[Python-Dev] Proper tail recursion

[Christopher T King]

On Thu, 15 Jul 2004, Bob Ippolito wrote:

> On Jul 15, 2004, at 11:10 AM, Christopher T King wrote:
> 
> But in this case what is tail-call optimization going to do for you?  
> You still require a stack at least the size of the height of your tree 
> because of traverse(t.left) since that can not be tail-call optimized 
> away, with the proposed algorithm.

In Andrew's example, he noted that it would only help for list-like 
structures (i.e. those with mostly right nodes).

> I think Guido is in the right here, if you want to work around the 
> recursion limit, use Stackless..  It should already be able to go just 
> about as deep as you want.

You're right -- even if Stackless doesn't do tail call optimization,
implementation should be trivial.  But there's no guarantee when or even
if Stackless will be merged with CPython, and until that happens,
Stackless isn't an option for many (most?) people.