@@ -1,7 +1,4 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FlexibleContexts #-}
4−{-# LANGUAGE OverloadedStrings #-}
52module ProjectM36.RelationalExpression where
63import ProjectM36.Relation
74import ProjectM36.Tuple
@@ -10,44 +7,32 @@ import ProjectM36.Base
107import qualified Data.UUID as U
118import ProjectM36.Error
129import ProjectM36.AtomType
13−import ProjectM36.Attribute (emptyAttributes, attributesFromList)
10+import ProjectM36.Attribute (emptyAttributes)
1411import ProjectM36.ScriptSession
1512import ProjectM36.DataTypes.Primitive
1613import ProjectM36.AtomFunction
1714import ProjectM36.DatabaseContextFunction
1815import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
20−import ProjectM36.Transaction
2116import qualified ProjectM36.Attribute as A
2217import qualified Data.Map as M
2318import qualified Data.HashSet as HS
2419import qualified Data.Set as S
2520import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
21+import Control.Exception
2722import Data.Maybe
2823import Data.Either
2924import Data.Char (isUpper)
30−import Data.Time
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
3325import qualified Data.Text as T
3426import qualified Data.Vector as V
3527import qualified ProjectM36.TypeConstructorDef as TCD
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
28+import Control.Monad.Trans.Except
29+import Control.Monad.Trans.Reader
4330import Test.QuickCheck
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
31+import GHC
4932import GHC.Paths
50−#endif
33+import Data.Time.Clock
34+import Data.Time.Calendar
35+import qualified Data.List.NonEmpty as NE
5136
5237data DatabaseContextExprDetails = CountUpdatedTuples
5338
@@ -64,63 +49,42 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
6449 Right ts -> ts
6550
6651-- | Used to start a fresh database state for a new database context expression.
67−mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68−mkDatabaseContextEvalState context = DatabaseContextEvalState {
69− dbc_context = context,
70− dbc_accum = M.empty,
71− dbc_dirty = False
52+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
53+freshDatabaseState context = DatabaseStateElems {
54+ context = context,
55+ accum = M.empty,
56+ dirty = False
7257 } --future work: propagate return accumulator
7358
7459-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
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))
60+data RelationalExprStateElems = RelationalExprStateTupleElems {
61+ elems_context :: DatabaseContext,
62+ elems_graph :: TransactionGraph,
63+ elems_extra :: Maybe (Either RelationTuple Attributes) }
64+
65+{-
66+data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
67+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
68+ RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
69+ -}
8670
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)))
71+instance Show RelationalExprStateElems where
72+ show e@RelationalExprStateTupleElems{..} = "RelationalExprStateTupleElems " ++ show (elems_extra e)
73+
74+mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
75+mkRelationalExprState = RelationalExprStateElems
76+
77+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
78+mergeTuplesIntoRelationalExprState tupIn e@RelationalExprStateElems{..} =
79+ e{elems_extra = <$> elems_extra e } RelationalExprStateTupleElems ctx tupIn
80+mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
81+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
82+ RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
83+
84+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
85+mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
86+mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
87+mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
12488
12589type ResultAccumName = StringType
12690
@@ -130,403 +94,443 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
13094 resultAccumResult :: Relation
13195 }
13296
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
97+data DatabaseStateElems = DatabaseStateElems {
98+ context :: DatabaseContext, --new, alterable context for a new transaction
99+ accum :: M.Map ResultAccumName ResultAccum,
100+ dirty :: DirtyFlag
137101 }
138102
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
142− }
143−
144−mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145−mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146−
147−type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
103+type DatabaseState a = State DatabaseStateElems a
148104
149−runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150−runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151− where
152− freshEnv = mkDatabaseContextEvalState ctx
153−
154−
155−dbcTransId :: DatabaseContextEvalMonad TransactionId
156−dbcTransId = dce_transId <$> RWS.ask
157−
158−dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159−dbcGraph = dce_graph <$> RWS.ask
105+getStateContext :: DatabaseState DatabaseContext
106+getStateContext = context <$> get
160107
161−dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162−dbcRelationalExprEnv =
163− mkRelationalExprEnv <$> getStateContext <*> dbcGraph
164−
165−getStateContext :: DatabaseContextEvalMonad DatabaseContext
166−getStateContext = gets dbc_context
167−
168−putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
108+putStateContext :: DatabaseContext -> DatabaseState ()
169109putStateContext ctx' = do
170110 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− }
111+ put (s {context = ctx'})
180112
181−type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
182−
183−gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184−gfTransForId tid = do
185− graph <- gfGraph
186− lift $ except $ transactionForId tid graph
187−
188−gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189−gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190−gfDatabaseContextForMarker UncommittedContextMarker = do
191− mctx <- gre_context <$> askEnv
192− case mctx of
193− Nothing -> throwError NoUncommittedContextInEvalError
194− Just ctx -> pure ctx
195−
196−runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197−runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
198−
199−freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200−freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
201− gre_context = mctx,
202− gre_graph = graph,
203− gre_extra = Nothing
204− }
205−
206−gfGraph :: GraphRefRelationalExprM TransactionGraph
207−gfGraph = asks gre_graph
113+type RelationalExprState a = Reader RelationalExprStateElems a
114+
115+stateElemsContext :: RelationalExprStateElems -> DatabaseContext
116+stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
117+stateElemsContext (RelationalExprStateElems ctx) = ctx
118+stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
119+
120+setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
121+setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
122+setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
123+setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
124+
125+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
126+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError GraphRefRelationalExpr)
127+evalRelationalExpr (RelationVariable name _) = do
128+ relvarTable <- fmap (relationVariables . stateElemsContext) ask
129+ return $ case M.lookup name relvarTable of
130+ Just res -> Right res
131+ Nothing -> Left $ RelVarNotDefinedError name
132+
133+evalRelationalExpr (Project attrNames expr) = do
134+ eAttrNameSet <- evalAttributeNames attrNames expr
135+ case eAttrNameSet of
136+ Left err -> pure (Left err)
137+ Right attrNameSet -> do
138+ rel <- evalRelationalExpr expr
139+ case rel of
140+ Right rel2 -> pure $ Right (Project (AttributeNames attrNameSet) rel2)
141+ Left err -> pure $ Left err
142+
143+evalRelationalExpr (Union exprA exprB) = do
144+ relA <- evalRelationalExpr exprA
145+ relB <- evalRelationalExpr exprB
146+ case relA of
147+ Left err -> return $ Left err
148+ Right relA2 -> case relB of
149+ Left err -> return $ Left err
150+ Right relB2 -> return $ Right (Union relA2 relB2)
151+
152+evalRelationalExpr (Join exprA exprB) = do
153+ relA <- evalRelationalExpr exprA
154+ relB <- evalRelationalExpr exprB
155+ case relA of
156+ Left err -> return $ Left err
157+ Right relA2 -> case relB of
158+ Left err -> return $ Left err
159+ Right relB2 -> return $ Right (Join relA2 relB2)
160+
161+evalRelationalExpr (Difference exprA exprB) = do
162+ relA <- evalRelationalExpr exprA
163+ relB <- evalRelationalExpr exprB
164+ case relA of
165+ Left err -> return $ Left err
166+ Right relA2 -> case relB of
167+ Left err -> return $ Left err
168+ Right relB2 -> return $ Right (Difference relA2 relB2)
169+
170+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
171+ case mkRelation attributeSet tupleSet of
172+ Right rel -> return $ Right (ExistingRelation rel)
173+ Left err -> return $ Left err
174+
175+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
176+ currentContext <- fmap stateElemsContext ask
177+ let tConss = typeConstructorMapping currentContext
178+ -- 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
179+ runExceptT $ do
180+ mAttrs <- case mAttrExprs of
181+ Just _ ->
182+ Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
183+ Nothing -> pure Nothing
184+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
185+ let attrs = fromMaybe firstTupleAttrs mAttrs
186+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
187+ expr <- either throwE pure (mkRelation attrs (RelationTupleSet tuples))
188+ pure (ExistingRelation expr)
189+
190+evalRelationalExpr (ExistingRelation rel) = pure (Right (ExistingRelation rel))
208191
209−envContext :: RelationalExprEnv -> DatabaseContext
210−envContext = re_context
192+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
193+ evald <- evalRelationalExpr relExpr
194+ case evald of
195+ Right expr -> return $ Right (Rename oldAttrName newAttrName expr)
196+ Left err -> return $ Left err
211197
212−setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213−setEnvContext e ctx = e { re_context = ctx }
198+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
199+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
200+ case eOldAttrNameSet of
201+ Left err -> pure (Left err)
202+ Right oldAttrNameSet -> do
203+ evald <- evalRelationalExpr relExpr
204+ case evald of
205+ Right expr -> return $ Right (Group (AttributeNames oldAttrNameSet) newAttrName expr)
206+ Left err -> return $ Left err
207+
208+evalRelationalExpr (Ungroup attrName relExpr) = do
209+ evald <- evalRelationalExpr relExpr
210+ case evald of
211+ Right expr -> return $ Right (Ungroup attrName expr)
212+ Left err -> return $ Left err
213+
214+evalRelationalExpr (Restrict predicateExpr relExpr) = do
215+ evald <- evalRelationalExpr relExpr
216+ ePred <- processRestrictionPredicateExpr predicateExpr
217+ case evald of
218+ Left err -> return $ Left err
219+ Right expr -> case ePred of
220+ Left err -> pure (Left err)
221+ Right pred -> pure $ Right (Restrict pred expr)
222+
223+evalRelationalExpr (Equals relExprA relExprB) = do
224+ evaldA <- evalRelationalExpr relExprA
225+ evaldB <- evalRelationalExpr relExprB
226+ case evaldA of
227+ Left err -> return $ Left err
228+ Right exprA -> case evaldB of
229+ Left err -> return $ Left err
230+ Right exprB -> return $ Right (Equals exprA exprB)
231+{-
232+evalRelationalExpr (With views mainExpr) = do
233+ rstate <- ask
234+
235+ let addScopedView ctx (vname,vexpr) = if vname `M.member` relationVariables ctx then
236+ Left (RelVarAlreadyDefinedError vname)
237+ else
238+ case runState (evalDatabaseContextExpr (Assign vname vexpr)) (freshDatabaseState ctx) of
239+ (Left err,_) -> Left err
240+ (Right (), (ctx',_,_)) -> Right ctx'
241+
242+ case foldM addScopedView (stateElemsContext rstate) views of
243+ Left err -> return $ Left err
244+ Right ctx'' -> do
245+ let evalMainExpr expr = runReader (evalRelationalExpr expr) (RelationalExprStateElems ctx'')
246+ case evalMainExpr mainExpr of
247+ Left err -> return $ Left err
248+ Right rel -> return $ Right rel
249+-}
250+--warning: copy-pasta from above- refactor
251+evalRelationalExpr (NotEquals relExprA relExprB) = do
252+ evaldA <- evalRelationalExpr relExprA
253+ evaldB <- evalRelationalExpr relExprB
254+ case evaldA of
255+ Left err -> return $ Left err
256+ Right exprA -> case evaldB of
257+ Left err -> return $ Left err
258+ Right exprB -> return $ Right (NotEquals exprA exprB)
259+
260+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
261+evalRelationalExpr (Extend tupleExpression relExpr) = do
262+ eExpr <- evalRelationalExpr relExpr
263+ case eExpr of
264+ Left err -> pure (Left err)
265+ Right expr -> do
266+ eTupProc <- processExtendTupleExpr tupleExpression
267+ case eTupProc of
268+ Left err -> pure (Left err)
269+ Right tupProc -> pure (Right (Extend tupProc expr))
214270
215271--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217−setRelVar relVarName relExpr = do
272+setRelVar :: RelVarName -> GraphRefRelationalExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
273+setRelVar relVarName relExpr transId graph = do
218274 currentContext <- getStateContext
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
275+ let newRelVars = M.insert relVarName relExpr $ relationVariables currentContext
222276 potentialContext = currentContext { relationVariables = newRelVars }
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 ()
277+ --determine when to check constraints
278+
279+ case checkConstraints potentialContext transId graph of
280+ Left err -> pure (Left err)
281+ Right _ -> do
282+ putStateContext potentialContext
283+ return (Right ())
236284
237285-- 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
238−deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
286+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239287deleteRelVar relVarName = do
240288 currContext <- getStateContext
241289 let relVars = relationVariables currContext
242290 if M.notMember relVarName relVars then
243− pure ()
291+ pure (Right ())
244292 else do
245293 let newRelVars = M.delete relVarName relVars
246294 newContext = currContext { relationVariables = newRelVars }
247295 putStateContext newContext
248− pure ()
296+ pure (Right ())
249297
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
298+evalDatabaseContextExpr :: DatabaseContextExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
299+evalDatabaseContextExpr NoOperation _ _ = pure (Right ())
252300
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
301+evalDatabaseContextExpr (Define relVarName attrExprs) transId graph = do
255302 relvars <- fmap relationVariables getStateContext
256303 tConss <- fmap typeConstructorMapping getStateContext
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)
304+ let eAttrs = map (evalAttrExpr tConss) attrExprs
305+ attrErrs = lefts eAttrs
306+ attrsList = rights eAttrs
307+ if not (null attrErrs) then
308+ pure (Left (someErrors attrErrs))
309+ else do
310+ let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
311+ if not (null atomTypeErrs) then
312+ pure (Left (someErrors atomTypeErrs))
313+ else
314+ case M.member relVarName relvars of
315+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
316+ False -> setRelVar relVarName (ExistingRelation emptyRelation) transId graph >> pure (Right ())
267317 where
268318 attrs = A.attributesFromList attrsList
269319 emptyRelation = Relation attrs emptyTupleSet
270320
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
321+evalDatabaseContextExpr (Undefine relVarName) _ _ = deleteRelVar relVarName
272322
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
323+evalDatabaseContextExpr (Assign relVarName expr) transId graph = do
275324 context <- getStateContext
276325 let existingRelVar = M.lookup relVarName (relationVariables context)
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
326+ relExprState = mkRelationalExprState context
279327 case existingRelVar of
280328 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
329+ let ervExpr = runReader (evalRelationalExpr expr) relExprState
330+ case ervExpr of
331+ Left err -> pure (Left err)
332+ Right rvExpr -> setRelVar relVarName rvExpr transId graph
286333 Just existingRel -> do
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
334+ let eExpectedType = typeForGraphRefRelationalExpr existingRel graph
335+ eNewExprType = runReader (typeForRelationalExpr expr transId graph) relExprState
288336 case eExpectedType of
289− Left err -> dbErr err
337+ Left err -> pure (Left err)
290338 Right expectedType ->
291339 case eNewExprType of
292− Left err -> dbErr err
340+ Left err -> pure (Left err)
293341 Right newExprType -> do
294342 if newExprType == expectedType then do
295− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296− setRelVar relVarName expr
343+ let ervExpr = runReader (evalRelationalExpr expr) relExprState
344+ case ervExpr of
345+ Left err -> pure (Left err)
346+ Right rvExpr -> setRelVar relVarName rvExpr transId graph
297347 else
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
299−
300−evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301− gfExpr <- relVarByName relVarName
302− let optExpr = applyUnionCollapse (Union
303− relExpr
304− gfExpr)
305− evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
306−
307−evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308− gfExpr <- relVarByName relVarName
309− let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310− setRelVar relVarName optExpr
348+ pure (Left (RelationTypeMismatchError (attributes expectedType) (attributes newExprType)))
349+
350+evalDatabaseContextExpr (Insert relVarName relExpr) tid graph =
351+ evalDatabaseContextExpr (Assign relVarName (Union (RelationVariable relVarName ())
352+ relExpr)) tid graph
353+
354+evalDatabaseContextExpr (Delete relVarName predicate) transId graph = do
355+ ctx <- getStateContext
356+ let rv = RelationVariable relVarName transId
357+ rvState = mkRelationalExprState ctx
358+ case runReader (processRestrictionPredicateExpr predicate) rvState of
359+ Left err -> pure (Left err)
360+ Right graphRefPredicate ->
361+ setRelVar relVarName (Restrict (NotPredicate graphRefPredicate) rv) transId graph
311362
312363--union of restricted+updated portion and the unrestricted+unupdated portion
313−evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314− rvExpr <- relVarByName relVarName
315− graph <- re_graph <$> dbcRelationalExprEnv
364+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) transId graph = do
316365 context <- getStateContext
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
366+ let rvState = mkRelationalExprState context
367+ relVarTable = relationVariables context
368+ case runReader (processRestrictionPredicateExpr restrictionPredicateExpr) rvState of
369+ Left err -> pure (Left err)
370+ Right graphRefPredicate ->
371+ case M.lookup relVarName relVarTable of
372+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
373+ Just existingRvExpr -> do
374+ let unrestrictedPortion = Restrict (NotPredicate graphRefPredicate) rv
375+ rv = RelationVariable relVarName transId
376+ tmpAttr attr = "_tmp_" <> attr --this could certainly be improved to verify that there is no attribute name conflict
377+ updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
378+ projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
379+ restrictedPortion = Restrict graphRefPredicate
380+ updated = foldr (\(oldname, atomExpr) accum ->
381+ let procAtomExpr = processAtomExpr atomExpr transId in
337382 updateAttr oldname procAtomExpr accum
338− ) restrictedPortion (M.toList atomExprMap)
383+ ) rv (M.toList atomExprMap)
339384 -- 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)
385+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
386+ setRelVar relVarName (Union unrestrictedPortion updatedPortion) transId graph
342387
343−evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
388+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) transId graph = do
344389 currContext <- getStateContext
345− transId <- dbcTransId
346− graph <- dbcGraph
347390 let currDeps = inclusionDependencies currContext
348391 newDeps = M.insert newDepName newDep currDeps
349392 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
393+ pure (Left (InclusionDependencyNameInUseError newDepName))
351394 else do
352395 let potentialContext = currContext { inclusionDependencies = newDeps }
353− -- if the potential context passes all constraints, then save it
354− -- potential optimization: validate only the new constraint- all old constraints must already hold
355396 case checkConstraints potentialContext transId graph of
356− Left err -> dbErr err
357− Right _ ->
397+ Left err -> pure (Left err)
398+ Right _ -> do
358399 putStateContext potentialContext
400+ return (Right ())
359401
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
402+evalDatabaseContextExpr (RemoveInclusionDependency depName) _ _ = do
361403 currContext <- getStateContext
362404 let currDeps = inclusionDependencies currContext
363405 newDeps = M.delete depName currDeps
364406 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
366− else
407+ pure (Left (InclusionDependencyNameNotInUseError depName))
408+ else do
367409 putStateContext $ currContext {inclusionDependencies = newDeps }
410+ return (Right ())
368411
369412-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
413+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) _ _ = do
371414 currentContext <- getStateContext
372415 let nots = notifications currentContext
373416 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
417+ pure (Left (NotificationNameInUseError notName))
375418 else do
376419 let newNotifications = M.insert notName newNotification nots
377420 newNotification = Notification { changeExpr = triggerExpr,
378421 reportOldExpr = resultOldExpr,
379422 reportNewExpr = resultNewExpr}
380423 putStateContext $ currentContext { notifications = newNotifications }
424+ return (Right ())
381425
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
426+evalDatabaseContextExpr (RemoveNotification notName) _ _ = do
383427 currentContext <- getStateContext
384428 let nots = notifications currentContext
385429 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
430+ pure (Left (NotificationNameNotInUseError notName))
387431 else do
388432 let newNotifications = M.delete notName nots
389433 putStateContext $ currentContext { notifications = newNotifications }
390−
434+ pure (Right ())
391435
392436-- | Adds type and data constructors to the database context.
393437-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
438+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) _ _ = do
395439 currentContext <- getStateContext
396440 let oldTypes = typeConstructorMapping currentContext
397441 tConsName = TCD.name tConsDef
398442 -- validate that the constructor's types exist
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)
443+ case validateTypeConstructorDef tConsDef dConsDefList of
444+ errs@(_:_) -> pure (Left (someErrors errs))
445+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
446+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403447 | otherwise -> do
404448 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405449 putStateContext $ currentContext { typeConstructorMapping = newTypes }
450+ pure (Right ())
406451
407452-- | 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.
408−evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
453+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) _ _ = do
409454 currentContext <- getStateContext
410455 let oldTypes = typeConstructorMapping currentContext
411456 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
457+ pure (Left (AtomTypeNameNotInUseError tConsName))
413458 else do
414459 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415460 putStateContext $ currentContext { typeConstructorMapping = newTypes }
461+ pure (Right ())
416462
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
463+evalDatabaseContextExpr (MultipleExpr exprs) transId graph = do
418464 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
420−
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
465+ evald <- forM exprs (\expr -> evalDatabaseContextExpr expr transId graph)
466+ --some lifting magic needed here
467+ case lefts evald of
468+ [] -> pure (Right ())
469+ errs -> pure (Left (someErrors errs))
470+
471+evalDatabaseContextExpr (RemoveAtomFunction funcName) _ _ = do
422472 currentContext <- getStateContext
423473 let atomFuncs = atomFunctions currentContext
424474 case atomFunctionForName funcName atomFuncs of
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)
475+ Left err -> pure (Left err)
476+ Right realFunc -> if isScriptedAtomFunction realFunc then do
477+ let updatedFuncs = HS.delete realFunc atomFuncs
478+ putStateContext (currentContext {atomFunctions = updatedFuncs })
479+ pure (Right ())
480+ else
481+ pure (Left (PrecompiledFunctionRemoveError funcName))
432482
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
483+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) _ _ = do
434484 context <- getStateContext
435485 let dbcFuncs = dbcFunctions context
436486 case databaseContextFunctionForName funcName dbcFuncs of
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)
487+ Left err -> pure (Left err)
488+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
489+ let updatedFuncs = HS.delete realFunc dbcFuncs
490+ putStateContext (context { dbcFunctions = updatedFuncs })
491+ pure (Right ())
492+ else
493+ pure (Left (PrecompiledFunctionRemoveError funcName))
444494
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
495+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) _ _ = do
446496 context <- getStateContext
447− graph <- dbcGraph
448497 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
498+ let relExprState = mkRelationalExprState context
499+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450500 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452501 case eFunc of
453− Left err -> dbErr err
502+ Left err -> pure (Left err)
454503 Right func -> do
455504 let expectedArgCount = length (dbcFuncType func)
456505 actualArgCount = length atomArgExprs
457506 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
507+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
459508 else
460509 --check that the atom types are valid
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
510+ case lefts eAtomTypes of
511+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
512+ [] -> do
513+ let atomTypes = rights eAtomTypes
514+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
515+ Left err -> Just err
516+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
517+ typeErrors = catMaybes mValidTypes
518+ eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471519 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
520+ pure (Left (someErrors (lefts eAtomArgs)))
473521 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
522+ pure (Left (someErrors typeErrors))
475523 else
476524 case evalDatabaseContextFunction func (rights eAtomArgs) context of
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
525+ Left err -> pure (Left err)
526+ Right newContext -> putStateContext newContext >> pure (Right ())
527+
528+evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> TransactionId -> TransactionGraph -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
529+evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction funcName funcType script) =
530+ case mScriptSession of
531+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
532+ Just scriptSession -> do
533+ res <- try $ runGhc (Just libdir) $ do
530534 setSession (hscEnv scriptSession)
531535 let atomFuncs = atomFunctions currentContext
532536 case extractAtomFunctionType funcType of
@@ -552,13 +556,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552556 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553557 Right eContext -> case eContext of
554558 Left err -> pure (Left err)
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
559+ Right context' -> pure (Right context')
560+
561+evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextFunction funcName funcType script) =
562+ case mScriptSession of
563+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
564+ Just scriptSession -> do
562565 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563566 let last2Args = reverse (take 2 (reverse funcType))
564567 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +571,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568571 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569572 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
570573 else do
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
574+ res <- try $ runGhc (Just libdir) $ do
572575 setSession (hscEnv scriptSession)
573576 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574577 pure $ case eCompiledFunc of
@@ -593,86 +596,78 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593596 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594597 Right eContext -> case eContext of
595598 Left err -> pure (Left err)
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
599+ Right context' -> pure (Right context')
600+evalDatabaseContextIOExpr _ currentContext _ _ (LoadAtomFunctions modName funcName modPath) = do
601+ eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600602 case eLoadFunc of
601603 Left LoadSymbolError -> pure (Left LoadFunctionError)
602604 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603605 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
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
606+ in pure (Right newContext)
607+evalDatabaseContextIOExpr _ currentContext _ _ (LoadDatabaseContextFunctions modName funcName modPath) = do
608+ eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608609 case eLoadFunc of
609610 Left LoadSymbolError -> pure (Left LoadFunctionError)
610611 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611612 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
613−#endif
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
613+ in pure (Right newContext)
614+
615+evalDatabaseContextIOExpr _ currentContext transId graph (CreateArbitraryRelation relVarName attrExprs range) =
615616 --Define
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
617+ case runState (evalDatabaseContextExpr (Define relVarName attrExprs) transId graph) (freshDatabaseState currentContext) of
618+ (Left err,_) -> pure (Left err)
619+ (Right (), elems) -> do
625620 --Assign
626621 let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
622+ relVarTable = relationVariables (context elems)
628623 case existingRelVar of
629624 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630625 Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
626+ case typeForGraphRefRelationalExpr existingRel graph of
633627 Left err -> pure (Left err)
634628 Right relType -> do
635629 let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
630+ tcMap = typeConstructorMapping (context elems)
631+ eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638632 case eitherRel of
639633 Left err -> pure $ Left err
640634 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')
635+ case runState (setRelVar relVarName (ExistingRelation rel) transId graph) elems of
636+ (Left err,_) -> pure (Left err)
637+ (Right (), elems') -> pure $ Right (context elems)
638+
639+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
640+updateTupleWithAtomExprs exprMap context tupIn = do
641+ --resolve all atom exprs
642+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
643+ atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
644+ pure (attrName, atom)
645+ ) (M.toList exprMap)
646+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
644647
645648--run verification on all constraints
646649checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
650+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
648651 mapM_ (uncurry checkIncDep) (M.toList deps)
649652 where
650653 potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
651654 tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
652655 utctDayTime = secondsToDiffTime 0 }
653656 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− }
657+ tempTrans = Transaction U.nil (TransactionInfo (transId NE.:| []) tempStamp) tempSchemas
659658
660659 deps = inclusionDependencies 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
660+ eval expr = evalReader (evalRelationalExpr expr)
661+ evalReader f = runReader f (RelationalExprStateElems context)
662662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663− let process = runProcessExprM UncommittedContextMarker
664− gfSubsetExpr = process (processRelationalExpr subsetExpr)
665− gfSupersetExpr = process (processRelationalExpr supersetExpr)
663+ let gfSubsetExpr = processRelationalExpr subsetExpr transId
664+ gfSupersetExpr = processRelationalExpr supersetExpr transId
666665 --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.
667− let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668− runGfRel = runGraphRefRelationalExprM gfEnv
669− typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670− typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
666+ typeSub <- evalReader (typeForRelationalExpr subsetExpr transId graph)
667+ typeSuper <- evalReader (typeForRelationalExpr supersetExpr transId graph)
671668 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672669 let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675− case gfEvald of
670+ case evalGraphRefRelationalExpr checkExpr potentialGraph of
676671 Left err -> Left err
677672 Right resultRel -> if resultRel == relationTrue then
678673 pure ()
@@ -682,81 +677,90 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
682677-- 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
683678-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
684679
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
686−typeForRelationalExpr expr = do
680+typeForRelationalExpr :: RelationalExpr -> TransactionId -> TransactionGraph -> RelationalExprState (Either RelationalError Relation)
681+typeForRelationalExpr expr transId graph = do
682+ rstate <- ask
683+ let context = stateElemsContext rstate
687684 --replace the relationVariables context element with a cloned set of relation devoid of tuples
688685 --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
686+ let gfExpr = processRelationalExpr expr transId
687+ pure (typeForGraphRefRelationalExpr gfExpr graph)
688+
689+--returns a database context with all tuples removed
690+--this is useful for type checking and optimization
691+{-
692+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
693+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
694+ where
695+ relVars = M.map (\rel -> ExistingRelation (Relation (attributes rel) emptyTupleSet)) (relationVariables contextIn)
696+-}
695697
696698liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697699liftE v = do
698700 y <- lift v
699701 case y of
700− Left err -> throwError err
702+ Left err -> throwE err
701703 Right val -> pure val
702704
703705{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
704−predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
705−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
706− expr1v <- predicateRestrictionFilter attrs expr1
707− expr2v <- predicateRestrictionFilter attrs expr2
708− pure (\x -> do
709− ev1 <- expr1v x
710− ev2 <- expr2v x
711− pure (ev1 && ev2))
712−
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714− expr1v <- predicateRestrictionFilter attrs expr1
715− expr2v <- predicateRestrictionFilter attrs expr2
706+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExprBase a -> RelationalExprState (Either RelationalError RestrictionFilter)
707+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
708+ runExceptT $ do
709+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
710+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
711+ pure (\x -> do
712+ ev1 <- expr1v x
713+ ev2 <- expr2v x
714+ pure (ev1 && ev2))
715+
716+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
717+ runExceptT $ do
718+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
719+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716720 pure (\x -> do
717721 ev1 <- expr1v x
718722 ev2 <- expr2v x
719723 pure (ev1 || ev2))
720724
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
725+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
722726
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
724− exprv <- predicateRestrictionFilter attrs expr
725− pure (fmap not . exprv)
727+predicateRestrictionFilter attrs (NotPredicate expr) =
728+ runExceptT $ do
729+ exprv <- liftE (predicateRestrictionFilter attrs expr)
730+ pure (fmap not . exprv)
726731
727732--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
728733predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
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
734+ rstate <- ask
735+ pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
735736 Left err -> Left err
736737 Right rel -> if arity rel /= 0 then
737738 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
738739 else
739− pure (rel == relationTrue))
740+ pure (rel == relationTrue)))
740741
741742predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
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
743+ rstate <- ask
744+ let (attrs', ctxtup') = case rstate of
745+ RelationalExprStateElems _ -> (attrs, emptyTuple)
746+ RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
747+ RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
748+ runExceptT $ do
749+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
750+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747751 Right attr -> Right attr
748752 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749753 Right ctxattr -> Right ctxattr
750754 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751755 Left err -> Left err
752756 Left err -> Left err
753− if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755− else
757+ if atomExprType /= A.atomType attr then
758+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
759+ else
756760 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757761 Right atomCmp -> atomCmp == atomIn
758762 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
763+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
760764 in
761765 pure $ case atomForAttributeName attrName tupleIn of
762766 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,15 +771,16 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
767771-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768772predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769773 --merge attrs into the state attributes
770− renv <- askEnv
771− aType <- typeForGraphRefAtomExpr attrs atomExpr
772− if aType /= BoolAtomType then
773− throwError (AtomTypeMismatchError aType BoolAtomType)
774− else
774+ rstate <- ask
775+ runExceptT $ do
776+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
777+ if aType /= BoolAtomType then
778+ throwE (AtomTypeMismatchError aType BoolAtomType)
779+ else
775780 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777− Left err -> Left err
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
781+ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
782+ Left err -> Left err
783+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
779784
780785tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781786tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
@@ -783,311 +788,249 @@ tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName r
783788 else
784789 Right rel
785790
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788−-- renv <- askEnv
791+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
792+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
793+ rstate <- ask
789794 -- check that the attribute name is not in use
790795 case tupleExprCheckNewAttrName newAttrName relIn of
791− Left err -> throwError err
792− Right _ -> do
793− atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
794− atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
796+ Left err -> pure (Left err)
797+ Right _ -> runExceptT $ do
798+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
799+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795800 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796801 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
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)
802+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
803+ Left err -> Left err
804+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
802805 )
803806
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
807+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
808+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
809+ Right atom -> pure (Right atom)
810+ err@(Left (NoSuchAttributeNamesError _)) -> do
811+ rstate <- ask
812+ case rstate of
813+ RelationalExprStateElems _ -> pure err
814+ RelationalExprStateAttrsElems _ _ -> pure err
815+ RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
816+ Left err -> pure (Left err)
817+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
818+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
819+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
820+ context <- fmap stateElemsContext ask
821+ runExceptT $ do
822+ let functions = atomFunctions context
823+ func <- either throwE pure (atomFunctionForName funcName functions)
824+ let expectedArgCount = length (atomFuncType func) - 1
825+ actualArgCount = length argTypes
826+ safeInit [] = [] -- different behavior from normal init
827+ safeInit xs = init xs
828+ if expectedArgCount /= actualArgCount then
829+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
830+ else do
828831 let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
829− mapM_ (\(expType, actType) ->
830− lift $ except (atomTypeVerify expType actType)) zippedArgs
831− evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
832+ mapM_ (\(expType, eActType) -> do
833+ actType <- either throwE pure eActType
834+ either throwE pure (atomTypeVerify expType actType)) zippedArgs
835+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832836 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
837+ Left err -> throwE (AtomFunctionUserError err)
834838 Right result -> do
835839 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
840+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837841 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
842+evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
839843 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
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
844+ rstate <- ask
845+ runExceptT $ do
846+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
847+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
848+ pure (RelationAtom relAtom)
849+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
850+ rstate <- lift ask
851+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
852+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
853+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
849854 pure (ConstructedAtom dConsName aType argAtoms)
850855
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
856+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
857+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
858+ rstate <- ask
854859 case A.atomTypeForAttributeName attrName attrs of
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
860+ Right aType -> pure (Right aType)
861+ Left err@(NoSuchAttributeNamesError _) -> case rstate of
862+ RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
863+ Left err' -> pure (Left err')
864+ Right attr -> pure (Right (A.atomType attr))
865+ RelationalExprStateElems _ -> pure (Left err)
866+ RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
867+ Left err' -> pure (Left err')
868+ Right atom -> pure (Right (atomTypeForAtom atom))
869+ Left err -> pure (Left err)
870+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
871+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
872+ context <- fmap stateElemsContext ask
873+ let funcs = atomFunctions context
870874 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
875+ Left err -> pure (Left err)
872876 Right func -> do
873877 let funcRetType = last (atomFuncType func)
874878 funcArgTypes = init (atomFuncType func)
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)
879+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
880+ case lefts eArgTypes of
881+ errs@(_:_) -> pure (Left (someErrors errs))
882+ [] -> do
883+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
884+ argTypes = rights eArgTypes
885+ case eTvMap of
886+ Left err -> pure (Left err)
887+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
888+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
889+ rstate <- lift ask
890+ relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
882891 pure (RelationAtomType (attributes relType))
883892-- grab the type of the data constructor, then validate that the args match the expected types
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
893+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
894+ runExceptT $ do
895+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
896+ context <- fmap stateElemsContext (lift ask)
897+ either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
889898
890899-- | Validate that the type of the AtomExpr matches the expected type.
891−verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892−verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893− env <- askEnv
900+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
901+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
902+ rstate <- lift ask
894903 case A.atomTypeForAttributeName attrName (attributes relIn) of
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
904+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
905+ (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
906+ RelationalExprStateTupleElems _ _ -> throwE err
907+ RelationalExprStateElems _ -> throwE err
908+ RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
909+ Left err' -> throwE err'
910+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
911+ Left err -> throwE err
912+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
913+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
914+ rstate <- ask
910915 let functions = atomFunctions context
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)
916+ context = stateElemsContext rstate
917+ runExceptT $ do
918+ func <- either throwE pure (atomFunctionForName funcName functions)
919+ let expectedArgTypes = atomFuncType func
920+ funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
921+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
922+ Left err -> throwE err
923+ Right x -> pure x
924+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
925+ if length funcArgTypes /= length expectedArgTypes - 1 then
926+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
921927 else
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
928+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
929+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
930+ rstate <- lift ask
931+ relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
932+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
933+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
934+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
935+ either throwE pure (atomTypeVerify expectedType cType)
931936
932937-- | Look up the type's name and create a new attribute.
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
938+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
939+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
940+ aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
941+ validateAtomType aType aTypes
942+ Right (Attribute attrName aType)
939943
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
944+evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
945+
946+evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
947+evalTupleExpr mAttrs (TupleExpr tupMap) = do
948+ context <- fmap stateElemsContext ask
949+ runExceptT $ do
992950 -- 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
993951 -- 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
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
952+ let attrs = fromMaybe A.emptyAttributes mAttrs
953+ attrAtoms <- mapM (\(attrName, aExpr) -> do
954+ --provided when the relation header is available
955+ let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
956+ unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
957+ resolvedType <- case eExpectedAtomType of
1001958 Left _ -> pure unresolvedType
1002− Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
959+ Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1003960 --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
961+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
962+ pure (attrName, newAtom, resolvedType)
963+ ) (M.toList tupMap)
964+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
965+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
966+ tup = mkRelationTuple tupAttrs atoms
967+ tConss = typeConstructorMapping context
968+ finalAttrs = fromMaybe tupAttrs mAttrs
1011969 --verify that the attributes match
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
970+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
971+ tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
972+ _ <- either throwE pure (validateTuple tup' tConss)
973+ pure tup'
974+
975+evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
976+evalAttributeNames attrNames expr = do
977+ eExprType <- typeForRelationalExpr expr
978+ case eExprType of
979+ Left err -> pure (Left err)
980+ Right exprTyp -> do
981+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
982+ case attrNames of
983+ AttributeNames names ->
984+ case A.projectionAttributesForNames names (attributes exprTyp) of
985+ Left err -> pure (Left err)
986+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
987+
988+ InvertedAttributeNames names -> do
989+ let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
990+ if not (S.null nonExistentAttributeNames) then
991+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
992+ else
993+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
994+
995+ UnionAttributeNames namesA namesB -> do
996+ eNameSetA <- evalAttributeNames namesA expr
997+ case eNameSetA of
998+ Left err -> pure (Left err)
999+ Right nameSetA -> do
1000+ eNameSetB <- evalAttributeNames namesB expr
1001+ case eNameSetB of
1002+ Left err -> pure (Left err)
1003+ Right nameSetB ->
1004+ pure (Right (S.union nameSetA nameSetB))
1005+
1006+ IntersectAttributeNames namesA namesB -> do
1007+ eNameSetA <- evalAttributeNames namesA expr
1008+ case eNameSetA of
1009+ Left err -> pure (Left err)
1010+ Right nameSetA -> do
1011+ eNameSetB <- evalAttributeNames namesB expr
1012+ case eNameSetB of
1013+ Left err -> pure (Left err)
1014+ Right nameSetB ->
1015+ pure (Right (S.intersection nameSetA nameSetB))
1016+
1017+ RelationalExprAttributeNames attrExpr -> do
1018+ eAttrExprType <- typeForRelationalExpr attrExpr
1019+ case eAttrExprType of
1020+ Left err -> pure (Left err)
1021+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1022+
1023+evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1024+evalGraphRefRelationalExpr (RelationVariable name tid) graph = do
1025+ ctx <- dbContextForTransId tid graph
10361026 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)
1027+ Nothing -> Left (RelVarNotDefinedError name)
1028+ Just rv -> evalGraphRefRelationalExpr rv graph
10861029
10871030dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
10881031dbContextForTransId tid graph = do
10891032 trans <- transactionForId tid graph
1090− pure (concreteDatabaseContext trans)
1033+ pure (concreteDatabaseContext ctx)
10911034
10921035transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
10931036transactionForId tid graph
@@ -1100,293 +1043,113 @@ transactionForId tid graph
11001043 where
11011044 matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
11021045
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
1046+processRestrictionPredicateExpr :: RestrictionPredicateExpr -> RelationalExprState (Either RelationalError GraphRefRestrictionPredicateExpr)
1047+processRestrictionPredicateExpr TruePredicate = TruePredicate
1048+processRestrictionPredicateExpr (AndPredicate a b) = pure $ AndPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1049+processRestrictionPredicateExpr (OrPredicate a b) = OrPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1050+processRestrictionPredicateExpr (NotPredicate a) = pure $ NotPredicate <$> processRestrictionPredicateExpr a
1051+processRestrictionPredicateExpr (RelationalExprPredicate expr) = pure $ RelationalExprPredicate <$> evalRelationalExpr expr
1052+processRestrictionPredicateExpr (AtomExprPredicate expr) = AtomExprPredicate <$> evalAtomExpr expr
1053+processRestrictionPredicateExpr (AttributeEqualityPredicate nam expr) = AttributeEqualityPredicate nam <$> evalAtomExpr expr
1054+
1055+processExtendTupleExpr :: ExtendTupleExpr -> RelationalExprState (Either RelationalError (ExtendTupleExprBase a))
1056+processExtendTupleExpr (AttributeExtendTupleExpr nam atomExpr) = do
1057+ eExpr <- evalAtomExpr atomExpr
1058+ case eExpr of
1059+ Left err -> pure (Left err)
1060+ Right expr -> pure (Right (AttributeExtendTupleExpr nam expr))
1061+
1062+typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1063+typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) _ = mkRelation attrs emptyTupleSet
1064+typeForGraphRefRelationalExpr (ExistingRelation rel) _ = pure (emptyRelationWithAttrs (attributes rel))
1065+typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) graph =
1066+ case mAttrExprs of
1067+ Just attrExprs -> do
1068+ attrs <- mapM (\e -> evalGraphRefAttributeExpr e graph) attrExprs
1069+ pure (emptyRelationWithAttrs attrs)
1070+typeForGraphRefRelationalExpr (RelationVariable rvName tid) graph = do
1071+ trans <- transactionForId tid graph
1072+ let relVars = relationVariables (concreteDatabaseContext trans)
11201073 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')))
1074+ Nothing -> Left $ RelVarNotDefinedError name
1075+ Just rvExpr -> typeForGraphRefRelationalExpr rvExpr graph
1076+typeForGraphRefRelationalExpr (Project attrNames expr) graph = do
1077+ exprType <- typeForGraphRefRelationalExpr expr graph
1078+ projectionAttrs <- evalGraphRefAttributeNames attrNames expr graph
1079+ project projectionAttrs exprType
1080+
1081+evalGraphRefAttributeNames :: AttributeNames -> GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError (S.Set AttributeName)
1082+evalGraphRefAttributeNames attrNames expr graph = do
1083+ exprTyp <- typeForGraphRefRelationalExpr expr graph
1084+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
11751085 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)))
1086+ AttributeNames names ->
1087+ case A.projectionAttributesForNames names (attributes exprTyp) of
1088+ Left err -> pure (Left err)
1089+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
11801090
1181− InvertedAttributeNames names -> do
1091+ InvertedAttributeNames names -> do
11821092 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
11831093 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
1094+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
11851095 else
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
1096+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
11871097
1188− UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
1191− pure (S.union nameSetA nameSetB)
1098+ UnionAttributeNames namesA namesB -> do
1099+ eNameSetA <- evalAttributeNames namesA expr
1100+ case eNameSetA of
1101+ Left err -> pure (Left err)
1102+ Right nameSetA -> do
1103+ eNameSetB <- evalAttributeNames namesB expr
1104+ case eNameSetB of
1105+ Left err -> pure (Left err)
1106+ Right nameSetB ->
1107+ pure (Right (S.union nameSetA nameSetB))
11921108
1193− IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
1196− pure (S.intersection nameSetA nameSetB)
1109+ IntersectAttributeNames namesA namesB -> do
1110+ eNameSetA <- evalAttributeNames namesA expr
1111+ case eNameSetA of
1112+ Left err -> pure (Left err)
1113+ Right nameSetA -> do
1114+ eNameSetB <- evalAttributeNames namesB expr
1115+ case eNameSetB of
1116+ Left err -> pure (Left err)
1117+ Right nameSetB ->
1118+ pure (Right (S.intersection nameSetA nameSetB))
1119+
1120+ RelationalExprAttributeNames attrExpr -> do
1121+ eAttrExprType <- typeForRelationalExpr attrExpr
1122+ case eAttrExprType of
1123+ Left err -> pure (Left err)
1124+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
11971125
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
12731126
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
12831127
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−
1128+
1129+processAtomExpr :: AtomExpr -> TransactionId -> GraphRefAtomExpr
1130+processAtomExpr (AttributeAtomExpr nam) _ = AttributeAtomExpr nam
1131+processAtomExpr (NakedAtomExpr atom) _ = NakedAtomExpr atom
1132+processAtomExpr (FunctionAtomExpr fName atomExprs ()) tid = FunctionAtomExpr fName (fmap processAtomExpr tid) tid
1133+processAtomExpr (RelationAtomExpr expr) tid = RelationAtomExpr (processRelationalExpr expr tid)
1134+processAtomExpr (ConstructedAtomExpr dConsName atomExprs) = ConstructedAtomExpr dConsName (fmap processAtomExpr tid) tid
1135+
1136+processTupleExpr :: TupleExpr -> TransactionId -> GraphRefTupleExpr
1137+processTupleExpr (TupleExpr tMap) tid = TupleExpr (M.map (processAtomExpr tid) tMap)
1138+
1139+evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> TransactionGraph -> Either RelationalError Attribute
1140+evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) graph = do
1141+ trans <- transactionForId tid graph
1142+ let tConsMap = typeConstructorMapping (concreteDatabaseContext trans)
1143+ aType <- atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
1144+ validateAtomType aType tConsMap
1145+ pure (Attribute attrName aType)
1146+
1147+--convert AttributeExpr to GraphRefAttributeExpr
1148+processAttributeExpr :: AttributeExpr -> TransactionId -> GraphRefAttributeExpr
1149+processAttributeExpr (AttributeAndTypeNameExpr nam tCons ()) tid = AttributeAndTypeNameExpr nam tCons tid
1150+processAttributeExpr (NakedAttributeExpr attr) = NakedAttributeExpr attr
1151+
1152+-- convert a RelationalExpr into a GraphRefRelationalExpr
1153+processRelationalExpr :: RelationalExpr -> TransactionId -> GraphRefRelationalExpr
1154+processRelationalExpr (MakeRelationFromExprs mAttrs tupleExprs) =
1155+ MakeRelationFromExprs (fmap (fmap processAttributeExpr) mAttrs) (processTupleExprs tupleExprs)