Common data in datatype constructors
Implement common data within datatypes (models single one-level inheritance) this means that the base datatype definition can hold some data which all constructors also hold though this could be expressed by all constructors having a common first argument, this sugar would probably be useful. I'm thinking of exceptions here. currently, exception handling needs three global variables. Adding more information to exceptions will extend that number and I'd like to keep it to 1 we could have a single object holding the exception plus information (need to think about it).