@@ -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
@@ -7,32 +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
20+import ProjectM36.Transaction
1621import qualified ProjectM36.Attribute as A
1722import qualified Data.Map as M
1823import qualified Data.HashSet as HS
1924import qualified Data.Set as S
2025import Control.Monad.State hiding (join)
21−import Control.Exception
26+import Data.Bifunctor (second)
2227import Data.Maybe
2328import Data.Either
2429import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2533import qualified Data.Text as T
2634import qualified Data.Vector as V
2735import qualified ProjectM36.TypeConstructorDef as TCD
28−import Control.Monad.Trans.Except
29−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
3043import Test.QuickCheck
31−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
3249import GHC.Paths
33−import Data.Time.Clock
34−import Data.Time.Calendar
35−import qualified Data.List.NonEmpty as NE
50+#endif
3651
3752data DatabaseContextExprDetails = CountUpdatedTuples
3853
@@ -49,41 +64,63 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
4964 Right ts -> ts
5065
5166-- | Used to start a fresh database state for a new database context expression.
52−freshDatabaseState :: DatabaseContext -> DatabaseStateElems
53−freshDatabaseState context = DatabaseStateElems {
54− context = context,
55− accum = M.empty,
56− dirty = False
67+mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68+mkDatabaseContextEvalState context = DatabaseContextEvalState {
69+ dbc_context = context,
70+ dbc_accum = M.empty,
71+ dbc_dirty = False
5772 } --future work: propagate return accumulator
5873
5974-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
60−data RelationalExprStateElems = RelationalExprStateTupleElems
61− DatabaseContext
62− TransactionGraph
63− Maybe (Either RelationTuple Attributes)
64−
65−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
66− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
67− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
68−
69−instance Show RelationalExprStateElems where
70− show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
71− show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
72− show (RelationalExprStateElems _) = "RelationalExprStateElems"
73−
74−mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
75−mkRelationalExprState = RelationalExprStateElems
76−
77−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
78−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
79−mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
80−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
81− RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
75+data RelationalExprEnv = RelationalExprEnv {
76+ re_context :: DatabaseContext,
77+ re_graph :: TransactionGraph,
78+ re_extra :: Maybe (Either RelationTuple Attributes)
79+ }
80+
81+envTuple :: GraphRefRelationalExprEnv -> RelationTuple
82+envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
83+
84+envAttributes :: GraphRefRelationalExprEnv -> Attributes
85+envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
8286
83−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
84−mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
85−mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
86−mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
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 }
115+ where
116+ new_elems = Just (Left newTuple)
117+ mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (envTuple env))
118+ newTuple = mkRelationTupleFromMap mergedTupMap
119+
120+mergeAttributesIntoGraphRefRelationalExprEnv :: Attributes -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
121+mergeAttributesIntoGraphRefRelationalExprEnv attrsIn e = e { gre_extra = newattrs }
122+ where
123+ newattrs = Just (Right (A.union attrsIn (envAttributes e)))
87124
88125type ResultAccumName = StringType
89126
@@ -93,443 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
93130 resultAccumResult :: Relation
94131 }
95132
96−data DatabaseStateElems = DatabaseStateElems {
97− context :: DatabaseContext, --new, alterable context for a new transaction
98− accum :: M.Map ResultAccumName ResultAccum,
99− 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
100137 }
101138
102−type DatabaseState a = State DatabaseStateElems a
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
142+ }
143+
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146+
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
103148
104−getStateContext :: DatabaseState DatabaseContext
105−getStateContext = context <$> get
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> 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
106160
107−putStateContext :: DatabaseContext -> DatabaseState ()
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 ()
108169putStateContext ctx' = do
109170 s <- get
110− put (s {context = ctx'})
111−
112−type RelationalExprState a = Reader RelationalExprStateElems a
113−
114−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
115−stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
116−stateElemsContext (RelationalExprStateElems ctx) = ctx
117−stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
118−
119−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
120−setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
121−setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
122−setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
123−
124−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
125−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError GraphRefRelationalExpr)
126−evalRelationalExpr (RelationVariable name _) = do
127− relvarTable <- fmap (relationVariables . stateElemsContext) ask
128− return $ case M.lookup name relvarTable of
129− Just res -> Right res
130− Nothing -> Left $ RelVarNotDefinedError name
131−
132−evalRelationalExpr (Project attrNames expr) = do
133− eAttrNameSet <- evalAttributeNames attrNames expr
134− case eAttrNameSet of
135− Left err -> pure (Left err)
136− Right attrNameSet -> do
137− rel <- evalRelationalExpr expr
138− case rel of
139− Right rel2 -> pure $ Right (Project (AttributeNames attrNameSet) rel2)
140− Left err -> pure $ Left err
141−
142−evalRelationalExpr (Union exprA exprB) = do
143− relA <- evalRelationalExpr exprA
144− relB <- evalRelationalExpr exprB
145− case relA of
146− Left err -> return $ Left err
147− Right relA2 -> case relB of
148− Left err -> return $ Left err
149− Right relB2 -> return $ Right (Union relA2 relB2)
150−
151−evalRelationalExpr (Join exprA exprB) = do
152− relA <- evalRelationalExpr exprA
153− relB <- evalRelationalExpr exprB
154− case relA of
155− Left err -> return $ Left err
156− Right relA2 -> case relB of
157− Left err -> return $ Left err
158− Right relB2 -> return $ Right (Join relA2 relB2)
159−
160−evalRelationalExpr (Difference exprA exprB) = do
161− relA <- evalRelationalExpr exprA
162− relB <- evalRelationalExpr exprB
163− case relA of
164− Left err -> return $ Left err
165− Right relA2 -> case relB of
166− Left err -> return $ Left err
167− Right relB2 -> return $ Right (Difference relA2 relB2)
168−
169−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
170− case mkRelation attributeSet tupleSet of
171− Right rel -> return $ Right (ExistingRelation rel)
172− Left err -> return $ Left err
173−
174−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
175− currentContext <- fmap stateElemsContext ask
176− let tConss = typeConstructorMapping currentContext
177− -- 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
178− runExceptT $ do
179− mAttrs <- case mAttrExprs of
180− Just _ ->
181− Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
182− Nothing -> pure Nothing
183− tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
184− let attrs = fromMaybe firstTupleAttrs mAttrs
185− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
186− expr <- either throwE pure (mkRelation attrs (RelationTupleSet tuples))
187− 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+ }
188180
189−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+ }
190205
191−evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
192− evald <- evalRelationalExpr relExpr
193− case evald of
194− Right expr -> return $ Right (Rename oldAttrName newAttrName expr)
195− Left err -> return $ Left err
206+gfGraph :: GraphRefRelationalExprM TransactionGraph
207+gfGraph = asks gre_graph
196208
197−evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
198− eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
199− case eOldAttrNameSet of
200− Left err -> pure (Left err)
201− Right oldAttrNameSet -> do
202− evald <- evalRelationalExpr relExpr
203− case evald of
204− Right expr -> return $ Right (Group (AttributeNames oldAttrNameSet) newAttrName expr)
205− Left err -> return $ Left err
206−
207−evalRelationalExpr (Ungroup attrName relExpr) = do
208− evald <- evalRelationalExpr relExpr
209− case evald of
210− Right expr -> return $ Right (Ungroup attrName expr)
211− Left err -> return $ Left err
212−
213−evalRelationalExpr (Restrict predicateExpr relExpr) = do
214− evald <- evalRelationalExpr relExpr
215− ePred <- processRestrictionPredicateExpr predicateExpr
216− case evald of
217− Left err -> return $ Left err
218− Right expr -> case ePred of
219− Left err -> pure (Left err)
220− Right pred -> pure $ Right (Restrict pred expr)
221−
222−evalRelationalExpr (Equals relExprA relExprB) = do
223− evaldA <- evalRelationalExpr relExprA
224− evaldB <- evalRelationalExpr relExprB
225− case evaldA of
226− Left err -> return $ Left err
227− Right exprA -> case evaldB of
228− Left err -> return $ Left err
229− Right exprB -> return $ Right (Equals exprA exprB)
230−{-
231−evalRelationalExpr (With views mainExpr) = do
232− rstate <- ask
233−
234− let addScopedView ctx (vname,vexpr) = if vname `M.member` relationVariables ctx then
235− Left (RelVarAlreadyDefinedError vname)
236− else
237− case runState (evalDatabaseContextExpr (Assign vname vexpr)) (freshDatabaseState ctx) of
238− (Left err,_) -> Left err
239− (Right (), (ctx',_,_)) -> Right ctx'
240−
241− case foldM addScopedView (stateElemsContext rstate) views of
242− Left err -> return $ Left err
243− Right ctx'' -> do
244− let evalMainExpr expr = runReader (evalRelationalExpr expr) (RelationalExprStateElems ctx'')
245− case evalMainExpr mainExpr of
246− Left err -> return $ Left err
247− Right rel -> return $ Right rel
248−-}
249−--warning: copy-pasta from above- refactor
250−evalRelationalExpr (NotEquals relExprA relExprB) = do
251− evaldA <- evalRelationalExpr relExprA
252− evaldB <- evalRelationalExpr relExprB
253− case evaldA of
254− Left err -> return $ Left err
255− Right exprA -> case evaldB of
256− Left err -> return $ Left err
257− Right exprB -> return $ Right (NotEquals exprA exprB)
258−
259−-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
260−evalRelationalExpr (Extend tupleExpression relExpr) = do
261− eExpr <- evalRelationalExpr relExpr
262− case eExpr of
263− Left err -> pure (Left err)
264− Right expr -> do
265− eTupProc <- processExtendTupleExpr tupleExpression
266− case eTupProc of
267− Left err -> pure (Left err)
268− 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 }
269214
270215--helper function to process relation variable creation/assignment
271−setRelVar :: RelVarName -> GraphRefRelationalExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
272−setRelVar relVarName relExpr transId graph = do
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217+setRelVar relVarName relExpr = do
273218 currentContext <- getStateContext
274− 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
275222 potentialContext = currentContext { relationVariables = newRelVars }
276− --determine when to check constraints
277−
278− case checkConstraints potentialContext transId graph of
279− Left err -> pure (Left err)
280− Right _ -> do
281− putStateContext potentialContext
282− 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 ()
283236
284237-- 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
285−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
286239deleteRelVar relVarName = do
287240 currContext <- getStateContext
288241 let relVars = relationVariables currContext
289242 if M.notMember relVarName relVars then
290− pure (Right ())
243+ pure ()
291244 else do
292245 let newRelVars = M.delete relVarName relVars
293246 newContext = currContext { relationVariables = newRelVars }
294247 putStateContext newContext
295− pure (Right ())
248+ pure ()
296249
297−evalDatabaseContextExpr :: DatabaseContextExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
298−evalDatabaseContextExpr NoOperation _ _ = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
299252
300−evalDatabaseContextExpr (Define relVarName attrExprs) transId graph = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
301255 relvars <- fmap relationVariables getStateContext
302256 tConss <- fmap typeConstructorMapping getStateContext
303− let eAttrs = map (evalAttrExpr tConss) attrExprs
304− attrErrs = lefts eAttrs
305− attrsList = rights eAttrs
306− if not (null attrErrs) then
307− pure (Left (someErrors attrErrs))
308− else do
309− let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
310− if not (null atomTypeErrs) then
311− pure (Left (someErrors atomTypeErrs))
312− else
313− case M.member relVarName relvars of
314− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
315− 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)
316267 where
317268 attrs = A.attributesFromList attrsList
318269 emptyRelation = Relation attrs emptyTupleSet
319270
320−evalDatabaseContextExpr (Undefine relVarName) _ _ = deleteRelVar relVarName
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
321272
322−evalDatabaseContextExpr (Assign relVarName expr) transId graph = do
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
323275 context <- getStateContext
324276 let existingRelVar = M.lookup relVarName (relationVariables context)
325− relExprState = mkRelationalExprState context
277+ reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278+ eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
326279 case existingRelVar of
327280 Nothing -> do
328− let ervExpr = runReader (evalRelationalExpr expr) relExprState
329− case ervExpr of
330− Left err -> pure (Left err)
331− 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
332286 Just existingRel -> do
333− let eExpectedType = typeForGraphRefRelationalExpr existingRel graph
334− eNewExprType = runReader (typeForRelationalExpr expr transId graph) relExprState
287+ let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
335288 case eExpectedType of
336− Left err -> pure (Left err)
289+ Left err -> dbErr err
337290 Right expectedType ->
338291 case eNewExprType of
339− Left err -> pure (Left err)
292+ Left err -> dbErr err
340293 Right newExprType -> do
341294 if newExprType == expectedType then do
342− let ervExpr = runReader (evalRelationalExpr expr) relExprState
343− case ervExpr of
344− Left err -> pure (Left err)
345− Right rvExpr -> setRelVar relVarName rvExpr transId graph
295+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296+ setRelVar relVarName expr
346297 else
347− pure (Left (RelationTypeMismatchError (attributes expectedType) (attributes newExprType)))
348−
349−evalDatabaseContextExpr (Insert relVarName relExpr) tid graph =
350− evalDatabaseContextExpr (Assign relVarName (Union (RelationVariable relVarName ())
351− relExpr)) tid graph
352−
353−evalDatabaseContextExpr (Delete relVarName predicate) transId graph = do
354− ctx <- getStateContext
355− let rv = RelationVariable relVarName transId
356− rvState = mkRelationalExprState ctx
357− case runReader (processRestrictionPredicateExpr predicate) rvState of
358− Left err -> pure (Left err)
359− Right graphRefPredicate ->
360− 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
361311
362312--union of restricted+updated portion and the unrestricted+unupdated portion
363−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) transId graph = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
364316 context <- getStateContext
365− let rvState = mkRelationalExprState context
366− relVarTable = relationVariables context
367− case runReader (processRestrictionPredicateExpr restrictionPredicateExpr) rvState of
368− Left err -> pure (Left err)
369− Right graphRefPredicate ->
370− case M.lookup relVarName relVarTable of
371− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
372− Just existingRvExpr -> do
373− let unrestrictedPortion = Restrict (NotPredicate graphRefPredicate) rv
374− rv = RelationVariable relVarName transId
375− tmpAttr attr = "_tmp_" <> attr --this could certainly be improved to verify that there is no attribute name conflict
376− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
377− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
378− restrictedPortion = Restrict graphRefPredicate
379− updated = foldr (\(oldname, atomExpr) accum ->
380− 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
381337 updateAttr oldname procAtomExpr accum
382− ) rv (M.toList atomExprMap)
338+ ) restrictedPortion (M.toList atomExprMap)
383339 -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
384− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
385− setRelVar relVarName (Union unrestrictedPortion updatedPortion) transId graph
340+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341+ setRelVar relVarName (Union unrestrictedPortion updatedPortion)
386342
387−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) transId graph = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
388344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
389347 let currDeps = inclusionDependencies currContext
390348 newDeps = M.insert newDepName newDep currDeps
391349 if M.member newDepName currDeps then
392− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
393351 else do
394352 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
395355 case checkConstraints potentialContext transId graph of
396− Left err -> pure (Left err)
397− Right _ -> do
356+ Left err -> dbErr err
357+ Right _ ->
398358 putStateContext potentialContext
399− return (Right ())
400359
401−evalDatabaseContextExpr (RemoveInclusionDependency depName) _ _ = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
402361 currContext <- getStateContext
403362 let currDeps = inclusionDependencies currContext
404363 newDeps = M.delete depName currDeps
405364 if M.notMember depName currDeps then
406− pure (Left (InclusionDependencyNameNotInUseError depName))
407− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
408367 putStateContext $ currContext {inclusionDependencies = newDeps }
409− return (Right ())
410368
411369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
412−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) _ _ = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
413371 currentContext <- getStateContext
414372 let nots = notifications currentContext
415373 if M.member notName nots then
416− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
417375 else do
418376 let newNotifications = M.insert notName newNotification nots
419377 newNotification = Notification { changeExpr = triggerExpr,
420378 reportOldExpr = resultOldExpr,
421379 reportNewExpr = resultNewExpr}
422380 putStateContext $ currentContext { notifications = newNotifications }
423− return (Right ())
424381
425−evalDatabaseContextExpr (RemoveNotification notName) _ _ = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
426383 currentContext <- getStateContext
427384 let nots = notifications currentContext
428385 if M.notMember notName nots then
429− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
430387 else do
431388 let newNotifications = M.delete notName nots
432389 putStateContext $ currentContext { notifications = newNotifications }
433− pure (Right ())
390+
434391
435392-- | Adds type and data constructors to the database context.
436393-- validate that the type *and* constructor names are unique! not yet implemented!
437−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) _ _ = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
438395 currentContext <- getStateContext
439396 let oldTypes = typeConstructorMapping currentContext
440397 tConsName = TCD.name tConsDef
441398 -- validate that the constructor's types exist
442− case validateTypeConstructorDef tConsDef dConsDefList of
443− errs@(_:_) -> pure (Left (someErrors errs))
444− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
445− | 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)
446403 | otherwise -> do
447404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
448405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
449− pure (Right ())
450406
451407-- | 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.
452−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) _ _ = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
453409 currentContext <- getStateContext
454410 let oldTypes = typeConstructorMapping currentContext
455411 if isNothing (findTypeConstructor tConsName oldTypes) then
456− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
457413 else do
458414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
459415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
460− pure (Right ())
461416
462−evalDatabaseContextExpr (MultipleExpr exprs) transId graph = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
463418 --the multiple expressions must pass the same context around- not the old unmodified context
464− evald <- forM exprs (\expr -> evalDatabaseContextExpr expr transId graph)
465− --some lifting magic needed here
466− case lefts evald of
467− [] -> pure (Right ())
468− errs -> pure (Left (someErrors errs))
469−
470−evalDatabaseContextExpr (RemoveAtomFunction funcName) _ _ = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
471422 currentContext <- getStateContext
472423 let atomFuncs = atomFunctions currentContext
473424 case atomFunctionForName funcName atomFuncs of
474− Left err -> pure (Left err)
475− Right realFunc -> if isScriptedAtomFunction realFunc then do
476− let updatedFuncs = HS.delete realFunc atomFuncs
477− putStateContext (currentContext {atomFunctions = updatedFuncs })
478− pure (Right ())
479− else
480− 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)
481432
482−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) _ _ = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
483434 context <- getStateContext
484435 let dbcFuncs = dbcFunctions context
485436 case databaseContextFunctionForName funcName dbcFuncs of
486− Left err -> pure (Left err)
487− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
488− let updatedFuncs = HS.delete realFunc dbcFuncs
489− putStateContext (context { dbcFunctions = updatedFuncs })
490− pure (Right ())
491− else
492− 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)
493444
494−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) _ _ = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
495446 context <- getStateContext
447+ graph <- dbcGraph
496448 --resolve atom arguments
497− let relExprState = mkRelationalExprState context
498− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
499450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
500452 case eFunc of
501− Left err -> pure (Left err)
453+ Left err -> dbErr err
502454 Right func -> do
503455 let expectedArgCount = length (dbcFuncType func)
504456 actualArgCount = length atomArgExprs
505457 if expectedArgCount /= actualArgCount then
506− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
507459 else
508460 --check that the atom types are valid
509− case lefts eAtomTypes of
510− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
511− [] -> do
512− let atomTypes = rights eAtomTypes
513− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
514− Left err -> Just err
515− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
516− typeErrors = catMaybes mValidTypes
517− eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
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
469+ typeErrors = catMaybes mValidTypes
470+ eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
518471 if length (lefts eAtomArgs) > 1 then
519− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
520473 else if not (null typeErrors) then
521− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
522475 else
523476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
524− Left err -> pure (Left err)
525− Right newContext -> putStateContext newContext >> pure (Right ())
526−
527−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> TransactionId -> TransactionGraph -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
528−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction funcName funcType script) =
529− case mScriptSession of
530− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
531− Just scriptSession -> do
532− 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
533530 setSession (hscEnv scriptSession)
534531 let atomFuncs = atomFunctions currentContext
535532 case extractAtomFunctionType funcType of
@@ -555,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction fun
555552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
556553 Right eContext -> case eContext of
557554 Left err -> pure (Left err)
558− Right context' -> pure (Right context')
559−
560−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextFunction funcName funcType script) =
561− case mScriptSession of
562− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
563− 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
564562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
565563 let last2Args = reverse (take 2 (reverse funcType))
566564 atomArgs = take (length funcType - 2) funcType
@@ -570,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
570568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
571569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
572570 else do
573− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
574572 setSession (hscEnv scriptSession)
575573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
576574 pure $ case eCompiledFunc of
@@ -595,78 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
595593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
596594 Right eContext -> case eContext of
597595 Left err -> pure (Left err)
598− Right context' -> pure (Right context')
599−evalDatabaseContextIOExpr _ currentContext _ _ (LoadAtomFunctions modName funcName modPath) = do
600− 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
601600 case eLoadFunc of
602601 Left LoadSymbolError -> pure (Left LoadFunctionError)
603602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
604603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
605− in pure (Right newContext)
606−evalDatabaseContextIOExpr _ currentContext _ _ (LoadDatabaseContextFunctions modName funcName modPath) = do
607− 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
608608 case eLoadFunc of
609609 Left LoadSymbolError -> pure (Left LoadFunctionError)
610610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in pure (Right newContext)
613−
614−evalDatabaseContextIOExpr _ currentContext transId graph (CreateArbitraryRelation relVarName attrExprs range) =
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
615615 --Define
616− case runState (evalDatabaseContextExpr (Define relVarName attrExprs) transId graph) (freshDatabaseState currentContext) of
617− (Left err,_) -> pure (Left err)
618− (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
619625 --Assign
620626 let existingRelVar = M.lookup relVarName relVarTable
621− relVarTable = relationVariables (context elems)
627+ relVarTable = relationVariables (dbc_context dbstate)
622628 case existingRelVar of
623629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
624630 Just existingRel -> do
625− case typeForGraphRefRelationalExpr existingRel graph of
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
626633 Left err -> pure (Left err)
627634 Right relType -> do
628635 let expectedAttributes = attributes relType
629− tcMap = typeConstructorMapping (context elems)
630− eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
636+ tcMap = typeConstructorMapping (dbc_context dbstate)
637+ eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
631638 case eitherRel of
632639 Left err -> pure $ Left err
633640 Right rel ->
634− case runState (setRelVar relVarName (ExistingRelation rel) transId graph) elems of
635− (Left err,_) -> pure (Left err)
636− (Right (), elems') -> pure $ Right (context elems)
637−
638−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
639−updateTupleWithAtomExprs exprMap context tupIn = do
640− --resolve all atom exprs
641− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
642− atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
643− pure (attrName, atom)
644− ) (M.toList exprMap)
645− 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')
646644
647645--run verification on all constraints
648646checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
649−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
650648 mapM_ (uncurry checkIncDep) (M.toList deps)
651649 where
652650 potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
653651 tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
654652 utctDayTime = secondsToDiffTime 0 }
655653 tempSchemas = Schemas context M.empty
656− 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+ }
657659
658660 deps = inclusionDependencies context
659− eval expr = evalReader (evalRelationalExpr expr)
660− evalReader f = runReader f (RelationalExprStateElems context)
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
661662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
662− let gfSubsetExpr = processRelationalExpr subsetExpr transId
663− gfSupersetExpr = processRelationalExpr supersetExpr transId
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
664666 --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.
665− typeSub <- evalReader (typeForRelationalExpr subsetExpr transId graph)
666− typeSuper <- evalReader (typeForRelationalExpr supersetExpr transId graph)
667+ let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668+ runGfRel = runGraphRefRelationalExprM gfEnv
669+ typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670+ typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
667671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
668672 let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
669− case evalGraphRefRelationalExpr checkExpr potentialGraph of
673+ gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674+ gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675+ case gfEvald of
670676 Left err -> Left err
671677 Right resultRel -> if resultRel == relationTrue then
672678 pure ()
@@ -676,90 +682,81 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
676682-- 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
677683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
678684
679−typeForRelationalExpr :: RelationalExpr -> TransactionId -> TransactionGraph -> RelationalExprState (Either RelationalError Relation)
680−typeForRelationalExpr expr transId graph = do
681− rstate <- ask
682− let context = stateElemsContext rstate
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
686+typeForRelationalExpr expr = do
683687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
684688 --evalRelationalExpr could still return an existing relation with tuples, so strip them
685− let gfExpr = processRelationalExpr expr transId
686− pure (typeForGraphRefRelationalExpr gfExpr graph)
687−
688−--returns a database context with all tuples removed
689−--this is useful for type checking and optimization
690−{-
691−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
692−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
693− where
694− relVars = M.map (\rel -> ExistingRelation (Relation (attributes rel) emptyTupleSet)) (relationVariables contextIn)
695−-}
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
696695
697696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
698697liftE v = do
699698 y <- lift v
700699 case y of
701− Left err -> throwE err
700+ Left err -> throwError err
702701 Right val -> pure val
703702
704703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
705−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExprBase a -> RelationalExprState (Either RelationalError RestrictionFilter)
706−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
707− runExceptT $ do
708− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
709− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
710− pure (\x -> do
711− ev1 <- expr1v x
712− ev2 <- expr2v x
713− pure (ev1 && ev2))
714−
715−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
716− runExceptT $ do
717− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
718− 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
719716 pure (\x -> do
720717 ev1 <- expr1v x
721718 ev2 <- expr2v x
722719 pure (ev1 || ev2))
723720
724−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
725722
726−predicateRestrictionFilter attrs (NotPredicate expr) =
727− runExceptT $ do
728− exprv <- liftE (predicateRestrictionFilter attrs expr)
729− pure (fmap not . exprv)
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
730726
731727--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
732728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
733− rstate <- ask
734− 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
735735 Left err -> Left err
736736 Right rel -> if arity rel /= 0 then
737737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
738738 else
739− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
740740
741741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
742− rstate <- ask
743− let (attrs', ctxtup') = case rstate of
744− RelationalExprStateElems _ -> (attrs, emptyTuple)
745− RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
746− RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
747− runExceptT $ do
748− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
749− 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
750747 Right attr -> Right attr
751748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
752749 Right ctxattr -> Right ctxattr
753750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
754751 Left err -> Left err
755752 Left err -> Left err
756− if atomExprType /= A.atomType attr then
757− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
758− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
759756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
760757 Right atomCmp -> atomCmp == atomIn
761758 Left _ -> False
762− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
763760 in
764761 pure $ case atomForAttributeName attrName tupleIn of
765762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -770,16 +767,15 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
770767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
771768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
772769 --merge attrs into the state attributes
773− rstate <- ask
774− runExceptT $ do
775− aType <- liftE (typeFromAtomExpr attrs atomExpr)
776− if aType /= BoolAtomType then
777− throwE (AtomTypeMismatchError aType BoolAtomType)
778− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
779775 pure (\tupleIn ->
780− case runReader (evalAtomExpr tupleIn atomExpr) rstate of
781− Left err -> Left err
782− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
783779
784780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
785781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
@@ -787,249 +783,311 @@ tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName r
787783 else
788784 Right rel
789785
790−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
791−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
792− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
793789 -- check that the attribute name is not in use
794790 case tupleExprCheckNewAttrName newAttrName relIn of
795− Left err -> pure (Left err)
796− Right _ -> runExceptT $ do
797− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
798− 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
799795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
800796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
801− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
802− Left err -> Left err
803− 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)
804802 )
805803
806−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
807−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
808− Right atom -> pure (Right atom)
809− err@(Left (NoSuchAttributeNamesError _)) -> do
810− rstate <- ask
811− case rstate of
812− RelationalExprStateElems _ -> pure err
813− RelationalExprStateAttrsElems _ _ -> pure err
814− RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
815− Left err -> pure (Left err)
816−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
817−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
818− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
819− context <- fmap stateElemsContext ask
820− runExceptT $ do
821− let functions = atomFunctions context
822− func <- either throwE pure (atomFunctionForName funcName functions)
823− let expectedArgCount = length (atomFuncType func) - 1
824− actualArgCount = length argTypes
825− safeInit [] = [] -- different behavior from normal init
826− safeInit xs = init xs
827− if expectedArgCount /= actualArgCount then
828− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
829− 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
830828 let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
831− mapM_ (\(expType, eActType) -> do
832− actType <- either throwE pure eActType
833− either throwE pure (atomTypeVerify expType actType)) zippedArgs
834− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
829+ mapM_ (\(expType, actType) ->
830+ lift $ except (atomTypeVerify expType actType)) zippedArgs
831+ evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
835832 case evalAtomFunction func evaldArgs of
836− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
837834 Right result -> do
838835 --validate that the result matches the expected type
839− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
840837 pure result
841−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
842839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
843− rstate <- ask
844− runExceptT $ do
845− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
846− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
847− pure (RelationAtom relAtom)
848−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
849− rstate <- lift ask
850− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
851− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
852− 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
853849 pure (ConstructedAtom dConsName aType argAtoms)
854850
855−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
856−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
857− rstate <- ask
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
858854 case A.atomTypeForAttributeName attrName attrs of
859− Right aType -> pure (Right aType)
860− Left err@(NoSuchAttributeNamesError _) -> case rstate of
861− RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
862− Left err' -> pure (Left err')
863− Right attr -> pure (Right (A.atomType attr))
864− RelationalExprStateElems _ -> pure (Left err)
865− RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
866− Left err' -> pure (Left err')
867− Right atom -> pure (Right (atomTypeForAtom atom))
868− Left err -> pure (Left err)
869−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
870−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
871− context <- fmap stateElemsContext ask
872− let funcs = atomFunctions context
855+ Right aType -> pure aType
856+ Left err@(NoSuchAttributeNamesError _) ->
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
873870 case atomFunctionForName funcName funcs of
874− Left err -> pure (Left err)
871+ Left err -> throwError err
875872 Right func -> do
876873 let funcRetType = last (atomFuncType func)
877874 funcArgTypes = init (atomFuncType func)
878− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
879− case lefts eArgTypes of
880− errs@(_:_) -> pure (Left (someErrors errs))
881− [] -> do
882− let eTvMap = resolveTypeVariables funcArgTypes argTypes
883− argTypes = rights eArgTypes
884− case eTvMap of
885− Left err -> pure (Left err)
886− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
887−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
888− rstate <- lift ask
889− relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
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)
890882 pure (RelationAtomType (attributes relType))
891883-- grab the type of the data constructor, then validate that the args match the expected types
892−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
893− runExceptT $ do
894− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
895− context <- fmap stateElemsContext (lift ask)
896− 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
897889
898890-- | Validate that the type of the AtomExpr matches the expected type.
899−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
900−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
901− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
902894 case A.atomTypeForAttributeName attrName (attributes relIn) of
903− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
904− (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
905− RelationalExprStateTupleElems _ _ -> throwE err
906− RelationalExprStateElems _ -> throwE err
907− RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
908− Left err' -> throwE err'
909− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
910− Left err -> throwE err
911−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
912−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
913− rstate <- ask
895+ Right aType -> lift $ except $ atomTypeVerify expectedType aType
896+ (Left err@(NoSuchAttributeNamesError _)) ->
897+ let attrs' = envAttributes env in
898+ if attrs' == emptyAttributes then
899+ throwError err
900+ else
901+ case A.attributeForName attrName attrs' of
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
914910 let functions = atomFunctions context
915− context = stateElemsContext rstate
916− runExceptT $ do
917− func <- either throwE pure (atomFunctionForName funcName functions)
918− let expectedArgTypes = atomFuncType func
919− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
920− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
921− Left err -> throwE err
922− Right x -> pure x
923− ) $ zip3 funcArgExprs expectedArgTypes [1..]
924− if length funcArgTypes /= length expectedArgTypes - 1 then
925− 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)
926921 else
927− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
928−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
929− rstate <- lift ask
930− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
931− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
932−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
933− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
934− 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
935931
936932-- | Look up the type's name and create a new attribute.
937−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
938−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
939− aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
940− validateAtomType aType aTypes
941− 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
942939
943−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
944−
945−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
946−evalTupleExpr mAttrs (TupleExpr tupMap) = do
947− context <- fmap stateElemsContext ask
948− 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
949992 -- 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
950993 -- 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
951− let attrs = fromMaybe A.emptyAttributes mAttrs
952− attrAtoms <- mapM (\(attrName, aExpr) -> do
953− --provided when the relation header is available
954− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
955− unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
956− 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
9571001 Left _ -> pure unresolvedType
958− Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
9591003 --resolve atom typevars based on resolvedType?
960− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
961− pure (attrName, newAtom, resolvedType)
962− ) (M.toList tupMap)
963− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
964− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
965− tup = mkRelationTuple tupAttrs atoms
966− tConss = typeConstructorMapping context
967− 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
9681011 --verify that the attributes match
969− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
970− tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
971− _ <- either throwE pure (validateTuple tup' tConss)
972− pure tup'
973−
974−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
975−evalAttributeNames attrNames expr = do
976− eExprType <- typeForRelationalExpr expr
977− case eExprType of
978− Left err -> pure (Left err)
979− Right exprTyp -> do
980− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
981− case attrNames of
982− AttributeNames names ->
983− case A.projectionAttributesForNames names (attributes exprTyp) of
984− Left err -> pure (Left err)
985− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
986−
987− InvertedAttributeNames names -> do
988− let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
989− if not (S.null nonExistentAttributeNames) then
990− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
991− else
992− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
993−
994− UnionAttributeNames namesA namesB -> do
995− eNameSetA <- evalAttributeNames namesA expr
996− case eNameSetA of
997− Left err -> pure (Left err)
998− Right nameSetA -> do
999− eNameSetB <- evalAttributeNames namesB expr
1000− case eNameSetB of
1001− Left err -> pure (Left err)
1002− Right nameSetB ->
1003− pure (Right (S.union nameSetA nameSetB))
1004−
1005− IntersectAttributeNames namesA namesB -> do
1006− eNameSetA <- evalAttributeNames namesA expr
1007− case eNameSetA of
1008− Left err -> pure (Left err)
1009− Right nameSetA -> do
1010− eNameSetB <- evalAttributeNames namesB expr
1011− case eNameSetB of
1012− Left err -> pure (Left err)
1013− Right nameSetB ->
1014− pure (Right (S.intersection nameSetA nameSetB))
1015−
1016− RelationalExprAttributeNames attrExpr -> do
1017− eAttrExprType <- typeForRelationalExpr attrExpr
1018− case eAttrExprType of
1019− Left err -> pure (Left err)
1020− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1021−
1022−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1023−evalGraphRefRelationalExpr (RelationVariable name tid) graph = do
1024− 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
10251036 case M.lookup name (relationVariables ctx) of
1026− Nothing -> Left (RelVarNotDefinedError name)
1027− 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)
10281086
10291087dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
10301088dbContextForTransId tid graph = do
10311089 trans <- transactionForId tid graph
1032− pure (concreteDatabaseContext ctx)
1090+ pure (concreteDatabaseContext trans)
10331091
10341092transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
10351093transactionForId tid graph
@@ -1042,113 +1100,293 @@ transactionForId tid graph
10421100 where
10431101 matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
10441102
1045−processRestrictionPredicateExpr :: RestrictionPredicateExpr -> RelationalExprState (Either RelationalError GraphRefRestrictionPredicateExpr)
1046−processRestrictionPredicateExpr TruePredicate = TruePredicate
1047−processRestrictionPredicateExpr (AndPredicate a b) = pure $ AndPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1048−processRestrictionPredicateExpr (OrPredicate a b) = OrPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1049−processRestrictionPredicateExpr (NotPredicate a) = pure $ NotPredicate <$> processRestrictionPredicateExpr a
1050−processRestrictionPredicateExpr (RelationalExprPredicate expr) = pure $ RelationalExprPredicate <$> evalRelationalExpr expr
1051−processRestrictionPredicateExpr (AtomExprPredicate expr) = AtomExprPredicate <$> evalAtomExpr expr
1052−processRestrictionPredicateExpr (AttributeEqualityPredicate nam expr) = AttributeEqualityPredicate nam <$> evalAtomExpr expr
1053−
1054−processExtendTupleExpr :: ExtendTupleExpr -> RelationalExprState (Either RelationalError (ExtendTupleExprBase a))
1055−processExtendTupleExpr (AttributeExtendTupleExpr nam atomExpr) = do
1056− eExpr <- evalAtomExpr atomExpr
1057− case eExpr of
1058− Left err -> pure (Left err)
1059− Right expr -> pure (Right (AttributeExtendTupleExpr nam expr))
1060−
1061−typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1062−typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) _ = mkRelation attrs emptyTupleSet
1063−typeForGraphRefRelationalExpr (ExistingRelation rel) _ = pure (emptyRelationWithAttrs (attributes rel))
1064−typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) graph =
1065− case mAttrExprs of
1066− Just attrExprs -> do
1067− attrs <- mapM (\e -> evalGraphRefAttributeExpr e graph) attrExprs
1068− pure (emptyRelationWithAttrs attrs)
1069−typeForGraphRefRelationalExpr (RelationVariable rvName tid) graph = do
1070− trans <- transactionForId tid graph
1071− 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
10721120 case M.lookup rvName relVars of
1073− Nothing -> Left $ RelVarNotDefinedError name
1074− Just rvExpr -> typeForGraphRefRelationalExpr rvExpr graph
1075−typeForGraphRefRelationalExpr (Project attrNames expr) graph = do
1076− exprType <- typeForGraphRefRelationalExpr expr graph
1077− projectionAttrs <- evalGraphRefAttributeNames attrNames expr graph
1078− project projectionAttrs exprType
1079−
1080−evalGraphRefAttributeNames :: AttributeNames -> GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError (S.Set AttributeName)
1081−evalGraphRefAttributeNames attrNames expr graph = do
1082− exprTyp <- typeForGraphRefRelationalExpr expr graph
1083− 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')))
10841175 case attrNames of
1085− AttributeNames names ->
1086− case A.projectionAttributesForNames names (attributes exprTyp) of
1087− Left err -> pure (Left err)
1088− 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)))
10891180
1090− InvertedAttributeNames names -> do
1181+ InvertedAttributeNames names -> do
10911182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
10921183 if not (S.null nonExistentAttributeNames) then
1093− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
10941185 else
1095− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
10961187
1097− UnionAttributeNames namesA namesB -> do
1098− eNameSetA <- evalAttributeNames namesA expr
1099− case eNameSetA of
1100− Left err -> pure (Left err)
1101− Right nameSetA -> do
1102− eNameSetB <- evalAttributeNames namesB expr
1103− case eNameSetB of
1104− Left err -> pure (Left err)
1105− Right nameSetB ->
1106− 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)
11071192
1108− IntersectAttributeNames namesA namesB -> do
1109− eNameSetA <- evalAttributeNames namesA expr
1110− case eNameSetA of
1111− Left err -> pure (Left err)
1112− Right nameSetA -> do
1113− eNameSetB <- evalAttributeNames namesB expr
1114− case eNameSetB of
1115− Left err -> pure (Left err)
1116− Right nameSetB ->
1117− 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)
11181197
1119− RelationalExprAttributeNames attrExpr -> do
1120− eAttrExprType <- typeForRelationalExpr attrExpr
1121− case eAttrExprType of
1122− Left err -> pure (Left err)
1123− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1124−
1125−
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
11261270
1271+instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272+ getContext = gfDatabaseContextForMarker UncommittedContextMarker
11271273
1128−processAtomExpr :: AtomExpr -> TransactionId -> GraphRefAtomExpr
1129−processAtomExpr (AttributeAtomExpr nam) _ = AttributeAtomExpr nam
1130−processAtomExpr (NakedAtomExpr atom) _ = NakedAtomExpr atom
1131−processAtomExpr (FunctionAtomExpr fName atomExprs ()) tid = FunctionAtomExpr fName (fmap processAtomExpr tid) tid
1132−processAtomExpr (RelationAtomExpr expr) tid = RelationAtomExpr (processRelationalExpr expr tid)
1133−processAtomExpr (ConstructedAtomExpr dConsName atomExprs) = ConstructedAtomExpr dConsName (fmap processAtomExpr tid) tid
1134−
1135−processTupleExpr :: TupleExpr -> TransactionId -> GraphRefTupleExpr
1136−processTupleExpr (TupleExpr tMap) tid = TupleExpr (M.map (processAtomExpr tid) tMap)
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
11371391
1138−evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> TransactionGraph -> Either RelationalError Attribute
1139−evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) graph = do
1140− trans <- transactionForId tid graph
1141− let tConsMap = typeConstructorMapping (concreteDatabaseContext trans)
1142− aType <- atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
1143− validateAtomType aType tConsMap
1144− pure (Attribute attrName aType)
1145−
1146−--convert AttributeExpr to GraphRefAttributeExpr
1147−processAttributeExpr :: AttributeExpr -> TransactionId -> GraphRefAttributeExpr
1148−processAttributeExpr (AttributeAndTypeNameExpr nam tCons ()) tid = AttributeAndTypeNameExpr nam tCons tid
1149−processAttributeExpr (NakedAttributeExpr attr) = NakedAttributeExpr attr
1150−
1151−-- convert a RelationalExpr into a GraphRefRelationalExpr
1152−processRelationalExpr :: RelationalExpr -> TransactionId -> GraphRefRelationalExpr
1153−processRelationalExpr (MakeRelationFromExprs mAttrs tupleExprs) =
1154− MakeRelationFromExprs (fmap (fmap processAttributeExpr) mAttrs) (processTupleExprs tupleExprs)
1392+