a first Hello World class
add a simple Money class
added toString
implemented hashCode and equals and toString and a niche helper function, by deleting code
adding money

+ is a legal operator
the result type is optional
throwing an exception actually has the type Nothing
if isn't a statement, but an expression
seperated Money trait from SingleCurrency implementation

a trait is like an interface
pattern matching including a guard clause
companion object as singleton, and for simple object creation
MoneyBag   way to much stuff

companion objects
foldLeft
getOrElse
varargs
the double parens problem of Scala
Tuples
Maps
used -> instead of plain tuples
adding of simpleCurrencies of different currency
adding tests for small lessons
MoneyBag, first tests
adding different currencies
adding of money bags
Merge branch 'master' of github.com:schauder/scalatutorial
Erste Aufgaben
add worksheet about the difference of append with Set and Seq
flatMap und map
tupel
Typo gefixt, ein wenig umsortiert
Option, Some, None