From: Horst Duchene Date: 2002-09-18T06:48:26+09:00 Subject: Re: Dependency "trees" - suggestions? You migth also have a look at http://rgl.sourceforge.net/ which provides a method RGL::Graph#acyclic? for directed graphs. Horst > > In other words, whenever a node is added, it must be checked that it > hasn't produced a cycle. > > > > The million dollar question: how? > > I am sure there is one for this too. You may want to search for DAG > construction algorithms in Google. > HTH, > > -- shanko > > >