bin/node_modules/plist/node_modules/xmlbuilder/node_modules/lodash-node/modern/internals/baseClone.js

/**
 * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/>
 * Build: `lodash modularize modern exports="node" -o ./modern/`
 * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <http://lodash.com/license>
 */
var assign = require('../objects/assign'),
    forEach = require('../collections/forEach'),
    forOwn = require('../objects/forOwn'),
    getArray = require('./getArray'),
    isArray = require('../objects/isArray'),
    isObject = require('../objects/isObject'),
    releaseArray = require('./releaseArray'),
    slice = require('./slice');

/** Used to match regexp flags from their coerced string values */
var reFlags = /\w*$/;

/** `Object#toString` result shortcuts */
var argsClass = '[object Arguments]',
    arrayClass = '[object Array]',
    boolClass = '[object Boolean]',
    dateClass = '[object Date]',
    funcClass = '[object Function]',
    numberClass = '[object Number]',
    objectClass = '[object Object]',
    regexpClass = '[object RegExp]',
    stringClass = '[object String]';

/** Used to identify object classifications that `_.clone` supports */
var cloneableClasses = {};
cloneableClasses[funcClass] = false;
cloneableClasses[argsClass] = cloneableClasses[arrayClass] =
cloneableClasses[boolClass] = cloneableClasses[dateClass] =
cloneableClasses[numberClass] = cloneableClasses[objectClass] =
cloneableClasses[regexpClass] = cloneableClasses[stringClass] = true;

/** Used for native method references */
var objectProto = Object.prototype;

/** Used to resolve the internal [[Class]] of values */
var toString = objectProto.toString;

/** Native method shortcuts */
var hasOwnProperty = objectProto.hasOwnProperty;

/** Used to lookup a built-in constructor by [[Class]] */
var ctorByClass = {};
ctorByClass[arrayClass] = Array;
ctorByClass[boolClass] = Boolean;
ctorByClass[dateClass] = Date;
ctorByClass[funcClass] = Function;
ctorByClass[objectClass] = Object;
ctorByClass[numberClass] = Number;
ctorByClass[regexpClass] = RegExp;
ctorByClass[stringClass] = String;

/**
 * The base implementation of `_.clone` without argument juggling or support
 * for `thisArg` binding.
 *
 * @private
 * @param {*} value The value to clone.
 * @param {boolean} [isDeep=false] Specify a deep clone.
 * @param {Function} [callback] The function to customize cloning values.
 * @param {Array} [stackA=[]] Tracks traversed source objects.
 * @param {Array} [stackB=[]] Associates clones with source counterparts.
 * @returns {*} Returns the cloned value.
 */
function baseClone(value, isDeep, callback, stackA, stackB) {
  if (callback) {
    var result = callback(value);
    if (typeof result != 'undefined') {
      return result;
    }
  }
  // inspect [[Class]]
  var isObj = isObject(value);
  if (isObj) {
    var className = toString.call(value);
    if (!cloneableClasses[className]) {
      return value;
    }
    var ctor = ctorByClass[className];
    switch (className) {
      case boolClass:
      case dateClass:
        return new ctor(+value);

      case numberClass:
      case stringClass:
        return new ctor(value);

      case regexpClass:
        result = ctor(value.source, reFlags.exec(value));
        result.lastIndex = value.lastIndex;
        return result;
    }
  } else {
    return value;
  }
  var isArr = isArray(value);
  if (isDeep) {
    // check for circular references and return corresponding clone
    var initedStack = !stackA;
    stackA || (stackA = getArray());
    stackB || (stackB = getArray());

    var length = stackA.length;
    while (length--) {
      if (stackA[length] == value) {
        return stackB[length];
      }
    }
    result = isArr ? ctor(value.length) : {};
  }
  else {
    result = isArr ? slice(value) : assign({}, value);
  }
  // add array properties assigned by `RegExp#exec`
  if (isArr) {
    if (hasOwnProperty.call(value, 'index')) {
      result.index = value.index;
    }
    if (hasOwnProperty.call(value, 'input')) {
      result.input = value.input;
    }
  }
  // exit for shallow clone
  if (!isDeep) {
    return result;
  }
  // add the source value to the stack of traversed objects
  // and associate it with its clone
  stackA.push(value);
  stackB.push(result);

  // recursively populate clone (susceptible to call stack limits)
  (isArr ? forEach : forOwn)(value, function(objValue, key) {
    result[key] = baseClone(objValue, isDeep, callback, stackA, stackB);
  });

  if (initedStack) {
    releaseArray(stackA);
    releaseArray(stackB);
  }
  return result;
}

module.exports = baseClone;