@@ -1,4 +1,7 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2+{-# LANGUAGE FlexibleInstances #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE OverloadedStrings #-}
25module ProjectM36.RelationalExpression where
36import ProjectM36.Relation
47import ProjectM36.Tuple
@@ -7,33 +10,44 @@ import ProjectM36.Base
710import qualified Data.UUID as U
811import ProjectM36.Error
912import ProjectM36.AtomType
10−import ProjectM36.Attribute (emptyAttributes)
13+import ProjectM36.Attribute (emptyAttributes, attributesFromList)
1114import ProjectM36.ScriptSession
1215import ProjectM36.DataTypes.Primitive
1316import ProjectM36.AtomFunction
1417import ProjectM36.DatabaseContextFunction
1518import ProjectM36.Arbitrary
19+import ProjectM36.GraphRefRelationalExpr
1620import ProjectM36.Transaction
1721import qualified ProjectM36.Attribute as A
1822import qualified Data.Map as M
1923import qualified Data.HashSet as HS
2024import qualified Data.Set as S
2125import Control.Monad.State hiding (join)
22−import Control.Exception
26+import Data.Bifunctor (second)
2327import Data.Maybe
2428import Data.Either
2529import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2633import qualified Data.Text as T
2734import qualified Data.Vector as V
2835import qualified ProjectM36.TypeConstructorDef as TCD
29−import Control.Monad.Trans.Except
30−import Control.Monad.Trans.Reader
36+import qualified Control.Monad.RWS.Strict as RWS
37+import Control.Monad.RWS.Strict (RWST, execRWST, runRWST)
38+import Control.Monad.Except hiding (join)
39+import Control.Monad.Trans.Except (except)
40+import Control.Monad.Reader as R hiding (join)
41+import ProjectM36.NormalizeExpr
42+import ProjectM36.WithNameExpr
3143import Test.QuickCheck
32−import GHC
44+import qualified Data.Functor.Foldable as Fold
45+import Control.Applicative
46+#ifdef PM36_HASKELL_SCRIPTING
47+import GHC hiding (getContext)
48+import Control.Exception
3349import GHC.Paths
34−import Data.Time.Clock
35−import Data.Time.Calendar
36−import qualified Data.List.NonEmpty as NE
50+#endif
3751
3852data DatabaseContextExprDetails = CountUpdatedTuples
3953
@@ -50,54 +64,63 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
5064 Right ts -> ts
5165
5266-- | Used to start a fresh database state for a new database context expression.
53−freshDatabaseState :: DatabaseContext -> DatabaseStateElems
54−freshDatabaseState context = DatabaseStateElems {
55− context = context,
56− accum = M.empty,
57− dirty = False
67+mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68+mkDatabaseContextEvalState context = DatabaseContextEvalState {
69+ dbc_context = context,
70+ dbc_accum = M.empty,
71+ dbc_dirty = False
5872 } --future work: propagate return accumulator
5973
6074-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
61−data RelationalExprStateElems = RelationalExprStateElems {
62− elems_context :: DatabaseContext,
63− elems_graph :: TransactionGraph,
64− elems_currentTransId :: TransactionId,
65− elems_extra :: Maybe (Either RelationTuple Attributes)
75+data RelationalExprEnv = RelationalExprEnv {
76+ re_context :: DatabaseContext,
77+ re_graph :: TransactionGraph,
78+ re_extra :: Maybe (Either RelationTuple Attributes)
6679 }
6780
68−stateTuple :: RelationalExprStateElems -> RelationTuple
69−stateTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (elems_extra e))
81+envTuple :: GraphRefRelationalExprEnv -> RelationTuple
82+envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
7083
71−stateAttributes :: RelationalExprStateElems -> Attributes
72−stateAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (elems_extra e))
73−{-
74−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
75− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
76− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
77− -}
84+envAttributes :: GraphRefRelationalExprEnv -> Attributes
85+envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
7886
79−instance Show RelationalExprStateElems where show e@RelationalExprStateElems{} = "RelationalExprStateElems " ++ show (elems_extra e)
80−
81−mkRelationalExprState :: DatabaseContext -> TransactionId -> TransactionGraph -> RelationalExprStateElems
82−mkRelationalExprState ctx currentTransId graph =
83− RelationalExprStateElems
84− { elems_context = ctx,
85− elems_graph = graph,
86− elems_currentTransId = currentTransId,
87− elems_extra = Nothing }
88−
89−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
90−mergeTuplesIntoRelationalExprState tupIn e@RelationalExprStateElems{} =
91− e{elems_extra = new_elems }
87+instance Show RelationalExprEnv where
88+ show e@RelationalExprEnv{} = "RelationalExprEnv " ++ show (re_extra e)
89+
90+--used to eval relationalexpr
91+type RelationalExprM a = ReaderT RelationalExprEnv (ExceptT RelationalError Identity) a
92+
93+runRelationalExprM :: RelationalExprEnv -> RelationalExprM a -> Either RelationalError a
94+runRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
95+
96+reGraph :: RelationalExprM TransactionGraph
97+reGraph = asks re_graph
98+
99+reContext :: RelationalExprM DatabaseContext
100+reContext = asks re_context
101+
102+mkRelationalExprEnv :: DatabaseContext -> TransactionGraph -> RelationalExprEnv
103+mkRelationalExprEnv ctx graph =
104+ RelationalExprEnv
105+ { re_context = ctx,
106+ re_graph = graph,
107+ re_extra = Nothing }
108+
109+askEnv :: GraphRefRelationalExprM GraphRefRelationalExprEnv
110+askEnv = R.ask
111+
112+mergeTuplesIntoGraphRefRelationalExprEnv :: RelationTuple -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
113+mergeTuplesIntoGraphRefRelationalExprEnv tupIn env =
114+ env { gre_extra = new_elems }
92115 where
93116 new_elems = Just (Left newTuple)
94− mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (stateTuple e))
117+ mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (envTuple env))
95118 newTuple = mkRelationTupleFromMap mergedTupMap
96−
97−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
98−mergeAttributesIntoRelationalExprState attrsIn e@RelationalExprStateElems{} = e{elems_extra = newattrs }
119+
120+mergeAttributesIntoGraphRefRelationalExprEnv :: Attributes -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
121+mergeAttributesIntoGraphRefRelationalExprEnv attrsIn e = e { gre_extra = newattrs }
99122 where
100− newattrs = Just (Right (A.union attrsIn (stateAttributes e)))
123+ newattrs = Just (Right (A.union attrsIn (envAttributes e)))
101124
102125type ResultAccumName = StringType
103126
@@ -107,440 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
107130 resultAccumResult :: Relation
108131 }
109132
110−data DatabaseStateElems = DatabaseStateElems {
111− context :: DatabaseContext, --new, alterable context for a new transaction
112− accum :: M.Map ResultAccumName ResultAccum,
113− dirty :: DirtyFlag
133+data DatabaseContextEvalState = DatabaseContextEvalState {
134+ dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135+ dbc_accum :: M.Map ResultAccumName ResultAccum,
136+ dbc_dirty :: DirtyFlag
114137 }
115138
116−type DatabaseState a = State DatabaseStateElems a
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
142+ }
117143
118−getStateContext :: DatabaseState DatabaseContext
119−getStateContext = context <$> get
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
120146
121−putStateContext :: DatabaseContext -> DatabaseState ()
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
148+
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151+ where
152+ freshEnv = mkDatabaseContextEvalState ctx
153+
154+
155+dbcTransId :: DatabaseContextEvalMonad TransactionId
156+dbcTransId = dce_transId <$> RWS.ask
157+
158+dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159+dbcGraph = dce_graph <$> RWS.ask
160+
161+dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162+dbcRelationalExprEnv =
163+ mkRelationalExprEnv <$> getStateContext <*> dbcGraph
164+
165+getStateContext :: DatabaseContextEvalMonad DatabaseContext
166+getStateContext = gets dbc_context
167+
168+putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
122169putStateContext ctx' = do
123170 s <- get
124− put (s {context = ctx'})
125−
126−type RelationalExprState a = Reader RelationalExprStateElems a
127−
128−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
129−stateElemsContext = elems_context
130−
131−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
132−setStateElemsContext e ctx = e { elems_context = ctx }
133−
134−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
135−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError GraphRefRelationalExpr)
136−evalRelationalExpr (RelationVariable name _) = do
137− relvarTable <- fmap (relationVariables . stateElemsContext) ask
138− return $ case M.lookup name relvarTable of
139− Just res -> Right res
140− Nothing -> Left $ RelVarNotDefinedError name
141−
142−evalRelationalExpr (Project attrNames expr) = do
143− eAttrNameSet <- evalAttributeNames attrNames expr
144− case eAttrNameSet of
145− Left err -> pure (Left err)
146− Right attrNameSet -> do
147− rel <- evalRelationalExpr expr
148− case rel of
149− Right rel2 -> pure $ Right (Project (AttributeNames attrNameSet) rel2)
150− Left err -> pure $ Left err
151−
152−evalRelationalExpr (Union exprA exprB) = do
153− relA <- evalRelationalExpr exprA
154− relB <- evalRelationalExpr exprB
155− case relA of
156− Left err -> return $ Left err
157− Right relA2 -> case relB of
158− Left err -> return $ Left err
159− Right relB2 -> return $ Right (Union relA2 relB2)
160−
161−evalRelationalExpr (Join exprA exprB) = do
162− relA <- evalRelationalExpr exprA
163− relB <- evalRelationalExpr exprB
164− case relA of
165− Left err -> return $ Left err
166− Right relA2 -> case relB of
167− Left err -> return $ Left err
168− Right relB2 -> return $ Right (Join relA2 relB2)
169−
170−evalRelationalExpr (Difference exprA exprB) = do
171− relA <- evalRelationalExpr exprA
172− relB <- evalRelationalExpr exprB
173− case relA of
174− Left err -> return $ Left err
175− Right relA2 -> case relB of
176− Left err -> return $ Left err
177− Right relB2 -> return $ Right (Difference relA2 relB2)
178−
179−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
180− case mkRelation attributeSet tupleSet of
181− Right rel -> return $ Right (ExistingRelation rel)
182− Left err -> return $ Left err
183−
184−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
185− currentContext <- fmap stateElemsContext ask
186− let tConss = typeConstructorMapping currentContext
187− -- if the mAttrExprs is Nothing, then we should attempt to infer the tuple attributes from the first tuple itself- note that this is not always possible
188− runExceptT $ do
189− mAttrs <- case mAttrExprs of
190− Just _ ->
191− Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
192− Nothing -> pure Nothing
193− tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
194− let attrs = fromMaybe firstTupleAttrs mAttrs
195− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
196− expr <- either throwE pure (mkRelation attrs (RelationTupleSet tuples))
197− pure (ExistingRelation expr)
171+ put (s {dbc_context = ctx', dbc_dirty = True})
172+
173+-- | The context is optionally passed down along in cases where the current context is uncommitted.
174+data GraphRefRelationalExprEnv =
175+ GraphRefRelationalExprEnv {
176+ gre_context :: Maybe DatabaseContext,
177+ gre_graph :: TransactionGraph,
178+ gre_extra :: Maybe (Either RelationTuple Attributes)
179+ }
198180
199−evalRelationalExpr (ExistingRelation rel) = pure (Right (ExistingRelation rel))
181+type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
182+
183+gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184+gfTransForId tid = do
185+ graph <- gfGraph
186+ lift $ except $ transactionForId tid graph
187+
188+gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189+gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190+gfDatabaseContextForMarker UncommittedContextMarker = do
191+ mctx <- gre_context <$> askEnv
192+ case mctx of
193+ Nothing -> throwError NoUncommittedContextInEvalError
194+ Just ctx -> pure ctx
195+
196+runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197+runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
198+
199+freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200+freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
201+ gre_context = mctx,
202+ gre_graph = graph,
203+ gre_extra = Nothing
204+ }
200205
201−evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
202− evald <- evalRelationalExpr relExpr
203− case evald of
204− Right expr -> return $ Right (Rename oldAttrName newAttrName expr)
205− Left err -> return $ Left err
206+gfGraph :: GraphRefRelationalExprM TransactionGraph
207+gfGraph = asks gre_graph
206208
207−evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
208− eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
209− case eOldAttrNameSet of
210− Left err -> pure (Left err)
211− Right oldAttrNameSet -> do
212− evald <- evalRelationalExpr relExpr
213− case evald of
214− Right expr -> return $ Right (Group (AttributeNames oldAttrNameSet) newAttrName expr)
215− Left err -> return $ Left err
216−
217−evalRelationalExpr (Ungroup attrName relExpr) = do
218− evald <- evalRelationalExpr relExpr
219− case evald of
220− Right expr -> return $ Right (Ungroup attrName expr)
221− Left err -> return $ Left err
222−
223−evalRelationalExpr (Restrict predicateExpr relExpr) = do
224− evald <- evalRelationalExpr relExpr
225− ePred <- processRestrictionPredicateExpr predicateExpr
226− case evald of
227− Left err -> return $ Left err
228− Right expr -> case ePred of
229− Left err -> pure (Left err)
230− Right pred -> pure $ Right (Restrict pred expr)
231−
232−evalRelationalExpr (Equals relExprA relExprB) = do
233− evaldA <- evalRelationalExpr relExprA
234− evaldB <- evalRelationalExpr relExprB
235− case evaldA of
236− Left err -> return $ Left err
237− Right exprA -> case evaldB of
238− Left err -> return $ Left err
239− Right exprB -> return $ Right (Equals exprA exprB)
240−{-
241−evalRelationalExpr (With views mainExpr) = do
242− rstate <- ask
243−
244− let addScopedView ctx (vname,vexpr) = if vname `M.member` relationVariables ctx then
245− Left (RelVarAlreadyDefinedError vname)
246− else
247− case runState (evalDatabaseContextExpr (Assign vname vexpr)) (freshDatabaseState ctx) of
248− (Left err,_) -> Left err
249− (Right (), (ctx',_,_)) -> Right ctx'
250−
251− case foldM addScopedView (stateElemsContext rstate) views of
252− Left err -> return $ Left err
253− Right ctx'' -> do
254− let evalMainExpr expr = runReader (evalRelationalExpr expr) (RelationalExprStateElems ctx'')
255− case evalMainExpr mainExpr of
256− Left err -> return $ Left err
257− Right rel -> return $ Right rel
258−-}
259−--warning: copy-pasta from above- refactor
260−evalRelationalExpr (NotEquals relExprA relExprB) = do
261− evaldA <- evalRelationalExpr relExprA
262− evaldB <- evalRelationalExpr relExprB
263− case evaldA of
264− Left err -> return $ Left err
265− Right exprA -> case evaldB of
266− Left err -> return $ Left err
267− Right exprB -> return $ Right (NotEquals exprA exprB)
268−
269−-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
270−evalRelationalExpr (Extend tupleExpression relExpr) = do
271− eExpr <- evalRelationalExpr relExpr
272− case eExpr of
273− Left err -> pure (Left err)
274− Right expr -> do
275− eTupProc <- processExtendTupleExpr tupleExpression
276− case eTupProc of
277− Left err -> pure (Left err)
278− Right tupProc -> pure (Right (Extend tupProc expr))
209+envContext :: RelationalExprEnv -> DatabaseContext
210+envContext = re_context
211+
212+setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213+setEnvContext e ctx = e { re_context = ctx }
279214
280215--helper function to process relation variable creation/assignment
281−setRelVar :: RelVarName -> GraphRefRelationalExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
282−setRelVar relVarName relExpr transId graph = do
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217+setRelVar relVarName relExpr = do
283218 currentContext <- getStateContext
284− let newRelVars = M.insert relVarName relExpr $ relationVariables currentContext
219+ --prevent recursive relvar definition by resolving references to relvars in previous states
220+ relExpr' <- resolve relExpr
221+ let newRelVars = M.insert relVarName relExpr' $ relationVariables currentContext
285222 potentialContext = currentContext { relationVariables = newRelVars }
286− --determine when to check constraints
287−
288− case checkConstraints potentialContext transId graph of
289− Left err -> pure (Left err)
290− Right _ -> do
291− putStateContext potentialContext
292− return (Right ())
223+ --optimization: if the relexpr is unchanged, skip the update
224+ if M.lookup relVarName (relationVariables currentContext) == Just relExpr then
225+ pure ()
226+ else do
227+ --determine when to check constraints
228+ graph <- dbcGraph
229+ tid <- dbcTransId
230+ case checkConstraints potentialContext tid graph of
231+ Left err -> dbErr err
232+ Right _ -> putStateContext potentialContext
233+
234+--fast-path insertion- we already know that the previous relvar validated correctly, so we can validate just the relation that is being inserted for attribute matches- without this, even a single tuple relation inserted causes the entire relation to be re-validated unnecessarily
235+--insertIntoRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
293236
294237-- it is not an error to delete a relvar which does not exist, just like it is not an error to insert a pre-existing tuple into a relation
295−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
296239deleteRelVar relVarName = do
297240 currContext <- getStateContext
298241 let relVars = relationVariables currContext
299242 if M.notMember relVarName relVars then
300− pure (Right ())
243+ pure ()
301244 else do
302245 let newRelVars = M.delete relVarName relVars
303246 newContext = currContext { relationVariables = newRelVars }
304247 putStateContext newContext
305− pure (Right ())
248+ pure ()
306249
307−evalDatabaseContextExpr :: DatabaseContextExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
308−evalDatabaseContextExpr NoOperation _ _ = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
309252
310−evalDatabaseContextExpr (Define relVarName attrExprs) transId graph = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
311255 relvars <- fmap relationVariables getStateContext
312256 tConss <- fmap typeConstructorMapping getStateContext
313− let eAttrs = map (evalAttrExpr tConss) attrExprs
314− attrErrs = lefts eAttrs
315− attrsList = rights eAttrs
316− if not (null attrErrs) then
317− pure (Left (someErrors attrErrs))
318− else do
319− let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
320− if not (null atomTypeErrs) then
321− pure (Left (someErrors atomTypeErrs))
322− else
323− case M.member relVarName relvars of
324− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
325− False -> setRelVar relVarName (ExistingRelation emptyRelation) transId graph >> pure (Right ())
257+ graph <- dbcGraph
258+ let eAttrs = runGraphRefRelationalExprM gfEnv (mapM evalGraphRefAttrExpr attrExprs)
259+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
260+ case eAttrs of
261+ Left err -> dbErr err
262+ Right attrsList -> do
263+ lift $ except $ validateAttributes tConss (A.attributesFromList attrsList)
264+ case M.member relVarName relvars of
265+ True -> dbErr (RelVarAlreadyDefinedError relVarName)
266+ False -> setRelVar relVarName (ExistingRelation emptyRelation)
326267 where
327268 attrs = A.attributesFromList attrsList
328269 emptyRelation = Relation attrs emptyTupleSet
329270
330−evalDatabaseContextExpr (Undefine relVarName) _ _ = deleteRelVar relVarName
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
331272
332−evalDatabaseContextExpr (Assign relVarName expr) transId graph = do
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
333275 context <- getStateContext
334276 let existingRelVar = M.lookup relVarName (relationVariables context)
335− relExprState = mkRelationalExprState context transId graph
277+ reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278+ eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
336279 case existingRelVar of
337280 Nothing -> do
338− let ervExpr = runReader (evalRelationalExpr expr) relExprState
339− case ervExpr of
340− Left err -> pure (Left err)
341− Right rvExpr -> setRelVar relVarName rvExpr transId graph
281+ case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282+ Left err -> dbErr err
283+ Right reltype -> do
284+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285+ setRelVar relVarName expr
342286 Just existingRel -> do
343− let eExpectedType = typeForGraphRefRelationalExpr existingRel graph
344− eNewExprType = runReader (typeForRelationalExpr expr) relExprState
287+ let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
345288 case eExpectedType of
346− Left err -> pure (Left err)
289+ Left err -> dbErr err
347290 Right expectedType ->
348291 case eNewExprType of
349− Left err -> pure (Left err)
292+ Left err -> dbErr err
350293 Right newExprType -> do
351294 if newExprType == expectedType then do
352− let ervExpr = runReader (evalRelationalExpr expr) relExprState
353− case ervExpr of
354− Left err -> pure (Left err)
355− Right rvExpr -> setRelVar relVarName rvExpr transId graph
295+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296+ setRelVar relVarName expr
356297 else
357− pure (Left (RelationTypeMismatchError (attributes expectedType) (attributes newExprType)))
358−
359−evalDatabaseContextExpr (Insert relVarName relExpr) tid graph =
360− evalDatabaseContextExpr (Assign relVarName (Union (RelationVariable relVarName ())
361− relExpr)) tid graph
362−
363−evalDatabaseContextExpr (Delete relVarName predicate) transId graph = do
364− ctx <- getStateContext
365− let rv = RelationVariable relVarName transId
366− rvState = mkRelationalExprState ctx transId graph
367− case runReader (processRestrictionPredicateExpr predicate) rvState of
368− Left err -> pure (Left err)
369− Right graphRefPredicate ->
370− setRelVar relVarName (Restrict (NotPredicate graphRefPredicate) rv) transId graph
298+ dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
299+
300+evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301+ gfExpr <- relVarByName relVarName
302+ let optExpr = applyUnionCollapse (Union
303+ relExpr
304+ gfExpr)
305+ evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
306+
307+evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308+ gfExpr <- relVarByName relVarName
309+ let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310+ setRelVar relVarName optExpr
371311
372312--union of restricted+updated portion and the unrestricted+unupdated portion
373−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) transId graph = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
374316 context <- getStateContext
375− let rvState = mkRelationalExprState context transId graph
376− relVarTable = relationVariables context
377− case runReader (processRestrictionPredicateExpr restrictionPredicateExpr) rvState of
378− Left err -> pure (Left err)
379− Right graphRefPredicate ->
380− case M.lookup relVarName relVarTable of
381− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
382− Just existingRvExpr -> do
383− let unrestrictedPortion = Restrict (NotPredicate graphRefPredicate) rv
384− rv = RelationVariable relVarName transId
385− tmpAttr attr = "_tmp_" <> attr --this could certainly be improved to verify that there is no attribute name conflict
386− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
387− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
388− restrictedPortion = Restrict graphRefPredicate
389− updated = foldr (\(oldname, atomExpr) accum ->
390− let procAtomExpr = processAtomExpr atomExpr transId in
317+ let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
318+ --get the current attributes name in the relvar to ensure that we don't conflict when renaming
319+ eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
320+ exprType' <- case eExprType of
321+ Left err -> throwError err
322+ Right t -> pure t
323+ let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
324+ tmpAttr = tmpAttrC 1
325+ tmpAttrC :: Int -> AttributeName -> AttributeName
326+ tmpAttrC c attr =
327+ let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
328+ if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
329+ tmpAttrC (c+1) attr
330+ else
331+ tmpAttrName
332+ updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
333+ projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
334+ restrictedPortion = Restrict pred' rvExpr
335+ updated = foldr (\(oldname, atomExpr) accum ->
336+ let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
391337 updateAttr oldname procAtomExpr accum
392− ) rv (M.toList atomExprMap)
338+ ) restrictedPortion (M.toList atomExprMap)
393339 -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
394− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
395− setRelVar relVarName (Union unrestrictedPortion updatedPortion) transId graph
340+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341+ setRelVar relVarName (Union unrestrictedPortion updatedPortion)
396342
397−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) transId graph = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
398344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
399347 let currDeps = inclusionDependencies currContext
400348 newDeps = M.insert newDepName newDep currDeps
401349 if M.member newDepName currDeps then
402− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
403351 else do
404352 let potentialContext = currContext { inclusionDependencies = newDeps }
353+ -- if the potential context passes all constraints, then save it
354+ -- potential optimization: validate only the new constraint- all old constraints must already hold
405355 case checkConstraints potentialContext transId graph of
406− Left err -> pure (Left err)
407− Right _ -> do
356+ Left err -> dbErr err
357+ Right _ ->
408358 putStateContext potentialContext
409− return (Right ())
410359
411−evalDatabaseContextExpr (RemoveInclusionDependency depName) _ _ = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
412361 currContext <- getStateContext
413362 let currDeps = inclusionDependencies currContext
414363 newDeps = M.delete depName currDeps
415364 if M.notMember depName currDeps then
416− pure (Left (InclusionDependencyNameNotInUseError depName))
417− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
418367 putStateContext $ currContext {inclusionDependencies = newDeps }
419− return (Right ())
420368
421369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
422−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) _ _ = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
423371 currentContext <- getStateContext
424372 let nots = notifications currentContext
425373 if M.member notName nots then
426− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
427375 else do
428376 let newNotifications = M.insert notName newNotification nots
429377 newNotification = Notification { changeExpr = triggerExpr,
430378 reportOldExpr = resultOldExpr,
431379 reportNewExpr = resultNewExpr}
432380 putStateContext $ currentContext { notifications = newNotifications }
433− return (Right ())
434381
435−evalDatabaseContextExpr (RemoveNotification notName) _ _ = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
436383 currentContext <- getStateContext
437384 let nots = notifications currentContext
438385 if M.notMember notName nots then
439− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
440387 else do
441388 let newNotifications = M.delete notName nots
442389 putStateContext $ currentContext { notifications = newNotifications }
443− pure (Right ())
390+
444391
445392-- | Adds type and data constructors to the database context.
446393-- validate that the type *and* constructor names are unique! not yet implemented!
447−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) _ _ = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
448395 currentContext <- getStateContext
449396 let oldTypes = typeConstructorMapping currentContext
450397 tConsName = TCD.name tConsDef
451398 -- validate that the constructor's types exist
452− case validateTypeConstructorDef tConsDef dConsDefList of
453− errs@(_:_) -> pure (Left (someErrors errs))
454− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
455− | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
399+ case validateTypeConstructorDef tConsDef dConsDefList oldTypes of
400+ Left err -> throwError err
401+ Right () | T.null tConsName || not (isUpper (T.head tConsName)) -> dbErr (InvalidAtomTypeName tConsName)
402+ | isJust (findTypeConstructor tConsName oldTypes) -> dbErr (AtomTypeNameInUseError tConsName)
456403 | otherwise -> do
457404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
458405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
459− pure (Right ())
460406
461407-- | Removing the atom constructor prevents new atoms of the type from being created. Existing atoms of the type remain. Thus, the atomTypes list in the DatabaseContext need not be all-inclusive.
462−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) _ _ = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
463409 currentContext <- getStateContext
464410 let oldTypes = typeConstructorMapping currentContext
465411 if isNothing (findTypeConstructor tConsName oldTypes) then
466− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
467413 else do
468414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
469415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
470− pure (Right ())
471416
472−evalDatabaseContextExpr (MultipleExpr exprs) transId graph = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
473418 --the multiple expressions must pass the same context around- not the old unmodified context
474− evald <- forM exprs (\expr -> evalDatabaseContextExpr expr transId graph)
475− --some lifting magic needed here
476− case lefts evald of
477− [] -> pure (Right ())
478− errs -> pure (Left (someErrors errs))
479−
480−evalDatabaseContextExpr (RemoveAtomFunction funcName) _ _ = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
481422 currentContext <- getStateContext
482423 let atomFuncs = atomFunctions currentContext
483424 case atomFunctionForName funcName atomFuncs of
484− Left err -> pure (Left err)
485− Right realFunc -> if isScriptedAtomFunction realFunc then do
486− let updatedFuncs = HS.delete realFunc atomFuncs
487− putStateContext (currentContext {atomFunctions = updatedFuncs })
488− pure (Right ())
489− else
490− pure (Left (PrecompiledFunctionRemoveError funcName))
425+ Left err -> dbErr err
426+ Right realFunc ->
427+ if isScriptedAtomFunction realFunc then do
428+ let updatedFuncs = HS.delete realFunc atomFuncs
429+ putStateContext (currentContext {atomFunctions = updatedFuncs })
430+ else
431+ dbErr (PrecompiledFunctionRemoveError funcName)
491432
492−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) _ _ = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
493434 context <- getStateContext
494435 let dbcFuncs = dbcFunctions context
495436 case databaseContextFunctionForName funcName dbcFuncs of
496− Left err -> pure (Left err)
497− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
498− let updatedFuncs = HS.delete realFunc dbcFuncs
499− putStateContext (context { dbcFunctions = updatedFuncs })
500− pure (Right ())
501− else
502− pure (Left (PrecompiledFunctionRemoveError funcName))
437+ Left err -> dbErr err
438+ Right realFunc ->
439+ if isScriptedDatabaseContextFunction realFunc then do
440+ let updatedFuncs = HS.delete realFunc dbcFuncs
441+ putStateContext (context { dbcFunctions = updatedFuncs })
442+ else
443+ dbErr (PrecompiledFunctionRemoveError funcName)
503444
504−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) transId graph = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
505446 context <- getStateContext
447+ graph <- dbcGraph
506448 --resolve atom arguments
507− let relExprState = mkRelationalExprState context transId graph
508− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
509450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
510452 case eFunc of
511− Left err -> pure (Left err)
453+ Left err -> dbErr err
512454 Right func -> do
513455 let expectedArgCount = length (dbcFuncType func)
514456 actualArgCount = length atomArgExprs
515457 if expectedArgCount /= actualArgCount then
516− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
517459 else
518460 --check that the atom types are valid
519− case lefts eAtomTypes of
520− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
521− [] -> do
522− let atomTypes = rights eAtomTypes
523− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
524− Left err -> Just err
525− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
461+ case eAtomTypes of
462+ Left err -> dbErr err
463+ Right atomTypes -> do
464+ let mValidTypes = zipWith (\ expType actType
465+ -> case atomTypeVerify expType actType of
466+ Left err -> Just err
467+ Right _ -> Nothing)
468+ (dbcFuncType func) atomTypes
526469 typeErrors = catMaybes mValidTypes
527− eAtomArgs = unimplemented
528− --eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
470+ eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
529471 if length (lefts eAtomArgs) > 1 then
530− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
531473 else if not (null typeErrors) then
532− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
533475 else
534476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
535− Left err -> pure (Left err)
536− Right newContext -> putStateContext newContext >> pure (Right ())
537−
538−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> TransactionId -> TransactionGraph -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
539−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction funcName funcType script) =
540− case mScriptSession of
541− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
542− Just scriptSession -> do
543− res <- try $ runGhc (Just libdir) $ do
477+ Left err -> dbErr err
478+ Right newContext -> putStateContext newContext
479+data DatabaseContextIOEvalEnv = DatabaseContextIOEvalEnv
480+ { dbcio_transId :: TransactionId,
481+ dbcio_graph :: TransactionGraph,
482+ dbcio_mScriptSession :: Maybe ScriptSession
483+ }
484+
485+type DatabaseContextIOEvalMonad a = RWST DatabaseContextIOEvalEnv () DatabaseContextEvalState IO a
486+
487+runDatabaseContextIOEvalMonad :: DatabaseContextIOEvalEnv -> DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ()) -> IO (Either RelationalError DatabaseContextEvalState)
488+runDatabaseContextIOEvalMonad env ctx m = do
489+ res <- runRWST m env freshState
490+ case res of
491+ (Left err,_,_) -> pure (Left err)
492+ (Right (),s,_) -> pure (Right s)
493+ where
494+ freshState = mkDatabaseContextEvalState ctx
495+
496+requireScriptSession :: DatabaseContextIOEvalMonad (Either RelationalError ScriptSession)
497+requireScriptSession = do
498+ env <- RWS.ask
499+ case dbcio_mScriptSession env of
500+ Nothing -> pure $ Left $ ScriptError ScriptCompilationDisabledError
501+ Just ss -> pure (Right ss)
502+
503+putDBCIOContext :: DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ())
504+putDBCIOContext ctx = do
505+ RWS.modify (\dbstate -> dbstate { dbc_context = ctx})
506+ pure (Right ())
507+
508+getDBCIOContext :: DatabaseContextIOEvalMonad DatabaseContext
509+getDBCIOContext = dbc_context <$> RWS.get
510+
511+getDBCIORelationalExprEnv :: DatabaseContextIOEvalMonad RelationalExprEnv
512+getDBCIORelationalExprEnv = do
513+ context <- getDBCIOContext
514+ mkRelationalExprEnv context . dbcio_graph <$> RWS.ask
515+
516+evalGraphRefDatabaseContextIOExpr :: GraphRefDatabaseContextIOExpr -> DatabaseContextIOEvalMonad (Either RelationalError ())
517+#if !defined(PM36_HASKELL_SCRIPTING)
518+evalGraphRefDatabaseContextIOExpr AddAtomFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
519+evalGraphRefDatabaseContextIOExpr AddDatabaseContextFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
520+evalGraphRefDatabaseContextIOExpr LoadAtomFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
521+evalGraphRefDatabaseContextIOExpr LoadDatabaseContextFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
522+#else
523+evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = do
524+ eScriptSession <- requireScriptSession
525+ currentContext <- getDBCIOContext
526+ case eScriptSession of
527+ Left err -> pure (Left err)
528+ Right scriptSession -> do
529+ res <- liftIO $ try $ runGhc (Just libdir) $ do
544530 setSession (hscEnv scriptSession)
545531 let atomFuncs = atomFunctions currentContext
546532 case extractAtomFunctionType funcType of
@@ -566,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction fun
566552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
567553 Right eContext -> case eContext of
568554 Left err -> pure (Left err)
569− Right context' -> pure (Right context')
570−
571−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextFunction funcName funcType script) =
572− case mScriptSession of
573− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
574− Just scriptSession -> do
555+ Right context' -> putDBCIOContext context'
556+evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType script) = do
557+ eScriptSession <- requireScriptSession
558+ currentContext <- getDBCIOContext
559+ case eScriptSession of
560+ Left err -> pure (Left err)
561+ Right scriptSession -> do
575562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
576563 let last2Args = reverse (take 2 (reverse funcType))
577564 atomArgs = take (length funcType - 2) funcType
@@ -581,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
581568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
582569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
583570 else do
584− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
585572 setSession (hscEnv scriptSession)
586573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
587574 pure $ case eCompiledFunc of
@@ -606,79 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
606593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
607594 Right eContext -> case eContext of
608595 Left err -> pure (Left err)
609− Right context' -> pure (Right context')
610−evalDatabaseContextIOExpr _ currentContext _ _ (LoadAtomFunctions modName funcName modPath) = do
611− eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
596+ Right context' -> putDBCIOContext context'
597+evalGraphRefDatabaseContextIOExpr (LoadAtomFunctions modName funcName modPath) = do
598+ currentContext <- getDBCIOContext
599+ eLoadFunc <- liftIO $ loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
612600 case eLoadFunc of
613601 Left LoadSymbolError -> pure (Left LoadFunctionError)
614602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
615603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
616− in pure (Right newContext)
617−evalDatabaseContextIOExpr _ currentContext _ _ (LoadDatabaseContextFunctions modName funcName modPath) = do
618− eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
604+ in putDBCIOContext newContext
605+evalGraphRefDatabaseContextIOExpr (LoadDatabaseContextFunctions modName funcName modPath) = do
606+ currentContext <- getDBCIOContext
607+ eLoadFunc <- liftIO $ loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
619608 case eLoadFunc of
620609 Left LoadSymbolError -> pure (Left LoadFunctionError)
621610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
622611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
623− in pure (Right newContext)
624−
625−evalDatabaseContextIOExpr _ currentContext transId graph (CreateArbitraryRelation relVarName attrExprs range) =
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
626615 --Define
627− case runState (evalDatabaseContextExpr (Define relVarName attrExprs) transId graph) (freshDatabaseState currentContext) of
628− (Left err,_) -> pure (Left err)
629− (Right (), elems) -> do
616+ currentContext <- getDBCIOContext
617+ env <- RWS.ask
618+ --create graph ref expr
619+ let gfExpr = Define relVarName attrExprs
620+ evalEnv = mkDatabaseContextEvalEnv (dbcio_transId env) (dbcio_graph env)
621+ graph = dbcio_graph env
622+ case runDatabaseContextEvalMonad currentContext evalEnv (evalGraphRefDatabaseContextExpr gfExpr) of
623+ Left err -> pure (Left err)
624+ Right dbstate -> do
630625 --Assign
631626 let existingRelVar = M.lookup relVarName relVarTable
632− relVarTable = relationVariables (context elems)
627+ relVarTable = relationVariables (dbc_context dbstate)
633628 case existingRelVar of
634629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
635630 Just existingRel -> do
636− case typeForGraphRefRelationalExpr existingRel graph of
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
637633 Left err -> pure (Left err)
638634 Right relType -> do
639635 let expectedAttributes = attributes relType
640− tcMap = typeConstructorMapping (context elems)
641− eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
636+ tcMap = typeConstructorMapping (dbc_context dbstate)
637+ eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
642638 case eitherRel of
643639 Left err -> pure $ Left err
644640 Right rel ->
645− case runState (setRelVar relVarName (ExistingRelation rel) transId graph) elems of
646− (Left err,_) -> pure (Left err)
647− (Right (), elems') -> pure $ Right (context elems)
648−
649−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> TransactionGraph -> RelationTuple -> Either RelationalError RelationTuple
650−updateTupleWithAtomExprs exprMap context graph tupIn = do
651− --resolve all atom exprs
652− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
653− let atom = unimplemented
654− --atom <- runReader (evalAtomExpr tupIn atomExpr) (mkRelationalExprState context graph)
655− pure (attrName, atom)
656− ) (M.toList exprMap)
657− pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
641+ case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642+ Left err -> pure (Left err)
643+ Right dbstate' -> putDBCIOContext (dbc_context dbstate')
658644
659645--run verification on all constraints
660646checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
661−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
662648 mapM_ (uncurry checkIncDep) (M.toList deps)
663649 where
664650 potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
665651 tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
666652 utctDayTime = secondsToDiffTime 0 }
667653 tempSchemas = Schemas context M.empty
668− tempTrans = Transaction U.nil (TransactionInfo (transId NE.:| []) tempStamp) tempSchemas
654+ tempTrans = Transaction U.nil tempTransInfo tempSchemas
655+ tempTransInfo = TransactionInfo { parents = transId NE.:| [],
656+ stamp = tempStamp,
657+ merkleHash = mempty
658+ }
669659
670660 deps = inclusionDependencies context
671− eval expr = evalReader (evalRelationalExpr expr)
672− evalReader f = runReader f (mkRelationalExprState context transId graph)
661+ -- no optimization available here, really? perhaps the optimizer should be passed down to here or the eval function should be passed through the environment
673662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
674− let gfSubsetExpr = evalReader (processRelationalExpr subsetExpr)
675− gfSupersetExpr = evalReader (processRelationalExpr supersetExpr)
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
676666 --if both expressions are of a single-attribute (such as with a simple foreign key), the names of the attributes are irrelevant (they need not match) because the expression is unambiguous, but special-casing this to rename the attribute automatically would not be orthogonal behavior and probably cause confusion. Instead, special case the error to make it clear.
677− typeSub <- evalReader (typeForRelationalExpr subsetExpr)
678− typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
667+ let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668+ runGfRel = runGraphRefRelationalExprM gfEnv
669+ typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670+ typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
679671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
680672 let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
681− case evalGraphRefRelationalExpr checkExpr potentialGraph of
673+ gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674+ gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675+ case gfEvald of
682676 Left err -> Left err
683677 Right resultRel -> if resultRel == relationTrue then
684678 pure ()
@@ -688,88 +682,81 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
688682-- the type of a relational expression is equal to the relation attribute set returned from executing the relational expression; therefore, the type can be cheaply derived by evaluating a relational expression and ignoring and tuple processing
689683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
690684
691−typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
692686typeForRelationalExpr expr = do
693− graph <- elems_graph <$> ask
694687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
695688 --evalRelationalExpr could still return an existing relation with tuples, so strip them
696− gfExpr <- processRelationalExpr expr
697− pure (typeForGraphRefRelationalExpr gfExpr graph)
698−
699−--returns a database context with all tuples removed
700−--this is useful for type checking and optimization
701−{-
702−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
703−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
704− where
705− relVars = M.map (\rel -> ExistingRelation (Relation (attributes rel) emptyTupleSet)) (relationVariables contextIn)
706−-}
689+ graph <- reGraph
690+ context <- reContext
691+ let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
692+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
693+ runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
694+ lift $ except runGf
707695
708696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
709697liftE v = do
710698 y <- lift v
711699 case y of
712− Left err -> throwE err
700+ Left err -> throwError err
713701 Right val -> pure val
714702
715703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
716−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExprBase a -> RelationalExprState (Either RelationalError RestrictionFilter)
717−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
718− runExceptT $ do
719− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
720− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
721− pure (\x -> do
722− ev1 <- expr1v x
723− ev2 <- expr2v x
724− pure (ev1 && ev2))
725−
726−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
727− runExceptT $ do
728− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
729− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
704+predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
705+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
706+ expr1v <- predicateRestrictionFilter attrs expr1
707+ expr2v <- predicateRestrictionFilter attrs expr2
708+ pure (\x -> do
709+ ev1 <- expr1v x
710+ ev2 <- expr2v x
711+ pure (ev1 && ev2))
712+
713+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714+ expr1v <- predicateRestrictionFilter attrs expr1
715+ expr2v <- predicateRestrictionFilter attrs expr2
730716 pure (\x -> do
731717 ev1 <- expr1v x
732718 ev2 <- expr2v x
733719 pure (ev1 || ev2))
734720
735−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
736722
737−predicateRestrictionFilter attrs (NotPredicate expr) =
738− runExceptT $ do
739− exprv <- liftE (predicateRestrictionFilter attrs expr)
740− pure (fmap not . exprv)
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
741726
742727--optimization opportunity: if the subexpression does not reference attributes in the top-level expression, then it need only be evaluated once, statically, outside the tuple filter- see historical implementation here
743−{-
744728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
745− rstate <- ask
746− pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
729+ renv <- askEnv
730+ let eval :: RelationTuple -> Either RelationalError Relation
731+ eval tup =
732+ let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup renv in
733+ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
734+ pure (\tup -> case eval tup of
747735 Left err -> Left err
748736 Right rel -> if arity rel /= 0 then
749737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
750738 else
751− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
752740
753741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
754− rstate <- ask
755− let attrs' = stateAttributes rstate
756− ctxtup' = stateTuple rstate
757− runExceptT $ do
758− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
759− attr <- either throwE pure $ case A.attributeForName attrName attrs of
742+ env <- askEnv
743+ let attrs' = A.union attrs (envAttributes env)
744+ ctxtup' = envTuple env
745+ atomExprType <- typeForGraphRefAtomExpr attrs' atomExpr
746+ attr <- lift $ except $ case A.attributeForName attrName attrs of
760747 Right attr -> Right attr
761748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
762749 Right ctxattr -> Right ctxattr
763750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
764751 Left err -> Left err
765752 Left err -> Left err
766− if atomExprType /= A.atomType attr then
767− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
768− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
769756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
770757 Right atomCmp -> atomCmp == atomIn
771758 Left _ -> False
772− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
773760 in
774761 pure $ case atomForAttributeName attrName tupleIn of
775762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -780,267 +767,322 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
780767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
781768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
782769 --merge attrs into the state attributes
783− rstate <- ask
784− runExceptT $ do
785− aType <- liftE (typeFromAtomExpr attrs atomExpr)
786− if aType /= BoolAtomType then
787− throwE (AtomTypeMismatchError aType BoolAtomType)
788− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
789775 pure (\tupleIn ->
790− case runReader (evalAtomExpr tupleIn atomExpr) rstate of
791− Left err -> Left err
792− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
793−-}
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
779+
794780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
795781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
796782 Left (AttributeNameInUseError attrName)
797783 else
798784 Right rel
799785
800−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
801−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
802− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
803789 -- check that the attribute name is not in use
804790 case tupleExprCheckNewAttrName newAttrName relIn of
805− Left err -> pure (Left err)
806− Right _ -> runExceptT $ do
807− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
808− atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
791+ Left err -> throwError err
792+ Right _ -> do
793+ atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
794+ atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
809795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
810796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
811− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in
812− case unimplemented {-runReader (evalAtomExpr tup atomExpr) substate-} of
813− Left err -> Left err
814− Right atom -> Right (tupleAtomExtend newAttrName atom tup)
797+ env <- ask
798+ pure (newAndOldAttrs, \tup -> do
799+ let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup env
800+ atom <- runGraphRefRelationalExprM gfEnv (evalGraphRefAtomExpr tup atomExpr)
801+ Right (tupleAtomExtend newAttrName atom tup)
815802 )
816803
817−
818−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
819−evalAtomExpr = undefined
820−{-
821−
822−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
823− Right atom -> pure (Right atom)
824− err@(Left (NoSuchAttributeNamesError _)) -> do
825− rstate <- ask
826− let stateTup = stateTuple rstate
827− pure (atomForAttributeName attrName stateTup)
828− Left err -> pure (Left err)
829−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
830−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
831− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
832− context <- fmap stateElemsContext ask
833− runExceptT $ do
834− let functions = atomFunctions context
835− func <- either throwE pure (atomFunctionForName funcName functions)
836− let expectedArgCount = length (atomFuncType func) - 1
837− actualArgCount = length argTypes
838− safeInit [] = [] -- different behavior from normal init
839− safeInit xs = init xs
840− if expectedArgCount /= actualArgCount then
841− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
842− else do
804+evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
805+evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806+ case atomForAttributeName attrName tupIn of
807+ Right atom -> pure atom
808+ Left err@(NoSuchAttributeNamesError _) -> do
809+ env <- askEnv
810+ case gre_extra env of
811+ Nothing -> throwError err
812+ Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
813+ Just (Right _) -> throwError err
814+ Left err -> throwError err
815+evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
816+evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
817+ argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
818+ context <- gfDatabaseContextForMarker tid
819+ let functions = atomFunctions context
820+ func <- lift $ except (atomFunctionForName funcName functions)
821+ let expectedArgCount = length (atomFuncType func) - 1
822+ actualArgCount = length argTypes
823+ safeInit [] = [] -- different behavior from normal init
824+ safeInit xs = init xs
825+ if expectedArgCount /= actualArgCount then
826+ throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
827+ else do
843828 let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
844− mapM_ (\(expType, eActType) -> do
845− actType <- either throwE pure eActType
846− either throwE pure (atomTypeVerify expType actType)) zippedArgs
847− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
829+ mapM_ (\(expType, actType) ->
830+ lift $ except (atomTypeVerify expType actType)) zippedArgs
831+ evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
848832 case evalAtomFunction func evaldArgs of
849− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
850834 Right result -> do
851835 --validate that the result matches the expected type
852− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
853837 pure result
854−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
855839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
856− rstate <- ask
857− runExceptT $ do
858− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
859− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
860− pure (RelationAtom relAtom)
861−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
862− rstate <- lift ask
863− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
864− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
865− argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
840+ env <- ask
841+ let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn env
842+ relAtom <- lift $ except $ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
843+ pure (RelationAtom relAtom)
844+evalGraphRefAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs _) = do --why is the tid unused here? suspicious
845+ let mergeEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn
846+ aType <- local mergeEnv (typeForGraphRefAtomExpr (tupleAttributes tupIn) cons)
847+ argAtoms <- local mergeEnv $
848+ mapM (evalGraphRefAtomExpr tupIn) dConsArgs
866849 pure (ConstructedAtom dConsName aType argAtoms)
867−-}
868−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
869−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
870− rstate <- ask
850+
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
871854 case A.atomTypeForAttributeName attrName attrs of
872− Right aType -> pure (Right aType)
855+ Right aType -> pure aType
873856 Left err@(NoSuchAttributeNamesError _) ->
874− let stateTup = stateTuple rstate
875− stateAttrs = stateAttributes rstate in
876− case A.attributeForName attrName stateAttrs of
877− Right attr -> pure (Right (A.atomType attr))
878− Left _ -> case atomForAttributeName attrName stateTup of
879− Right atom -> pure (Right (atomTypeForAtom atom))
880− Left _ -> pure (Left err)
881−
882−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
883−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
884− context <- fmap stateElemsContext ask
885− let funcs = atomFunctions context
857+ let envTup = envTuple renv
858+ envAttrs = envAttributes renv in
859+ case A.attributeForName attrName envAttrs of
860+ Right attr -> pure (A.atomType attr)
861+ Left _ -> case atomForAttributeName attrName envTup of
862+ Right atom -> pure (atomTypeForAtom atom)
863+ Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
864+ throwError err
865+ Left err -> throwError err
866+
867+typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
868+typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
869+ funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
886870 case atomFunctionForName funcName funcs of
887− Left err -> pure (Left err)
871+ Left err -> throwError err
888872 Right func -> do
889873 let funcRetType = last (atomFuncType func)
890874 funcArgTypes = init (atomFuncType func)
891− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
892− case lefts eArgTypes of
893− errs@(_:_) -> pure (Left (someErrors errs))
894− [] -> do
895− let eTvMap = resolveTypeVariables funcArgTypes argTypes
896− argTypes = rights eArgTypes
897− case eTvMap of
898− Left err -> pure (Left err)
899− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
900−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = do
901− relType <- local (mergeAttributesIntoRelationalExprState attrs) (typeForRelationalExpr relExpr)
902− case relType of
903− Left err -> pure (Left err)
904− Right relType' ->
905− pure (pure (RelationAtomType (attributes relType')))
875+ argTypes <- mapM (typeForGraphRefAtomExpr attrs) atomArgs
876+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
877+ case eTvMap of
878+ Left err -> throwError err
879+ Right tvMap -> lift $ except $ resolveFunctionReturnValue funcName tvMap funcRetType
880+typeForGraphRefAtomExpr attrs (RelationAtomExpr relExpr) = do
881+ relType <- R.local (mergeAttributesIntoGraphRefRelationalExprEnv attrs) (typeForGraphRefRelationalExpr relExpr)
882+ pure (RelationAtomType (attributes relType))
906883-- grab the type of the data constructor, then validate that the args match the expected types
907−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
908− runExceptT $ do
909− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
910− context <- fmap stateElemsContext (lift ask)
911− either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
884+typeForGraphRefAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs tid) =
885+ do
886+ argsTypes <- mapM (typeForGraphRefAtomExpr attrs) dConsArgs
887+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
888+ lift $ except $ atomTypeForDataConstructor tConsMap dConsName argsTypes
912889
913890-- | Validate that the type of the AtomExpr matches the expected type.
914−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
915−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
916− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
917894 case A.atomTypeForAttributeName attrName (attributes relIn) of
918− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
895+ Right aType -> lift $ except $ atomTypeVerify expectedType aType
919896 (Left err@(NoSuchAttributeNamesError _)) ->
920− let attrs' = stateAttributes rstate in
897+ let attrs' = envAttributes env in
921898 if attrs' == emptyAttributes then
922− throwE err
899+ throwError err
923900 else
924901 case A.attributeForName attrName attrs' of
925− Left err' -> throwE err'
926− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
927−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
928−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
929− rstate <- ask
902+ Left err' -> throwError err'
903+ Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
904+ Left err -> throwError err
905+
906+verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907+ lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
908+verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
909+ context <- gfDatabaseContextForMarker tid
930910 let functions = atomFunctions context
931− context = stateElemsContext rstate
932− runExceptT $ do
933− func <- either throwE pure (atomFunctionForName funcName functions)
934− let expectedArgTypes = atomFuncType func
935− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
936− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
937− Left err -> throwE err
938− Right x -> pure x
939− ) $ zip3 funcArgExprs expectedArgTypes [1..]
940− if length funcArgTypes /= length expectedArgTypes - 1 then
941− throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
911+ func <- lift $ except $ atomFunctionForName funcName functions
912+ let expectedArgTypes = atomFuncType func
913+ funcArgVerifier (atomExpr, expectedType2, argCount) = do
914+ let handler :: RelationalError -> GraphRefRelationalExprM AtomType
915+ handler (AtomTypeMismatchError expSubType actSubType) = throwError (AtomFunctionTypeError funcName argCount expSubType actSubType)
916+ handler err = throwError err
917+ verifyGraphRefAtomExprTypes relIn atomExpr expectedType2 `catchError` handler
918+ funcArgTypes <- mapM funcArgVerifier $ zip3 funcArgExprs expectedArgTypes [1..]
919+ if length funcArgTypes /= length expectedArgTypes - 1 then
920+ throwError (AtomTypeCountError funcArgTypes expectedArgTypes)
942921 else
943− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
944−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
945− rstate <- lift ask
946− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
947− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
948−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
949− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
950− either throwE pure (atomTypeVerify expectedType cType)
922+ lift $ except $ atomTypeVerify expectedType (last expectedArgTypes)
923+verifyGraphRefAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType =
924+ do
925+ let mergedAttrsEnv e = mergeAttributesIntoGraphRefRelationalExprEnv (attributes relIn) e
926+ relType <- R.local mergedAttrsEnv (typeForGraphRefRelationalExpr relationExpr)
927+ lift $ except $ atomTypeVerify expectedType (RelationAtomType (attributes relType))
928+verifyGraphRefAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = do
929+ cType <- typeForGraphRefAtomExpr (attributes rel) cons
930+ lift $ except $ atomTypeVerify expectedType cType
951931
952932-- | Look up the type's name and create a new attribute.
953−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
954−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
955− aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
956− validateAtomType aType aTypes
957− Right (Attribute attrName aType)
933+evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
934+evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
935+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
936+ aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
937+ lift $ except $ validateAtomType aType tConsMap
938+ pure $ Attribute attrName aType
958939
959−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
960−
961−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
962−evalTupleExpr mAttrs (TupleExpr tupMap) = do
963− context <- fmap stateElemsContext ask
964− runExceptT $ do
940+evalGraphRefAttrExpr (NakedAttributeExpr attr) = pure attr
941+
942+-- for tuple type concrete resolution (Nothing ==> Maybe Int) when the attributes hint is Nothing, we need to first process all the tuples, then extract the concrete types on a per-attribute basis, then reprocess the tuples to include the concrete types
943+evalGraphRefTupleExprs :: Maybe Attributes -> GraphRefTupleExprs -> GraphRefRelationalExprM [RelationTuple]
944+evalGraphRefTupleExprs _ (TupleExprs _ []) = pure []
945+evalGraphRefTupleExprs mAttrs (TupleExprs fixedMarker tupleExprL) = do
946+ tuples <- mapM (evalGraphRefTupleExpr mAttrs) tupleExprL
947+ finalAttrs <- case mAttrs of
948+ Just attrs -> pure attrs
949+ Nothing ->
950+ case tuples of
951+ [] -> pure emptyAttributes
952+ (headTuple:tailTuples) -> do
953+ --gather up resolved atom types or throw an error if an attribute cannot be made concrete from the inferred types- this could still fail if the type cannot be inferred (e.g. from [Nothing, Nothing])
954+ let
955+ processTupleAttrs (tupAttr, accAttr) =
956+ --if the attribute is a constructedatomtype, we can recurse into it to potentially resolve type variables
957+ if isResolvedAttribute accAttr && tupAttr == accAttr then
958+ pure accAttr
959+ else
960+ lift $ except $ resolveAttributes accAttr tupAttr
961+ mostResolvedTypes <-
962+ foldM (\acc tup -> do
963+ let zipped = zip (V.toList . attributesVec $ tupleAttributes tup) acc
964+ accNames = S.fromList $ map A.attributeName acc
965+ tupNames = A.attributeNameSet (tupleAttributes tup)
966+ attrNamesDiff = S.union (S.difference accNames tupNames) (S.difference tupNames accNames)
967+ unless (null attrNamesDiff) (throwError (AttributeNamesMismatchError attrNamesDiff))
968+ nextTupleAttrs <- mapM processTupleAttrs zipped
969+ let diff = A.attributesDifference (A.attributesFromList nextTupleAttrs) (A.attributesFromList acc)
970+ if diff == A.emptyAttributes then
971+ pure nextTupleAttrs
972+ else
973+ throwError (TupleAttributeTypeMismatchError diff)
974+ ) (V.toList . attributesVec $ tupleAttributes headTuple) tailTuples
975+ pure (A.attributesFromList mostResolvedTypes)
976+ --strategy: if all the tuple expr transaction markers refer to one location, then we can pass the type constructor mapping from that location, otherwise, we cannot assume that the types are the same
977+ tConsMap <- case singularTransactions tupleExprL of
978+ SingularTransactionRef commonTransId ->
979+ typeConstructorMapping <$> gfDatabaseContextForMarker commonTransId
980+ NoTransactionsRef ->
981+ typeConstructorMapping <$> gfDatabaseContextForMarker fixedMarker
982+ -- if there are multiple transaction markers in the TupleExprs, then we can't assume a single type constructor mapping- this could be improved in the future, but if all the tuples are fully resolved, then we don't need further resolution
983+ _ -> throwError TupleExprsReferenceMultipleMarkersError
984+ lift $ except $ validateAttributes tConsMap finalAttrs
985+ mapM (lift . except . resolveTypesInTuple finalAttrs tConsMap) tuples
986+
987+
988+--resolveAttributes (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",IntegerAtomType),("b",TypeVariableType "b")]))) (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",TypeVariableType "a"),("b",TextAtomType)])))
989+
990+evalGraphRefTupleExpr :: Maybe Attributes -> GraphRefTupleExpr -> GraphRefRelationalExprM RelationTuple
991+evalGraphRefTupleExpr mAttrs (TupleExpr tupMap) = do
965992 -- it's not possible for AtomExprs in tuple constructors to reference other Attributes' atoms due to the necessary order-of-operations (need a tuple to pass to evalAtomExpr)- it may be possible with some refactoring of type usage or delayed evaluation- needs more thought, but not a priority
966993 -- I could adjust this logic so that when the attributes are not specified (Nothing), then I can attempt to extract the attributes from the tuple- the type resolution will blow up if an ambiguous data constructor is used (Left 4) and this should allow simple cases to "relation{tuple{a 4}}" to be processed
967− let attrs = fromMaybe A.emptyAttributes mAttrs
968− attrAtoms <- mapM (\(attrName, aExpr) -> do
969− --provided when the relation header is available
970− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
971− unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
972− resolvedType <- case eExpectedAtomType of
994+ let attrs = fromMaybe A.emptyAttributes mAttrs
995+ resolveOneAtom (attrName, aExpr) =
996+ do
997+ --provided when the relation header is available
998+ let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
999+ unresolvedType <- typeForGraphRefAtomExpr attrs aExpr
1000+ resolvedType <- case eExpectedAtomType of
9731001 Left _ -> pure unresolvedType
974− Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
9751003 --resolve atom typevars based on resolvedType?
976− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
977− pure (attrName, newAtom, resolvedType)
978− ) (M.toList tupMap)
979− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
980− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
981− tup = mkRelationTuple tupAttrs atoms
982− tConss = typeConstructorMapping context
983− finalAttrs = fromMaybe tupAttrs mAttrs
1004+ newAtom <- evalGraphRefAtomExpr emptyTuple aExpr
1005+ pure (attrName, newAtom, resolvedType)
1006+ attrAtoms <- mapM resolveOneAtom (M.toList tupMap)
1007+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
1008+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
1009+ tup = mkRelationTuple tupAttrs atoms
1010+ finalAttrs = fromMaybe tupAttrs mAttrs
9841011 --verify that the attributes match
985− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
986− tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
987− _ <- either throwE pure (validateTuple tup' tConss)
988− pure tup'
989−
990−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
991−evalAttributeNames attrNames expr = do
992− eExprType <- typeForRelationalExpr expr
993− case eExprType of
994− Left err -> pure (Left err)
995− Right exprTyp -> do
996− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
997− case attrNames of
998− AttributeNames names ->
999− case A.projectionAttributesForNames names (attributes exprTyp) of
1000− Left err -> pure (Left err)
1001− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1002−
1003− InvertedAttributeNames names -> do
1004− let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1005− if not (S.null nonExistentAttributeNames) then
1006− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1007− else
1008− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1009−
1010− UnionAttributeNames namesA namesB -> do
1011− eNameSetA <- evalAttributeNames namesA expr
1012− case eNameSetA of
1013− Left err -> pure (Left err)
1014− Right nameSetA -> do
1015− eNameSetB <- evalAttributeNames namesB expr
1016− case eNameSetB of
1017− Left err -> pure (Left err)
1018− Right nameSetB ->
1019− pure (Right (S.union nameSetA nameSetB))
1020−
1021− IntersectAttributeNames namesA namesB -> do
1022− eNameSetA <- evalAttributeNames namesA expr
1023− case eNameSetA of
1024− Left err -> pure (Left err)
1025− Right nameSetA -> do
1026− eNameSetB <- evalAttributeNames namesB expr
1027− case eNameSetB of
1028− Left err -> pure (Left err)
1029− Right nameSetB ->
1030− pure (Right (S.intersection nameSetA nameSetB))
1031−
1032− RelationalExprAttributeNames attrExpr -> do
1033− eAttrExprType <- typeForRelationalExpr attrExpr
1034− case eAttrExprType of
1035− Left err -> pure (Left err)
1036− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1037−
1038−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1039−evalGraphRefRelationalExpr (RelationVariable name tid) graph = do
1040− ctx <- dbContextForTransId tid graph
1012+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
1013+ --we can't resolve types here- they have to be resolved at the atom level where the graph ref is held
1014+ --tup' <- lift $ except (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
1015+ let tup' = reorderTuple finalAttrs tup
1016+ --TODO: restore type resolution
1017+-- _ <- lift $ except (validateTuple tup' tConss)
1018+ pure tup'
1019+
1020+--temporary implementation until we have a proper planner+executor
1021+evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1022+evalGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1023+ mAttrs <- case mAttrExprs of
1024+ Just _ ->
1025+ Just . A.attributesFromList <$> mapM evalGraphRefAttrExpr (fromMaybe [] mAttrExprs)
1026+ Nothing -> pure Nothing
1027+ tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1028+ let attrs = fromMaybe firstTupleAttrs mAttrs
1029+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
1030+ lift $ except $ mkRelation attrs (RelationTupleSet tuples)
1031+evalGraphRefRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
1032+ lift $ except $ mkRelation attributeSet tupleSet
1033+evalGraphRefRelationalExpr (ExistingRelation rel) = pure rel
1034+evalGraphRefRelationalExpr (RelationVariable name tid) = do
1035+ ctx <- gfDatabaseContextForMarker tid
10411036 case M.lookup name (relationVariables ctx) of
1042− Nothing -> Left (RelVarNotDefinedError name)
1043− Just rv -> evalGraphRefRelationalExpr rv graph
1037+ Nothing -> throwError (RelVarNotDefinedError name)
1038+ Just rv -> evalGraphRefRelationalExpr rv
1039+evalGraphRefRelationalExpr (Project attrNames expr) = do
1040+ attrNameSet <- evalGraphRefAttributeNames attrNames expr
1041+ rel <- evalGraphRefRelationalExpr expr
1042+ lift $ except $ project attrNameSet rel
1043+evalGraphRefRelationalExpr (Union exprA exprB) = do
1044+ relA <- evalGraphRefRelationalExpr exprA
1045+ relB <- evalGraphRefRelationalExpr exprB
1046+ lift $ except $ union relA relB
1047+evalGraphRefRelationalExpr (Join exprA exprB) = do
1048+ relA <- evalGraphRefRelationalExpr exprA
1049+ relB <- evalGraphRefRelationalExpr exprB
1050+ lift $ except $ join relA relB
1051+evalGraphRefRelationalExpr (Rename oldName newName expr) = do
1052+ rel <- evalGraphRefRelationalExpr expr
1053+ lift $ except $ rename oldName newName rel
1054+evalGraphRefRelationalExpr (Difference exprA exprB) = do
1055+ relA <- evalGraphRefRelationalExpr exprA
1056+ relB <- evalGraphRefRelationalExpr exprB
1057+ lift $ except $ difference relA relB
1058+evalGraphRefRelationalExpr (Group groupAttrNames newAttrName expr) = do
1059+ groupNames <- evalGraphRefAttributeNames groupAttrNames expr
1060+ rel <- evalGraphRefRelationalExpr expr
1061+ lift $ except $ group groupNames newAttrName rel
1062+evalGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1063+ rel <- evalGraphRefRelationalExpr expr
1064+ lift $ except $ ungroup groupAttrName rel
1065+evalGraphRefRelationalExpr (Restrict predExpr expr) = do
1066+ rel <- evalGraphRefRelationalExpr expr
1067+ filt <- predicateRestrictionFilter (attributes rel) predExpr
1068+ lift $ except $ restrict filt rel
1069+evalGraphRefRelationalExpr (Equals exprA exprB) = do
1070+ relA <- evalGraphRefRelationalExpr exprA
1071+ relB <- evalGraphRefRelationalExpr exprB
1072+ pure $ if relA == relB then relationTrue else relationFalse
1073+evalGraphRefRelationalExpr (NotEquals exprA exprB) = do
1074+ relA <- evalGraphRefRelationalExpr exprA
1075+ relB <- evalGraphRefRelationalExpr exprB
1076+ pure $ if relA == relB then relationFalse else relationTrue
1077+evalGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1078+ rel <- evalGraphRefRelationalExpr expr
1079+ (newAttrs, tupProc) <- extendGraphRefTupleExpressionProcessor rel extendTupleExpr
1080+ lift $ except $ relMogrify tupProc newAttrs rel
1081+evalGraphRefRelationalExpr expr@With{} =
1082+ --strategy A: add relation variables to the contexts in the graph
1083+ --strategy B: drop in macros in place (easier programmatically)
1084+ --strategy B implementation
1085+ evalGraphRefRelationalExpr (substituteWithNameMacros [] expr)
10441086
10451087dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
10461088dbContextForTransId tid graph = do
@@ -1058,143 +1100,293 @@ transactionForId tid graph
10581100 where
10591101 matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
10601102
1061−processRestrictionPredicateExpr :: RestrictionPredicateExpr -> RelationalExprState (Either RelationalError GraphRefRestrictionPredicateExpr)
1062−processRestrictionPredicateExpr TruePredicate = pure (Right TruePredicate)
1063−processRestrictionPredicateExpr (AndPredicate a b) = do
1064− a' <- processRestrictionPredicateExpr a
1065− b' <- processRestrictionPredicateExpr b
1066− case a' of
1067− Left err -> pure (Left err)
1068− Right a'' -> case b' of
1069− Left err -> pure (Left err)
1070− Right b'' ->
1071− pure (Right (AndPredicate a'' b''))
1072−processRestrictionPredicateExpr (OrPredicate a b) = do
1073− a' <- processRestrictionPredicateExpr a
1074− b' <- processRestrictionPredicateExpr b
1075− case a' of
1076− Left err -> pure (Left err)
1077− Right a'' -> case b' of
1078− Left err -> pure (Left err)
1079− Right b'' ->
1080− pure (Right (OrPredicate a'' b''))
1081−processRestrictionPredicateExpr (NotPredicate a) = do
1082− a' <- processRestrictionPredicateExpr a
1083− case a' of
1084− Left err -> pure (Left err)
1085− Right a'' ->
1086− pure (Right (NotPredicate a''))
1087−processRestrictionPredicateExpr (RelationalExprPredicate expr) = do
1088− e <- evalRelationalExpr expr
1089− pure $ case e of
1090− Left err -> Left err
1091− Right e' -> Right (RelationalExprPredicate e')
1092−processRestrictionPredicateExpr (AtomExprPredicate expr) = do
1093− tid <- elems_currentTransId <$> ask
1094− let e = processAtomExpr expr tid
1095− pure (Right (AtomExprPredicate e))
1096−processRestrictionPredicateExpr (AttributeEqualityPredicate nam expr) = do
1097− tid <- elems_currentTransId <$> ask
1098− let e = processAtomExpr expr tid
1099− pure (Right (AttributeEqualityPredicate nam e))
1100−processExtendTupleExpr :: ExtendTupleExpr -> RelationalExprState (Either RelationalError (ExtendTupleExprBase a))
1101−processExtendTupleExpr (AttributeExtendTupleExpr nam atomExpr) = do
1102− eExpr <- evalAtomExpr atomExpr
1103− case eExpr of
1104− Left err -> pure (Left err)
1105− Right expr -> pure (Right (AttributeExtendTupleExpr nam expr))
1106−
1107−typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1108−typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) _ = mkRelation attrs emptyTupleSet
1109−typeForGraphRefRelationalExpr (ExistingRelation rel) _ = pure (emptyRelationWithAttrs (attributes rel))
1110−typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) graph =
1111− case mAttrExprs of
1112− Just attrExprs -> do
1113− attrs <- mapM (\e -> evalGraphRefAttributeExpr e graph) attrExprs
1114− pure (emptyRelationWithAttrs attrs)
1115−typeForGraphRefRelationalExpr (RelationVariable rvName tid) graph = do
1116− trans <- transactionForId tid graph
1117− let relVars = relationVariables (concreteDatabaseContext trans)
1103+typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1104+typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = lift $ except $ mkRelation attrs emptyTupleSet
1105+typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (emptyRelationWithAttrs (attributes rel))
1106+typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1107+ mAttrs <- case mAttrExprs of
1108+ Just attrExprs -> do
1109+ attrs <- mapM evalGraphRefAttributeExpr attrExprs
1110+ pure (Just (attributesFromList attrs))
1111+ Nothing -> pure Nothing
1112+ tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1113+ let retAttrs = case tuples of
1114+ (tup:_) -> tupleAttributes tup
1115+ [] -> fromMaybe A.emptyAttributes mAttrs
1116+ pure $ emptyRelationWithAttrs retAttrs
1117+
1118+typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119+ relVars <- relationVariables <$> gfDatabaseContextForMarker tid
11181120 case M.lookup rvName relVars of
1119− Nothing -> Left $ RelVarNotDefinedError name
1120− Just rvExpr -> typeForGraphRefRelationalExpr rvExpr graph
1121−typeForGraphRefRelationalExpr (Project attrNames expr) graph = do
1122− exprType <- typeForGraphRefRelationalExpr expr graph
1123− projectionAttrs <- evalGraphRefAttributeNames attrNames expr graph
1124− project projectionAttrs exprType
1125−
1126−evalGraphRefAttributeNames :: AttributeNames -> GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError (S.Set AttributeName)
1127−evalGraphRefAttributeNames attrNames expr graph = do
1128− exprTyp <- typeForGraphRefRelationalExpr expr graph
1129− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
1121+ Nothing -> throwError (RelVarNotDefinedError rvName)
1122+ Just rvExpr ->
1123+ typeForGraphRefRelationalExpr rvExpr
1124+typeForGraphRefRelationalExpr (Project attrNames expr) = do
1125+ exprType' <- typeForGraphRefRelationalExpr expr
1126+ projectionAttrs <- evalGraphRefAttributeNames attrNames expr
1127+ lift $ except $ project projectionAttrs exprType'
1128+typeForGraphRefRelationalExpr (Union exprA exprB) = do
1129+ exprA' <- typeForGraphRefRelationalExpr exprA
1130+ exprB' <- typeForGraphRefRelationalExpr exprB
1131+ lift $ except $ union exprA' exprB'
1132+typeForGraphRefRelationalExpr (Join exprA exprB) = do
1133+ exprA' <- typeForGraphRefRelationalExpr exprA
1134+ exprB' <- typeForGraphRefRelationalExpr exprB
1135+ lift $ except $ join exprA' exprB'
1136+typeForGraphRefRelationalExpr (Rename oldAttr newAttr expr) = do
1137+ expr' <- typeForGraphRefRelationalExpr expr
1138+ lift $ except $ rename oldAttr newAttr expr'
1139+typeForGraphRefRelationalExpr (Difference exprA exprB) = do
1140+ exprA' <- typeForGraphRefRelationalExpr exprA
1141+ exprB' <- typeForGraphRefRelationalExpr exprB
1142+ lift $ except $ difference exprA' exprB'
1143+typeForGraphRefRelationalExpr (Group groupNames attrName expr) = do
1144+ expr' <- typeForGraphRefRelationalExpr expr
1145+ groupNames' <- evalGraphRefAttributeNames groupNames expr
1146+ lift $ except $ group groupNames' attrName expr'
1147+typeForGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1148+ expr' <- typeForGraphRefRelationalExpr expr
1149+ lift $ except $ ungroup groupAttrName expr'
1150+typeForGraphRefRelationalExpr (Restrict pred' expr) = do
1151+ expr' <- typeForGraphRefRelationalExpr expr
1152+ filt <- predicateRestrictionFilter (attributes expr') pred'
1153+ lift $ except $ restrict filt expr'
1154+typeForGraphRefRelationalExpr Equals{} =
1155+ pure relationFalse
1156+typeForGraphRefRelationalExpr NotEquals{} =
1157+ pure relationFalse
1158+typeForGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1159+ rel <- typeForGraphRefRelationalExpr expr
1160+ evalGraphRefRelationalExpr (Extend extendTupleExpr (ExistingRelation rel))
1161+typeForGraphRefRelationalExpr expr@(With withs _) = do
1162+ let expr' = substituteWithNameMacros [] expr
1163+ checkMacroName (WithNameExpr macroName tid) = do
1164+ rvs <- relationVariables <$> gfDatabaseContextForMarker tid
1165+ case M.lookup macroName rvs of
1166+ Just _ -> lift $ except $ Left (RelVarAlreadyDefinedError macroName) --this error does not include the transaction marker, but should be good enough to identify the cause
1167+ Nothing -> pure ()
1168+ mapM_ (checkMacroName . fst) withs
1169+ typeForGraphRefRelationalExpr expr'
1170+
1171+evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1172+evalGraphRefAttributeNames attrNames expr = do
1173+ exprType' <- typeForGraphRefRelationalExpr expr
1174+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
11301175 case attrNames of
1131− AttributeNames names ->
1132− case A.projectionAttributesForNames names (attributes exprTyp) of
1133− Left err -> pure (Left err)
1134− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1176+ AttributeNames names ->
1177+ case A.projectionAttributesForNames names (attributes exprType') of
1178+ Left err -> throwError err
1179+ Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
11351180
1136− InvertedAttributeNames names -> do
1181+ InvertedAttributeNames names -> do
11371182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
11381183 if not (S.null nonExistentAttributeNames) then
1139− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
11401185 else
1141− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
11421187
1143− UnionAttributeNames namesA namesB -> do
1144− eNameSetA <- evalAttributeNames namesA expr
1145− case eNameSetA of
1146− Left err -> pure (Left err)
1147− Right nameSetA -> do
1148− eNameSetB <- evalAttributeNames namesB expr
1149− case eNameSetB of
1150− Left err -> pure (Left err)
1151− Right nameSetB ->
1152− pure (Right (S.union nameSetA nameSetB))
1188+ UnionAttributeNames namesA namesB -> do
1189+ nameSetA <- evalGraphRefAttributeNames namesA expr
1190+ nameSetB <- evalGraphRefAttributeNames namesB expr
1191+ pure (S.union nameSetA nameSetB)
11531192
1154− IntersectAttributeNames namesA namesB -> do
1155− eNameSetA <- evalAttributeNames namesA expr
1156− case eNameSetA of
1157− Left err -> pure (Left err)
1158− Right nameSetA -> do
1159− eNameSetB <- evalAttributeNames namesB expr
1160− case eNameSetB of
1161− Left err -> pure (Left err)
1162− Right nameSetB ->
1163− pure (Right (S.intersection nameSetA nameSetB))
1193+ IntersectAttributeNames namesA namesB -> do
1194+ nameSetA <- evalGraphRefAttributeNames namesA expr
1195+ nameSetB <- evalGraphRefAttributeNames namesB expr
1196+ pure (S.intersection nameSetA nameSetB)
11641197
1165− RelationalExprAttributeNames attrExpr -> do
1166− eAttrExprType <- typeForRelationalExpr attrExpr
1167− case eAttrExprType of
1168− Left err -> pure (Left err)
1169− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1170−
1171−
1198+ RelationalExprAttributeNames attrExpr -> do
1199+ attrExprType <- typeForGraphRefRelationalExpr attrExpr
1200+ pure (A.attributeNameSet (attributes attrExprType))
1201+
1202+evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
1203+evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) = do
1204+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
1205+ case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1206+ Left err -> throwError err
1207+ Right aType -> do
1208+ case validateAtomType aType tConsMap of
1209+ Left err -> throwError err
1210+ Right _ -> pure (Attribute attrName aType)
1211+evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1212+
1213+mkEmptyRelVars :: RelationVariables -> RelationVariables
1214+mkEmptyRelVars = M.map mkEmptyRelVar
1215+ where
1216+ mkEmptyRelVar expr@MakeRelationFromExprs{} = expr --do not truncate here because we might lose essential type information in emptying the tuples
1217+ mkEmptyRelVar (MakeStaticRelation attrs _) = MakeStaticRelation attrs emptyTupleSet
1218+ mkEmptyRelVar (ExistingRelation rel) = ExistingRelation (emptyRelationWithAttrs (attributes rel))
1219+ mkEmptyRelVar rv@RelationVariable{} = Restrict (NotPredicate TruePredicate) rv
1220+ mkEmptyRelVar (Project attrNames expr) = Project attrNames (mkEmptyRelVar expr)
1221+ mkEmptyRelVar (Union exprA exprB) = Union (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1222+ mkEmptyRelVar (Join exprA exprB) = Join (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1223+ mkEmptyRelVar (Rename nameA nameB expr) = Rename nameA nameB (mkEmptyRelVar expr)
1224+ mkEmptyRelVar (Difference exprA exprB) = Difference (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1225+ mkEmptyRelVar (Group attrNames attrName expr) = Group attrNames attrName (mkEmptyRelVar expr)
1226+ mkEmptyRelVar (Ungroup attrName expr) = Ungroup attrName (mkEmptyRelVar expr)
1227+ mkEmptyRelVar (Restrict pred' expr) = Restrict pred' (mkEmptyRelVar expr)
1228+ mkEmptyRelVar (Equals exprA exprB) = Equals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1229+ mkEmptyRelVar (NotEquals exprA exprB) = NotEquals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1230+ mkEmptyRelVar (Extend extTuple expr) = Extend extTuple (mkEmptyRelVar expr)
1231+ mkEmptyRelVar (With macros expr) = With (map (second mkEmptyRelVar) macros) (mkEmptyRelVar expr)
1232+
1233+
1234+dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235+dbErr err = lift (except (Left err))
1236+
1237+-- | Return a Relation describing the relation variables.
1238+relationVariablesAsRelation :: DatabaseContext -> TransactionGraph -> Either RelationalError Relation
1239+relationVariablesAsRelation ctx graph = do
1240+ let subrelAttrs = A.attributesFromList [Attribute "attribute" TextAtomType, Attribute "type" TextAtomType]
1241+ attrs = A.attributesFromList [Attribute "name" TextAtomType,
1242+ Attribute "attributes" (RelationAtomType subrelAttrs)]
1243+ relVars = relationVariables ctx
1244+ mkRvDesc (rvName, gfExpr) = do
1245+ let gfEnv = freshGraphRefRelationalExprEnv (Just ctx) graph
1246+ gfType <- runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
1247+ pure (rvName, gfType)
1248+ relVarToAtomList (rvName, rel) = [TextAtom rvName, attributesToRel (attributesVec (attributes rel))]
1249+ attrAtoms a = [TextAtom (A.attributeName a), TextAtom (prettyAtomType (A.atomType a))]
1250+ attributesToRel attrl = case mkRelationFromList subrelAttrs (map attrAtoms (V.toList attrl)) of
1251+ Left err -> error ("relationVariablesAsRelation pooped " ++ show err)
1252+ Right rel -> RelationAtom rel
1253+ rvs <- mapM mkRvDesc (M.toList relVars)
1254+ let tups = map relVarToAtomList rvs
1255+ mkRelationFromList attrs tups
1256+
1257+-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258+evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259+evalRelationalExpr expr = do
1260+ graph <- reGraph
1261+ context <- reContext
1262+ let expr' = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
1263+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
1264+ case runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr expr') of
1265+ Left err -> throwError err
1266+ Right rel -> pure rel
1267+
1268+class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269+ getContext :: m DatabaseContext
11721270
1271+instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272+ getContext = gfDatabaseContextForMarker UncommittedContextMarker
11731273
1174−processAtomExpr :: AtomExpr -> TransactionId -> GraphRefAtomExpr
1175−processAtomExpr (AttributeAtomExpr nam) _ = AttributeAtomExpr nam
1176−processAtomExpr (NakedAtomExpr atom) _ = NakedAtomExpr atom
1177−processAtomExpr (FunctionAtomExpr fName atomExprs ()) tid = FunctionAtomExpr fName (fmap processAtomExpr tid) tid
1178−processAtomExpr (RelationAtomExpr expr) tid = RelationAtomExpr (processRelationalExpr expr tid)
1179−processAtomExpr (ConstructedAtomExpr dConsName atomExprs) = ConstructedAtomExpr dConsName (fmap processAtomExpr tid) tid
1180−
1181−processTupleExpr :: TupleExpr -> TransactionId -> GraphRefTupleExpr
1182−processTupleExpr (TupleExpr tMap) tid = TupleExpr (M.map (processAtomExpr tid) tMap)
1183−
1184−evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> TransactionGraph -> Either RelationalError Attribute
1185−evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) graph = do
1186− trans <- transactionForId tid graph
1187− let tConsMap = typeConstructorMapping (concreteDatabaseContext trans)
1188− aType <- atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
1189− validateAtomType aType tConsMap
1190− pure (Attribute attrName aType)
1191−
1192−--convert AttributeExpr to GraphRefAttributeExpr
1193−processAttributeExpr :: AttributeExpr -> TransactionId -> GraphRefAttributeExpr
1194−processAttributeExpr (AttributeAndTypeNameExpr nam tCons ()) tid = AttributeAndTypeNameExpr nam tCons tid
1195−processAttributeExpr (NakedAttributeExpr attr) = NakedAttributeExpr attr
1196−
1197−-- convert a RelationalExpr into a GraphRefRelationalExpr
1198−processRelationalExpr :: RelationalExpr -> RelationalExprState GraphRefRelationalExpr
1199−processRelationalExpr (MakeRelationFromExprs mAttrs tupleExprs) = do
1200− MakeRelationFromExprs (fmap (fmap processAttributeExpr) mAttrs) (processTupleExprs tupleExprs)
1274+instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275+ getContext = getStateContext
1276+
1277+relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278+relVarByName rvName = do
1279+ relvars <- relationVariables <$> getContext
1280+ case M.lookup rvName relvars of
1281+ Nothing -> throwError (RelVarNotDefinedError rvName)
1282+ Just gfexpr -> pure gfexpr
1283+
1284+-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285+class ResolveGraphRefTransactionMarker a where
1286+ resolve :: a -> DatabaseContextEvalMonad a
1287+
1288+-- s := s union t
1289+instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290+ resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291+ MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292+ resolve orig@MakeStaticRelation{} = pure orig
1293+ resolve orig@ExistingRelation{} = pure orig
1294+ resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295+ rvMap <- relationVariables <$> getStateContext
1296+ case M.lookup rvName rvMap of
1297+ Nothing -> pure orig
1298+ Just resolvedRv -> resolve resolvedRv
1299+ resolve orig@RelationVariable{} = pure orig
1300+ resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301+ resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302+ resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303+ resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304+ resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305+ resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306+ resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307+ resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308+ resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309+ resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310+ resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311+ resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312+
1313+instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314+ resolve (TupleExprs marker tupleExprs) =
1315+ TupleExprs marker <$> mapM resolve tupleExprs
1316+
1317+instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318+ resolve (TupleExpr tupMap) = do
1319+ tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320+ pure (TupleExpr (M.fromList tupMap'))
1321+
1322+instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323+ resolve orig@AttributeNames{} = pure orig
1324+ resolve orig@InvertedAttributeNames{} = pure orig
1325+ resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326+ resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327+ resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328+
1329+instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330+ resolve TruePredicate = pure TruePredicate
1331+ resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332+ resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333+ resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334+ resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335+ resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336+ resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337+
1338+instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339+ resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340+
1341+instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342+ resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343+
1344+instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345+ resolve orig@AttributeAtomExpr{} = pure orig
1346+ resolve orig@NakedAtomExpr{} = pure orig
1347+ resolve (FunctionAtomExpr nam atomExprs marker) =
1348+ FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349+ resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350+ resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351+ ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352+
1353+--convert series of simple Union queries into MakeStaticRelation
1354+-- this is especially useful for long, nested applications of Union with simple tuples
1355+-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356+
1357+--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358+
1359+applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360+applyUnionCollapse = Fold.cata opt
1361+ where
1362+ opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363+ opt (UnionF exprA exprB) | exprA == exprB = exprA
1364+ opt (UnionF
1365+ exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366+ exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367+ | tupExprsNull tupExprs1 = exprB
1368+ | tupExprsNull tupExprs2 = exprA
1369+ opt x = Fold.embed x
1370+ tupExprsNull (TupleExprs _ []) = True
1371+ tupExprsNull _ = False
1372+
1373+
1374+--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375+--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376+-- =>
1377+-- update x where y=1 set (x:=6,z:=11)
1378+-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379+
1380+--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381+
1382+--DELETE optimization
1383+-- if a restriction matches a previous restriction, combine them
1384+-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385+applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386+applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387+ case expr of
1388+ orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389+ _ -> orig
1390+applyRestrictionCollapse expr = expr
1391+
1392+