Where should evaluate live?

[ocharles]

I find myself often wanting or needing evaluate, but the one from base requires liftIO. This seems like a shame, given that we have MonadThrow (Eff es). Should effectful provide it's own evaluate? Should it be added to MonadThrow?

[arybczak]

Having evaluateEff :: a -> Eff es a (given that instances of classes from exceptions are always available) sounds reasonable to me.

[arybczak]

Actually, I think I'll add Effectful.Exception module to effectful-core that just exports Control.Exception.Safe fromsafe-exceptions and then evaluate and evaluateDeep can be added there. It'll also improve discoverability, since some people miss that effectful works out of the box with MonadThrow/MonadCatch/MonadMask.

It's tempting to export Control.Monad.Catch from exceptions instead to avoid the extra dependency, but over the years I realized that safe-exceptions makes it way easier to write code that handles async exceptions properly (especially for people who are not experts in the matter) and ultimately this is more important.

[ocharles]

That sounds good to me. Would you also specialize all of this to Eff?

[arybczak]

No, simply re-export the module since it works out of the box. I like avoiding unnecessary work ;)

[arybczak]

Done in #252.