rearranging modules

haskell-experiments/haskell-experiments.cabal

@@ -93,6 +93,7 @@ library langfeatures
     Datalog.DatalogParser
     Datalog.NaiveDatabase
     Datalog.Rules
+    Datalog.DatalogDB
   ghc-options:     -Wall
   default-extensions:
     OverloadedStrings 

haskell-experiments/src/Datalog/DatalogDB.hs

@@ -0,0 +1,25 @@
+{-# HLINT ignore "Redundant flip" #-}
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
+
+module Datalog.DatalogDB where
+
+import Control.Exception.Base
+import Data.List
+import Data.Map (Map)
+import Data.Map qualified as Map
+import Data.Maybe
+import Data.Set (Set)
+import Data.Set qualified as Set
+import Data.Text (Text)
+import Data.Void
+import Datalog.DatalogParser (Head (HeadSingle), Literal (..), Statement (..), Term (..), parseDatalog)
+import Text.Megaparsec (ParseErrorBundle)
+import Datalog.Rules
+
+class DatalogDB db where
+  emptyDB :: db
+  lookupRelation :: db -> Text -> Maybe Relation
+  insertRelation :: db -> Relation -> db

haskell-experiments/src/Datalog/NaiveDatabase.hs

@@ -20,6 +20,7 @@ import Data.Void
 import Datalog.DatalogParser (Head (HeadSingle), Literal (..), Statement (..), Term (..), parseDatalog)
 import Text.Megaparsec (ParseErrorBundle)
 import Datalog.Rules
+import Datalog.DatalogDB
 
 data NaiveDatabase = NaiveDatabase
   { relations :: Map RelationId Relation
@@ -95,11 +96,6 @@ withFacts =
     newRelationMap = Map.insert relationName newRelation relationMap
     newConstantSet = Set.union constantSet $ Set.fromList terms
 
-data BodyConstraint = BodyConstraint
-  { _subRelation :: Relation
-  , _elements :: [RuleElement]
-  }
-
 data RuleContext = RuleContext
   { __relation :: Relation
   , _variableNames :: [Text]
@@ -108,24 +104,6 @@ data RuleContext = RuleContext
   , _db :: NaiveDatabase
   }
 
-appendRule :: Relation -> RelationRule -> Relation
-appendRule relation rule =
-  relation {
-    _rules = rule : (_rules relation)
-  }
-  -- Relation { _name = _name relation
-  -- , _arity = _arity relation
-  -- , _tuples = _tuples relation
-  -- , _rules = rule : (_rules relation)
-  -- } 
-
-toRuleBodyElement :: BodyConstraint -> RuleBodyElement
-toRuleBodyElement (BodyConstraint subRelation elements) =
-  RuleBodyElement { 
-    _subRelationId = _name subRelation
-    , _ruleElements = elements
-    }
-
 withFactsAndRules :: [Text] -> [Text] -> NaiveDatabase
 withFactsAndRules facts = foldr (addRule . extractRule) (withFacts facts)
  where

haskell-experiments/src/Datalog/Rules.hs

@@ -47,7 +47,21 @@ data Relation = Relation
 type Constant = Term
 type RelationId = Text
 
-class DatalogDB db where
+data BodyConstraint = BodyConstraint
-  emptyDB :: db
+  { _subRelation :: Relation
-  lookupRelation :: db -> Text -> Maybe Relation
+  , _elements :: [RuleElement]
-  insertRelation :: db -> Relation -> db
+  }
+
+appendRule :: Relation -> RelationRule -> Relation
+appendRule relation rule =
+  relation {
+    _rules = rule : (_rules relation)
+  }
+
+toRuleBodyElement :: BodyConstraint -> RuleBodyElement
+toRuleBodyElement (BodyConstraint subRelation elements) =
+  RuleBodyElement { 
+    _subRelationId = _name subRelation
+    , _ruleElements = elements
+    }
+