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RheinJUG 2010 - Sprechen Sie Scala?
This document discusses the Scala programming language. It begins by asking why Scala should be used instead of Java on the JVM. It then provides quotes from experts like James Gosling and Charles Nutter saying Scala is the heir to Java and they would have used Scala instead of creating other languages if they knew about it earlier. The document then discusses key aspects of Scala like being object-functional, statically typed, expression-oriented, concise, pragmatic and interoperable with Java. It concludes by advertising live demos that will showcase features like classes, testing with ScalaTest, implicit conversions, functional programming with lists, traits, type parameters and pattern matching.
RheinJUG 2010 - Sprechen Sie Scala?
- 1. SPRECHEN SIE SCALA? Heiko Seeberger, WeigleWilczek rheinjug Düsseldorf, 18.03.2010
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- 3. WARUM SCALA? Which ProgrammingLanguage would you use now on top of JVM, except Java? - Scala. James Gosling
- 4. WARUM SCALA? Scala, itmust be stated, is the current heir apparent to the Java throne. Charles Nutter
- 5. WARUM SCALA? I canhonestly say if someone had shown me ... Scala ... back in 2003 I'd probably have never created Groovy. James Strachan
- 6. obje eift kt-fu pis iert a us ger nkti ona tisc h ty l sta leich ark tgew sst icht ig WAS IST SCALA? au sdr uck knap inte rope p un d pr ati sch rabe äzis e p ragm l mit Java
- 7. Seit 2003 Version 2.8 AUSGEREIFT
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- 9. Any AnyVal AnyRef Int Unit ScalaObject Long scala.* val scala.* ref java.* ref Null Nothing ALLES IST EIN OBJEKT
- 10. Keine Seiteneffekte 1, 2, 3 f a, b, c Funktionen höherer Ordnung FUNKTIONALE PROGRAMMIERUNG
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- 12. Semicolon Inference Type Inference Infix Operator Notation Implicit Conversions LEICHTGEWICHTIG
- 13. AUSDRUCKSSTARK "Calling Person.toString" when{ "first and last name are not-empty" should { "return first name blank last name" in { val person = new Person("John", "Doe") person.toString should be ("John Doe") } } }
- 14. KNAPP UND PRÄZISE publicclass Person { // Java private final String firstName; private final String lastName; public class Person(val firstName: String, Person(String firstName, String lastName) { val lastName: String) this.firstName = firstName; this.lastName = lastName; } public String getFirstName() { return firstName; } public String getLastName() { return lastName; } }
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- 16. INTEROPERABEL MIT JAVA scala>import org.apache.log4j._ import org.apache.log4j._ scala> val testLogger = Logger getLogger "test" testLogger: org.apache.log4j.Logger = ... Wichtig!
- 17. LIVE DEMO: HELLOWORLD
- 18. Klas sen- as sen Para thoden Kl m eter M e LIVE DEMO: OO-GRUNDLAGEN Defa Com ult-Ar pan gum Fe lder ion Obje ente cts
- 19. rkz eug st- We Te LIVE DEMO: SCALATEST DSL -Bei spie l
- 20. Für Libr ary-E ntw icklu ng LIVE DEMO: IMPLICIT CONVERSIONS pra che rbare S Skalie
- 21. Unv Type erän Infe ato ren Obje derl iche renc e O per kte LIVE DEMO: FUNKTIONALE LISTE nen g Funk ktio nun Fun Ord tion slite tio nen rer rale Funk h öhe
- 22. Meh rfac hver erbu ng r icht ig ge mac ht LIVE DEMO: TRAITS ns c atio M odifi ackabe St
- 23. Upp ma cht Low er B i g ge er Bo ound i cht und s eri cs r s Gen LIVE DEMO: TYP-PARAMETER i anz Kov aria ari anz In var nz trav Kon
- 24. Swit tern ch rich tern Pat tig g Pat d card ema nst ant Wil c ht Co LIVE DEMO: PATTERN MATCHING Vari ern Seq able att u ence Patt t or P Patt e rn st ruc ern Con
- 25. pra che er S in d L ite rale LIVE DEMO: XML-SUPPORT XPa th-A bfra gen
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- 27. DANKE seeberger@weiglewilczek.com XING Scala-Gruppe