Scala

For this course we will be using Scala. Scala is a mult-paradigm language that embraces both object-oriented and functional models of programming. Like Java, it runs on the JVM and can even use Java classes!

Setting up Ubuntu for Windows 10

Linux is a great tool for developers and it is important that you know are familiar with it for future employment. I am recommending that you use Ubuntu for Windows 10 as your development environment but it is not required. However, it does make installing Scala and other development tools easier so stray at your own peril. Follow these instructions for enabling Windows Subsystem for Linux. Once completed, install Ubuntu Linux for Windows 10.

Setting up Scala

Since Scala runs on Java's JVM, we first need to install the Java JDK. The following command may take a long time.

sudo apt-get install openjdk-11-jdk

Next install Scala by downloading and running my custom install script.

sudo apt-get install curl
wget http://jorr.cs.georgefox.edu/courses/csis430-algorithms/scala/sbt_install
sh sbt_install

Alternative Setups

If you use a Mac, do not have Windows 10, or have strong reservations about using Ubuntu on Windows 10, here are some alternative instructions for setting up Scala.

• Generic instructions for installing Scala
• Scala with Netbeans

Random Writer Example

First ensure that Git is installed.

sudo apt-get update
sudo apt-get install git

Change to whatever directory where you want to keep your code. Let's create a link to your documents then make a fold in there:

ln -s /mnt/c/Users/YOUR USERNAME/Documents/ Documents
cd Documents
mkdir src
cd src

Now download the random writer example.

git clone https://github.com/gfu-csis/csis430-markov.git

Now let's change to the project directory and download some example text

cd csis430-markov
wget http://www.gutenberg.org/cache/epub/10/pg10.txt

You should now see the example project in your documents folder. It should be visible via Ubuntu and the Windows file explorer as well. Build and run the project with the program sbt. sbt will need to download a lot of supporting files which may take awhile.

sbt "run 10 500 pg10.txt"

The output of the program will look something like this.

[info] Loading project definition from /mnt/c/Users/jorr/Documents/src/csis430-markov/project
[info] Loading settings for project csis430-markov from build.sbt ...
[info] Set current project to markov (in build file:/mnt/c/Users/jorr/Documents/src/csis430-markov/)
[info] Compiling 1 Scala source to /mnt/c/Users/jorr/Documents/src/csis430-markov/target/scala-2.12/classes ...
[info] Done compiling.
[info] Packaging /mnt/c/Users/jorr/Documents/src/csis430-markov/target/scala-2.12/markov_2.12-1.0.jar ...
[info] Done packaging.
[info] Running Markov 10 500 pg10.txt
hour was not yet come.8:21 Then said Jesus again unto them, Know ye Laban the son of Nahor? And theysaid, We know him....
[success] Total time: 5 s

Scala API & More

The best part of Scala are its collections, which implement the core of the functional paradigm. Iterable is perhaps the most useful Trait in Scala and I have provide the link to its API, along with some other useful links.

• Iterable
• Seq
• Map
• Scala API
• Scala for Java Programmers

1. GFU
2. CSIS
3. J. Walker Orr
4. CSIS 430
5. Environment