I'm still in favor of adding `EitherT` to `transformers` in addition to `ErrorT`. The only person who disagreed the last discussion was Ross, so it's a matter of convincing him. On Tue, Aug 13, 2013 at 1:36 AM, David Luposchainsky < dluposchainsky@googlemail.com> wrote:
Morning,
Another discussion that didn't reach conclusion: "Proposal to solve the `EitherT` problem." Let's do some proposal cleanup :-)
On 2013-06-16 23:52, Gabriel Gonzalez wrote:
Approach 2: Add `EitherT` to `transformers` alongside `ErrorT` and have them both implement `MonadError`.
That's the one I would recommend.
- Doesn't break anything, and gets rid of the "exception-vs-error" discussion.
- Not all uses of Either are to distinguish between success and failure, sometimes it's just a convenient way of short-circuiting.
- Fits in well with all the other transformers of type "MonadT".
- MonadError instance makes possible use as throw-catch-y transformer clear.
David