Scala :: operator, how it works?
- by Felix
Hello Guys,
in Scala, I can make a caseclass case class Foo(x:Int) and then put it in a list like so:
List(Foo(42))
Now, nothing strange here. The following is strange to me. The operator :: is a function on a list, right? With any function with 1 argument in Scala, I can call it with infix notation.
An example is 1 + 2 is a function (+) on the object Int. The class Foo I just defined does not have the :: operator, so how is the following possible:
Foo(40) :: List(Foo(2))
?
In scala 2.8 rc1, I get the following output from the interactive prompt:
scala> case class Foo(x:Int)
defined class Foo
scala> Foo(40) :: List(Foo(2))
res2: List[Foo] = List(Foo(40), Foo(2))
scala>
I can go on and use it, but if someone can explain it I will be glad :)
