code: function() {
                      var name, args;
  
                      if (!(name = /^([\w\-]+|%)\(/.exec(chunks[j]))) return;
  
                      name = name[1];
  
                      if (name === 'url') {
                          // url() is handled by the url parser instead
                          return null;
                      } else {
                          i += name.length;
                      }
  
                      $('('); // Parse the '(' and consume whitespace.
  
                      args = $(this.entities['arguments']);
  
                      if (!$(')')) return;
  
                      if (name) {
                          return new tree.Call(name, args, env.filename, i);
                      }
                  }
docs: A function call like rgb(255, 0, 255) The arguments are parsed with the `entities.arguments` parser.