suside

let UnionToString (u: 'a) =
    match FSharpValue.GetUnionFields(u, typeof<'a>) with
    | case, _ -> case.Name

let StringToUnion<'a> (s: string) =
    match FSharpType.GetUnionCases typeof<'a> |> Array.filter (fun case -> case.Name = s) with
    | [| case |] -> FSharpValue.MakeUnion(case, [||]) :?> 'a
    | _ -> failwithf "Unable to parse %A" s

type UnionStringSerializer<'a>() =