Re: [boost] [gsoc-2013] Boost.Expected

Subject: Re: [boost] [gsoc-2013] Boost.Expected
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-04-29 02:47:25

Le 29/04/13 08:29, Pierre T. a écrit :
> On 04/29/2013 08:11 AM, Vicente J. Botet Escriba wrote:
>> Le 28/04/13 23:28, Rob Stewart a écrit :
>>> On Apr 28, 2013, at 2:17 PM, "Pierre T." <ptalbot_at_[hidden]> wrote:
>>>
>>>> On 04/28/2013 07:30 PM, Vicente J. Botet Escriba wrote:
>>>>>>> Yes this is quite similar if we had exceptions and we had a
>>>>>>> try/catch block
>>>>>>>
>>>>>>> f0().then(f1).then(f2).then(f3).visit_error(error_visitor);
>>>>>>>
>>>>>>> try {
>>>>>>>   f3(f2(f1(f0())));
>>>>>>> } catch(...) {
>>>>>>>   error_visitor();
>>>>>>> }
>>> When the chain gets long, try blocks make increasing sense.
>> Agreed.
> Right, but we can work with non-exception based error.
An example with exception and non-exception would be welcome.
>>>
>>>>>>> It would be great if we could have the equivalent for
>>>>>>> try {
>>>>>>>   h(f(), g());
>>>>>>> } catch(...) {
>>>>>>>   error_visitor();
>>>>>>> }
>>>>>>>
>>>>>>> when_all(f(), g()).then(h).visit_error(error_visitor);
>>> "if_all" seems better than "when_all".
>>>
>> +1.
> +1 too. But I'd like to keep the "then" taking more than one function.
>
> e.then(h).then(f, g).then(h2).on_error(error_resolver);
>
> try{
>   h2(f(h()), g(h()));
> } catch(…) {
>   error_resolver();
> }
>
> The goal would be to enable any function composition.
>
>
Great.
Vicente