Stefan Tilkov:
Ruby ? die Programmiersprache der Zukunft
(Ruby ? Programming Language of the Future)

Why Ruby?

• it's different
• it supports growth
• it's expressive
• it's concise
• we can afford it
• Rails!
• it's fun

Quick Intro

• Type system: dynamic, strong, implicit
• interpreted (mostly...)
• very dynamic
• strong metaprogramming support
• purely object-oriented

code examples...

• loops
• lists and operations on lists
• hashes

comparison von Java code and Ruby code
to sort an array by lenght of elements

• methods
• classes

#{variableName} in string literals is
replaced by the variable's value

• inheritance
• modules (kind of container for methods)
• "getters" and "setters" (properties!)
• Attribute Accessor: short cut for properties (nice )

Metaprogramming with Ruby


Structures

Struct.new "Person", :first_name,
:last_name creates new class


Creating objects and classes by name

Kernel.const_get('String').new "Teststring"
creates String object

Test = Class.new


Indivual object methods

class << t1

def
object_method ...


Classes and constants


Runtime Definitions


Methods adding methods


Adding methods to existing classes like
String: (Re)opening classes


method_missing: Method called, when
a missing method is called, with name of called method as argument


short, declarative notation is "expanded"
to many method definitions



Ruby language implemenations

• MRI = Matz's Ruby Interpreter
• YARV = Yet anthother Ruby VM
• Rubinius: "Ruby in Ruby"
• JRuby: "Ruby in Java"

Ruby vs. other dynamic languages


Perl

• many libraries
• "write only" reputation
• weak (wierd) OO features
• very fast

Python

• great community
• extensive libraries
• extremely fast

Jython

• JVM version of Python
• neglected for a long time
• now supported by Sun

Groovy

• designed for the JVM
• supposedly easier for Java developers

Summary

Ruby: nice, concise, object-oriented
language

Killer feature: metaprogramming support

Killer framework: Ruby on Rails