diff options
Diffstat (limited to 'src/Hakyll/Core/DirectedGraph.hs')
| -rw-r--r-- | src/Hakyll/Core/DirectedGraph.hs | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/src/Hakyll/Core/DirectedGraph.hs b/src/Hakyll/Core/DirectedGraph.hs index b24ce25..bf52277 100644 --- a/src/Hakyll/Core/DirectedGraph.hs +++ b/src/Hakyll/Core/DirectedGraph.hs @@ -7,11 +7,10 @@ module Hakyll.Core.DirectedGraph , nodes , neighbours , reverse - , filter , reachableNodes ) where -import Prelude hiding (reverse, filter) +import Prelude hiding (reverse) import Data.Monoid (mconcat) import Data.Set (Set) import Data.Maybe (fromMaybe) @@ -53,24 +52,16 @@ reverse = mconcat . map reverse' . M.toList . unDirectedGraph reverse' (id', Node _ neighbours') = fromList $ zip (S.toList neighbours') $ repeat $ S.singleton id' --- | Filter a directed graph (i.e. remove nodes based on a predicate) +-- | Find all reachable nodes from a given set of nodes in the directed graph -- -filter :: Ord a - => (a -> Bool) -- ^ Predicate - -> DirectedGraph a -- ^ Graph - -> DirectedGraph a -- ^ Resulting graph -filter predicate = - DirectedGraph . M.filterWithKey (\k _ -> predicate k) . unDirectedGraph - --- | Find all reachable nodes from a given node in the directed graph --- -reachableNodes :: Ord a => a -> DirectedGraph a -> Set a -reachableNodes x graph = reachable (neighbours x graph) (S.singleton x) +reachableNodes :: Ord a => Set a -> DirectedGraph a -> Set a +reachableNodes set graph = reachable (setNeighbours set) set where reachable next visited | S.null next = visited | otherwise = reachable (sanitize neighbours') (next `S.union` visited) where sanitize = S.filter (`S.notMember` visited) - neighbours' = S.unions $ map (flip neighbours graph) - $ S.toList $ sanitize next + neighbours' = setNeighbours (sanitize next) + + setNeighbours = S.unions . map (flip neighbours graph) . S.toList |