Re: [boost] [coroutine] new versions

Subject: Re: [boost] [coroutine] new versions
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2012-10-05 15:27:49

Le 05/10/12 17:22, Oliver Kowalke a écrit :
> I've uploaded two re-factored versions - I think most of the 
> suggestions from the review are implemented (namespace is not 
> corrected and documentation not updated yet).
>
> 1.) http://ok73.ok.funpic.de/boost-coroutine-self.zip
> 2.) http://ok73.ok.funpic.de/boost-coroutine-coro.zip
>
> Version 1) requires that coroutine-fn has only one argument == 
> coroutine<>::self_t. Other arguments are accessed via 
> coroutine<>::self_t::get< int >() and results via coroutine<>::get().
> interface provides input/output iterators.
>
> typedef coroutine< int( int, int> > coro_t;
> int fn( coro_t::self_t & c) {
>     int x = c.get< 0 >();
>     int y = c.get< 1 >();
>     c.yield( x +y);
>     ...
> }
> coro_t coro( fn);
> int res = c( 3, 7).get();
>
>
> Version 2) requires that coroutine-fn has only one argument too == 
> coroutine<> with inverted signature. Other arguments are access via 
> coroutine<>::get().
> interface provides input/output iterators.
>
> typedef coroutine< int( int, int> > coro_t;
> int fn( coroutine< tuple< int, int >( int) & c) {
>     int x = c.get().get< 0 >();
>     int y = c.get().get< 1 >();
>     c( x +y);
>     ...
> }
> coro_t coro( fn);
> int res = c( 3, 7).get();
>
> Both implementations are not optimized - I think we should get a small 
> and clean interface first.
> Comments?
The single difference between both interfaces is that with fist the 
return is obtained using yield, while in the second is using the 
operator(). I prefer to use yield to return a result and the call 
operator to call to a coroutine. It is not enough clear to me what are 
the advantages of having a inversed coroutine as parameter.

Anyway, maybe the use of the get accessor can be made more readable 
without effort using tags

struct a{};
struct b{};
typedef coroutine< int( tagged<int, a>, tagged<int,b> > > coro_t;
int fn( coro_t::self_t & c) {
     int x = c.get< a >();
     int y = c.get< b >();
     c.yield( x +y);
     ...
}

Best,
Vicente