unique id for data types

[Barney Hilken]

Hi Simon, thanks for the response.

In fact I really only need NameCmp to be defined for datatypes of the  
form
	data T = T
but it's still a lot, so I was expecting to need an extension.  
Lexical comparison of fully qualified names is what I had in mind,  
but I wanted some confirmation that such things exist!

I could post a GHC feature request, but unless I get someone else  
interested in this, it would probably just sit in Trac indefinitely.  
Where should I look in the ghc source if I want to add it myself?

Barney.