@screeps/engine/dist/decycle.js

This is a module for Screeps standalone server. See [main repository](https://github.com/screeps/screeps) for more info.

'use strict';

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

/*
 cycle.js
 2013-02-19

 Public Domain.

 NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.

 This code should be minified before deployment.
 See http://javascript.crockford.com/jsmin.html

 USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO
 NOT CONTROL.
 */

/*jslint evil: true, regexp: true */

/*members $ref, apply, call, decycle, hasOwnProperty, length, prototype, push,
 retrocycle, stringify, test, toString
 */

module.exports = function (object) {

    // Make a deep copy of an object or array, assuring that there is at most
    // one instance of each object or array in the resulting structure. The
    // duplicate references (which might be forming cycles) are replaced with
    // an object of the form
    //      {$ref: PATH}
    // where the PATH is a JSONPath string that locates the first occurance.
    // So,
    //      var a = [];
    //      a[0] = a;
    //      return JSON.stringify(JSON.decycle(a));
    // produces the string '[{"$ref":"$"}]'.

    // JSONPath is used to locate the unique object. $ indicates the top level of
    // the object or array. [NUMBER] or [STRING] indicates a child member or
    // property.

    var objects = [],
        // Keep a reference to each unique object or array
    paths = []; // Keep the path to each unique object or array

    return function derez(value, path) {

        // The derez recurses through the object, producing the deep copy.

        var i, // The loop counter
        name, // Property name
        nu; // The new object or array

        // typeof null === 'object', so go on if this value is really an object but not
        // one of the weird builtin objects.

        if ((typeof value === 'undefined' ? 'undefined' : _typeof(value)) === 'object' && value !== null && !(value instanceof Boolean) && !(value instanceof Date) && !(value instanceof Number) && !(value instanceof RegExp) && !(value instanceof String)) {

            // If the value is an object or array, look to see if we have already
            // encountered it. If so, return a $ref/path object. This is a hard way,
            // linear search that will get slower as the number of unique objects grows.

            for (i = 0; i < objects.length; i += 1) {
                if (objects[i] === value) {
                    return { $ref: paths[i] };
                }
            }

            // Otherwise, accumulate the unique value and its path.

            objects.push(value);
            paths.push(path);

            // If it is an array, replicate the array.

            if (Object.prototype.toString.apply(value) === '[object Array]') {
                nu = [];
                for (i = 0; i < value.length; i += 1) {
                    nu[i] = derez(value[i], path + '[' + i + ']');
                }
            } else {

                // If it is an object, replicate the object.

                nu = {};
                for (name in value) {
                    if (Object.prototype.hasOwnProperty.call(value, name)) {
                        nu[name] = derez(value[name], path + '[' + JSON.stringify(name) + ']');
                    }
                }
            }
            return nu;
        }
        return value;
    }(object, '$');
};
//# sourceMappingURL=sourcemaps/decycle.js.map