Re: How to user-define a type equality constraint?

`Char` is defined in user code. What you really can't define are Char# and TYPE, and you can't modify `RuntimeRep`. Speaking of `Char#`, I see that in 9.0, at least, it has kind TYPE 'WordRep. Why is that not Word32Rep? On Mon, Apr 5, 2021, 10:50 PM Richard Eisenberg wrote:

On Apr 1, 2021, at 8:12 PM, Anthony Clayden wrote:

Can I user-define a conventional type-class that behaves more like `(~)`?

I don't think so.

But why does this matter? I can't define `Char` in user code, but it's exported from the Prelude and requires no extensions. While I can define Eq in user code, I can't make `deriving` work with my version. I can't define `error` in user code. There are many others, I'm sure.

So: why does this matter?

Thanks, Richard _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users