[Lemon-devel] Renaming basic classes

[Alpár Jüttner]

On Tue, 2007-09-18 at 16:57 +0200, Balazs Dezso wrote:
> Hi
> 
> Digraph, Graph vs. Graph, Bigraph
> 
> >_ However the renaming of graph types isn't so clear for me. Is it really the
> >_ best way to use 'digraph' for directed graphs? In this way our most general
> >_ graph type would be ListDigraph (or ListDiGraph). Isn't it too complicated,
> >_ especially for those who start using LEMON? And I think directed graphs are
> >_ used more frequently, so it is important to use simple names for them.
> >_ Moreover I think Digraph-Graph renaming would cause much more problems than
> >_ Arc-Edge renaming when we would like to convert source codes to the new
> >_ version. For example if we forget to change Edge to Arc somewhere, we will
> >_ get a compiler error, because the graph type doesn't have such typedef any
> >_ more. However if we forget to change e.g. ListGraph to ListDigraph, the
> >_ code will remain correct width Edge, EdgeIt, etc. but it does something
> >_ very different, because it became undirected. Or this whole theory isn't
> >_ correct?
> >_ Peter Kovacs

I don't think these are quite minor problems. If we provide a good conversion script, it will help to avoid this situation.

> > I miss the directed/undirected version of the bipartite graphs.
> 
> I think the directed bipartite graph is an irrelevant graph class. I do not 
> know algorithm which run on this type of graph. The residual graph of a 
> matching could be the only application, but in this case the algorithm does 
> not need to build explicit the graph.

It might be the case for general graph algorithms but when modeling real
life problem, I can easily imagine situations where directed bipartite
graphs must be used. E.g. think of the situation where there are servers
and clients, and you want to model the connections among them.

In fact, if we used 'Di' for denoting the directed graph, it wouldn't be
a problem to add it later.

Moreover I still think that neither 'Bigraph' nor 'BiGraph' is a good
name for the bipartite graph.

Alpar