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var clone = (function() {
'use strict';
/**
* Clones (copies) an Object using deep copying.
*
* This function supports circular references by default, but if you are certain
* there are no circular references in your object, you can save some CPU time
* by calling clone(obj, false).
*
* Caution: if `circular` is false and `parent` contains circular references,
* your program may enter an infinite loop and crash.
*
* @param `parent` - the object to be cloned
* @param `circular` - set to true if the object to be cloned may contain
* circular references. (optional - true by default)
* @param `depth` - set to a number if the object is only to be cloned to
* a particular depth. (optional - defaults to Infinity)
* @param `prototype` - sets the prototype to be used when cloning an object.
* (optional - defaults to parent prototype).
*/
function clone(parent, circular, depth, prototype) {
var filter;
if (typeof circular === 'object') {
depth = circular.depth;
prototype = circular.prototype;
filter = circular.filter;
circular = circular.circular
}
// maintain two arrays for circular references, where corresponding parents
// and children have the same index
var allParents = [];
var allChildren = [];
var useBuffer = typeof Buffer != 'undefined';
if (typeof circular == 'undefined')
circular = true;
if (typeof depth == 'undefined')
depth = Infinity;
// recurse this function so we don't reset allParents and allChildren
function _clone(parent, depth) {
// cloning null always returns null
if (parent === null)
return null;
if (depth == 0)
return parent;
var child;
var proto;
if (typeof parent != 'object') {
return parent;
}
if (clone.__isArray(parent)) {
child = [];
} else if (clone.__isRegExp(parent)) {
child = new RegExp(parent.source, __getRegExpFlags(parent));
if (parent.lastIndex) child.lastIndex = parent.lastIndex;
} else if (clone.__isDate(parent)) {
child = new Date(parent.getTime());
} else if (useBuffer && Buffer.isBuffer(parent)) {
child = new Buffer(parent.length);
parent.copy(child);
return child;
} else {
if (typeof prototype == 'undefined') {
proto = Object.getPrototypeOf(parent);
child = Object.create(proto);
}
else {
child = Object.create(prototype);
proto = prototype;
}
}
if (circular) {
var index = allParents.indexOf(parent);
if (index != -1) {
return allChildren[index];
}
allParents.push(parent);
allChildren.push(child);
}
for (var i in parent) {
var attrs;
if (proto) {
attrs = Object.getOwnPropertyDescriptor(proto, i);
}
if (attrs && attrs.set == null) {
continue;
}
child[i] = _clone(parent[i], depth - 1);
}
return child;
}
return _clone(parent, depth);
}
/**
* Simple flat clone using prototype, accepts only objects, usefull for property
* override on FLAT configuration object (no nested props).
*
* USE WITH CAUTION! This may not behave as you wish if you do not know how this
* works.
*/
clone.clonePrototype = function clonePrototype(parent) {
if (parent === null)
return null;
var c = function () {};
c.prototype = parent;
return new c();
};
// private utility functions
function __objToStr(o) {
return Object.prototype.toString.call(o);
};
clone.__objToStr = __objToStr;
function __isDate(o) {
return typeof o === 'object' && __objToStr(o) === '[object Date]';
};
clone.__isDate = __isDate;
function __isArray(o) {
return typeof o === 'object' && __objToStr(o) === '[object Array]';
};
clone.__isArray = __isArray;
function __isRegExp(o) {
return typeof o === 'object' && __objToStr(o) === '[object RegExp]';
};
clone.__isRegExp = __isRegExp;
function __getRegExpFlags(re) {
var flags = '';
if (re.global) flags += 'g';
if (re.ignoreCase) flags += 'i';
if (re.multiline) flags += 'm';
return flags;
};
clone.__getRegExpFlags = __getRegExpFlags;
return clone;
})();
if (typeof module === 'object' && module.exports) {
module.exports = clone;
}
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