Fix the input type of Operators.toRichTraversable

[joshualande]

I could be missing something obvious, but I think Operators.toRichTraversable should take a TraversableOnce instead of a Traversable. This will allow it to be less restrictive in the input types that it allows.

Currently:

scala> import com.twitter.algebird.Operators.toRichTraversable

scala> val x: Traversable[Int] = Traversable(1, 2, 3)
x: Traversable[Int] = List(1, 2, 3)
scala> x.monoidSum
res11: Int = 6

scala> val y: TraversableOnce[Int] = Traversable(1, 2, 3)
y: TraversableOnce[Int] = List(1, 2, 3)
scala> y.monoidSum
<console>:17: error: value monoidSum is not a member of TraversableOnce[Int]
              y.monoidSum
                ^

With my fix:

scala> val y: TraversableOnce[Int] = Traversable(1, 2, 3)
y: TraversableOnce[Int] = List(1, 2, 3)

scala> y.monoidSum
res0: Int = 6

[joshualande]

Hmm, it looks my branch didn't build, but I can't figure out what the issue was (https://travis-ci.org/twitter/algebird/jobs/121875937). Does anybody know why it failed?

[isnotinvain]

from the log looks like it got stuck:

No output has been received in the last 10 minutes, this potentially indicates a stalled build or something wrong with the build itself.

If you hit the restart button it may just work.

[isnotinvain]

Is TraversableOnce the right type here? Reading the scala docs, TraversableOnce is the common type between Iterator and Traverseable so that sounds right -- does that imply that Traversables themselves can only be iterated a single time? I can't seem to find that contract.

[joshualande]

Hi Alex!

Apparently I would need write access to Algebird to restart the build: http://stackoverflow.com/questions/17606874/trigger-a-travis-ci-rebuild-without-pushing-a-commit. Is there any chance that you or another owner could restart the build?

Concerning your comment about types, the RichTraversable type takes a TraversableOnce so allowing toRichTraversable to take a TraversableOnce will allow a larger range of objects to be passed into the function.

Does that make sense!

Joshua

[isnotinvain]

Yeah that makes sense. I'll restart the build for you.

[joshualande]

@isnotinvain thanks so much!!!

[joshualande]

@isnotinvain looks like all tests pass now!!! Thanks for your help!

[joshualande]

@johnynek thanks so much for the help!!!

[johnynek]

@joshualande thank you!