coroutine support

[Jochen Theodorou]

Charles Oliver Nutter schrieb:
> On Fri, Nov 13, 2009 at 11:09 AM, Jochen Theodorou <blackdrag at gmx.org> wrote:
>> the alternative would be to generate for run something like:
>>
>> private Object run$co(Context context) {
>>   l0:
>>   switch (context.jumpToLabel) {
>>      case 1: jmp l1
>>   }
>>   context.l0=0;
>>   for (;context.l0<10; context.l0++) {
>>     System.out.println(context.l0);
>>     l1:
>>     context.jumpToLabel=1;
>>     return null;
>>   }
>>   context.jumpToLabel=-1;
>>   return null;
>> }
>>
>> jumpToLabel is used to identify the entry/exit point, context will hold
>> all local variables (l*)
>>
>> Where would such an approach be not as good as yours?
> 
> This is basically what all the bytecode-weaving coroutine/continuation
> libraries do. Jython also does this for their
> lambda/generator/coroutine stuff so they can jump in and out. The
> primary issue is that you can only jump in and out of the methods you
> have performed this transformation on. That means you can't call
> through any untransformed code and expect to be able to resume it.

but isn't here yield responsible for that? Does this means the coroutine 
support here will allow calling yield from outside or from deep down the 
stack? It will it mean the stack will be kept? This was not clear from 
the first post. Since only one Thread is used I assumed it might not be 
the case.

bye Jochen

-- 
Jochen "blackdrag" Theodorou
The Groovy Project Tech Lead (http://groovy.codehaus.org)
http://blackdragsview.blogspot.com/