Continuations and threads (was Re: Iterators & generators)

Toby Dickenson mbel44 at
Fri Feb 18 06:12:35 EST 2000

Paul Prescod <paul at> wrote:

>You can also use continuations to implement back-tracking. You try one
>path and if it fails you "jump back" and try the other.

What are the implications for the continuation-naive in a
post-stackless world. What about functions such as...

def x():

Today, either of three things happen:
1. before() throws
2. before() and after() are called exactly once each
3. x() never returns because y() never returns

As I understand continuations, we now have the possibility of y()
returning more than once, with after() called more times than before()

more-basic-than-goto is not an exaggeration.

Toby Dickenson
tdickenson at

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