[Haskell-cafe] Client-extensible heterogeneous types

[Stephen Tetley]

On 12 October 2010 14:08, Jacek Generowicz <Jacek.Generowicz at cern.ch> wrote:

> Reading the GHC docs on Data.Dynamic, I infer that Data.Dynamic is
> non-standard, but, in principle, portable to other implementations.
>
> Is that understanding correct?

Yes - Data.Dynamic uses some GHC specifics but there are other
"lightweight" encodings of dynamic types that I think just use
existential types (which John Lato mentioned).