Thread: Parametrized Types

I wonder if I could make parametrized types:
  * complex numbers with a certain precision
  * cities or countries ... types --- strings would be stored in another table

The problem is that the inpu/output functions accept only the value. I would like postgres to Communicate an optional
valuestored 
in pg_types ... a new field.

   Is that easy; where to start ??



PS: I am working on a "system"  to  co-operate with Emacs-widget library to permit a comfortable editing of records. If
interestedmail me.