test.swift

func someCondition(_: Int) -> Bool {
    return true
}

func foo() {
    func loop(_ index: Int) {
        if (index < 100) {
            if someCondition(index) {
                return loop(index + 3)
            } else {
                // body
                return loop(index + 1)
            }
        }
    }

    loop(0)
}