Making your system ready for Scala (Eclipse)

Scala is a general purpose programming language designed to express common programming patterns in a concise, elegant, and type-safe way. It smoothly integrates features of object-oriented and functional languages, enabling Java and other programmers to be more productive. Code sizes are typically reduced by a factor of two to three when compared to an equivalent Java application.

Scala is supported by major java ide, which is comprised of eclipse, IDEA and netbeans. I choose eclipse plugin because I am more familiar of it.

Steps on installing scala-eclipse plugin:

1. In your eclipse, go to Help -> Install New Software.
2. If you want to install the niggler build of the plugin go to this site:

http://scala-ide.org/download/nightly.html

choose any of the 4 update site there. I choose the For Scala 2.10 master trunk.

If you want to install the stable version of the plugin go to this site:

http://scala-ide.org/download/current.html

and choose between Scala 2.9.x support or 2.8.x support.

3. If you are a maven user and want a better integration of maven for scala, you can use this update site:

http://alchim31.free.fr/m2e-scala/update-site/.

If installation failed, you can download the maven-eclipse-scala plugin manually in this site: https://github.com/sonatype/m2eclipse-scala/downloads. I downloaded the 0.2.3 version. then install it locally through: go to Help -> Install New Software -> Add -> Archive then browser the downloaded maven-eclipse-scala .jar file then okey

Tween Eclipse

Scala IDE is a resource eater. The default resource allocated by eclipse will not be enough to make the most of Scala IDE. You will need to tween the eclipse.ini and add this codes

--launcher.XXMaxPermSize

256m

-vmargs

-Xms256m

-Xmx1024m

-XX:PermSize=64m

-Xss1M

-server

-XX:+DoEscapeAnalysis

launcher.XXmaxPermSize is the maximum PermGen size of the launcher

All values after -vmargs are arguments meant for the JVM, this means that the Minimun HEAP size is 256m and its maximum capacity is 1024m (defined by -Xms and -Xmx). The initial PermGenSize of the VM is 64m (-XX:PermSize). The size of the stack for each thread is 1m defined by -Xss. The last argument says the vm can do Escape Analysis that means that it  will only be available on servers by means of -server properties.

Options:

You can also show Heap Status by going to Preference -> General -> Check Show heap status. With this you can manually trigger GC.

Resources

http://www.scala-lang.org/node/25

http://www.scala-ide.org/