[RxScala] rxjava-scalaz: providing some type class instances.

[everpeace]

Introduced 'rxjava-scalaz' project. This project provides some type class instances for Observable.

• Monoid:
  Observable obviously forms a monoid in terms of concatenation.
• Functor, Applicative, Monad, MonadPlus:
  Observable can be a Stream-like Monad and can be MonadPlus as well as Monoid.
• Traverse, Foldable:
  Observable can be Stream-like traversable. Please note that the operations for the instance is blocking calls.
• etc.

About testing, property based tests are applied by Scalaz's ScalaCheck binding.
For getting started, please refer to rx.java.scala.scalaz.examples.RxScalazDemo, or README.md.

Sample Usages

import scalaz._, Scalaz._
import rx.lang.scala.Observable
import rx.lang.scala.scalaz._

Observable.items(1, 2) |+| Observable.items(3, 4)               // === Observable.items(1 2 3 4)
Observable.items(1, 2) ∘ {_ + 1}                                // === Observable.items(2, 3)
(Observable.items(1, 2) |@| Observable.items(3, 4)) {_ + _}     // === Observable.items(4, 5, 5, 6)
1.η[Observable]                                                 // === Observable.items(1)
(Observable.items(3) >>= {(i: Int) => Observable.items(i + 1)}) // === Observable.items(4)

My original proposal is #1167

[cloudbees-pull-request-builder]

RxJava-pull-requests #1195 FAILURE
Looks like there's a problem with this pull request

[cloudbees-pull-request-builder]

RxJava-pull-requests #1196 FAILURE
Looks like there's a problem with this pull request

[cloudbees-pull-request-builder]

RxJava-pull-requests #1197 SUCCESS
This pull request looks good

[cloudbees-pull-request-builder]

RxJava-pull-requests #1202 SUCCESS
This pull request looks good

[benjchristensen]

Looks good to me ... just holding off on merge/release for a few days (for build server reasons).

Once we split RxScala into its own top-level project this looks like it would make sense to be a contrib module of it. Am I correct in that?

[everpeace]

Looks good to me ... just holding off on merge/release for a few days (for build server reasons).

Thanks! OK. I'm looking forward to it.

Once we split RxScala into its own top-level project this looks like it would make sense to be
a contrib module of it. Am I correct in that?

Definitely!
By the way, the plan splitting RxScala was new to me! I'm glad to hear about when it would be occured.

[benjchristensen]

I hope to have it done in the next month or two. Once 0.20 goes out (with #1000 done) then we are ready to move to 1.0 Release Candidates and split the project up.

[everpeace]

Good news. Thanks. Yes, I think backpressure is really nice capability, which provides more flexible flow controllability to users.

[benjchristensen]

So ... this is merged into trunk, but I had issues with the Netflix build system that releases to Maven Central. It had issues with this:

Artifact 'org.scalaz:scalaz-core_2.10:7.0.4@jar' not found.

I couldn't figure it out so let 0.19.2 go without this module and am waiting on someone who knows this stuff better than I helping me.

[everpeace]

Sorry for inconvenience. Please go ahead without this module.
But I'm not sure why this error happens either...

[benjchristensen]

It's something with the Netflix build server because it works fine from CloudBees and my local dev machine.

[everpeace]

It's something with the Netflix build server because it works fine from CloudBees and my local dev machine.

@benjchristensen Did you, or any other guys, get any progress on this issue?

I would be very happy if you would revert the commit (fe83a31) by the next release.

If there is something I could help, please free to tell me.

Thanks,

[benjchristensen]

It is now released in 0.19.6.

[everpeace]

@benjchristensen I really appreciate it!