Re: [Boost-users] [graph] abort algorithm execution from a visitor

Subject: Re: [Boost-users] [graph] abort algorithm execution from a visitor
From: Frank Tetzel (s1445051_at_[hidden])
Date: 2016-02-23 15:27:18

Hi,

thank you for the quick answer.

> for early exiting e.g. a BGL Dijkstra algorithm you can throw your
> local type as a signal and than catch this on the call site.
> 
> Here are two early exit visitors I found useful:
> > https://gist.github.com/daniel-j-h/0301b07ff3324b44e0c5  
> 
> The first one is for the classical One-To-Many routing, the second one
> for One-To-Many routing scenario.
> 
> The call site could look similar to:
> 
>     try {
>       dijkstra_shortest_paths_no_color_map(graph,
>         source,
>         predecessor_map(predMap)
>         .weight_map(weightMap)
>         .disance_map(distanceMap)
>        .visitor(stopOnTarget<Graph>{target}));
>     } catch (const stopSearchSignal&) { }

So, throwing an exception is the way to go. I kinda dislike having
exceptions in my normal execution, but well. It's even in the FAQ which
i should have read before posting the question. Sorry for the noise.

> If you need more advanced features e.g. you want to do a bidirectional
> Dijkstra aborting in "the middle", follow this thread:
> > http://lists.boost.org/boost-users/2015/11/85302.php  

Very interesting. Bidirectional search was next on my list, but i was
more interested in doing it in parallel instead of concurrently. Still
a nice solution. I have to do some reading up on coroutines.

Regards,
Frank