Re: Extensible data types?

[Keith Wansbrough]

> In the Clean Object I/O library we encountered a similar challenge and 
> solved it using type constructor classes. The solution can also be used in 
> Haskell. The basic idea is as follows:
> 

I didn't read your message in detail, but I wonder if this is related
to the trick TclHaskell / FranTk use to deal with configuration lists?

--KW 8-)