Parse input "arrays" in JS

input_parse.js

function parseInputs(data) {
    var ret = {};
retloop:
    for (var input in data) {
        var val = data[input];

        var parts = input.split('[');       
        var last = ret;

        for (var i in parts) {
            var part = parts[i];
            if (part.substr(-1) == ']') {
                part = part.substr(0, part.length - 1);
            }

            if (i == parts.length - 1) {
                last[part] = val;
                continue retloop;
            } else if (!last.hasOwnProperty(part)) {
                last[part] = {};
            }
            last = last[part];
        }
    }
    return ret;
}
var data = {
    "nom": "123",
    "items[install][item_id_4]": "4",
    "items[install][item_id_5]": "16",
    "items[options][takeover]": "yes"
};
var out = parseInputs(data);
console.log('\n***Moment of truth:\n');
console.log(out);