gistfile1.hs

queryNode source node = bool
    where (bool,_) = queryNodeWithPath source node []

queryNodeWithPath :: (Ord a) => [a] -> TrieNode a -> [[a]] -> (Bool,[[a]])
queryNodeWithPath source@(s:_)  node@TrieNode{ nodeType = Top, children=ch} acc
          | Map.member s ch = queryNodeWithPath source (ch ! s) acc
          | otherwise       = (False,acc)
queryNodeWithPath source node@TrieNode{ wordFragment = target, nodeType=nT, children=ch } acc = case matchData of
                          ExactMatchDatum {shared=source} 
                                          | nT == Word -> (True, (target:acc))
                                          | otherwise  -> (False,acc)
                          TargetIsSmallerDatum {suffixS= suffixStringOfSource@(s:_)}
                              | Map.member s ch -> queryNodeWithPath suffixStringOfSource (ch ! s) (target:acc )
                              | otherwise  -> (False,acc)
                          otherwise -> (False,acc)
                        where matchData = source =><= target