pub(all) enum ExamResult {
  Pass
  Fail
}

pub(all) struct Student {
  id : String
  score : Double
}

fn count_qualified_students(students : Array[Student], is_qualified : (Student) -> ExamResult) -> Int

fn fib(n : Int) -> Int64

fn is_qualified(student : Student, criteria : Double) -> ExamResult

fn sum(data~ : Array[Int], start? : Int, length? : Int) -> Int