[Haskell-cafe] Client-extensible heterogeneous types

[Jacek Generowicz]

On 2010 Oct 12, at 15:44, John Lato wrote:

> It's not plain Haskell, but I'm surprised nobody mentioned the  
> ExistentialQuantification extension, which unless I'm missing  
> something provides exactly what you want.

Yes, it does appear to be *exactly* what I want.

Thanks.

(Now, how about those HLists?)