如何在scala中返回一个函数

How can I return a function side-effecting lexical closure https://stackoverflow.com/questions/22288329/side-effecting-lexical-closure-vs-function-in-scala¹ in Scala?

例如，我正在看Go 中的代码示例 http://golang.org/doc/play/#598466966704134886:

...    
// 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())

印刷 1 2 3 5 8

我不知道如何在 Scala 中编写相同的内容。

^{1. Corrected after Apocalisp https://stackoverflow.com/questions/4262241/how-to-return-a-function-in-scala/4262932#4262932 comment}

稍微短一点，不需要退货。

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