renaming accessors

haskell-experiments/src/Datalog/InMemoryDB.hs

@@ -18,31 +18,31 @@ import Datalog.Rules
 import Datalog.DatalogDB
 
 data InMemoryDB = InMemoryDB
-  { relations :: Map RelationId Relation
+  { _relations :: Map RelationId Relation
-  , constants :: Set Constant
+  , _constants :: Set Constant
   } deriving (Show, Eq)
 
 instance DatalogDB InMemoryDB where
   emptyDB :: InMemoryDB
   emptyDB = InMemoryDB
-    { relations = Map.empty
+    { _relations = Map.empty
-    , constants = Set.empty -- the Herbrand universe
+    , _constants = Set.empty -- the Herbrand universe
     }
 
   lookupRelation :: InMemoryDB -> Text -> Maybe Relation
   lookupRelation db relationName =
-    Map.lookup relationName $ relations db
+    Map.lookup relationName $ _relations db
 
   insertRelation :: InMemoryDB -> Relation -> InMemoryDB
   insertRelation db relation =
     db {
-      relations = Map.insert (_name relation) relation (relations db)
+      _relations = Map.insert (_name relation) relation (_relations db)
     }
 
   addConstants :: InMemoryDB -> Set Constant -> InMemoryDB
   addConstants db newConstants =
     db {
-      constants = Set.union newConstants (constants db)
+      _constants = Set.union newConstants (_constants db)
     }
 
 withFacts :: DatalogDB db => [Text] -> db

haskell-experiments/src/Datalog/NaiveQE.hs

@@ -28,7 +28,10 @@ data (DatalogDB db) => NaiveQE db = NaiveQE
 
 instance QueryEngine NaiveQE where
   queryEngine :: (DatalogDB db) => db -> NaiveQE db
-  queryEngine db = NaiveQE { }
+  queryEngine db = NaiveQE { 
+    db = db,
+    herbrand = computeHerbrand db
+  }
   query :: (DatalogDB db) => NaiveQE db -> Text -> Text
   query qe queryText =
     case parseDatalog queryText of
@@ -36,3 +39,10 @@ instance QueryEngine NaiveQE where
       Right otherStatement -> throw $ NonQueryException queryText otherStatement
       Left ex -> throw $ CannotParseStatementException queryText ex
 
+computeHerbrand :: (DatalogDB db) => db -> Map Text Relation
+computeHerbrand db =
+  computeHerbrandSub Map.empty where
+  computeHerbrandSub :: Map Text Relation -> Map Text Relation
+  computeHerbrandSub facts = facts
+    -- for_ (Map.toList myMap) $ \(k,v) ->
+

haskell-experiments/test/Test/Datalog/InMemoryDBSpec.hs

@@ -31,9 +31,9 @@ spec = do
               [ "parent(\"alice\", \"bob\")."
               , "parent(\"bob\", \"carol\")."
               ]
-      constants db
+      _constants db
         `shouldBe` Set.fromList (Sym <$> ["alice", "bob", "carol"])
-      relations db
+      _relations db
         `shouldBe` Map.fromList
           [
             ( "parent"
@@ -78,10 +78,10 @@ spec = do
               , _rules = [ancestorRule, ancestorRule2]
               }
 
-      constants db
+      _constants db
         `shouldBe` Set.fromList (Sym <$> ["alice", "bob", "carol"])
 
-      relations db
+      _relations db
         `shouldBe` Map.fromList
           [ ("ancestor", ancestorRelation)
           , ("parent", parentRelation)
@@ -104,10 +104,10 @@ spec = do
               , _tuples = Set.empty
               , _rules = [ancestorRule]
               }
-      relations db
+      _relations db
         `shouldBe` Map.singleton "ancestor" ancestorRelation
 
-      constants db
+      _constants db
         `shouldBe` Set.fromList (Sym <$> ["patriarch"])
 
     it "can ingest facts and rules with duplicate head entries" do
@@ -127,10 +127,10 @@ spec = do
               , _tuples = Set.empty
               , _rules = [equivalentRule]
               }
-      relations db
+      _relations db
         `shouldBe` Map.singleton "equivalent" equivalentRelation
 
-      constants db
+      _constants db
         `shouldBe` Set.empty
 
     it "can ingest a theory of equivalence relations" do
@@ -167,10 +167,10 @@ spec = do
               , _tuples = Set.empty
               , _rules = [rule1, rule2, rule3]
               }
-      relations db
+      _relations db
         `shouldBe` Map.singleton "equivalent" equivalentRelation
 
-      constants db
+      _constants db
         `shouldBe` Set.empty
 
     it "can do basic queries" do