Meaning of Element methods

[Samuele Pretini]

Hi at all,

I'm new student of Scala.

During some test that I'm doing, I have seen the class scala.collection.IndexedSeqLike.Elements

In this class there is a method: aggregate

The signature of the method is the question: 

def aggregate[B](z: ⇒ B)(seqop: (B, A) ⇒ B, combop: (B, B) ⇒ B): B

1. What's mean of  z: => B ?
   
2. What's mean of the 2 parenthesis: (z: ⇒ B)(seqop: (B, A) ⇒ B, combop: (B, B) ⇒ B)

Can someone of us to explain to me?

Thanks a lot. :-)

[som-snytt]

You'll find satisfying answers on http://stackoverflow.com/questions/tagged/scala or possibly quicker answers on https://gitter.im/scala/scala or the scala-user group.

The key phrases are by-name parameter and currying.