message: Flatten indentation a little with `while let`
diff: @@ -128,11 +128,10 @@ impl<'input> Iterator for Lexer<'input> {
  type Item = Result<(BytePos, Token<'input>, BytePos), Error>;
  fn next(&mut self) -> Option<Result<(BytePos, Token<'input>, BytePos), Error>> {
  - loop {
  - return match self.bump() {
  - Some((start, ch)) => {
  + while let Some((start, ch)) = self.bump() {
  let end = start.map(|x| x + 1);
  - match ch {
  +
  + return match ch {
  '=' => Some(Ok((start, Token::Equals, end))),
  ';' => Some(Ok((start, Token::Semi, end))),
  ',' => Some(Ok((start, Token::Comma, end))),
  @@ -157,11 +156,10 @@ impl<'input> Iterator for Lexer<'input> {
  ch if is_ident_start(ch) => Some(Ok(self.ident(start))),
  ch if ch.is_whitespace() => continue,
  _ => Some(error(ErrorCode::UnrecognizedToken, start)),
  - }
  - }
  - None => None,
  };
  }
  +
  + None
  }
  }
  