Ubaldo Pescatore ubaldop

Getting Started in Scala

This is my attempt to give Scala newcomers a quick-and-easy rundown to the prerequisite steps they need to a) try Scala, and b) get a standard project up and running on their machine. I'm not going to talk about the language at all; there are plenty of better resources a google search away. This is just focused on the prerequisite tooling and machine setup. I will not be assuming you have any background in JVM languages. So if you're coming from Python, Ruby, JavaScript, Haskell, or anywhere… I hope to present the information you need without assuming anything.

Disclaimer It has been over a decade since I was new to Scala, and when I was new to Scala, I was coming from a Java and Ruby background. This has probably caused me to unknowingly make some assumptions. Please feel free to call me out in comments/tweets!

One assumption I'm knowingly making is that you're on a Unix-like platform. Sorry, Windows users.

Getting the JVM

Advanced Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

	#!/bin/bash

	################
	# Uncomment if you want the script to always use the scripts
	# directory as the folder to look through
	#REPOSITORIES="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
	REPOSITORIES=`pwd`

	IFS=$'\n'

	-module(assignment1).
	-export([perimeter/1, area/1, enclose/1, bits/1, directBits/1]).

	%%%ASSIGNEMENT ABOUT perimeter, area and enclose functions

	perimeter({'circle', {_X,_Y}, R}) -> (R+R)*math:pi();
	perimeter({'rectangle', {_X,_Y}, H,W}) -> (H+W)*2;
	perimeter({'triangle', {_X,_Y}, A,B,C}) -> A+B+C.

	area({'circle', {_X,_Y}, R}) -> (RR)math:pi();

	-module(pattern_matching).
	-export([exclusiveOr/2,exclusiveOr2/2,exclusiveOr3/2, maxThree/3, howManyEquals/3]).

	exclusiveOr(X,Y) ->
	not(X==Y).

	exclusiveOr2(X,Y) ->
	(X=/=Y).

	exclusiveOr3(X,Y) when (X and Y) -> false;

	#!/bin/bash

	if [[ $# -le 1 ]] ; then
	echo 'No plugins parameters provided. Please run the script with a plugin type and name. (e.g.: devices persistence)'
	exit 0
	fi

	freedomoticHome=$(pwd)

	echo "Building freedomotic..."

	Loading global plugins from /home/user/.sbt/0.13/plugins
	Loading project definition from /home/user/development/scala/scalagoon/myplugin/project
	Set current project to myplugin (in build file:/home/user/development/scala/scalagoon/myplugin/)
	[warn] Binary version (2.11) for dependency org.scala-lang#scala-library;2.11.8
	[warn] in it.flatmap#myplugin;0.0.1 differs from Scala binary version in project (2.10).
	Wrote /home/user/development/scala/scalagoon/myplugin/target/scala-2.10/sbt-0.13/myplugin-0.0.1.pom
	:: delivering :: it.flatmap#myplugin;0.0.1 :: 0.0.1 :: integration :: Thu Nov 10 19:46:49 CET 2016
	delivering ivy file to /home/user/development/scala/scalagoon/myplugin/target/scala-2.10/sbt-0.13/ivy-0.0.1.xml
	Packaging /home/user/development/scala/scalagoon/myplugin/target/scala-2.10/sbt-0.13/myplugin-0.0.1.jar ...
	Done packaging.

	# -- mode: ruby --
	# vi: set ft=ruby :

	box = 'ubuntu/trusty64'
	hostname = 'emberclibox'
	domain = 'example.com'
	ip = '192.168.42.42'
	ram = '512'

	$rootScript = <<SCRIPT

	#!/bin/bash

	if [ ! -f ~/runonce ] #here the check is on the root home directory
	then
	echo ':::: setting up liquidprompt to vagrant machine ::::'

	echo "Installing liquidprompt..."
	cd /home/vagrant/
	git clone https://github.com/nojhan/liquidprompt.git
	source liquidprompt/liquidprompt