Scala for n00bs by a n00b.
- 1. A quick introduction to: BRANDON L. GULLA CS722 - FALL 2014
- 2. History of Scala Founded in 2001 by Martin Odersky at the Ecole Polytechnique Fédérale de Lausanne in France (surprise). Wanted to create a language to solve functional programming problems from the research/scientific fields while maintaining the awesomeness that comes with object-oriented programming languages such as Java. Scala's codebase had roots in Martin's previous work named Funnel. Martin was lazy* though... *you'll get the pun later.
- 4. Java as a foundation. Odersky decided to create his new language on top of the Java Virtual Machine. Scala is actually a library included in the Java CLASSPATH. Martin decided to make the Scala language translate into Java byte code, a instruction set that could be read on everything from toasters to high-end enterprise work stations. Confused?
- 5. Java Byte Code, Demystified
- 6. What's Scala look like? Hello World! • Scala source code files are saved as ___.scala just like ___.java • You compile scala with the scalac tool (included in the scala binary libraries)
- 7. But I like bells and whistles... Scala was born to solve functional problems that mathematicians and Data-Scientists were facing. Just because the language is powerful for extremely nerdy problems, it doesn't mean that it can't be pretty too! Since Scala shares the same VirtualMachine as Java, it can actually use ANY Java package available, including GUI libraries such as Swing!
- 9. But Why Scala? Isn't Java awesome enough? No! Well, actually Java is pretty awesome, but you can extend that awesomeness in Scala by using the same packages! Example: import apache.commons.io._ Scala was created to meet the increasing scalability concerns of distributed computing clusters. Big Data Big Data Big Data.
- 10. How is Scala Different?... Like languages such as SmallTalk and Objective-C, everything in Scala is an object. There are no primitives in Scala (int, double, etc) but have been replaced by Int, Double, Float, etc. Even operators (+,-) are objects and thus can be re-defined! Lambda / Anonymous Functions: Scala allows you to create anonymous or Lambda functions. Lambda functions are functional definitions that are not bound to an identifier. They are often passed to another function as an argument. An example is below. You can actually pass a function as an argument parameter to another function!
- 11. How is Scala Different?... (continued) Reduced boilerplate. Map Reduce job in Java takes ~130 lines, but it only takes 4 lines in Scala. val s = for (x <- 1 to 25 if x*x > 50) yield 2*x While everything is technically an object, Scala is a strictly-typed programming language. This is a huge improvement over previously used programming languages such as python and ruby. Scala code can be decompiled to readable Java code, with the exception of certain constructor operations. The return operator is unnecessary in a function (although allowed); the value of the last executed statement or expression is normally the function's value. Polymorphism in Scala is identical to Java.
- 12. How is Scala Different?... (continued some more ) Functions do not need parenthesis to be called. Function or method foo() can also be called as just foo and method foo.toString() can also be called as just foo toString. Default visibility in Scala is ‘public’. It's fast.
- 13. Scala can be run in an interactive shell!
- 14. Examples
- 16. Future of Scala in Industry
- 17. Scala is the Hipster of Programming Languages
- 18. • Who Uses Scala?
- 19. Questions? ****( I'm no expert, so be nice) Scala is open-sourced! Check it out on GitHub (github.com/scala) Check out books such as Scala for the Java Developer and Scala for the Impatient.