I began something a year ago and got diverted by work. Feel free to
use it in any way you like.
http://svn.dsource.org/projects/dranges/trunk/dranges/docs/graphalgorithm.html
http://svn.dsource.org/projects/dranges/trunk/dranges/docs/graph.html
http://svn.dsource.org/projects/dranges/trunk/dranges/docs/graphrange.htm
I didn't update it in a year so it's probably horribly bit-rotten
(what with Phobos changing at a rapid pace). I also didn't try it on
large graphs, my goal was only to trace a dependency graph between
Phobos' modules.
Ah that looks very similar to what I was thinking of.
Thanks, will have a look.