[Haskell-cafe] Reading open data types

[Benja Fallenstein]

2007/6/14, Stefan O'Rear <stefanor at cox.net>:
> On Wed, Jun 13, 2007 at 05:12:25PM +0300, Benja Fallenstein wrote:
> > However, this is still kind of boring. Is there a better way? If not,
> > would it be a good idea to have compiler support for building this
> > kind of type table?
>
> The compiler does build exactly such a table - it's called a symbol
> table.  If you aren't afraid of massive overkill, you can use hs-plugins
> to write String -> exists a. Read a => a   .

Now *there* is an idea. :-) Hah.

Massive overkill, indeed, but you'd call 'eval' only once for every
type tag, of course, and cache the result, so the overhead would be
O(1) per run of the application.

- Benja