From the Scalapeño 2013 conference: http://scalapeno.underscore.co.il/ It’s no secret that in Israel, C# is one of the leading languages for development. This stems from various reasons, ranging from the power of the language to the ubiquity of Microsoft’s technologies in government and defense organizations. When it first came out, C# was Microsoft’s answer to Java and the two were on-par. Since then, C# has grown leaps and bounds and Java, while still sitting on top of the powerful JVM with a huge, open ecosystem created over nearly two decades, was left behind. Developers looking to stop paying the Microsoft-tax were faced with a language that simply did not meet their expectations. Scala is the one of the answers to this growing need for a new, modern language for the JVM. This lecture introduces the language, comparing its idioms to those of C#, and introduces you some of the tools and frameworks to get you started with it.

1. Scala for C# Developers
Omer van Kloeten

2. Hi!
 CTO at
 Eight years working in C#
 Two years suffering Java
 Two years enjoying Scala
 newBrandAnalytics
 AppMyDay

3. What is Scala?
 JVM Language
 Academic roots
 Released 2003
 Maintained by TypeSafe
 Continuously updated

4. Why should I care?
 CLR vs. JVM
 The Hummus Manifesto
 Java is old, Scala is the new hotness
 Learn, learn, learn

5. Who uses Scala?

6. Similar Backgrounds
 Trying to replace Java
 Benevolent Dictators
 Design-by-committee sucks!
 Strongly and statically typed
 Object-functional

7. Imperative vs. Functional
Imperative C# Functional LINQ…
…But In Reality

8. Functional First
Functional C# Functional Scala
 Slight differences
 Underscores… underscores everywhere!
 Strict (immediate) vs. Non-Strict (lazy)
 people.view().filter…
 Lots more than we can cover here…

9. Syntax Doesn’t Matter, Right?
C#
 class Foo: Bar, IBaz
 class Foo<TBar>
 interface IFoo
 int foo(string s) { return 42;
}
 ...
Scala
 class Foo extends Bar with Baz
 class Foo[TBar]
 trait Foo
 def foo(s: String) = 42
 ...

10. Syntax Doesn’t Matter,
Defaults Do
C#
 Private by default
 Non-virtual by default
Scala
 Public by default
 Virtual by default
 Java mentality

11. Immutable By Default
 val and var
 C#’s readonly
 lazy val
 .NET’s Lazy[T]
 Collections

12. Tuples and Case Classes
 Tuples
 First-class citizen
 Completely typed

13. Tuples and Case Classes
 Tuples
 First-class citizen
 Completely typed
 Case classes
 Easy, immutable types

14. Everything Is An Expression

15. Pattern Matching: Basics

16. Pattern Matching: Unapply

17. Pattern Matching: Collections

18. Pattern Matching: Summary
 switch/case on steroids
 First-class language construct
 Statically checked for comprehensiveness

19. What Scala Doesn’t Have
 A fast compiler
 C#’s value types
 Built-ins
 Structs
 Enums
 Partial types and methods
 Getters and Setters
 Well, no, but…
 Native for or foreach support

20. Wait, what?!
Well, kinda… ...is translated to:

21. Language Topics Not Covered :(
 Streams
 Type inference
 Tail recursion
 Multiple inheritance
 Operators
 Implicits
 Structural Type Definitions
 Companion objects
 Parallelization and
concurrency
 Monads
 Macros
 Reflection
 More underscores!

22. Tooling and Libraries
 Almost twenty years of Java
 Scala wrappers
 Great community
 Engineers
 Scientists

23. Tooling: IDEs
 Scala plugin
 JetBrains
 of ReSharper fame
 Scala over Eclipse
 TypeSafe
 Maintainers of Scala
NetBeans, Sublime, etc.

24. Tooling: REPL

25. Tooling: Build System
Maven
 Better than Ant
 Bloated
 Written in Java for Java
SBT
 Simple Build Tool
 Irony
 Written in Scala for Scala

26. Frameworks
 Web Frameworks
 Play! Framework
 Lift
 Scalatra
 Object-Relational Mappers
 Slick
 Squeryl
 Unit Testing
 Specs2
 ScalaTest

27. Where Do I Start?
 Base stuff:
 Download and install latest JDK (from oracle.com)
 Go to http://scala-lang.org/downloads, download
and install the MSI
 IntelliJ IDEA:
 Go to http://jetbrains.com/idea/download,
download and install the Community Edition
 Demo

28. Where Do I Start?
 Twitter’s Scala School
 A Tour of Scala
 Another Tour of Scala
 Functional Programming Principles in Scala
 Scala By Example (PDF)
 Programming in Scala (Book)

29. Thank you
Questions?
@omervk