Whither System.Linq.AsyncEnumerable?

[Damien-The-Unbeliever]

IEnumerable has a companion class - System.Linq.Enumerable - that provides LINQ to Objects implementation.

IAsyncEnumerable doesn't seem to have such a companion. Is this a deliberate decision? I can't find any discussion on this but I may be searching wrong.

In the meantime, I've spent a couple of weekends trying to build my own. It doesn't seem undoable but perhaps there's a reason it's undesirable?

(It is, however, undoubtedly tedious to produce all of the overloads)

[jkotas]

Take a look at https://github.com/dotnet/reactive and https://www.nuget.org/packages/System.Linq.Async

[jkotas]

@bartdesmet @onovotny

[clairernovotny]

/cc @terrajobst

[Damien-The-Unbeliever]

I'm looking for the pull model of enumerable, not the push model of reactive. My own attempt is https://github.com/Damien-The-Unbeliever/Linq.AsyncEnumerable

[svick]

@Damien-The-Unbeliever

I'm looking for the pull model of enumerable, not the push model of reactive.

That's exactly what the System.Linq.Async package offers, since it uses IAsyncEnumerable<T>, even though its source is in the reactive repo.

[bartdesmet]

System.Linq.Async is indeed what you're looking for. See https://github.com/dotnet/reactive/tree/master/Ix.NET/Source/System.Linq.Async for the source. It's 100% isomorphic to System.Linq and has all the operators, including support for cancellation and support for deep asynchrony of predicates, selectors, etc.

[Damien-The-Unbeliever]

Yeah, I see it now. Thanks

[CodingOctocat]

System.Linq.Async is indeed what you're looking for. See https://github.com/dotnet/reactive/tree/master/Ix.NET/Source/System.Linq.Async for the source. It's 100% isomorphic to System.Linq and has all the operators, including support for cancellation and support for deep asynchrony of predicates, selectors, etc.

If I have a IAsyncEnumerable that contains 20 elements, each element takes 1 seconds to get, and if I just want to get the last element, then it takes 20 seconds for me to use Last()?

This is crazy!

I wish I could use IEnumerable so that I could quickly enumerate the elements and then manually await it, but the asynchronous data source forced me to use The IAsyncEnumerable.

[svick]

@CodingNinjaOctocat That sounds like you want IEnumerable<Task<T>>, instead of IAsyncEnumerable<T>. What's preventing you from using that?

[CodingOctocat]

@CodingNinjaOctocat That sounds like you want IEnumerable<Task<T>>, instead of IAsyncEnumerable<T>. What's preventing you from using that?

You're right, I test it over and over again, IEnumerable<Task> is the best choice.

[stephentoub]

#111685 has added System.Linq.AsyncEnumerable.