dynamic types

[Manuel M T Chakravarty]

Glynn Clements <glynn.clements@virgin.net> wrote,

> Fergus Henderson wrote:
> 
> > > Maybe in Haskell 2.
> > 
> > Yes, it would be nice to have a built-in, type-safe, version of Dynamic
> > in Haskell 2.
> 
> It would also be nice if it were a little less abstract; e.g. either
> exposing the constructors for Dynamic and TypeRep or providing
> suitable accessors would be preferable to having to parse the result
> of "show".

You may want to have a look at one of the papers from the
2002 Haskell Workshop:

  http://portal.acm.org/citation.cfm?id=581690.581698&coll=portal&dl=ACM&type=series&idx=unknown&part=series&WantType=proceedings&title=unknown&CFID=6867124&CFTOKEN=53197642

You can get quite far with H98 + existentials.

Cheers,
Manuel