Scala : language of the future

SCALA : language of the future

by Robin SyihabMindtalk: @robin

Twitter: @anvieEmail: robin@mindtalk.com

Scala is

a Modern Programming language.Created by Martin Odersky.Static TypingOOP + FPCompiled into bytecode and run on top of JVM.Java compatible binaries.a better Java.

“If I were to pick a language to use today other than Java, it would be Scala”

~ James Gosling (father of Java).

Scala is

JVM Language

Java & Scala timeline

JVM Languages available today

ScalaGroovyFantomClojureJRubyJythonKotlin

Java & JVML timeline

“The legacy of Java will be the platform, not the language.”~ Martin Fowler (OOP programming expert)

Scala is

Scalable Language

“No other language on the JVM seems as capable of being a

"replacement for Java" as Scala.”~ Charlies Nutter (JRuby lead)

Scala in production

Scala Job Trends

Java vs Scala (syntax)

Java

Scala

Scala

Java

Singleton

Scala

Java

Singleton Use

Scala

Java

Regex

Scala is powerful for functional

programming

Scala

Java

Partitioning

Scala

Java

Calculating average

Scala is more than“syntactic sugar language”

Scala is OOP

http://www.ibs.ro

Scala OOP

Object inheritanceObject and method accessibility (public, protected, private).Static method.Mutable & Immutable variable.

Scala OOP

Everything return value

Traits

Like interfaces in java, butcan have implementationscan have fieldscan mix-in

Scala is Functional

XML LiteralsScala support XML literals inside of code

XML literals

Lazy variable evaluation

Lazy Variable Evaluation

// Use case

Pattern Matching

animal match { case cat:Cat => cat.meow()

case tiger:Tiger => tiger.hoa()

}

Pattern Matching

Pattern Matching: data extraction

Pattern Matching: data extraction + guardian

Implicit definition

http://www.iwallscreen.com

“robin@mindtalk.com”.md5

Implicit definition: View bounds

robin say “hello”

robin.say(“hello”)

Lenient Invocation Syntax

object method parameter

Lenient Invocation Syntax

h(x) = y f(x, y)⟼

Currying Function

We need this simple code run robustly:+ no crash when exception happen.+ handle unicode UTF-8 correctly.+ no memory leak.

Currying Function

Currying Function

Partial Function

http://bertzzie.com

Partial Function

PipeliningPattern Matching

Partial Function: Pipelining

Execution

Partial Function: Pipelining

Partial Function: Pattern Matching

Parameter

Partial Function: Pattern Matching

ActorConcurrent Programming

When to use Actor?

If we want to build distributed system.Handle massive concurrent request.Needs for build event-driven asynchronous application.High performance lightweight than Thread.

Scala Actor Local

Akka Actor: Distributed

100.10.10.1

Actor A

100.10.10.2

Actor B

100.10.10.3

Actor C

100.10.10.4

Actor D

event stream

http://akka.io/

Akka Actor

Support local & remote actorSelf-healing using supervisorDecentralized

Adaptive load balancing Configuration-driven

ExtensibleSmall memory footprint ~2.5 million actors per GB of HeapEvent stream easy to handle cluster state

Akka Actor in production

TDD in Scalahttp://lostechies.com

Scala testing framework

ScalatestJUnitSpec2Gatling (performance test)

Specs2 Unit test

Specs2 Acceptance test

Specs2

Ok thats sound interesting,but wait...

how with the development tools?

http://www.thetinylife.com

Development tools

IDE

Scala-IDE (eclipse based)

NetBeans

IntellijIdea

Emacs (ENSIME)

Build System

Maven

SBT (Simple Build Tools)

Project generator

Giter8

JRebel (incremental development)

giter8

Build Scala “hello world”application in minute

Thank you