anchor.diff:  
     /// Constructs options for the interactive checker for the given file in the project under the given configuration.
     member x.GetCheckerOptions(fileName, projFilename, source, files, args) =
  -    let ext = Path.GetExtension(fileName)
       let opts =
         if LanguageService.IsAScript fileName then
           // We are in a stand-alone file or we are in a project, but currently editing a script file
  
positive.code:   
    /// Parses and checks the given file in the given project under the given configuration. Asynchronously
    /// returns the results of checking the file.
    member x.ParseAndCheckFileInProject(projectFilename, fileName:string, src, files, args, storeAst) = 
     async {
      let opts = x.GetCheckerOptions(fileName, projectFilename,  src, files , args)
      Debug.WriteLine(sprintf "Parsing: Trigger parse (fileName=%s)" fileName)
  
      // storeAst is passed from monodevelop when it finds files with the same name in other projects. 
      // It will then ask for a reparse of all files in the second project. If storeAst = false, do nothing. 
      if not storeAst then return ParseAndCheckResults.Empty else
      let! results = mbox.PostAndAsyncReply(fun r -> fileName, src, opts, r)
      Debug.WriteLine(sprintf "Worker: Starting background compilations")
      checker.StartBackgroundCompile(opts)
      return results
     }
  
    member x.ParseFileInProject(projectFilename, fileName:string, src, args) = 
      let opts = x.GetCheckerOptions(fileName, projectFilename, src, [| |], args)
      Debug.WriteLine(sprintf "Parsing: Get untyped parse result (fileName=%s)" fileName)
      checker.ParseFileInProject(fixFileName fileName, src, opts)
  
    member internal x.TryGetStaleTypedParseResult(fileName:string, options, src, stale)  = 
  
negative.code:     let opts = 
        
        // We are in a project - construct options using current properties
          Debug.WriteLine (sprintf "LanguageService: GetProjectCheckerOptions: Creating for project '%s'" projFilename )
  
          {ProjectFileName = projFilename
           ProjectFileNames = files
  