```fun example(computeFoo: () -> Foo) { val...

# announcements

[karelpeeters]

fun example(computeFoo: () -> Foo) {
    val memoizedFoo by lazy(computeFoo)
    if (someCondition && memoizedFoo.isValid()){
        memoizedFoo.doSomething()
    }
}

Let's say computeFoo is a slow function, and we want to avoid calling it whenever possible. In the above code, if someCondition == false the && will "short-circuit", meaning it won't even bother to evaluate the right side since false && x is guaranteed to be false. That means that the code behind lazy doesn't call computeFoo at all. If on the other hand someCondition == true, memoizedFoo.isValid() will be evaluated, lazy will call computeFoo and the result will be available in memoizedFoo.