Function clone

libs/echarts/echarts.simple.js:309–349

* Those data types can be cloned: * Plain object, Array, TypedArray, number, string, null, undefined. * Those data types will be assgined using the orginal data: * BUILTIN_OBJECT * Instance of user defined class will be cloned to a plain object, without * properties in prototype. * Oth

(source)

 * @return {*} new
 */
function clone(source) {
    if (source == null || typeof source !== 'object') {
        return source;
    }

    var result = source;
    var typeStr = objToString.call(source);

    if (typeStr === '[object Array]') {
        if (!isPrimitive(source)) {
            result = [];
            for (var i = 0, len = source.length; i < len; i++) {
                result[i] = clone(source[i]);
            }
        }
    }
    else if (TYPED_ARRAY[typeStr]) {
        if (!isPrimitive(source)) {
            var Ctor = source.constructor;
            if (source.constructor.from) {
                result = Ctor.from(source);
            }
            else {
                result = new Ctor(source.length);
                for (var i = 0, len = source.length; i < len; i++) {
                    result[i] = clone(source[i]);
                }
            }
        }
    }
    else if (!BUILTIN_OBJECT[typeStr] && !isPrimitive(source) && !isDom(source)) {
        result = {};
        for (var key in source) {
            if (source.hasOwnProperty(key)) {
                result[key] = clone(source[key]);
            }
        }
    }

    return result;
}

/**
 * @memberOf module:zrender/core/util