Function copy

lib/test/angular/1.4.3/angular.js:864–956

* @ngdoc function * @name angular.copy * @module ng * @kind function * * @description * Creates a deep copy of `source`, which should be an object or an array. * * * If no destination is supplied, a copy of the object or array is created. * * If a destination is provided, all of its element

(source, destination, stackSource, stackDest)

 </example>
 */
function copy(source, destination, stackSource, stackDest) {
  if (isWindow(source) || isScope(source)) {
    throw ngMinErr('cpws',
      "Can't copy! Making copies of Window or Scope instances is not supported.");
  }
  if (isTypedArray(destination)) {
    throw ngMinErr('cpta',
      "Can't copy! TypedArray destination cannot be mutated.");
  }

  if (!destination) {
    destination = source;
    if (isObject(source)) {
      var index;
      if (stackSource && (index = stackSource.indexOf(source)) !== -1) {
        return stackDest[index];
      }

      // TypedArray, Date and RegExp have specific copy functionality and must be
      // pushed onto the stack before returning.
      // Array and other objects create the base object and recurse to copy child
      // objects. The array/object will be pushed onto the stack when recursed.
      if (isArray(source)) {
        return copy(source, [], stackSource, stackDest);
      } else if (isTypedArray(source)) {
        destination = new source.constructor(source);
      } else if (isDate(source)) {
        destination = new Date(source.getTime());
      } else if (isRegExp(source)) {
        destination = new RegExp(source.source, source.toString().match(/[^\/]*$/)[0]);
        destination.lastIndex = source.lastIndex;
      } else {
        var emptyObject = Object.create(getPrototypeOf(source));
        return copy(source, emptyObject, stackSource, stackDest);
      }

      if (stackDest) {
        stackSource.push(source);
        stackDest.push(destination);
      }
    }
  } else {
    if (source === destination) throw ngMinErr('cpi',
      "Can't copy! Source and destination are identical.");

    stackSource = stackSource || [];
    stackDest = stackDest || [];

    if (isObject(source)) {
      stackSource.push(source);
      stackDest.push(destination);
    }

    var result, key;
    if (isArray(source)) {
      destination.length = 0;
      for (var i = 0; i < source.length; i++) {
        destination.push(copy(source[i], null, stackSource, stackDest));