anchor.diff:      ItValue : (obj * Type) option
       Result : (obj * Type) option }
   
  +/// Record that is reported by the `EvaluationFailed` event when something
  +/// goes wrong during evalutaiton of an expression
  +type FsiEvaluationFailedInfo = 
  +  { 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[]) =
     // Initialize F# Interactive evaluation session
  
positive.code:   /// given script file - this is for correct usage of #I and #r with relative paths.
    /// Note however that __SOURCE_DIRECTORY___ does not currently pick this up.
    member internal x.Evaluate(text:string, ?asExpression, ?file) =
      try
        let asExpression = defaultArg asExpression false
        file |> Option.iter (fun file ->
          let dir = Path.GetDirectoryName(file)
          fsiSession.EvalInteraction(sprintf "System.IO.Directory.SetCurrentDirectory(@\"%s\")" dir)
  
negative.code:   let fsiConfig = FsiEvaluationSession.GetDefaultConfiguration(new InteractiveSettings())
    let argv = Array.append [|"C:\\test.exe"; "--quiet"; "--noninteractive"|] (defaultArg options [||])
    let fsiSession = FsiEvaluationSession(fsiConfig, argv, inStream, outStream, errStream)
    let evalFailed = new Event<_>()
  
    /// Registered transformations for pretty printing values
    /// (the default formats value as a string and emits single CodeBlock)
  