JS code: ns coerce and "gen" check

gistfile1.txt

        ns: {
            coerce: function (namespace, hash, back) {
                hash = hash || {};
                back = back || false;
                var nsSplit = namespace.split('.'),
                    newHash = hash,
                    stop = nsSplit.length - (back && 1 || 0),
                    ns;

                if (_.isEmpty(namespace)) {
                    return newHash
                }

                for (var nsi = 0; nsi < stop; nsi++) {
                    ns = nsSplit[nsi];
                    newHash = newHash[ns];
                    if (!newHash) {
                        return;
                    }
                }
                return newHash;
            },
            // todo: older func check validity.
            gen: function (namespace, last, first) {
                var nsSplit = namespace.split('.'),
                    newHash = first || {},
                    outputHash = newHash,
                    ns;
                last = last || {};
                for (var nsi = 0; nsi < nsSplit.length; nsi++) {
                    ns = nsSplit[nsi];
                    if (nsi === nsSplit.length - 1) {
                        newHash[ns] = last;
                    } else {
                        newHash[ns] = {};
                    }
                    newHash = newHash[ns];
                }
                return outputHash;
            }
        }