anchor.diff:      _ -> None
   
   /// Format a source string using given config and write to a text writer
  -let processSourceString fsi inStr (tw : TextWriter) config =
  -    Context.create config inStr 
  -    |> genParsedInput (parse fsi inStr) 
  -    |> dump
  -    |> tw.Write
  +let processSourceString fsi s (tw : TextWriter) config =
  +    tw.Write(formatSourceString fsi s config)
   
   /// Format a source string using given config and write to a text writer; return None if failed
  -let tryProcessSourceString fsi inStr tw config =
  -    try
  -        Some (processSourceString fsi inStr tw config)
  +let tryProcessSourceString fsi s tw config =
  +    try
  +        Some (processSourceString fsi s tw config)
       with 
       _ -> None
   
  
positive.code:                 | RecType -> "type"
                  | RecLet -> "let rec"
                  | _ -> "and"
              /// Replace "and" by "type" or "let rec"
              if r.StartLine = r.EndLine then (pattern.Replace(sel, replacement, 1), p)
              else (new String(' ', startCol) + pattern.Replace(sel, replacement, 1), RecType)
          elif r.StartLine = r.EndLine then (sel, NoPatch)
  
negative.code:     parseWith fileName s
  
  /// Format a source string using given config
  let formatSourceString fsi s config =    
      Context.create config s 
      |> genParsedInput (parse fsi s) 
      |> dump
      |> integrateComments s
  
  /// Format a source string using given config; return None if failed
  let tryFormatSourceString fsi s config =
  