Dear all,
I'm still playing around with functors, modules and polymorphism but
I've some problems with this last concept.

In the attached files I have tried to implement a sort of function with
a variable number of arguments (based on continuation) and to generalize
the approach I've used a functor (OpVarADT) where I defined the
operation of type 'a -> 'b -> 'c but seems that it is not general enough
to contain int->int->int or 'a -> 'a list -> 'a list

This is the functor instantiation with the errors I get:

   # module M0 = Continuation(StringConcat) ;;
   Error: Signature mismatch:
          Modules do not match:
            sig val op : 'a -> 'a list -> 'a list val init : 'a list end
          is not included in
            OpVarADT.OpVarADT
          Values do not match:
            val op : 'a -> 'a list -> 'a list
          is not included in
            val op : 'a -> 'b -> 'c
   # module M1 = Continuation(Sum) ;;
   Error: Signature mismatch:
          Modules do not match:
            sig val op : int -> int -> int val init : int end
          is not included in
            OpVarADT.OpVarADT
          Values do not match:
            val op : int -> int -> int
          is not included in
            val op : 'a -> 'b -> 'c

I'm sure I'm doing something wrong but I can't see what, any help is
welcome

TIA

Walter

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