text: /* -*- Mode: js; js-indent-level: 2; -*- */
  /*
   * Copyright 2014 Mozilla Foundation and contributors
   * Licensed under the New BSD license. See LICENSE or:
   * http://opensource.org/licenses/BSD-3-Clause
   */
  if (typeof define !== 'function') {
      var define = require('amdefine')(module, require);
  }
  define(function (require, exports, module) {
  
    var util = require('./util');
  
    /**
     * Determine whether mappingB is after mappingA with respect to generated
     * position.
     */
    function generatedPositionAfter(mappingA, mappingB) {
      // Optimized for most common case
      var lineA = mappingA.generatedLine;
      var lineB = mappingB.generatedLine;
      var columnA = mappingA.generatedColumn;
      var columnB = mappingB.generatedColumn;
      return lineB > lineA || lineB == lineA && columnB >= columnA ||
             util.compareByGeneratedPositions(mappingA, mappingB) <= 0;
    }
  
    /**
     * A data structure to provide a sorted view of accumulated mappings in a
     * performance conscious manner. It trades a neglibable overhead in general
     * case for a large speedup in case of mappings being added in order.
     */
    function MappingList() {
      this._array = [];
      this._sorted = true;
      // Serves as infimum
      this._last = {generatedLine: -1, generatedColumn: 0};
    }
  
    /**
     * Iterate through internal items. This method takes the same arguments that
     * `Array.prototype.forEach` takes.
     *
     * NOTE: The order of the mappings is NOT guaranteed.
     */
    MappingList.prototype.unsortedForEach =
      function MappingList_forEach(aCallback, aThisArg) {
        this._array.forEach(aCallback, aThisArg);
      };
  
    /**
     * Add the given source mapping.
     *
     * @param Object aMapping
     */
    MappingList.prototype.add = function MappingList_add(aMapping) {
      var mapping;
      if (generatedPositionAfter(this._last, aMapping)) {
        this._last = aMapping;
        this._array.push(aMapping);
      } else {
        this._sorted = false;
        this._array.push(aMapping);
      }
    };
  
    /**
     * Returns the flat, sorted array of mappings. The mappings are sorted by
     * generated position.
     *
     * WARNING: This method returns internal data without copying, for
     * performance. The return value must NOT be mutated, and should be treated as
     * an immutable borrow. If you want to take ownership, you must make your own
     * copy.
     */
    MappingList.prototype.toArray = function MappingList_toArray() {
      if (!this._sorted) {
        this._array.sort(util.compareByGeneratedPositions);
        this._sorted = true;
      }
      return this._array;
    };
  
    exports.MappingList = MappingList;
  
  });
  