[Haskell-cafe] Collection of objects?

[Henning Thielemann]

On Fri, 17 Nov 2006, Valentin Gjorgjioski wrote:

> Is some kind of collection of object with different types in Haskell exist?
> Except the tuples, which have fixed length.
> I find this
> 
>    * Tuples heterogeneous, lists homogeneous.
>    * Tuples have a fixed length, or at least their length is encoded in
>      their type. That is, two tuples with different lengths will have
>      different types.
>    * Tuples always finite.
> 
> But I need something which is heterogeneous and non-fixed length. I'm used do
> Java, and this switch to functional languages is very strange to me. So, to be
> clear, I need something like LinkedList<Object> in java.
> 
> Can you please help me or suggest me, what can I use in this case?

If the number of types to cover is fixed, then I suggest a data type like

data T =
     ConsInt    Int
   | ConsString String
   | ConsChar   Char


Since this is a very FAQ I wonder why I don't find the answer in any of
the Haskell wikis.