What is the syntax meaning of “`class declaration head` { val_name : Type => `class body` }”

Question

When reading some articles about Scala, I found some examples with a curious syntax, which I might understand incorrectly

class Child[C <: Child[C]]         


        

Answer 1

In addition to the inheritance requirement in JaimeJorge's response, self types can be used to give the outer instance a name if you want to refer to it from an inner class:

scala> class Company(name: String) {
     |   company =>
     |   class Department(name: String) {
     |     override def toString = "Department "+ name +" of "+ company.name
     |   }
     | }
defined class Company

scala> val c = new Company("ACME")
c: Company = Company@56a57bb2

scala> val d = new c.Department("Marketing")
d: c.Department = Department Marketing of ACME