anchor.diff:  
   /// Creates recursive WiX directory and file tags from the given DirectoryInfo
   let rec wixDir fileFilter asSubDir (directoryInfo:DirectoryInfo) =
  +    dirCount <- dirCount + 1
       let dirs =
         directoryInfo
           |> subDirectories
  
positive.code: open System.IO
  
  let mutable internal fileCount = 0
  
  /// Creates a WiX File tag from the given FileInfo
  let wixFile (fileInfo:FileInfo) =
  
negative.code:       sprintf "<Component Id=\"%s\" Guid=\"%s\">\r\n%s\r\n</Component>\r\n" directoryInfo.Name (Guid.NewGuid().ToString()) files
  
      if asSubDir then
          sprintf "<Directory Id=\"di_%d\" Name=\"%s\">\r\n%s%s\r\n</Directory>\r\n" dirCount directoryInfo.Name dirs compo
      else
          sprintf "%s%s" dirs compo
  
  