Default error handlers

Question

Default error handlers

Closed this issue 5 years ago · 4 comments

Once any IO inside Scenario.eval() fails with some exception an application halts.
Can we implement a way of handling such exceptions inside scenarios? For example it would be useful to convert such handled exceptions into human-readable message.

Answer 1 · 2019-10-08T12:47:38.000Z

@augustjune, I can help implementing new features.

Answer 2 · 2019-10-08T17:13:34.000Z

Hi, thank you for your involvement.

I know this issue can be annoying (and dangerous) and actually I am working on this right now.
More specifically, I am thinking about providing MonadError instance for Scenario for F which are capable of error handling (which are most of the IO types people use). This is not complicated from the implementation point, but I have to consider the implications this will bring for Scenario type.

Answer 3 · 2019-10-09T21:27:03.000Z

Just finished the PR #59
Going to add a couple more enhancements and release it with v0.2.0

Answer 4 · 2019-10-17T16:55:47.000Z

With 0.2.0 release, new methods for error handling were added to Scenario.
You can use handleErrorWith and attempt directly on your scenario now in order to handle potential errors.
Additionally, there's MonadError instance for Scenario if you use it with effect-like F, so you have access to other methods like recover.