Calling an anonymous function from its own body

Hello,

I had a question regarding recursion calls to anonymous function.

Suppose I have an anonymous function and I want to make it recursive:

x => if x == 0 then 0 else x + callToItself(x - 1)

Obviously, callToItself is not valid syntax, but is there a way to implement this in Scala ? I think it would be nice if we could do that without having to use named functions like this, which clutters the code in my opinion:

x => 
    def f(x): Int => Int = if x == 0 then 0 else x + f(x - 1)
    f(x)

I've thought of using this.apply but it does not compile either.