fgl-bug

[Christian Maeder]

Hallo Martin,

I was going to use xdfWith from Data.Graph.Inductive.Query.DFS
with Data.Graph.Inductive.Graph.out' as second argument, but

1. xdfWith is not exported

2. out' seems to be wrong (by looking at the source code)

-- | All outward-directed 'LEdge's in a 'Context'.
out' :: Context a b -> [LEdge b]
out' c@(_,v,_,_) = map (\(l,w)->(w,v,l)) (context4l' c)
                                 ^^^
I think, the outgoing edge must be made as "(v,w,l)"!

inn' looks correct:

-- | All inward-directed 'LEdge's in a 'Context'.
inn' :: Context a b -> [LEdge b]
inn' c@(_,v,_,_) = map (\(l,w)->(w,v,l)) (context1l' c)

Can 1. and 2. be fixed?

I need the general xdfWith because I want to filter out some successors
(or maybe I can filter to whole graph first).

Cheers Christian