In pidgin OCaml I'd like to write something like

type complicated =
    IVal of int
    | StrVa, of string
    | SymTableVal of symTable
and
    symTable = Map(string -> complicated)

I tried many variations on using the Map module to implement a recursive data structure like this. I failed miserably. (The above wasn't the syntax I ever used, but it gets the idea across.)

However, when I create an object
class [ 'key, 'content ] table : ('key -> 'key -> int) ->
object
,,,
end

I can successfully declare
type complicated =
    IVal of int
    | StrVal of string
    | SymTableVal of (string, complicated) table
that does what I want.   Ithis isn't the whole declaration of complicated, but I believe once I get this declaration working, the more quirky variations work too.

Do I need one of the more advanced features of OCaml that I don't currently understand to use Map the way that I want without writing a whole table class? I don't even see how I can use Map from inside the table class to do what I want which would also be acceptable.

I don't want to have to break open the Map module to modify it and thus change the licensing of my final program.

Thanks

Bill