anchor.diff:          fsiSession.EvalInteraction(sprintf "System.IO.Directory.SetCurrentDirectory(@\"%s\")" dir)
           fsiSession.EvalInteraction(sprintf "#cd @\"%s\"" dir) )
         sbOut.Clear() |> ignore
  +      sbErr.Clear() |> ignore
         let sbConsole = new Text.StringBuilder()
         let prev = Console.Out
         try //try..finally to make sure console.out is re-set to prev
  
positive.code:   { Text : string
      AsExpression : bool
      File : string option
      Exception : exn }
  
  /// A wrapper for F# interactive serivice that is used to evaluate inline snippets
  type FsiEvaluator(?options:string[]) =
  
negative.code:       finally
          Console.SetOut(prev)
      with e ->
        evalFailed.Trigger { File=file; AsExpression=asExpression; Text=text; Exception=e; StdErr = sbErr.ToString() }
        { Output = None; Result = None; ItValue = None }
  
      /// This event is fired whenever an evaluation of an expression fails
  