Re: How to user-define a type equality constraint?
Richard Eisenberg <[email protected]> Tue, 6 Apr 2021 02:49:40 +0000
| Newsgroups | gmane.comp.lang.haskell.glasgow.user |
|---|---|
| Message-ID | <010f0178a515eb07-1f713804-df22-496f-91fc-b1f15e5baa1c-000000@us-east-2.amazonses.com> |
> On Apr 1, 2021, at 8:12 PM, Anthony Clayden <[email protected]> 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 [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users