Generators in D

[Piotr Szturmaj]

Sean Kelly wrote:
>
> On May 18, 2011, at 8:00 AM, Piotr Szturmaj wrote:
>
>> Sean Kelly wrote:
>>> On May 17, 2011, at 2:37 PM, Piotr Szturmaj wrote:
>>>>
>>>> But couldn't Fiber's stack be scanned for references to itself and readjusted?
>>>
>>> Without type information, there's no way to be sure that something is actually a reference, so corruption could occur.
>>
>> Then, how GC scan Fiber's stack for references? I thought some portion of GC code could be used for this.
>
> The GC is conservative.  If it encounters a value that matches the address of GCed memory, it won't collect the memory.

Ok. Maybe a requirement that cloneable fiber's function must be marked 
as @safe would work, as @safe functions can't take the address of a 
local variable or function parameter. Also asm and pointer arithmetic 
are prohibited. This way Fiber's stack can't have references to itself.

That should be enough to implement ForwardRange's save() for generators. 
Or still, I'm missing something I don't know yet :)