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

29 Apr 2013


      Le 29/04/13 08:29, Pierre T. a écrit :
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On 04/29/2013 08:11 AM, Vicente J. Botet Escriba wrote:
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Le 28/04/13 23:28, Rob Stewart a écrit :
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On Apr 28, 2013, at 2:17 PM, "Pierre T."  wrote:
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On 04/28/2013 07:30 PM, Vicente J. Botet Escriba wrote:
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> 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.
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> 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