如何在Scala中返回函数

Question

How can I return a function side-effecting lexical closure¹ in Scala?

For instance, I was looking at this code sample in Go:

...    
// fib returns a function that returns
// successive Fibonacci numbers.
func fib() func() int {
    a, b := 0, 1
    return func() int {
        a, b = b, a+b
        return b
    }
}
...
println(f(), f(), f(), f(), f())

prints 1 2 3 5 8

And I can't figure out how to write the same in Scala.

^{1. Corrected after Apocalisp comment}

Answer 1

Slightly shorter, you don't need the return.

def fib() = {
    var a = 0
    var b = 1
    () => { 
        val t = a;
        a = b
        b = t + b
        b
    }
}