With the advent of multi-core processors concurrent programming is becoming indispensable. Scala's primary concurrency construct is actors. Actors are basically concurrent processes that communicate by exchanging messages. Actors can also be seen as a form of active objects where invoking a method corresponds to sending a message. The Scala Actors library provides both asynchronous and synchronous message sends (the latter are implemented by exchanging several asynchronous messages). Moreover, actors may communicate using futures where requests are handled asynchronously, but return a representation (the future) that allows to await the reply. This tutorial is mainly designed as a walk-through of several complete example programs Our first example consists of two actors that exchange a bunch of messages and then terminate. The first actor sends "ping" messages to the second actor, which in turn sends "pong" messages back (for each received "ping" message one "pong" message).
Buildr is a build system for Java applications in Ruby Maven compatible * A simple way to specify projects, and build large projects out of smaller sub-projects. * Pre-canned tasks that require the least amount of configuration, keeping the build script DRY and simple. * Compiling, copying and filtering resources, JUnit/TestNG test cases, APT source code generation, Javadoc etc * A dependency mechanism that only builds what has changed since the last release. * A drop-in replacement for Maven 2.0, Buildr uses the same file layout, artifact specifications, local and remote repositories. * All your Ant tasks belong to us! Anything you can do with Ant, you can do with Buildr. * No overhead for building “plugins” or configuration. Just write new tasks or functions. * Buildr is Ruby all the way down. No one-off task is too demanding when you write code using variables, functions and objects. * Simple to upgrade to new versions. * fast