anchor.diff:                  let leftCol, rightCol = tok.LeftColumn, tok.LeftColumn + tok.FullMatchedLength
                   if leftCol <= colu - 1 && colu - 1 <= rightCol then
                       if tok.TokenName = "IDENT" then Ident
  -                    elif tok.ColorClass = TokenColorKind.Operator then Operator (lineStr.Substring(leftCol, rightCol - leftCol))
  +                    elif tok.CharClass = TokenCharKind.Operator then Operator (lineStr.Substring(leftCol, rightCol - leftCol))
                       else loop newLexState
                   else loop newLexState
           loop 0L
  
positive.code:     // get column number inside the line
      let colu = colu - lineStart
  
      let rec loop lexState =
          match lineTokenizer.ScanToken lexState with
          | None, _ -> None
          | Some tok, _ when tok.ColorClass = TokenColorKind.PreprocessorKeyword -> 
  
negative.code:             None
          | Some tok, newLexState ->
              let leftCol, rightCol = tok.LeftColumn, tok.LeftColumn + tok.FullMatchedLength
              if not skipOperator && leftCol <= colu && colu <= rightCol && tok.CharClass = TokenCharKind.Operator
              then Some (lineStart + leftCol, lineStart + rightCol)
              else loop newLexState (tok.CharClass = TokenCharKind.Operator)
      loop 0L false
  
             