Re: Generators/coroutines in future Ada?

[Victor Porton <porton@narod.ru>]

Dmitry A. Kazakov wrote:

> On 2017-07-11 21:22, J-P. Rosen wrote:
>> Le 11/07/2017 à 20:36, Victor Porton a écrit :
>>> This state also includes the point of execution (like "We are in the
>>> second loop in its second operator.")
>>>
>>>> This can easily be achieved with a function within a package, where the
>>>> package serves to protect and hide the function's state.
>>> Ada currently has no support to save such (point of execution) states.
>> It has. Make your generator a task, and have an accept when the data is
>> ready, which can be nested as deep as you want in any construct.
>> 
>> A task is a perfect abstraction for a thread of control that maintains
>> its own execution state!
> 
> Except that no control is required.
> 
> I don't understand what is wrong with:
> 
>     type Stateful is limited private;
>     function Generate (X : not null access Stateful) return Things;

The thing "wrong" with this, is that it is sometimes hard to implement 
Generate(). In Python this can be done in an easier way by using generators 
(Python's "yield" keywords).

-- 
Victor Porton - http://portonvictor.org