class Raabro::Tree

def extract_error
bro.pp(self, colors: true)
  err_tree, stack = lookup_error || lookup_all_error
  line, column = line_and_column(err_tree.offset)
  err_message =
    if stack
      path = stack
       .compact.reverse.take(3).reverse
       .collect(&:inspect).join('/')
      "parsing failed .../#{path}"
    else
      "parsing failed, not all input was consumed"
    end
  visual =
    visual(line, column)
  [ line, column, err_tree.offset, err_message, visual ]
end