push(']');
  };
  