Not compatible with netcoreapp3.1/netstandard2.1 target

[fradav]

When I choose netcoreapp3.1 target, Fable compilation fails with:

The type 'System.IAsyncDisposable' does not match the type 'IAsyncDisposable

Reverting to netstandard2.0 works.

[dbrattli]

Yes, IAsyncDisposable is now included so we should use that one instead for netcore. https://docs.microsoft.com/en-us/dotnet/api/system.iasyncdisposable?view=netcore-3.1

[fradav]

Unfortunately, the new DisposeAsync returns a ValueTask not an Async. Just avoid the namespace conflict should be the most sensible?

[dbrattli]

Yes, that is probably the the most sensible. Have been working so much with Oryx and Task lately that I've forgot for a moment that AsyncRx is Async 😄.

[fradav]

I see you updated AsyncRx, but you didn't change the name of the interface, so it's still a potential clash and we have to carefully fully qualify everywhere we make an "open System" (and that is often...)
Perhaps it's asking a lot, but would you mind to change IAsyncDisposable for IFSharpAsyncDisposable for example ? I really think it's more future proof.

[dbrattli]

The other option I'm considering is to rewrite the library to Task and use IAsyncDisposable when available. I just need to figure out how to handle this in Fable, but it should map better to promise anyways.

[fradav]

Pardon my ignorance but what's the advantages of Task over Async, other than the former is ubiquitous in .net ecosystem?

[dbrattli]

giraffe-fsharp/Giraffe#53

[fradav]

Ok, I didn't know about performance improvements. What do you think about this https://github.com/pimbrouwers/falco over giraffe ?

[dbrattli]

Haven't tried it. But looking at the data-types of Falco I can see that Giraffe has another trick up its sleeve and uses continuations to improve the speed further: https://medium.com/@gerardtoconnor/carry-on-continuation-over-binding-pipelines-for-functional-web-58bd7e6ea009

[dbrattli]

I use the same trick to speed up Async vs Sync handling for maps and filters i.e https://github.com/dbrattli/Fable.Reaction/blob/master/AsyncRx/src/Transform.fs#L10

Thus map and mapAsync uses the same implementation, without map having to get any penalty for being sync.

[fradav]

Did you see that : fsharp/fslang-suggestions#866 ?

[dbrattli]

Added suggested fix: https://github.com/dbrattli/Fable.Reaction/blob/master/AsyncRx/src/Builder.fs#L39

Name of interface renamed to IAsyncRxDisposable.

[dbrattli]

Closing as this issue should be fixed. Please re-open if you find any problems.

[fradav]

Everything works fine, many thanks!
Thanks also for this neat and cleanly designed Fable library. I must admit it is the main reason I'm sticking with Fable/F# for frontend projects.
I think it is a very nice implementation of the meiosis pattern