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Scala 2.12.0-RC1 released

issues.scala-lang.org

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Re: Scala 2.12.0-RC1 released

#11

too bad they require JDK8 while App Engine supports only JDK7 :(

doesn't the Flexible Environment fit for you? https://cloud.google.com/appengine/docs

i haven't explored it, but from cursory look it's more "work" (and more expensive) than the one that comes out-of-the-box

Re: Scala 2.12.0-RC1 released

#12
post #4

too bad they require JDK8 while App Engine supports only JDK7 :(

What does this mean? They probably require JDK8 for compiling/building the class files, but can you target 1.7? See target flag for javac ( http://stackoverflow.com/a/21206909 )

You can only make use of the target flag when not making use of new bytecodes oder APIs introduced in a specific Java version.

Scala 2.12 is replacing some of their own code with Java 8 new features, so they rely on a Java 8 compatible JVM.

This will also prevent Scala 2.12 to target Android, because even Android N isn't 100% Java 8 compatible, specially the low level JVM features like invokedynamic and method handles are not supported on DEX format.

Re: Scala 2.12.0-RC1 released

#14
Great.

What's the status on performance slowdown wrt to relying on Java 8 default methods in 2.12[1]? Hopefully this is not a JVM limitation[2] and can be sorted out during the RC cycle.

Fewer generated class files and improved performance would very much be a nice-to-have.

[1] http://www.scala-lang.org/blog/2016/07/08/trait-method-perfo...

[2] https://bugs.openjdk.java.net/browse/JDK-8161334

Re: Scala 2.12.0-RC1 released

#16

Great. What's the status on performance slowdown wrt to relying on Java 8 default methods in 2.12[1]? Hopefully this is not a JVM limitation[2] and can be sorted out during the RC cycle. Fewer generated class files and improved performance would very much be a nice-to-have. [1] http://www.scala-lang.org/blog/2016/07/08/trait-method-perfo... [2] https://bugs.openjdk.java.net/browse/JDK-8161334

The blog entry doesn't mention the impact of that performance regression on Scala 3 (aka Dotty).

Re: Scala 2.12.0-RC1 released

#17

Great. What's the status on performance slowdown wrt to relying on Java 8 default methods in 2.12[1]? Hopefully this is not a JVM limitation[2] and can be sorted out during the RC cycle. Fewer generated class files and improved performance would very much be a nice-to-have. [1] http://www.scala-lang.org/blog/2016/07/08/trait-method-perfo... [2] https://bugs.openjdk.java.net/browse/JDK-8161334

The blog entry doesn't mention the impact of that performance regression on Scala 3 (aka Dotty).

Sure, but Dotty is like hindsight, (arriving the year) 2020.

Regardless, there's a significant performance regression to sort out prior to the 2.12 GA. If it is a JVM limitation it won't be solved until at least Java 9 (according to the fix version listed in the bug report), which will mean 2.12 loses one of the stated goals of the release: reduction in number of generated class files (with perhaps slightly faster build times).

Anyway, we'll see in the coming weeks/months if a resolution or workaround manifests.

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