I used to Data.Graph in 'ad', before we hand-rolled an topSort for our particular acyclic case in response to it running out of stack space on large graphs.
w.r.t. the original question, I think the behavior of Graph equality is correct given the model used. There are observable differences between the two graphs, even though the strict traditional notion of a graph doesn't distinguish on the ordering of the successors of a field, the structure used by Graph does and cannot sensibly be made not to without sacrificing performance needlessly for the vast majority of users. There are other observable differences, e.g. changing array bounds that can affect equality as well.
-Edward
On Mon, Sep 3, 2012 at 5:11 AM, Mikhail Glushenkov
<the.dead.shall.rise@gmail.com> wrote:
Milan Straka <fox <at>
ucw.cz> writes:
>
> As far as I know, Data.Graph has not been given any attention in quite
> some time. I do not know whether someone is using it.