grammar Format {
  token TOP {
    [
      <comment>*
      [
        <section>
        [ <line> | <comment> ]*
      ]*
    ]*
  }

  rule section {
    '[' <identifier> <subsection>? ']'
  }

  rule subsection {
    '"' <identifier> '"'
  }

  rule identifier {
    <[A..Za..z]> <[A..Za..z0..9_-]>+
  }

  rule comment {
    <[";]> .*? $$
  }

  rule line {
    <key> '=' <value>
  }

  rule key {
    <identifier>
  }

  rule value {
    .*? $$
  }
}

Format.parse('lol.conf'.IO.slurp)