anchor.diff:  
           { Parse = userInfoP
             Format = userInfoF }
  +
  +    (* Lenses *)
  +
  +    static member UserInfo_ =
  +        (fun (UserInfo u) -> u), (fun u -> UserInfo u)
   
   (* Section 3.2.2 *)
   
  
positive.code: 
          let fragmentP =
              parser |>> Fragment
              //skipChar '#' >>. parser |>> Fragment
  
          let fragmentF =
              function | Fragment x -> formatter x
              //function | Fragment x -> append "#" >> formatter x
  
          { Parse = fragmentP
            Format = fragmentF }
  
      static member Format =
          Formatting.format Fragment.Mapping.Format
  
negative.code: 
          { Parse = portP
            Format = portF }
  
      (* Lenses *)
  
      static member Port_ =
          (fun (Port p) -> p), (fun p -> Port p)
  
  (* Path
  
  