anchor.diff:    let private extN<'T when 'T : comparison> head length (f: TypeCode -> byte [] -> ExtendedValue<'T>) =
       matchHead head
       >>. length
  -    >>= fun length -> binParser.byte1 >>= fun t -> binParser.byteN length |>> fun xs -> f t xs
  +    >>= fun length -> binParser.byte1 >>= fun t -> binParser.byteN length |>> f t
       |>> Extended
   
     let ext8<'T when 'T : comparison> (f: TypeCode -> byte [] -> ExtendedValue<'T>) =
  
positive.code:   let private fixExtN<'T when 'T : comparison> head data (f: TypeCode -> byte [] -> ExtendedValue<'T>) =
      matchHead head
      >>. binParser.byte1
      >>= fun t -> data |>> fun xs -> f t xs
      |>> Extended
  
    let fixExt1<'T when 'T : comparison> f = fixExtN<'T> HeadByte.FixExtended1 (binParser.byteN 1) f
  
negative.code:         simpleFixType
        ]
  
      let parse input = parser (fun t xs -> Raw(t, xs)) input
  