Internal and external iteration, fibers

[deadalnix]

On Monday, 21 January 2013 at 09:18:34 UTC, Timon Gehr wrote:
> On 01/21/2013 10:08 AM, deadalnix wrote:
>> On Monday, 21 January 2013 at 08:27:28 UTC, Nick Sabalausky 
>> wrote:
>>> Stackless "fibers": Requires gross syntactical contortions 
>>> much like
>>> opApply does.
>>
>> Can you explain more what a stackless fiber is ? From the 
>> linked posted
>> above I did really understood, as the example code clearly call
>> functions, which require stack.
>
> A stackless fiber does not have the execution stack as part of 
> its context. (Therefore it cannot yield from nested function 
> calls.)

Ho yeah, I looked at the implementation. It is mostly made of 
macro that create a function with a big switch in it.

Why can't this be done in D ? What are the major problems ?