fn pub static new(bytes: ref ByteArray) -> Lexer {
  Lexer(buffer: Buffer.new(bytes), keywords: Keywords.new(KEYWORDS))
}

fn pub mut buffer -> mut Buffer {
  @buffer
}

fn pub inline move each(fun: fn (Token)) {
  loop {
    match self.next {
      case Some(v) -> fun.call(v)
      case _ -> break
    }
  }
}

fn pub mut next -> Option[Token] {
  match @buffer.get {
    case bytes.DQUOTE -> Option.Some(helpers.double_string(@buffer))
    case bytes.SQUOTE -> Option.Some(helpers.single_string(@buffer))
    case bytes.HASH -> Option.Some(helpers.line_comment(@buffer))
    case byte if bytes.digit?(byte) -> Option.Some(helpers.integer(@buffer))
    case byte if bytes.letter?(byte) -> Option.Some(word)
    case byte if bytes.whitespace?(byte) -> {
      Option.Some(helpers.whitespace(@buffer))
    }
    case byte if bytes.multibyte?(byte) -> {
      Option.Some(helpers.multi_byte(@buffer))
    }
    case EOF -> Option.None
    case _ -> Option.Some(helpers.single_byte(@buffer))
  }
}

fn pub move to_array -> Array[Token] {
  let tokens = []

  each(fn (v) { tokens.push(v) })
  tokens
}