Question

class X extends Map[String, String] {
    def x(): X = { X() } // can't be compiled
}

can’t be compiled, the error is:

<console>:6: error: not found: value X
def x(): X = { X() } // can't be compiled

Why is X not found? I can’t see how to correct it.

---

UPDATE:

I know the reason now. What I want to do is create a class which extends HashMap, since Map() will return an instance of HashMap, so I thought I can just extends Map. Now, the correct code should be:

import scala.collection.immutable.HashMap
class X extends HashMap[String, String] {
    def x(): X = { new X() }
}

Answer 1

Try new X() instead of X() — you’ll get another error, but it’ll set you on the right track I believe.

In the latter case it is trying to invoke apply upon the expression denoted by X (e.g. imagine where X is defined as object X or val X) and not trying to invoke the constructor for class X.

Happy coding.