Singular Type Constructor

Dylan Thurston dpt@math.harvard.edu
Mon, 20 Aug 2001 23:25:10 -0400


On Mon, Jul 30, 2001 at 07:08:50PM -0700, Ashley Yakeley wrote:
> Consider:
> 
> --
> data T a = T
> --
> 
> Is there anything in the Prelude or a standard library that looks like 
> this? Should there be? What should it be called? 'Singleton'? 'Reified'? 
> 'T'?

What's wrong with State# a?  Why do you need any constructors at all?

Perhaps the name of State# should be changed, or maybe the syntax
should be extended to allow data types with _no_ alternatives.

Best,
	Dylan Thurston