@@ -1,34 +1,53 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2+{-# LANGUAGE FlexibleInstances #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE OverloadedStrings #-}
25module ProjectM36.RelationalExpression where
36import ProjectM36.Relation
47import ProjectM36.Tuple
58import ProjectM36.TupleSet
69import ProjectM36.Base
10+import qualified Data.UUID as U
711import ProjectM36.Error
812import ProjectM36.AtomType
9−import ProjectM36.Attribute (emptyAttributes)
13+import ProjectM36.Attribute (emptyAttributes, attributesFromList)
1014import ProjectM36.ScriptSession
1115import ProjectM36.DataTypes.Primitive
1216import ProjectM36.AtomFunction
1317import ProjectM36.DatabaseContextFunction
1418import ProjectM36.Arbitrary
19+import ProjectM36.GraphRefRelationalExpr
20+import ProjectM36.Transaction
1521import qualified ProjectM36.Attribute as A
1622import qualified Data.Map as M
1723import qualified Data.HashSet as HS
1824import qualified Data.Set as S
1925import Control.Monad.State hiding (join)
20−import Control.Exception
26+import Data.Bifunctor (second)
2127import Data.Maybe
2228import Data.Either
2329import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2433import qualified Data.Text as T
2534import qualified Data.Vector as V
2635import qualified ProjectM36.TypeConstructorDef as TCD
27−import Control.Monad.Trans.Except
28−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
2943import Test.QuickCheck
30−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
3149import GHC.Paths
50+#endif
3251
3352data DatabaseContextExprDetails = CountUpdatedTuples
3453
@@ -45,32 +64,63 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
4564 Right ts -> ts
4665
4766-- | Used to start a fresh database state for a new database context expression.
48−freshDatabaseState :: DatabaseContext -> DatabaseStateElems
49−freshDatabaseState ctx = (ctx, M.empty, False) --future work: propagate return accumulator
67+mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68+mkDatabaseContextEvalState context = DatabaseContextEvalState {
69+ dbc_context = context,
70+ dbc_accum = M.empty,
71+ dbc_dirty = False
72+ } --future work: propagate return accumulator
5073
5174-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
52−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
53− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
54− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
55−
56−instance Show RelationalExprStateElems where
57− show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
58− show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
59− show (RelationalExprStateElems _) = "RelationalExprStateElems"
60−
61−mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
62−mkRelationalExprState = RelationalExprStateElems
63−
64−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
65−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
66−mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
67−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
68− 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))
6986
70−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
71−mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
72−mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
73−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)))
74124
75125type ResultAccumName = StringType
76126
@@ -80,429 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
80130 resultAccumResult :: Relation
81131 }
82132
83−type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, 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
137+ }
84138
85−type DatabaseState a = State DatabaseStateElems a
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
142+ }
86143
87−getStateContext :: DatabaseState DatabaseContext
88−getStateContext = do
89− (ctx,_, _) <- get
90− pure ctx
91−
92−putStateContext :: DatabaseContext -> DatabaseState ()
93−putStateContext ctx = do
94− (_, accum, _) <- get
95− put (ctx, accum, True)
96−
97−type RelationalExprState a = Reader RelationalExprStateElems a
98−
99−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
100−stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
101−stateElemsContext (RelationalExprStateElems ctx) = ctx
102−stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
103−
104−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
105−setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
106−setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
107−setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
108−
109−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
110−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
111−evalRelationalExpr (RelationVariable name _) = do
112− relvarTable <- fmap (relationVariables . stateElemsContext) ask
113− return $ case M.lookup name relvarTable of
114− Just res -> Right res
115− Nothing -> Left $ RelVarNotDefinedError name
116−
117−evalRelationalExpr (Project attrNames expr) = do
118− eAttrNameSet <- evalAttributeNames attrNames expr
119− case eAttrNameSet of
120− Left err -> pure (Left err)
121− Right attrNameSet -> do
122− rel <- evalRelationalExpr expr
123− case rel of
124− Right rel2 -> pure $ project attrNameSet rel2
125− Left err -> pure $ Left err
126−
127−evalRelationalExpr (Union exprA exprB) = do
128− relA <- evalRelationalExpr exprA
129− relB <- evalRelationalExpr exprB
130− case relA of
131− Left err -> return $ Left err
132− Right relA2 -> case relB of
133− Left err -> return $ Left err
134− Right relB2 -> return $ union relA2 relB2
135−
136−evalRelationalExpr (Join exprA exprB) = do
137− relA <- evalRelationalExpr exprA
138− relB <- evalRelationalExpr exprB
139− case relA of
140− Left err -> return $ Left err
141− Right relA2 -> case relB of
142− Left err -> return $ Left err
143− Right relB2 -> return $ join relA2 relB2
144−
145−evalRelationalExpr (Difference exprA exprB) = do
146− relA <- evalRelationalExpr exprA
147− relB <- evalRelationalExpr exprB
148− case relA of
149− Left err -> return $ Left err
150− Right relA2 -> case relB of
151− Left err -> return $ Left err
152− Right relB2 -> return $ difference relA2 relB2
153−
154−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
155− case mkRelation attributeSet tupleSet of
156− Right rel -> return $ Right rel
157− Left err -> return $ Left err
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146+
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
148+
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151+ where
152+ freshEnv = mkDatabaseContextEvalState ctx
158153
159−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
160− currentContext <- fmap stateElemsContext ask
161− let tConss = typeConstructorMapping currentContext
162− -- 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
163− runExceptT $ do
164− mAttrs <- case mAttrExprs of
165− Just _ ->
166− Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
167− Nothing -> pure Nothing
168− tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
169− let attrs = fromMaybe firstTupleAttrs mAttrs
170− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
171− either throwE pure (mkRelation attrs (RelationTupleSet tuples))
154+
155+dbcTransId :: DatabaseContextEvalMonad TransactionId
156+dbcTransId = dce_transId <$> RWS.ask
157+
158+dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159+dbcGraph = dce_graph <$> RWS.ask
160+
161+dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162+dbcRelationalExprEnv =
163+ mkRelationalExprEnv <$> getStateContext <*> dbcGraph
164+
165+getStateContext :: DatabaseContextEvalMonad DatabaseContext
166+getStateContext = gets dbc_context
167+
168+putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
169+putStateContext ctx' = do
170+ s <- get
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+ }
172180
173−evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
181+type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
174182
175−evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
176− evald <- evalRelationalExpr relExpr
177− case evald of
178− Right rel -> return $ rename oldAttrName newAttrName rel
179− Left err -> return $ Left err
183+gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184+gfTransForId tid = do
185+ graph <- gfGraph
186+ lift $ except $ transactionForId tid graph
180187
181−evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
182− eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
183− case eOldAttrNameSet of
184− Left err -> pure (Left err)
185− Right oldAttrNameSet -> do
186− evald <- evalRelationalExpr relExpr
187− case evald of
188− Right rel -> return $ group oldAttrNameSet newAttrName rel
189− Left err -> return $ Left err
190−
191−evalRelationalExpr (Ungroup attrName relExpr) = do
192− evald <- evalRelationalExpr relExpr
193− case evald of
194− Right rel -> return $ ungroup attrName rel
195− Left err -> return $ Left err
196−
197−evalRelationalExpr (Restrict predicateExpr relExpr) = do
198− evald <- evalRelationalExpr relExpr
199− case evald of
200− Left err -> return $ Left err
201− Right rel -> do
202− eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
203− case eFilterFunc of
204− Left err -> return $ Left err
205− Right filterfunc ->
206− pure (restrict filterfunc rel)
207−
208−evalRelationalExpr (Equals relExprA relExprB) = do
209− evaldA <- evalRelationalExpr relExprA
210− evaldB <- evalRelationalExpr relExprB
211− case evaldA of
212− Left err -> return $ Left err
213− Right relA -> case evaldB of
214− Left err -> return $ Left err
215− Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
216−
217−--warning: copy-pasta from above- refactor
218−evalRelationalExpr (NotEquals relExprA relExprB) = do
219− evaldA <- evalRelationalExpr relExprA
220− evaldB <- evalRelationalExpr relExprB
221− case evaldA of
222− Left err -> return $ Left err
223− Right relA -> case evaldB of
224− Left err -> return $ Left err
225− Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
226−
227−-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
228−evalRelationalExpr (Extend tupleExpression relExpr) = do
229− rstate <- ask
230− let evald = runReader (evalRelationalExpr relExpr) rstate
231− case evald of
232− Left err -> pure (Left err)
233− Right rel -> do
234− tupProc <- extendTupleExpressionProcessor rel tupleExpression
235− case tupProc of
236− Left err -> pure (Left err)
237− Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
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+ }
205+
206+gfGraph :: GraphRefRelationalExprM TransactionGraph
207+gfGraph = asks gre_graph
208+
209+envContext :: RelationalExprEnv -> DatabaseContext
210+envContext = re_context
211+
212+setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213+setEnvContext e ctx = e { re_context = ctx }
238214
239215--helper function to process relation variable creation/assignment
240−setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
241−setRelVar relVarName rel = do
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217+setRelVar relVarName relExpr = do
242218 currentContext <- getStateContext
243− let newRelVars = M.insert relVarName rel $ 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
244222 potentialContext = currentContext { relationVariables = newRelVars }
245−
246− case checkConstraints potentialContext of
247− Left err -> pure (Left err)
248− Right _ -> do
249− putStateContext potentialContext
250− 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 ()
251236
252237-- 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
253−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
254239deleteRelVar relVarName = do
255240 currContext <- getStateContext
256241 let relVars = relationVariables currContext
257242 if M.notMember relVarName relVars then
258− pure (Right ())
243+ pure ()
259244 else do
260245 let newRelVars = M.delete relVarName relVars
261246 newContext = currContext { relationVariables = newRelVars }
262247 putStateContext newContext
263− pure (Right ())
248+ pure ()
264249
265−evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
266−evalDatabaseContextExpr NoOperation = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
267252
268−evalDatabaseContextExpr (Define relVarName attrExprs) = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
269255 relvars <- fmap relationVariables getStateContext
270256 tConss <- fmap typeConstructorMapping getStateContext
271− let eAttrs = map (evalAttrExpr tConss) attrExprs
272− attrErrs = lefts eAttrs
273− attrsList = rights eAttrs
274− if not (null attrErrs) then
275− pure (Left (someErrors attrErrs))
276− else do
277− let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
278− if not (null atomTypeErrs) then
279− pure (Left (someErrors atomTypeErrs))
280− else
281− case M.member relVarName relvars of
282− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
283− False -> setRelVar relVarName emptyRelation >> 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)
284267 where
285268 attrs = A.attributesFromList attrsList
286269 emptyRelation = Relation attrs emptyTupleSet
287270
288−evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
289272
290−evalDatabaseContextExpr (Assign relVarName expr) = do
291− -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
292275 context <- getStateContext
293− let existingRelVar = M.lookup relVarName relVarTable
294− relVarTable = relationVariables context
295− value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
296− case value of
297− Left err -> pure (Left err)
298− Right rel -> case existingRelVar of
299− Nothing -> setRelVar relVarName rel
300− Just existingRel -> let expectedAttributes = attributes existingRel
301− foundAttributes = attributes rel in
302− if A.attributesEqual expectedAttributes foundAttributes then
303− setRelVar relVarName rel
304− else
305− pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
306−
307−evalDatabaseContextExpr (Insert relVarName relExpr) = do
308− context <- getStateContext
309− let unionexp = Union relExpr rv
310− rv = RelationVariable relVarName ()
311− unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
312− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
313− case unioned of
314− Left err -> pure (Left err)
315− Right unioned' -> case origRel of
316− Left err -> pure (Left err)
317− Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
318− pure (Right ())
319− else
320− evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
321−
322−evalDatabaseContextExpr (Delete relVarName predicate) = do
323− context <- getStateContext
324− let rv = RelationVariable relVarName ()
325− let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
326− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
327− case updatedRel of
328− Left err -> pure (Left err)
329− Right updatedRel' -> case origRel of
330− Left err -> pure (Left err)
331− Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
332− pure (Right ())
333− else
334− setRelVar relVarName updatedRel'
276+ let existingRelVar = M.lookup relVarName (relationVariables context)
277+ reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278+ eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
279+ case existingRelVar of
280+ Nothing -> do
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
286+ Just existingRel -> do
287+ let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
288+ case eExpectedType of
289+ Left err -> dbErr err
290+ Right expectedType ->
291+ case eNewExprType of
292+ Left err -> dbErr err
293+ Right newExprType -> do
294+ if newExprType == expectedType then do
295+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296+ setRelVar relVarName expr
297+ else
298+ dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
335299
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
311+
336312--union of restricted+updated portion and the unrestricted+unupdated portion
337−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
338316 context <- getStateContext
339− let relVarTable = relationVariables context
340− case M.lookup relVarName relVarTable of
341− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
342− Just rel ->
343− case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
344− Left err -> pure (Left err)
345− Right predicateFunc -> do
346− let ret = do
347− restrictedPortion <- restrict predicateFunc rel
348− if cardinality restrictedPortion == Finite 0 then
349− pure Nothing
350− else do
351− unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
352− updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
353− updatedRel <- updatedPortion `union` unrestrictedPortion
354− pure (Just updatedRel)
355− case ret of
356− Left err -> pure (Left err)
357− Right Nothing -> pure (Right ())
358− Right (Just updatedRel) -> setRelVar relVarName updatedRel
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
337+ updateAttr oldname procAtomExpr accum
338+ ) restrictedPortion (M.toList atomExprMap)
339+ -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
340+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341+ setRelVar relVarName (Union unrestrictedPortion updatedPortion)
359342
360−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
361344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
362347 let currDeps = inclusionDependencies currContext
363348 newDeps = M.insert newDepName newDep currDeps
364349 if M.member newDepName currDeps then
365− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
366351 else do
367352 let potentialContext = currContext { inclusionDependencies = newDeps }
368− case checkConstraints potentialContext of
369− Left err -> pure (Left err)
370− Right _ -> do
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
355+ case checkConstraints potentialContext transId graph of
356+ Left err -> dbErr err
357+ Right _ ->
371358 putStateContext potentialContext
372− return (Right ())
373359
374−evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
375361 currContext <- getStateContext
376362 let currDeps = inclusionDependencies currContext
377363 newDeps = M.delete depName currDeps
378364 if M.notMember depName currDeps then
379− pure (Left (InclusionDependencyNameNotInUseError depName))
380− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
381367 putStateContext $ currContext {inclusionDependencies = newDeps }
382− return (Right ())
383368
384369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
385−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
386371 currentContext <- getStateContext
387372 let nots = notifications currentContext
388373 if M.member notName nots then
389− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
390375 else do
391376 let newNotifications = M.insert notName newNotification nots
392377 newNotification = Notification { changeExpr = triggerExpr,
393378 reportOldExpr = resultOldExpr,
394379 reportNewExpr = resultNewExpr}
395380 putStateContext $ currentContext { notifications = newNotifications }
396− return (Right ())
397381
398−evalDatabaseContextExpr (RemoveNotification notName) = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
399383 currentContext <- getStateContext
400384 let nots = notifications currentContext
401385 if M.notMember notName nots then
402− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
403387 else do
404388 let newNotifications = M.delete notName nots
405389 putStateContext $ currentContext { notifications = newNotifications }
406− pure (Right ())
390+
407391
408392-- | Adds type and data constructors to the database context.
409393-- validate that the type *and* constructor names are unique! not yet implemented!
410−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
411395 currentContext <- getStateContext
412396 let oldTypes = typeConstructorMapping currentContext
413397 tConsName = TCD.name tConsDef
414398 -- validate that the constructor's types exist
415− case validateTypeConstructorDef tConsDef dConsDefList of
416− errs@(_:_) -> pure (Left (someErrors errs))
417− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
418− | 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)
419403 | otherwise -> do
420404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
421405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
422− pure (Right ())
423406
424407-- | 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.
425−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
426409 currentContext <- getStateContext
427410 let oldTypes = typeConstructorMapping currentContext
428411 if isNothing (findTypeConstructor tConsName oldTypes) then
429− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
430413 else do
431414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
432415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
433− pure (Right ())
434416
435−evalDatabaseContextExpr (MultipleExpr exprs) = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
436418 --the multiple expressions must pass the same context around- not the old unmodified context
437− evald <- forM exprs evalDatabaseContextExpr
438− --some lifting magic needed here
439− case lefts evald of
440− [] -> pure (Right ())
441− errs -> pure (Left (someErrors errs))
442−
443−evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
444422 currentContext <- getStateContext
445423 let atomFuncs = atomFunctions currentContext
446424 case atomFunctionForName funcName atomFuncs of
447− Left err -> pure (Left err)
448− Right realFunc -> if isScriptedAtomFunction realFunc then do
449− let updatedFuncs = HS.delete realFunc atomFuncs
450− putStateContext (currentContext {atomFunctions = updatedFuncs })
451− pure (Right ())
452− else
453− 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)
454432
455−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
456434 context <- getStateContext
457435 let dbcFuncs = dbcFunctions context
458436 case databaseContextFunctionForName funcName dbcFuncs of
459− Left err -> pure (Left err)
460− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
461− let updatedFuncs = HS.delete realFunc dbcFuncs
462− putStateContext (context { dbcFunctions = updatedFuncs })
463− pure (Right ())
464− else
465− 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)
466444
467−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
468446 context <- getStateContext
447+ graph <- dbcGraph
469448 --resolve atom arguments
470− let relExprState = mkRelationalExprState context
471− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
472450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
473452 case eFunc of
474− Left err -> pure (Left err)
453+ Left err -> dbErr err
475454 Right func -> do
476455 let expectedArgCount = length (dbcFuncType func)
477456 actualArgCount = length atomArgExprs
478457 if expectedArgCount /= actualArgCount then
479− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
480459 else
481460 --check that the atom types are valid
482− case lefts eAtomTypes of
483− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
484− [] -> do
485− let atomTypes = rights eAtomTypes
486− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
487− Left err -> Just err
488− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
489− typeErrors = catMaybes mValidTypes
490− 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
491471 if length (lefts eAtomArgs) > 1 then
492− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
493473 else if not (null typeErrors) then
494− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
495475 else
496476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
497− Left err -> pure (Left err)
498− Right newContext -> putStateContext newContext >> pure (Right ())
499−
500−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
501−evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
502− case mScriptSession of
503− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
504− Just scriptSession -> do
505− 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
506530 setSession (hscEnv scriptSession)
507531 let atomFuncs = atomFunctions currentContext
508532 case extractAtomFunctionType funcType of
@@ -528,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcNam
528552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
529553 Right eContext -> case eContext of
530554 Left err -> pure (Left err)
531− Right context' -> pure (Right context')
532−
533−evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
534− case mScriptSession of
535− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
536− 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
537562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
538563 let last2Args = reverse (take 2 (reverse funcType))
539564 atomArgs = take (length funcType - 2) funcType
@@ -543,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
543568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
544569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
545570 else do
546− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
547572 setSession (hscEnv scriptSession)
548573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
549574 pure $ case eCompiledFunc of
@@ -568,68 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
568593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
569594 Right eContext -> case eContext of
570595 Left err -> pure (Left err)
571− Right context' -> pure (Right context')
572−evalDatabaseContextIOExpr _ currentContext (LoadAtomFunctions modName funcName modPath) = do
573− 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
574600 case eLoadFunc of
575601 Left LoadSymbolError -> pure (Left LoadFunctionError)
576602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
577603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
578− in pure (Right newContext)
579−evalDatabaseContextIOExpr _ currentContext (LoadDatabaseContextFunctions modName funcName modPath) = do
580− 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
581608 case eLoadFunc of
582609 Left LoadSymbolError -> pure (Left LoadFunctionError)
583610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
584611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
585− in pure (Right newContext)
586−
587−evalDatabaseContextIOExpr _ currentContext (CreateArbitraryRelation relVarName attrExprs range) =
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
588615 --Define
589− case runState ( evalDatabaseContextExpr (Define relVarName attrExprs)) (freshDatabaseState currentContext) of
590− (Left err,_) -> pure (Left err)
591− (Right (), elems@(ctx,_,_)) -> 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
592625 --Assign
593626 let existingRelVar = M.lookup relVarName relVarTable
594− relVarTable = relationVariables ctx
627+ relVarTable = relationVariables (dbc_context dbstate)
595628 case existingRelVar of
596629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
597630 Just existingRel -> do
598− let expectedAttributes = attributes existingRel
599− let tcMap = typeConstructorMapping ctx
600− eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
601− case eitherRel of
602− Left err -> pure $ Left err
603− Right rel ->
604− case runState (setRelVar relVarName rel) elems of
605− (Left err,_) -> pure (Left err)
606− (Right (), (ctx',_,_)) -> pure $ Right ctx'
607−
608−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
609−updateTupleWithAtomExprs exprMap context tupIn = do
610− --resolve all atom exprs
611− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
612− atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
613− pure (attrName, atom)
614− ) (M.toList exprMap)
615− pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633+ Left err -> pure (Left err)
634+ Right relType -> do
635+ let expectedAttributes = attributes relType
636+ tcMap = typeConstructorMapping (dbc_context dbstate)
637+ eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638+ case eitherRel of
639+ Left err -> pure $ Left err
640+ Right rel ->
641+ case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642+ Left err -> pure (Left err)
643+ Right dbstate' -> putDBCIOContext (dbc_context dbstate')
616644
617645--run verification on all constraints
618−checkConstraints :: DatabaseContext -> Either RelationalError ()
619−checkConstraints context = do
646+checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
620648 mapM_ (uncurry checkIncDep) (M.toList deps)
621− pure ()
622649 where
650+ potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
651+ tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
652+ utctDayTime = secondsToDiffTime 0 }
653+ tempSchemas = Schemas context M.empty
654+ tempTrans = Transaction U.nil tempTransInfo tempSchemas
655+ tempTransInfo = TransactionInfo { parents = transId NE.:| [],
656+ stamp = tempStamp,
657+ merkleHash = mempty
658+ }
659+
623660 deps = inclusionDependencies context
624− eval expr = evalReader (evalRelationalExpr expr)
625− 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
626662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
627666 --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.
628− typeSub <- evalReader (typeForRelationalExpr subsetExpr)
629− typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
667+ let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668+ runGfRel = runGraphRefRelationalExprM gfEnv
669+ typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670+ typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
630671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
631− let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
632− case eval checkExpr of
672+ let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673+ gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674+ gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675+ case gfEvald of
633676 Left err -> Left err
634677 Right resultRel -> if resultRel == relationTrue then
635678 pure ()
@@ -639,88 +682,81 @@ checkConstraints context = do
639682-- 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
640683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
641684
642−typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
643686typeForRelationalExpr expr = do
644− rstate <- ask
645− let context = stateElemsContext rstate
646687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
647− let context' = contextWithEmptyTupleSets context
648− rstate' = setStateElemsContext rstate context'
649− pure (runReader (evalRelationalExpr expr) rstate')
650−
651−--returns a database context with all tuples removed
652−--this is useful for type checking and optimization
653−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
654−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
655− where
656− relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
688+ --evalRelationalExpr could still return an existing relation with tuples, so strip them
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
657695
658696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
659697liftE v = do
660698 y <- lift v
661699 case y of
662− Left err -> throwE err
700+ Left err -> throwError err
663701 Right val -> pure val
664702
665703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
666−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
667−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
668− runExceptT $ do
669− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
670− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
671− pure (\x -> do
672− ev1 <- expr1v x
673− ev2 <- expr2v x
674− pure (ev1 && ev2))
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))
675712
676−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
677− runExceptT $ do
678− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
679− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
713+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714+ expr1v <- predicateRestrictionFilter attrs expr1
715+ expr2v <- predicateRestrictionFilter attrs expr2
680716 pure (\x -> do
681717 ev1 <- expr1v x
682718 ev2 <- expr2v x
683719 pure (ev1 || ev2))
684720
685−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
686722
687−predicateRestrictionFilter attrs (NotPredicate expr) =
688− runExceptT $ do
689− exprv <- liftE (predicateRestrictionFilter attrs expr)
690− pure (fmap not . exprv)
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
691726
692727--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
693728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
694− rstate <- ask
695− 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
696735 Left err -> Left err
697736 Right rel -> if arity rel /= 0 then
698737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
699738 else
700− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
701740
702741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
703− rstate <- ask
704− let (attrs', ctxtup') = case rstate of
705− RelationalExprStateElems _ -> (attrs, emptyTuple)
706− RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
707− RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
708− runExceptT $ do
709− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
710− 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
711747 Right attr -> Right attr
712748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
713749 Right ctxattr -> Right ctxattr
714750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
715751 Left err -> Left err
716752 Left err -> Left err
717− if atomExprType /= A.atomType attr then
718− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
719− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
720756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
721757 Right atomCmp -> atomCmp == atomIn
722758 Left _ -> False
723− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
724760 in
725761 pure $ case atomForAttributeName attrName tupleIn of
726762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -731,243 +767,626 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
731767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
732768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
733769 --merge attrs into the state attributes
734− rstate <- ask
735− runExceptT $ do
736− aType <- liftE (typeFromAtomExpr attrs atomExpr)
737− if aType /= BoolAtomType then
738− throwE (AtomTypeMismatchError aType BoolAtomType)
739− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
740775 pure (\tupleIn ->
741− pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
742− Left _ -> False
743− Right boolAtomValue -> boolAtomValue == BoolAtom True)
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
744779
745780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
746781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
747− Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
782+ Left (AttributeNameInUseError attrName)
748783 else
749784 Right rel
750785
751−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
752−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
753− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
754789 -- check that the attribute name is not in use
755790 case tupleExprCheckNewAttrName newAttrName relIn of
756− Left err -> pure (Left err)
757− Right _ -> runExceptT $ do
758− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
759− 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
760795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
761796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
762− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
763− Left err -> Left err
764− 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)
765802 )
766803
767−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
768−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
769− Right atom -> pure (Right atom)
770− err@(Left (NoSuchAttributeNamesError _)) -> do
771− rstate <- ask
772− case rstate of
773− RelationalExprStateElems _ -> pure err
774− RelationalExprStateAttrsElems _ _ -> pure err
775− RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
776− Left err -> pure (Left err)
777−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
778−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
779− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
780− context <- fmap stateElemsContext ask
781− runExceptT $ do
782− let functions = atomFunctions context
783− func <- either throwE pure (atomFunctionForName funcName functions)
784− let expectedArgCount = length (atomFuncType func) - 1
785− actualArgCount = length argTypes
786− safeInit [_] = []
787− safeInit [] = [] -- different behavior from normal init
788− safeInit (_:xs) = safeInit xs
789− if expectedArgCount /= actualArgCount then
790− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
791− else do
792− mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
793− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
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
828+ let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
829+ mapM_ (\(expType, actType) ->
830+ lift $ except (atomTypeVerify expType actType)) zippedArgs
831+ evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
794832 case evalAtomFunction func evaldArgs of
795− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
796834 Right result -> do
797835 --validate that the result matches the expected type
798− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
799837 pure result
800−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
801839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
802− rstate <- ask
803− runExceptT $ do
804− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
805− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
806− pure (RelationAtom relAtom)
807−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
808− rstate <- lift ask
809− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
810− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
811− 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
812849 pure (ConstructedAtom dConsName aType argAtoms)
813850
814−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
815−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
816− rstate <- ask
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
817854 case A.atomTypeForAttributeName attrName attrs of
818− Right aType -> pure (Right aType)
819− Left err@(NoSuchAttributeNamesError _) -> case rstate of
820− RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
821− Left err' -> pure (Left err')
822− Right attr -> pure (Right (A.atomType attr))
823− RelationalExprStateElems _ -> pure (Left err)
824− RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
825− Left err' -> pure (Left err')
826− Right atom -> pure (Right (atomTypeForAtom atom))
827− Left err -> pure (Left err)
828−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
829−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
830− context <- fmap stateElemsContext ask
831− 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
832870 case atomFunctionForName funcName funcs of
833− Left err -> pure (Left err)
871+ Left err -> throwError err
834872 Right func -> do
835873 let funcRetType = last (atomFuncType func)
836874 funcArgTypes = init (atomFuncType func)
837− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
838− case lefts eArgTypes of
839− errs@(_:_) -> pure (Left (someErrors errs))
840− [] -> do
841− let eTvMap = resolveTypeVariables funcArgTypes argTypes
842− argTypes = rights eArgTypes
843− case eTvMap of
844− Left err -> pure (Left err)
845− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
846−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
847− rstate <- lift ask
848− 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)
849882 pure (RelationAtomType (attributes relType))
850883-- grab the type of the data constructor, then validate that the args match the expected types
851−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
852− runExceptT $ do
853− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
854− context <- fmap stateElemsContext (lift ask)
855− 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
856889
857890-- | Validate that the type of the AtomExpr matches the expected type.
858−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
859−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
860− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
861894 case A.atomTypeForAttributeName attrName (attributes relIn) of
862− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
863− (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
864− RelationalExprStateTupleElems _ _ -> throwE err
865− RelationalExprStateElems _ -> throwE err
866− RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
867− Left err' -> throwE err'
868− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
869− Left err -> throwE err
870−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
871−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
872− 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
873910 let functions = atomFunctions context
874− context = stateElemsContext rstate
875− runExceptT $ do
876− func <- either throwE pure (atomFunctionForName funcName functions)
877− let expectedArgTypes = atomFuncType func
878− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
879− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
880− Left err -> throwE err
881− Right x -> pure x
882− ) $ zip3 funcArgExprs expectedArgTypes [1..]
883− if length funcArgTypes /= length expectedArgTypes - 1 then
884− 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)
885921 else
886− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
887−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
888− rstate <- lift ask
889− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
890− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
891−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
892− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
893− 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
894931
895932-- | Look up the type's name and create a new attribute.
896−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
897−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
898− aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
899− validateAtomType aType aTypes
900− Right (Attribute attrName aType)
901−
902−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
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
903939
904−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
905−evalTupleExpr attrs (TupleExpr tupMap) = do
906− context <- fmap stateElemsContext ask
907− 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
908992 -- 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
909993 -- 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
910− attrAtoms <- mapM (\(attrName, aExpr) -> do
911− newAtomType <- liftE (typeFromAtomExpr A.emptyAttributes aExpr)
912− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
913− pure (attrName, newAtom, newAtomType)
914− ) (M.toList tupMap)
915− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
916− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
917− tup = mkRelationTuple tupAttrs atoms
918− tConss = typeConstructorMapping context
919− finalAttrs = fromMaybe tupAttrs attrs
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
1001+ Left _ -> pure unresolvedType
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
1003+ --resolve atom typevars based on resolvedType?
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
9201011 --verify that the attributes match
921− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
922− tup' <- either throwE pure (resolveTypesInTuple finalAttrs (reorderTuple finalAttrs tup))
923− _ <- either throwE pure (validateTuple tup' tConss)
924− pure tup'
925−
926−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
927−evalAttributeNames attrNames expr = do
928− eExprType <- typeForRelationalExpr expr
929− case eExprType of
930− Left err -> pure (Left err)
931− Right exprTyp -> do
932− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
933− case attrNames of
934− AttributeNames names ->
935− case A.projectionAttributesForNames names (attributes exprTyp) of
936− Left err -> pure (Left err)
937− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
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
1036+ case M.lookup name (relationVariables ctx) of
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)
1086+
1087+dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
1088+dbContextForTransId tid graph = do
1089+ trans <- transactionForId tid graph
1090+ pure (concreteDatabaseContext trans)
1091+
1092+transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
1093+transactionForId tid graph
1094+ | tid == U.nil =
1095+ Left RootTransactionTraversalError
1096+ | S.null matchingTrans =
1097+ Left $ NoSuchTransactionError tid
1098+ | otherwise =
1099+ Right $ head (S.toList matchingTrans)
1100+ where
1101+ matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
1102+
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
1120+ case M.lookup rvName relVars of
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')))
1175+ case attrNames of
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)))
9381180
939− InvertedAttributeNames names -> do
1181+ InvertedAttributeNames names -> do
9401182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
9411183 if not (S.null nonExistentAttributeNames) then
942− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
9431185 else
944− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
9451187
946− UnionAttributeNames namesA namesB -> do
947− eNameSetA <- evalAttributeNames namesA expr
948− case eNameSetA of
949− Left err -> pure (Left err)
950− Right nameSetA -> do
951− eNameSetB <- evalAttributeNames namesB expr
952− case eNameSetB of
953− Left err -> pure (Left err)
954− Right nameSetB ->
955− 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)
9561192
957− IntersectAttributeNames namesA namesB -> do
958− eNameSetA <- evalAttributeNames namesA expr
959− case eNameSetA of
960− Left err -> pure (Left err)
961− Right nameSetA -> do
962− eNameSetB <- evalAttributeNames namesB expr
963− case eNameSetB of
964− Left err -> pure (Left err)
965− Right nameSetB ->
966− 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)
9671197
968− RelationalExprAttributeNames attrExpr -> do
969− eAttrExprType <- typeForRelationalExpr attrExpr
970− case eAttrExprType of
971− Left err -> pure (Left err)
972− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
973−
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
1270+
1271+instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272+ getContext = gfDatabaseContextForMarker UncommittedContextMarker
1273+
1274+instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275+ getContext = getStateContext
1276+
1277+relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278+relVarByName rvName = do
1279+ relvars <- relationVariables <$> getContext
1280+ case M.lookup rvName relvars of
1281+ Nothing -> throwError (RelVarNotDefinedError rvName)
1282+ Just gfexpr -> pure gfexpr
1283+
1284+-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285+class ResolveGraphRefTransactionMarker a where
1286+ resolve :: a -> DatabaseContextEvalMonad a
1287+
1288+-- s := s union t
1289+instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290+ resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291+ MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292+ resolve orig@MakeStaticRelation{} = pure orig
1293+ resolve orig@ExistingRelation{} = pure orig
1294+ resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295+ rvMap <- relationVariables <$> getStateContext
1296+ case M.lookup rvName rvMap of
1297+ Nothing -> pure orig
1298+ Just resolvedRv -> resolve resolvedRv
1299+ resolve orig@RelationVariable{} = pure orig
1300+ resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301+ resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302+ resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303+ resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304+ resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305+ resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306+ resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307+ resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308+ resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309+ resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310+ resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311+ resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312+
1313+instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314+ resolve (TupleExprs marker tupleExprs) =
1315+ TupleExprs marker <$> mapM resolve tupleExprs
1316+
1317+instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318+ resolve (TupleExpr tupMap) = do
1319+ tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320+ pure (TupleExpr (M.fromList tupMap'))
1321+
1322+instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323+ resolve orig@AttributeNames{} = pure orig
1324+ resolve orig@InvertedAttributeNames{} = pure orig
1325+ resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326+ resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327+ resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328+
1329+instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330+ resolve TruePredicate = pure TruePredicate
1331+ resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332+ resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333+ resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334+ resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335+ resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336+ resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337+
1338+instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339+ resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340+
1341+instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342+ resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343+
1344+instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345+ resolve orig@AttributeAtomExpr{} = pure orig
1346+ resolve orig@NakedAtomExpr{} = pure orig
1347+ resolve (FunctionAtomExpr nam atomExprs marker) =
1348+ FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349+ resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350+ resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351+ ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352+
1353+--convert series of simple Union queries into MakeStaticRelation
1354+-- this is especially useful for long, nested applications of Union with simple tuples
1355+-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356+
1357+--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358+
1359+applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360+applyUnionCollapse = Fold.cata opt
1361+ where
1362+ opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363+ opt (UnionF exprA exprB) | exprA == exprB = exprA
1364+ opt (UnionF
1365+ exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366+ exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367+ | tupExprsNull tupExprs1 = exprB
1368+ | tupExprsNull tupExprs2 = exprA
1369+ opt x = Fold.embed x
1370+ tupExprsNull (TupleExprs _ []) = True
1371+ tupExprsNull _ = False
1372+
1373+
1374+--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375+--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376+-- =>
1377+-- update x where y=1 set (x:=6,z:=11)
1378+-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379+
1380+--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381+
1382+--DELETE optimization
1383+-- if a restriction matches a previous restriction, combine them
1384+-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385+applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386+applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387+ case expr of
1388+ orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389+ _ -> orig
1390+applyRestrictionCollapse expr = expr
1391+
1392+