Instance for `Eff`?

Question

Instance for `Eff`?

natefaubion opened this issue 9 years ago · 7 comments

Is there a reason for there to not be an instance for Eff proper? I know in JS its "technically" not parallel. But if Eff was implemented on a true multi-threaded platform like the JVM, it definitely would be possible. Also I'd argue that a MonadPar instance for Eff is no different than MonadPar for Aff where you liftEff everything.

Answer 1 · 2016-08-19T16:33:07.000Z

I think it's a reasonable law that par f x y be observationally identical to par (flip f) y x and that seems false for Eff.

Answer 2 · 2016-08-19T16:34:50.000Z

That law does not necessarily hold for Aff.

Answer 3 · 2016-08-19T16:36:56.000Z

In fact it doesn't hold for anything that supports synchronicity on platforms without multithreading.

Answer 4 · 2016-08-19T16:39:29.000Z

Is the suggested instance par = liftA2?

Answer 5 · 2016-08-19T16:40:12.000Z

The suggested instance is implemented via the FFI, such that a platform that has true multithreading could have a better implementation.

Answer 6 · 2016-08-19T16:40:56.000Z

But yes, for the JS platform, that's what it would be.

Answer 7 · 2021-12-04T16:31:48.000Z

I'm guessing this issue applies to Effect now rather than Eff.