convert a flat object with namespaced keys to a heirarchical object

paths2object

/**
 * Converts a "flat" object with namespaced keys into a hierarchical object
 * @param {object} flat - A "flat" object with namespaced keys to turn into a hierarchical object
 * @returns object - the hierarchical object
 */
var _paths2obj = function (flat) {
    var root = {},
        keys = _.keys(flat),
        parts, entry, currentPart, pointer, i, il;
    
    for (entry in keys) {
        parts = entry.split('.');
        pointer = root;
        for (i=0, il=parts.length; i < il; i++) {
            currentPart = parts[i];
            pointer[currentPart] = pointer[currentPart] || {};
            pointer = pointer[currentPart];
        }
        pointer = flat[entry];
    }
            
    return root;
}