Re: Data.Graph transitive closure

I've actually wondered why Data.Graph existed since it is obviously not written for serious/heavy usage.

But it was! As I understand, it was originally part of GHC (ghc-0.29/ghc/compiler/utils/Digraph.lhs) for computing SCCs (in the graph of dependencies of declarations). So we can assume that it does this well. And I guess it's used for the very same purpose in Cabal and Agda. - J.