supporting doobie about eff HOT 5 CLOSED

I think an eff-doobie module sounds like a good idea. I have a few gripes with your implementation:

a) It's fixed to Task, instead of an arbitrary catchable, suspendable monad as in doobie-fs2 proper (which I'm calling Out[_])
b) There is no reason to have an output of Eff[fx1[Out], A], because all you need is an Out[A]. Logically as well this makes sense, because collapsing all of the binds is required for correct error handling behavior.
c) Is there no built-in way in doobie to do all of this error handling and recovery logic?

Feel free to open a PR though.

from eff.

Thanks, in that case I think I'm going to give it a shot (after addressing #98).

a) It's fixed to Task, instead of an arbitrary catchable, suspendable monad as in doobie-fs2 proper (which I'm calling Out[_])

Yes, I'll make sure to use the same monad restrictions as in doobie-fs2.

b) There is no reason to have an output of Eff[fx1[Out], A], because all you need is an Out[A]. Logically as well this makes sense, because collapsing all of the binds is required for correct error handling behavior.

Ah I see, you mean it's better to output directly (in this case) a Task[A] (using .detach)?

c) Is there no built-in way in doobie to do all of this error handling and recovery logic?

Yes, the Transactor has a Strategy which contains all the configurable bits (before, after, oops, and always). You can then use Strategy.wrap to apply this logic to ConnectionIO program or Strategy.wrapK to apply this logic to a Kleisli[F, Connection, ? program. But I'm not quite sure how to obtain a raw ConnectionIO or Kleisli[F, Connection, ? program form a generic stack in Eff, but we can discuss it in more detail when I prepare an initial PR.

from eff.

Sure. Just so you know, you cannot do the last thing you mentioned. The effects may not commute over ConnectionIO, you need ConnectionIO to be the only thing in the stack. As well I would need to see tests that the interpreter preserves ConnectionIO's transactions without splitting them into smaller transactions.

from eff.

Started working on this, but won't be able to release it before the release of doobie 0.4.2 (0.4.1 does not contain the new Transactor design that is needed).

from eff.

This is merged into master now.

from eff.