[+] def foldLeft ( z: B ) ( op: (B, A) => B ) : B

[+] def foldRight ( z: B ) ( op: (A, B) => B ) : B

[+] def foreach ( f: A => Unit ) : Unit

[+] def head : A

[+] def indexWhere ( p: A => Boolean ) : Int

[+] def isEmpty : Boolean

[+] def iterator : Iterator [ A ]

[+] def view : View [ A ]