Stackless & String-processing

[Neel Krishnaswami]

In article <000601bece8f$b549a420$51a22299 at tim>,
Tim Peters <tim_one at email.msn.com> wrote:
>[Neel Krishnaswami]
>
>> (I'd love to be able to define coroutines in Python like so:
>>
>> def evens(z):
>>     for elt in z:
>>         if z % 2 == 0:
>>             suspend(elt)
>
>
>> It would probably require some rethinking of Python's iteration
>> protocol though.)
>
>How do you intend to resume it?

I left this unspecified because I don't know the answer. :) I figured
that it could be rolled up into the iteration protocol and I could
use it without having to completely understand how it all works. 

[The iteration protocol]

>That's not a hangup; Guido already knows how to do it cleanly.  

Good -- now I don't have to worry at all. 

>BTW, generators are much easier to implement than coroutines -- the former
>don't require threads or stacklessness or continuations under the covers,
>just some relatively straightforward changes to Python's current
>implementation (Steven Majewski noted this 5 years ago).

What's the difference, exactly? AFAICT you need to save the execution
state when suspending both coroutines and generators, but I might be
missing something obvious....


Neel