module Data.RDF.MGraph(MGraph, empty, mkRdf, triplesOf, uniqTriplesOf, select, query)
where
import Prelude hiding (pred)
import Control.DeepSeq (NFData)
import Data.RDF.Types
import Data.RDF.Query
import Data.RDF.Namespace
import qualified Data.Map as Map
import Data.Hashable()
import Data.HashMap.Strict(HashMap)
import qualified Data.HashMap.Strict as HashMap
import Data.HashSet(HashSet)
import qualified Data.HashSet as Set
import Data.List
newtype MGraph = MGraph (TMaps, Maybe BaseUrl, PrefixMappings)
deriving (NFData)
instance RDF MGraph where
baseUrl = baseUrl'
prefixMappings = prefixMappings'
addPrefixMappings = addPrefixMappings'
empty = empty'
mkRdf = mkRdf'
triplesOf = triplesOf'
uniqTriplesOf = uniqTriplesOf'
select = select'
query = query'
instance Show MGraph where
show gr = concatMap (\t -> show t ++ "\n") (triplesOf gr)
type AdjacencyMap = HashMap Predicate (HashSet Node)
type Adjacencies = HashSet Node
type TMap = HashMap Node AdjacencyMap
type TMaps = (TMap, TMap)
baseUrl' :: MGraph -> Maybe BaseUrl
baseUrl' (MGraph (_, baseURL, _)) = baseURL
prefixMappings' :: MGraph -> PrefixMappings
prefixMappings' (MGraph (_, _, pms)) = pms
addPrefixMappings' :: MGraph -> PrefixMappings -> Bool -> MGraph
addPrefixMappings' (MGraph (ts, baseURL, pms)) pms' replace =
let merge = if replace then flip mergePrefixMappings else mergePrefixMappings
in MGraph (ts, baseURL, merge pms pms')
empty' :: MGraph
empty' = MGraph ((HashMap.empty, HashMap.empty), Nothing, PrefixMappings Map.empty)
mkRdf' :: Triples -> Maybe BaseUrl -> PrefixMappings -> MGraph
mkRdf' ts baseURL pms = MGraph (mergeTs (HashMap.empty, HashMap.empty) ts, baseURL, pms)
mergeTs :: TMaps -> [Triple] -> TMaps
mergeTs = foldl' mergeT
where
mergeT :: TMaps -> Triple -> TMaps
mergeT m t = mergeT' m (subjectOf t) (predicateOf t) (objectOf t)
mergeT' :: TMaps -> Subject -> Predicate -> Object -> TMaps
mergeT' (spo, ops) s p o = (mergeT'' spo s p o, mergeT'' ops o p s)
mergeT'' :: TMap -> Subject -> Predicate -> Object -> TMap
mergeT'' m s p o =
if s `HashMap.member` m then
(if p `HashMap.member` adjs then HashMap.insert s addPredObj m
else HashMap.insert s addNewPredObjMap m)
else HashMap.insert s newPredMap m
where
adjs = HashMap.lookupDefault HashMap.empty s m
newPredMap :: HashMap Predicate (HashSet Object)
newPredMap = HashMap.singleton p (Set.singleton o)
addNewPredObjMap :: HashMap Predicate (HashSet Object)
addNewPredObjMap = HashMap.insert p (Set.singleton o) adjs
addPredObj :: HashMap Predicate (HashSet Object)
addPredObj = HashMap.insert p (Set.insert o (get p adjs)) adjs
get = HashMap.lookupDefault Set.empty
triplesOf' :: MGraph -> Triples
triplesOf' (MGraph ((spoMap, _), _, _)) = concatMap (uncurry tripsSubj) subjPredMaps
where subjPredMaps = HashMap.toList spoMap
uniqTriplesOf' :: MGraph -> Triples
uniqTriplesOf' = nub . expandTriples
tripsSubj :: Subject -> AdjacencyMap -> Triples
tripsSubj s adjMap = concatMap (uncurry (tfsp s)) (HashMap.toList adjMap)
where tfsp = tripsForSubjPred
tripsForSubjPred :: Subject -> Predicate -> Adjacencies -> Triples
tripsForSubjPred s p adjs = map (Triple s p) (Set.toList adjs)
select' :: MGraph -> NodeSelector -> NodeSelector -> NodeSelector -> Triples
select' (MGraph ((spoMap,_),_,_)) subjFn predFn objFn =
map (\(s,p,o) -> Triple s p o) $ Set.toList $ sel1 subjFn predFn objFn spoMap
sel1 :: NodeSelector -> NodeSelector -> NodeSelector -> TMap -> HashSet (Node, Node, Node)
sel1 (Just subjFn) p o spoMap =
Set.unions $ map (sel2 p o) $ filter (\(x,_) -> subjFn x) $ HashMap.toList spoMap
sel1 Nothing p o spoMap = Set.unions $ map (sel2 p o) $ HashMap.toList spoMap
sel2 :: NodeSelector -> NodeSelector -> (Node, HashMap Node (HashSet Node)) -> HashSet (Node, Node, Node)
sel2 (Just predFn) mobjFn (s, ps) =
Set.map (\(p,o) -> (s,p,o)) $
foldl' Set.union Set.empty $
map (sel3 mobjFn) poMapS :: HashSet (Node, Node, Node)
where
poMapS :: [(Node, HashSet Node)]
poMapS = filter (\(k,_) -> predFn k) $ HashMap.toList ps
sel2 Nothing mobjFn (s, ps) =
Set.map (\(p,o) -> (s,p,o)) $
foldl' Set.union Set.empty $
map (sel3 mobjFn) poMaps
where
poMaps = HashMap.toList ps
sel3 :: NodeSelector -> (Node, HashSet Node) -> HashSet (Node, Node)
sel3 (Just objFn) (p, os) = Set.map (\o -> (p, o)) $ Set.filter objFn os
sel3 Nothing (p, os) = Set.map (\o -> (p, o)) os
query' :: MGraph -> Maybe Node -> Maybe Predicate -> Maybe Node -> Triples
query' (MGraph (m,_ , _)) subj pred obj = map f $ Set.toList $ q1 subj pred obj m
where f (s, p, o) = Triple s p o
q1 :: Maybe Node -> Maybe Node -> Maybe Node -> TMaps -> HashSet (Node, Node, Node)
q1 (Just s) p o (spoMap, _ ) = q2 p o (s, HashMap.lookupDefault HashMap.empty s spoMap)
q1 s p (Just o) (_ , opsMap) = Set.map (\(o',p',s') -> (s',p',o')) $ q2 p s (o, HashMap.lookupDefault HashMap.empty o opsMap)
q1 Nothing p o (spoMap, _ ) = Set.unions $ map (q2 p o) $ HashMap.toList spoMap
q2 :: Maybe Node -> Maybe Node -> (Node, HashMap Node (HashSet Node)) -> HashSet (Node, Node, Node)
q2 (Just p) o (s, pmap) =
maybe Set.empty (Set.map (\ (p', o') -> (s, p', o')) . q3 o . (p,)) $ HashMap.lookup p pmap
q2 Nothing o (s, pmap) = Set.map (\(x,y) -> (s,x,y)) $ Set.unions $ map (q3 o) opmaps
where opmaps ::[(Node, HashSet Node)]
opmaps = HashMap.toList pmap
q3 :: Maybe Node -> (Node, HashSet Node) -> HashSet (Node, Node)
q3 (Just o) (p, os) = if o `Set.member` os then Set.singleton (p, o) else Set.empty
q3 Nothing (p, os) = Set.map (\o -> (p, o)) os