anchor.diff:                  opts.Options, IsResultObsolete(fun () -> false), null)
             let errors =
               match res with
  -            | CheckFileAnswer.Succeeded(res) -> res.Errors
  +            | Some(CheckFileAnswer.Succeeded(res)) -> res.Errors
               | _ -> errors
             // Start full background parsing if requested..
             if full then checker.StartBackgroundCompile(opts.Options)
  
positive.code:         ( untypedInfo, opts.FileName, identToken, opts.Source,
            opts.Options, IsResultObsolete(fun () -> false), null)
      match info with
      | CheckFileAnswer.Succeeded(res) when res.HasFullTypeCheckInfo ->
          return res, res.Errors
      | _ ->
          do! Async.Sleep(200)
  
negative.code:       Option.map (fun (info:CheckFileResults) ->
          // Assume that we are inside identifier (F# services can also handle
          // case when we're in a string in '#r "Foo.dll"' but we don't do that)
          info.GetDeclarationLocation(line,col', lineStr, identIsland, true)
          ) (x.GetTypeCheckInfo(opts, time))
        ) (Parsing.findLongIdents(column, lineStr))
  
  