Scala`Application不带参数`编译错误

Question

I am trying to come up with a simple function that takes a function and list of integers and apply the function on every integer in the list -

    def IntOps(f: Int => Int)(values: List[Int]): Int = {
     if(values.isEmpty) 0
     //Getting "Application does not take parameters" in values.tail
     else IntOps(f(values.head)(values.tail))
    }
    IntOps(x=> x+x)(List(1, 2, 30)

I am getting a compiler error Application does not take parameters on values.tail , I am beginner to both Functional programming and scala so any pointers or answers to understand this would be great.

Answer 1

This line of code has two problems.

IntOps(f(values.head)(values.tail))

1. Errant parenthesis - IntOps takes two parameter lists with one parameter in each.
2. Wrong type of 1st argument - The 1st argument needs to be a function Int => Int , which is what f is, but you're invoking f , which returns an Int , which isn't what IntOps requires.