anchor.diff:  Directory.SetCurrentDirectory(__SOURCE_DIRECTORY__)
   let root = Directory.GetCurrentDirectory()
   let apiDocFilename = """M:\Coding\Applications\Dart\dart\pkg\analysis_server\tool\spec\spec_input.html"""
  -let outputFilename = """DanTup.DartAnalysis\Json.cs"""
  +let outputJsonFilename = """DanTup.DartAnalysis\Json.cs"""
   
   let doc = XDocument.Load(apiDocFilename)
   let ( !! ) : string -> XName = XName.op_Implicit;;
  
positive.code: 
  
  // Do the stuff!
  File.WriteAllText(outputFilename, getAllTypes())
  
negative.code:                 "Response"
                  (typeNode.Element(!!"result").Descendants(!!"field") |> collect getField)
  
  let getAllJsonTypes () =
      sprintf """// Code generated by UpdateJson.fsx. Do not hand-edit!
  
  namespace DanTup.DartAnalysis.Json
  