[Python-Dev] Stackless Python - Pros and Cons (original) (raw)

Thomas Wouters thomas@xs4all.net
Sun, 6 Aug 2000 23:05:45 +0200

On Sun, Aug 06, 2000 at 10:56:48PM +0200, Jack Jansen wrote:

Could the defenders of Stackless Python please explain why this is such a great idea? Just and Christian seem to swear by it, but I'd like to hear of some simple examples of programming tasks that will be programmable in 50% less code with it (or 50% more understandable code, for that matter).

That's continuations, not Stackless. Stackless itself is just a way of implementing the Python bytecode eval loop with minimized use of the C stack. It doesn't change any functionality except the internal dependance on the C stack (which is limited on some platforms.) Stackless also makes a number of things possible, like continuations.

Continuations can certainly reduce code, if used properly, and they can make it a lot more readable if the choice is between continuations or threaded spaghetti-code. It can, however, make code a lot less readable too, if used improperly, or when viewed by someone who doesn't grok continuations.

I'm +1 on Stackless, +0 on continuations. (Continuations are cool, and Pythonic in one sense (stackframes become even firster class citizens ;) but not easy to learn or get used to.)

And, similarly, could the detractors of Stackless Python explain why it is such a bad idea.

I think my main reservation towards Stackless is the change to ceval.c, which is likely to be involved (I haven't looked at it, yet) -- but ceval.c isn't a childrens' book now, and I think the added complexity (if any) is worth the loss of some of the dependancies on the C stack.

fl.0,02-ly y'rs,

Thomas Wouters <thomas@xs4all.net>

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