Javascript Object InputOutputter

var someObject = {
    'part1' : {
        'name': 'Part 1',
        'size': '20',
        'qty' : '50'
    },
    'part2' : {
        'name': 'Part 2',
        'size': '15',
        'qty' : '60'
    },
    'part3' : [
        {
            'name': 'Part 3A РУКУ!!!',
            'size': '10',
            'qty' : '20'
        }, {
            'name': 'Part 3B',
            'size': '5',
            'qty' : '20'
        }, {
            'name': 'Part 3C',
            'size': '7.5',
            'qty' : '20'
        }
    ]
};

//var o = {}, c = window.Configure = {}, seperator = '.';

var c = function(){
    this.o = {};
    this.seperator = ".";
    this.set = function(obj){
        this.o = obj;
    }
    this.write = function(p, d) {
        p = p.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
        p = p.replace(/^\./, ''); // strip leading dot
        // Split the path to an array and assaign the object
        // to a local variable
        var ps = p.split(this.seperator), co = this.o;

        // Iterate over the paths, skipping the last one
        for(var i = 0; i < ps.length - 1; i++)
        {
            // Grab the next path's value, creating an empty
            // object if it does not exist
            co = (co[ps[i]])? co[ps[i]] : co[ps[i]] = {};
        }

        // Assign the value to the object's last path
        co[ps[ps.length - 1]] = d;
    }
    this.read = function(p) {
        p = p.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
        p = p.replace(/^\./, ''); // strip leading dot
        var ps = p.split(this.seperator), co = this.o;
        /*
        for(var i = 0; i < ps.length; i++)
        {
            co = (co[ps[i]])? co[ps[i]] : co[ps[i]] = {};
        }
        */
        while (ps.length) {
            var n = ps.shift();
            if (n in co) {
                co = co[n];
            } else {
                return;
            }
        }
        return co;
    }

};

var n = new c();
n.set(someObject);
console.log('whas');
console.log('n.read part.name', n.read('part1.name'));
n.write('part3[0].name', "custom var");
console.log('part1.name now changed');
n.write('part1.name', "tmp");
console.log('n.read part.name', n.read('part1.name'));
console.log('----');
console.log('before', someObject);
console.log('someObject.part1.name', someObject.part1.name);
console.log('someObject.part3[0].name', someObject.part3[0].name);