Scala有智能编译器吗？ [英] Scala has smart compiler?

问题描述

我做了递归函数，就像

require : L (List[Int])

L模式匹配

1. 无=> Thread.dumpStack（）


2. x :: xs => print（x）+ function（xs）

1. Nil => Thread.dumpStack()
2. x :: xs => print(x) + function(xs)

def function(L : List[Int]) {
    L match {
        case Nil => Thread.dumpStack()
        case x :: xs => print(x + " "); function(xs)
    }
}

val l =（1至5 ）.toList //
function（l）

val l = (1 to 5).toList // function(l)

所以我认为此函数在堆栈帧中存在n次，但它发生一次，我认为此函数已经找到 Nil 并打印出异常 Thread.dumpStack 。

So I think this function in the stack frame n times, but it occurs one time, I think this function has already found Nil and print out exception Thread.dumpStack.

scala编译器是智能的还是其他？

Is scala compiler smart or other else?

推荐答案

您正在观察尾递归：从一次迭代到下一次迭代没有什么可存储的，因此编译器实质上将递归转换为while循环。 （所以，是的，编译器很聪明。）

You are observing tail recursion: there is nothing to store from one iteration to the next, so the recursion is essentially turned into a while loop by the compiler. (So, yes, the compiler is smart in that way.)

这篇关于Scala有智能编译器吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！