🚀 go-pugleaf

Hello,

I have just realized something about ML that I find rather odd and 
I am hoping to get some advice about consequences.

The oddity is that a value can escape the scope in which its type
definition was made.   Thus


	let 
	   datatype aType = constA | constB of int;
	in
	   constA
	end;


This of course returns the value 'constA', in the outer scope, but
in this scope there is no type for this value!!

I tried this SML of NJ and it accepted it and returned the message

		val it = constA : ?.aType
 
It seems to me that this can cause problem with the sematics of
the language and would be a problem in any language that allows
type definitions in inner scopes.  

Now my problem is that I don't know what the exact problems this 
could cause, and I was hoping that those who have had more experience
both defining and implementing ML could give their input.  

I have a copy of the Definition of ML, so if something there would
make this clear, please feel free to refer to it.

Vance


P.S.  :  I am also curious about a discussion about the problem
	 with arbitrary Type definitions in signatures.  Unfortuately
	 I did not save it.  If someone has the reference to the
	 relevant passage in the Definition Book I would love to
	 get that too.