anchor.diff:      context.loadAssembly <| Assembly.Load "mscorlib"
       List.iter context.loadAssembly (List.map Assembly.LoadFrom asmRefs)
   
  -    prologue ilGenerator
  -    try
  -        let body = Reader.parse fileName source
  -        let gen = gf.MakeBody context body
  -        gen.Generate ilGenerator
  -    with
  -    | ex -> printfn "File: %A\nForm: %A\nError: %A" fileName sexp ex.Source
  -
  -    epilogue context typeBuilder ilGenerator
  +    let body = Reader.parse fileName source
  +    compileMethod context gf body methodBuilder fileName
   
       typeBuilder.CreateType()
       |> ignore
  
positive.code: let private prologue (ilGen : ILGenerator) =
      ilGen.BeginScope()
  
  let private epilogue context typeBuilder (ilGen : ILGenerator) =
      ilGen.Emit OpCodes.Ret
      ilGen.EndScope()
  
  let compile (source : Stream) (assemblyName : string) (fileName : string) (asmRefs:string list): unit =
      let assemblyName = new AssemblyName(assemblyName)
  
negative.code:     let gf = new GeneratorFactory(typeBuilder) :> IGeneratorFactory
      assemblyBuilder.SetEntryPoint methodBuilder
      
      let context = Context.create ()
  
      //loading language runtime
  