Are any JavaScript engines tail call (TCO) optimized?

Question

我有一个用 JavaScript 实现的尾递归寻路算法，想知道是否有任何（所有？）浏览器可能会出现堆栈溢出异常。

Answer 1

The ECMAScript 4 specification was originally going to add support for TCO, but it was dropped:

No more tail calls in JavaScript?

As far as I know, no widely-available implementations of JavaScript currently do automatic TCO. This may be of use to you, though:

Tail Call Optimization

Essentially, using the accumulator pattern accomplish the same effect.

Answer 2

暂时没有快乐，但幸运的是，Harmony（ECMAScript 版本 6）有适当的尾调用http://wiki.ecmascript.org/doku.php?id=harmony:proper_tail_calls

Answer 3

Pretty much every browser you encounter will barf on "too much recursion". Here's an entry in the V8 bug tracker that will probably be interesting reading.

If it's simple self-recursion, it's probably worth the effort to use explicit iteration rather than hoping for tail-call elimination.

Answer 4

Tail call optimization will be supported In ECMAScript 6 strict mode in the future. Check http://www.2ality.com/2015/06/tail-call-optimization.html for details.

Check http://kangax.github.io/compat-table/es6/ for current engine support.

At the moment (18-07-2019) the following engines support tail call optimization:

• Safari >= 10
• iOS >= 10
• Kinoma XS6
• Duktape 2.3

support if "experimental JavaScript features"-flag is turned on:

• Node 6.5
• Chrome 54 / Opera 41 Current version of the compat table does not list it anymore

Answer 5

Tail call optimization is now available in LispyScript which compiles to JavaScript. You can read more about it here .

Answer 6

Currently no JavaScript implementations recognise tail recursion. Changes are being made in ECMAScript 6 , and as others have said, there is an open ticket on V8 .

Here you can see V8's generated assembler for a tail recursion function:

Example of how V8 compiles recursion

Compare that to how Clang has compiled the same function in C

Example of C compiler tail recursion

V8 retains the recursive call, whereas the C compiler has recognised the tail recursion and changed it into a loop.