code: function parse(str, arr) {
    return str.replace(/\.\w+|"[^"]*"|'[^']*'|\/([^/]+)\/|[a-zA-Z_]\w*/g, function(expr) {
      if(forbidden.indexOf(expr[0]) > -1) return expr;
      if(!~arr.indexOf(expr)) arr.push(expr);
      return 'model.' + expr;
    });
  }
docs: Parse expression and replace
  identifier.
  
  Examples:
  
  compile('name + last');
  // => model.name + model.last
  
  compile('name[0]');
  // => model.name[0]
  
  @param  {String} str
  @param  {Array} arr
  @return {String}
  @api private