@@ -1,53 +1,33 @@
1{-# LANGUAGE ScopedTypeVariables #-}
1{-# LANGUAGE ScopedTypeVariables #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FlexibleContexts #-}
4−{-# LANGUAGE OverloadedStrings #-}
5module ProjectM36.RelationalExpression where
2module ProjectM36.RelationalExpression where
6import ProjectM36.Relation
3import ProjectM36.Relation
7import ProjectM36.Tuple
4import ProjectM36.Tuple
8import ProjectM36.TupleSet
5import ProjectM36.TupleSet
9import ProjectM36.Base
6import ProjectM36.Base
10−import qualified Data.UUID as U
11import ProjectM36.Error
7import ProjectM36.Error
12import ProjectM36.AtomType
8import ProjectM36.AtomType
13−import ProjectM36.Attribute (emptyAttributes, attributesFromList)
9+import ProjectM36.Attribute (emptyAttributes)
14import ProjectM36.ScriptSession
10import ProjectM36.ScriptSession
15import ProjectM36.DataTypes.Primitive
11import ProjectM36.DataTypes.Primitive
16import ProjectM36.AtomFunction
12import ProjectM36.AtomFunction
17import ProjectM36.DatabaseContextFunction
13import ProjectM36.DatabaseContextFunction
18−import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
20−import ProjectM36.Transaction
21import qualified ProjectM36.Attribute as A
14import qualified ProjectM36.Attribute as A
22import qualified Data.Map as M
15import qualified Data.Map as M
23import qualified Data.HashSet as HS
16import qualified Data.HashSet as HS
24import qualified Data.Set as S
17import qualified Data.Set as S
25import Control.Monad.State hiding (join)
18import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
19+import Control.Exception
27import Data.Maybe
20import Data.Maybe
28import Data.Either
21import Data.Either
29import Data.Char (isUpper)
22import Data.Char (isUpper)
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
33import qualified Data.Text as T
23import qualified Data.Text as T
34import qualified Data.Vector as V
24import qualified Data.Vector as V
35import qualified ProjectM36.TypeConstructorDef as TCD
25import qualified ProjectM36.TypeConstructorDef as TCD
36−import qualified Control.Monad.RWS.Strict as RWS
26+import Control.Monad.Trans.Except
37−import Control.Monad.RWS.Strict (RWST, execRWST, runRWST)
38−import Control.Monad.Except hiding (join)
39−import Control.Monad.Trans.Except (except)
27+import Control.Monad.Trans.Reader
40−import Control.Monad.Reader as R hiding (join)
28+
41−import ProjectM36.NormalizeExpr
42−import ProjectM36.WithNameExpr
43−import Test.QuickCheck
44−import qualified Data.Functor.Foldable as Fold
45−import Control.Applicative
46−#ifdef PM36_HASKELL_SCRIPTING
47−import GHC hiding (getContext)
29+import GHC
48−import Control.Exception
49import GHC.Paths
30import GHC.Paths
52data DatabaseContextExprDetails = CountUpdatedTuples
32data DatabaseContextExprDetails = CountUpdatedTuples
@@ -64,63 +44,32 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
64 Right ts -> ts
44 Right ts -> ts
66-- | Used to start a fresh database state for a new database context expression.
46-- | Used to start a fresh database state for a new database context expression.
67−mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
47+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
68−mkDatabaseContextEvalState context = DatabaseContextEvalState {
69− dbc_context = context,
72− } --future work: propagate return accumulator
48+freshDatabaseState ctx = (ctx, M.empty, False) --future work: propagate return accumulator
74-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
50-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
75−data RelationalExprEnv = RelationalExprEnv {
51+data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
76− re_context :: DatabaseContext,
52+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
77− re_graph :: TransactionGraph,
53+ RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
78− re_extra :: Maybe (Either RelationTuple Attributes)
54+
79− }
55+instance Show RelationalExprStateElems where
80−
56+ show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
81−envTuple :: GraphRefRelationalExprEnv -> RelationTuple
57+ show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
82−envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
58+ show (RelationalExprStateElems _) = "RelationalExprStateElems"
84−envAttributes :: GraphRefRelationalExprEnv -> Attributes
60+mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
85−envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
61+mkRelationalExprState = RelationalExprStateElems
63+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
64+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
65+mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
66+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
67+ RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
87−instance Show RelationalExprEnv where
69+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
88− show e@RelationalExprEnv{} = "RelationalExprEnv " ++ show (re_extra e)
70+mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
89−
71+mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
90−--used to eval relationalexpr
72+mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
91−type RelationalExprM a = ReaderT RelationalExprEnv (ExceptT RelationalError Identity) a
93−runRelationalExprM :: RelationalExprEnv -> RelationalExprM a -> Either RelationalError a
94−runRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
96−reGraph :: RelationalExprM TransactionGraph
97−reGraph = asks re_graph
99−reContext :: RelationalExprM DatabaseContext
100−reContext = asks re_context
102−mkRelationalExprEnv :: DatabaseContext -> TransactionGraph -> RelationalExprEnv
103−mkRelationalExprEnv ctx graph =
107− re_extra = Nothing }
109−askEnv :: GraphRefRelationalExprM GraphRefRelationalExprEnv
112−mergeTuplesIntoGraphRefRelationalExprEnv :: RelationTuple -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
113−mergeTuplesIntoGraphRefRelationalExprEnv tupIn env =
114− env { gre_extra = new_elems }
116− new_elems = Just (Left newTuple)
117− mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (envTuple env))
118− newTuple = mkRelationTupleFromMap mergedTupMap
120−mergeAttributesIntoGraphRefRelationalExprEnv :: Attributes -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
121−mergeAttributesIntoGraphRefRelationalExprEnv attrsIn e = e { gre_extra = newattrs }
123− newattrs = Just (Right (A.union attrsIn (envAttributes e)))
125type ResultAccumName = StringType
74type ResultAccumName = StringType
@@ -130,403 +79,422 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
130 resultAccumResult :: Relation
79 resultAccumResult :: Relation
133−data DatabaseContextEvalState = DatabaseContextEvalState {
134− dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135− dbc_accum :: M.Map ResultAccumName ResultAccum,
82+type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
136− dbc_dirty :: DirtyFlag
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
84+type DatabaseState a = State DatabaseStateElems a
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
144−mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
86+getStateContext :: DatabaseState DatabaseContext
145−mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
87+getStateContext = do
146−
88+ (ctx,_, _) <- get
147−type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
89+ pure ctx
149−runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
91+putStateContext :: DatabaseContext -> DatabaseState ()
150−runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
92+putStateContext ctx = do
151− where
93+ (_, accum, _) <- get
152− freshEnv = mkDatabaseContextEvalState ctx
94+ put (ctx, accum, True)
96+type RelationalExprState a = Reader RelationalExprStateElems a
98+stateElemsContext :: RelationalExprStateElems -> DatabaseContext
99+stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
100+stateElemsContext (RelationalExprStateElems ctx) = ctx
101+stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
103+setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
104+setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
105+setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
106+setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
108+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
109+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
110+evalRelationalExpr (RelationVariable name _) = do
111+ relvarTable <- fmap (relationVariables . stateElemsContext) ask
112+ return $ case M.lookup name relvarTable of
113+ Just res -> Right res
114+ Nothing -> Left $ RelVarNotDefinedError name
116+evalRelationalExpr (Project attrNames expr) = do
117+ eAttrNameSet <- evalAttributeNames attrNames expr
118+ case eAttrNameSet of
119+ Left err -> pure (Left err)
120+ Right attrNameSet -> do
121+ rel <- evalRelationalExpr expr
123+ Right rel2 -> pure $ project attrNameSet rel2
124+ Left err -> pure $ Left err
126+evalRelationalExpr (Union exprA exprB) = do
127+ relA <- evalRelationalExpr exprA
128+ relB <- evalRelationalExpr exprB
130+ Left err -> return $ Left err
131+ Right relA2 -> case relB of
132+ Left err -> return $ Left err
133+ Right relB2 -> return $ union relA2 relB2
135+evalRelationalExpr (Join exprA exprB) = do
136+ relA <- evalRelationalExpr exprA
137+ relB <- evalRelationalExpr exprB
139+ Left err -> return $ Left err
140+ Right relA2 -> case relB of
141+ Left err -> return $ Left err
142+ Right relB2 -> return $ join relA2 relB2
144+evalRelationalExpr (Difference exprA exprB) = do
145+ relA <- evalRelationalExpr exprA
146+ relB <- evalRelationalExpr exprB
148+ Left err -> return $ Left err
149+ Right relA2 -> case relB of
150+ Left err -> return $ Left err
151+ Right relB2 -> return $ difference relA2 relB2
153+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
154+ case mkRelation attributeSet tupleSet of
155+ Right rel -> return $ Right rel
156+ Left err -> return $ Left err
154−
158+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
155−dbcTransId :: DatabaseContextEvalMonad TransactionId
159+ currentContext <- fmap stateElemsContext ask
156−dbcTransId = dce_transId <$> RWS.ask
160+ let tConss = typeConstructorMapping currentContext
157−
161+ -- 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
158−dbcGraph :: DatabaseContextEvalMonad TransactionGraph
162+ runExceptT $ do
159−dbcGraph = dce_graph <$> RWS.ask
163+ mAttrs <- case mAttrExprs of
161−dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
165+ Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
162−dbcRelationalExprEnv =
166+ Nothing -> pure Nothing
163− mkRelationalExprEnv <$> getStateContext <*> dbcGraph
167+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
164−
168+ let attrs = fromMaybe firstTupleAttrs mAttrs
165−getStateContext :: DatabaseContextEvalMonad DatabaseContext
169+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
166−getStateContext = gets dbc_context
170+ either throwE pure (mkRelation attrs (RelationTupleSet tuples))
168−putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
169−putStateContext ctx' = do
171− put (s {dbc_context = ctx', dbc_dirty = True})
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)
181−type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
172+evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
183−gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184−gfTransForId tid = do
186− lift $ except $ transactionForId tid graph
188−gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189−gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190−gfDatabaseContextForMarker UncommittedContextMarker = do
191− mctx <- gre_context <$> askEnv
193− Nothing -> throwError NoUncommittedContextInEvalError
194− Just ctx -> pure ctx
196−runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197−runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
199−freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200−freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
206−gfGraph :: GraphRefRelationalExprM TransactionGraph
174+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
207−gfGraph = asks gre_graph
175+ evald <- evalRelationalExpr relExpr
177+ Right rel -> return $ rename oldAttrName newAttrName rel
178+ Left err -> return $ Left err
209−envContext :: RelationalExprEnv -> DatabaseContext
180+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
210−envContext = re_context
181+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
211−
182+ case eOldAttrNameSet of
212−setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
183+ Left err -> pure (Left err)
213−setEnvContext e ctx = e { re_context = ctx }
184+ Right oldAttrNameSet -> do
185+ evald <- evalRelationalExpr relExpr
187+ Right rel -> return $ group oldAttrNameSet newAttrName rel
188+ Left err -> return $ Left err
190+evalRelationalExpr (Ungroup attrName relExpr) = do
191+ evald <- evalRelationalExpr relExpr
193+ Right rel -> return $ ungroup attrName rel
194+ Left err -> return $ Left err
196+evalRelationalExpr (Restrict predicateExpr relExpr) = do
197+ evald <- evalRelationalExpr relExpr
199+ Left err -> return $ Left err
201+ eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
203+ Left err -> return $ Left err
205+ pure (restrict filterfunc rel)
207+evalRelationalExpr (Equals relExprA relExprB) = do
208+ evaldA <- evalRelationalExpr relExprA
209+ evaldB <- evalRelationalExpr relExprB
211+ Left err -> return $ Left err
212+ Right relA -> case evaldB of
213+ Left err -> return $ Left err
214+ Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
216+--warning: copy-pasta from above- refactor
217+evalRelationalExpr (NotEquals relExprA relExprB) = do
218+ evaldA <- evalRelationalExpr relExprA
219+ evaldB <- evalRelationalExpr relExprB
221+ Left err -> return $ Left err
222+ Right relA -> case evaldB of
223+ Left err -> return $ Left err
224+ Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
226+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
227+evalRelationalExpr (Extend tupleExpression relExpr) = do
229+ let evald = runReader (evalRelationalExpr relExpr) rstate
231+ Left err -> pure (Left err)
233+ tupProc <- extendTupleExpressionProcessor rel tupleExpression
235+ Left err -> pure (Left err)
236+ Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
215--helper function to process relation variable creation/assignment
238--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
239+setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
217−setRelVar relVarName relExpr = do
240+setRelVar relVarName rel = do
218 currentContext <- getStateContext
241 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
242+ let newRelVars = M.insert relVarName rel $ relationVariables currentContext
222 potentialContext = currentContext { relationVariables = newRelVars }
243 potentialContext = currentContext { relationVariables = newRelVars }
223− --optimization: if the relexpr is unchanged, skip the update
244+
224− if M.lookup relVarName (relationVariables currentContext) == Just relExpr then
227− --determine when to check constraints
230− case checkConstraints potentialContext tid graph of
245+ case checkConstraints potentialContext of
231− Left err -> dbErr err
246+ Left err -> pure (Left err)
232− Right _ -> putStateContext potentialContext
248+ putStateContext potentialContext
233−
249+ return (Right ())
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 ()
237-- 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
251-- 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 ()
252+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239deleteRelVar relVarName = do
253deleteRelVar relVarName = do
240 currContext <- getStateContext
254 currContext <- getStateContext
241 let relVars = relationVariables currContext
255 let relVars = relationVariables currContext
242 if M.notMember relVarName relVars then
256 if M.notMember relVarName relVars then
243− pure ()
257+ pure (Right ())
245 let newRelVars = M.delete relVarName relVars
259 let newRelVars = M.delete relVarName relVars
246 newContext = currContext { relationVariables = newRelVars }
260 newContext = currContext { relationVariables = newRelVars }
247 putStateContext newContext
261 putStateContext newContext
248− pure ()
262+ pure (Right ())
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
264+evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
265+evalDatabaseContextExpr NoOperation = pure (Right ())
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
267+evalDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
255 relvars <- fmap relationVariables getStateContext
268 relvars <- fmap relationVariables getStateContext
256 tConss <- fmap typeConstructorMapping getStateContext
269 tConss <- fmap typeConstructorMapping getStateContext
257− graph <- dbcGraph
270+ let eAttrs = map (evalAttrExpr tConss) attrExprs
258− let eAttrs = runGraphRefRelationalExprM gfEnv (mapM evalGraphRefAttrExpr attrExprs)
259− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
260− case eAttrs of
271+ case lefts eAttrs of
261− Left err -> dbErr err
272+ err:_ -> pure (Left err)
262− Right attrsList -> do
263− lift $ except $ validateAttributes tConss (A.attributesFromList attrsList)
264− case M.member relVarName relvars of
273+ [] -> case M.member relVarName relvars of
265− True -> dbErr (RelVarAlreadyDefinedError relVarName)
274+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
266− False -> setRelVar relVarName (ExistingRelation emptyRelation)
275+ False -> setRelVar relVarName emptyRelation >> pure (Right ())
268− attrs = A.attributesFromList attrsList
277+ attrs = A.attributesFromList (rights eAttrs)
269− emptyRelation = Relation attrs emptyTupleSet
278+ emptyRelation = Relation attrs emptyTupleSet
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
280+evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
282+evalDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
283+ -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
275 context <- getStateContext
284 context <- getStateContext
276− let existingRelVar = M.lookup relVarName (relationVariables context)
285+ let existingRelVar = M.lookup relVarName relVarTable
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
286+ relVarTable = relationVariables context
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
287+ value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
289+ Left err -> pure (Left err)
279− case existingRelVar of
290+ Right rel -> case existingRelVar of
281− case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282− Left err -> dbErr err
284− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285− setRelVar relVarName expr
291+ Nothing -> setRelVar relVarName rel
286− Just existingRel -> do
292+ Just existingRel -> let expectedAttributes = attributes existingRel
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
293+ foundAttributes = attributes rel in
288− case eExpectedType of
294+ if A.attributesEqual expectedAttributes foundAttributes then
289− Left err -> dbErr err
290− Right expectedType ->
291− case eNewExprType of
292− Left err -> dbErr err
293− Right newExprType -> do
294− if newExprType == expectedType then do
295− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296− setRelVar relVarName expr
295+ setRelVar relVarName rel
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
297+ pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
300−evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
299+evalDatabaseContextExpr (Insert relVarName relExpr) = do
301− gfExpr <- relVarByName relVarName
300+ context <- getStateContext
302− let optExpr = applyUnionCollapse (Union
301+ let unionexp = Union relExpr rv
303− relExpr
302+ rv = RelationVariable relVarName ()
304− gfExpr)
303+ unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
305− evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
304+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
306+ Left err -> pure (Left err)
307+ Right unioned' -> case origRel of
308+ Left err -> pure (Left err)
309+ Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
312+ evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
314+evalDatabaseContextExpr (Delete relVarName predicate) = do
315+ context <- getStateContext
316+ let rv = RelationVariable relVarName ()
317+ let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
318+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
320+ Left err -> pure (Left err)
321+ Right updatedRel' -> case origRel of
322+ Left err -> pure (Left err)
323+ Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
326+ setRelVar relVarName updatedRel'
307−evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308− gfExpr <- relVarByName relVarName
309− let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310− setRelVar relVarName optExpr
312--union of restricted+updated portion and the unrestricted+unupdated portion
328--union of restricted+updated portion and the unrestricted+unupdated portion
313−evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
329+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
314− rvExpr <- relVarByName relVarName
315− graph <- re_graph <$> dbcRelationalExprEnv
316 context <- getStateContext
330 context <- getStateContext
317− let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
331+ let relVarTable = relationVariables context
318− --get the current attributes name in the relvar to ensure that we don't conflict when renaming
332+ case M.lookup relVarName relVarTable of
319− eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
333+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
320− exprType' <- case eExprType of
334+ Just rel ->
321− Left err -> throwError err
335+ case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
322− Right t -> pure t
336+ Left err -> pure (Left err)
323− let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
337+ Right predicateFunc -> do
324− tmpAttr = tmpAttrC 1
338+ let ret = do
325− tmpAttrC :: Int -> AttributeName -> AttributeName
339+ restrictedPortion <- restrict predicateFunc rel
326− tmpAttrC c attr =
340+ if cardinality restrictedPortion == Finite 0 then
327− let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
341+ pure Nothing
328− if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
331− tmpAttrName
343+ unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
332− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
344+ updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
333− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
345+ updatedRel <- updatedPortion `union` unrestrictedPortion
334− restrictedPortion = Restrict pred' rvExpr
346+ pure (Just updatedRel)
335− updated = foldr (\(oldname, atomExpr) accum ->
347+ case ret of
336− let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
348+ Left err -> pure (Left err)
337− updateAttr oldname procAtomExpr accum
349+ Right Nothing -> pure (Right ())
338− ) restrictedPortion (M.toList atomExprMap)
350+ Right (Just updatedRel) -> setRelVar relVarName updatedRel
339− -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
340− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341− setRelVar relVarName (Union unrestrictedPortion updatedPortion)
343−evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
352+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
344 currContext <- getStateContext
353 currContext <- getStateContext
345− transId <- dbcTransId
347 let currDeps = inclusionDependencies currContext
354 let currDeps = inclusionDependencies currContext
348 newDeps = M.insert newDepName newDep currDeps
355 newDeps = M.insert newDepName newDep currDeps
349 if M.member newDepName currDeps then
356 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
357+ pure (Left (InclusionDependencyNameInUseError newDepName))
352 let potentialContext = currContext { inclusionDependencies = newDeps }
359 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
355− case checkConstraints potentialContext transId graph of
360+ case checkConstraints potentialContext of
356− Left err -> dbErr err
361+ Left err -> pure (Left err)
357− Right _ ->
362+ Right _ -> do
358 putStateContext potentialContext
363 putStateContext potentialContext
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
366+evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
361 currContext <- getStateContext
367 currContext <- getStateContext
362 let currDeps = inclusionDependencies currContext
368 let currDeps = inclusionDependencies currContext
363 newDeps = M.delete depName currDeps
369 newDeps = M.delete depName currDeps
364 if M.notMember depName currDeps then
370 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
371+ pure (Left (InclusionDependencyNameNotInUseError depName))
367 putStateContext $ currContext {inclusionDependencies = newDeps }
373 putStateContext $ currContext {inclusionDependencies = newDeps }
369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
376-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
377+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
371 currentContext <- getStateContext
378 currentContext <- getStateContext
372 let nots = notifications currentContext
379 let nots = notifications currentContext
373 if M.member notName nots then
380 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
381+ pure (Left (NotificationNameInUseError notName))
376 let newNotifications = M.insert notName newNotification nots
383 let newNotifications = M.insert notName newNotification nots
377 newNotification = Notification { changeExpr = triggerExpr,
384 newNotification = Notification { changeExpr = triggerExpr,
378 reportOldExpr = resultOldExpr,
385 reportOldExpr = resultOldExpr,
379 reportNewExpr = resultNewExpr}
386 reportNewExpr = resultNewExpr}
380 putStateContext $ currentContext { notifications = newNotifications }
387 putStateContext $ currentContext { notifications = newNotifications }
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
390+evalDatabaseContextExpr (RemoveNotification notName) = do
383 currentContext <- getStateContext
391 currentContext <- getStateContext
384 let nots = notifications currentContext
392 let nots = notifications currentContext
385 if M.notMember notName nots then
393 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
394+ pure (Left (NotificationNameNotInUseError notName))
388 let newNotifications = M.delete notName nots
396 let newNotifications = M.delete notName nots
389 putStateContext $ currentContext { notifications = newNotifications }
397 putStateContext $ currentContext { notifications = newNotifications }
392-- | Adds type and data constructors to the database context.
400-- | Adds type and data constructors to the database context.
393-- validate that the type *and* constructor names are unique! not yet implemented!
401-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
402+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
395 currentContext <- getStateContext
403 currentContext <- getStateContext
396 let oldTypes = typeConstructorMapping currentContext
404 let oldTypes = typeConstructorMapping currentContext
397 tConsName = TCD.name tConsDef
405 tConsName = TCD.name tConsDef
398 -- validate that the constructor's types exist
406 -- validate that the constructor's types exist
399− case validateTypeConstructorDef tConsDef dConsDefList oldTypes of
407+ case validateTypeConstructorDef tConsDef dConsDefList of
400− Left err -> throwError err
408+ errs@(_:_) -> pure (Left (someErrors errs))
401− Right () | T.null tConsName || not (isUpper (T.head tConsName)) -> dbErr (InvalidAtomTypeName tConsName)
409+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
402− | isJust (findTypeConstructor tConsName oldTypes) -> dbErr (AtomTypeNameInUseError tConsName)
410+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403 | otherwise -> do
411 | otherwise -> do
404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
412 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
413 putStateContext $ currentContext { typeConstructorMapping = newTypes }
407-- | 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.
416-- | 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
417+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
409 currentContext <- getStateContext
418 currentContext <- getStateContext
410 let oldTypes = typeConstructorMapping currentContext
419 let oldTypes = typeConstructorMapping currentContext
411 if isNothing (findTypeConstructor tConsName oldTypes) then
420 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
421+ pure (Left (AtomTypeNameNotInUseError tConsName))
414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
423 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
424 putStateContext $ currentContext { typeConstructorMapping = newTypes }
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
427+evalDatabaseContextExpr (MultipleExpr exprs) = do
418 --the multiple expressions must pass the same context around- not the old unmodified context
428 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
429+ evald <- forM exprs evalDatabaseContextExpr
420−
430+ --some lifting magic needed here
432+ [] -> pure (Right ())
433+ errs -> pure (Left (someErrors errs))
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
435+evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
422 currentContext <- getStateContext
436 currentContext <- getStateContext
423 let atomFuncs = atomFunctions currentContext
437 let atomFuncs = atomFunctions currentContext
424 case atomFunctionForName funcName atomFuncs of
438 case atomFunctionForName funcName atomFuncs of
425− Left err -> dbErr err
439+ Left err -> pure (Left err)
427− if isScriptedAtomFunction realFunc then do
440+ Right realFunc -> if isScriptedAtomFunction realFunc then do
428− let updatedFuncs = HS.delete realFunc atomFuncs
441+ let updatedFuncs = HS.delete realFunc atomFuncs
429− putStateContext (currentContext {atomFunctions = updatedFuncs })
442+ putStateContext (currentContext {atomFunctions = updatedFuncs })
431− dbErr (PrecompiledFunctionRemoveError funcName)
445+ pure (Left (PrecompiledFunctionRemoveError funcName))
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
447+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
434 context <- getStateContext
448 context <- getStateContext
435 let dbcFuncs = dbcFunctions context
449 let dbcFuncs = dbcFunctions context
436 case databaseContextFunctionForName funcName dbcFuncs of
450 case databaseContextFunctionForName funcName dbcFuncs of
437− Left err -> dbErr err
451+ Left err -> pure (Left err)
439− if isScriptedDatabaseContextFunction realFunc then do
452+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
440− let updatedFuncs = HS.delete realFunc dbcFuncs
453+ let updatedFuncs = HS.delete realFunc dbcFuncs
441− putStateContext (context { dbcFunctions = updatedFuncs })
454+ putStateContext (context { dbcFunctions = updatedFuncs })
443− dbErr (PrecompiledFunctionRemoveError funcName)
457+ pure (Left (PrecompiledFunctionRemoveError funcName))
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
459+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
446 context <- getStateContext
460 context <- getStateContext
448 --resolve atom arguments
461 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
462+ let relExprState = mkRelationalExprState context
463+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
464 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452 case eFunc of
465 case eFunc of
453− Left err -> dbErr err
466+ Left err -> pure (Left err)
454 Right func -> do
467 Right func -> do
455 let expectedArgCount = length (dbcFuncType func)
468 let expectedArgCount = length (dbcFuncType func)
456 actualArgCount = length atomArgExprs
469 actualArgCount = length atomArgExprs
457 if expectedArgCount /= actualArgCount then
470 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
471+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
460 --check that the atom types are valid
473 --check that the atom types are valid
461− case eAtomTypes of
474+ case lefts eAtomTypes of
462− Left err -> dbErr err
475+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
463− Right atomTypes -> do
476+ [] -> do
464− let mValidTypes = zipWith (\ expType actType
477+ let atomTypes = rights eAtomTypes
465− -> case atomTypeVerify expType actType of
478+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
466− Left err -> Just err
479+ Left err -> Just err
468− (dbcFuncType func) atomTypes
480+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
469− typeErrors = catMaybes mValidTypes
481+ typeErrors = catMaybes mValidTypes
470− eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
482+ eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471 if length (lefts eAtomArgs) > 1 then
483 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
484+ pure (Left (someErrors (lefts eAtomArgs)))
473 else if not (null typeErrors) then
485 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
486+ pure (Left (someErrors typeErrors))
476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
488 case evalDatabaseContextFunction func (rights eAtomArgs) context of
477− Left err -> dbErr err
489+ Left err -> pure (Left err)
478− Right newContext -> putStateContext newContext
490+ Right newContext -> putStateContext newContext >> pure (Right ())
479−data DatabaseContextIOEvalEnv = DatabaseContextIOEvalEnv
491+
480− { dbcio_transId :: TransactionId,
492+evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
481− dbcio_graph :: TransactionGraph,
482− dbcio_mScriptSession :: Maybe ScriptSession
485−type DatabaseContextIOEvalMonad a = RWST DatabaseContextIOEvalEnv () DatabaseContextEvalState IO a
487−runDatabaseContextIOEvalMonad :: DatabaseContextIOEvalEnv -> DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ()) -> IO (Either RelationalError DatabaseContextEvalState)
488−runDatabaseContextIOEvalMonad env ctx m = do
489− res <- runRWST m env freshState
491− (Left err,_,_) -> pure (Left err)
492− (Right (),s,_) -> pure (Right s)
494− freshState = mkDatabaseContextEvalState ctx
496−requireScriptSession :: DatabaseContextIOEvalMonad (Either RelationalError ScriptSession)
497−requireScriptSession = do
499− case dbcio_mScriptSession env of
500− Nothing -> pure $ Left $ ScriptError ScriptCompilationDisabledError
501− Just ss -> pure (Right ss)
503−putDBCIOContext :: DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ())
504−putDBCIOContext ctx = do
505− RWS.modify (\dbstate -> dbstate { dbc_context = ctx})
508−getDBCIOContext :: DatabaseContextIOEvalMonad DatabaseContext
509−getDBCIOContext = dbc_context <$> RWS.get
511−getDBCIORelationalExprEnv :: DatabaseContextIOEvalMonad RelationalExprEnv
512−getDBCIORelationalExprEnv = do
513− context <- getDBCIOContext
514− mkRelationalExprEnv context . dbcio_graph <$> RWS.ask
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))
523−evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = do
493+evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
524− eScriptSession <- requireScriptSession
494+ case mScriptSession of
525− currentContext <- getDBCIOContext
495+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
526− case eScriptSession of
527− Left err -> pure (Left err)
528− Right scriptSession -> do
496+ Just scriptSession -> do
529− res <- liftIO $ try $ runGhc (Just libdir) $ do
497+ res <- try $ runGhc (Just libdir) $ do
530 setSession (hscEnv scriptSession)
498 setSession (hscEnv scriptSession)
531 let atomFuncs = atomFunctions currentContext
499 let atomFuncs = atomFunctions currentContext
532 case extractAtomFunctionType funcType of
500 case extractAtomFunctionType funcType of
@@ -537,7 +505,7 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
537 pure $ case eCompiledFunc of
505 pure $ case eCompiledFunc of
538 Left err -> Left (ScriptError err)
506 Left err -> Left (ScriptError err)
539 Right compiledFunc -> do
507 Right compiledFunc -> do
540− funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructorValidate False funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
508+ funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructor funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
541 let updatedFuncs = HS.insert newAtomFunc atomFuncs
509 let updatedFuncs = HS.insert newAtomFunc atomFuncs
542 newContext = currentContext { atomFunctions = updatedFuncs }
510 newContext = currentContext { atomFunctions = updatedFuncs }
543 newAtomFunc = AtomFunction { atomFuncName = funcName,
511 newAtomFunc = AtomFunction { atomFuncName = funcName,
@@ -552,13 +520,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
520 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553 Right eContext -> case eContext of
521 Right eContext -> case eContext of
554 Left err -> pure (Left err)
522 Left err -> pure (Left err)
555− Right context' -> putDBCIOContext context'
523+ Right context' -> pure (Right context')
556−evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType script) = do
525+evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
557− eScriptSession <- requireScriptSession
526+ case mScriptSession of
558− currentContext <- getDBCIOContext
527+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
559− case eScriptSession of
560− Left err -> pure (Left err)
561− Right scriptSession -> do
528+ Just scriptSession -> do
562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
529 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563 let last2Args = reverse (take 2 (reverse funcType))
530 let last2Args = reverse (take 2 (reverse funcType))
564 atomArgs = take (length funcType - 2) funcType
531 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +535,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
535 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
536 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
538+ res <- try $ runGhc (Just libdir) $ do
572 setSession (hscEnv scriptSession)
539 setSession (hscEnv scriptSession)
573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
540 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574 pure $ case eCompiledFunc of
541 pure $ case eCompiledFunc of
@@ -593,86 +560,47 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
560 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594 Right eContext -> case eContext of
561 Right eContext -> case eContext of
595 Left err -> pure (Left err)
562 Left err -> pure (Left err)
596− Right context' -> putDBCIOContext context'
563+ Right context' -> pure (Right context')
597−evalGraphRefDatabaseContextIOExpr (LoadAtomFunctions modName funcName modPath) = do
564+evalDatabaseContextIOExpr _ currentContext (LoadAtomFunctions modName funcName modPath) = do
598− currentContext <- getDBCIOContext
599− eLoadFunc <- liftIO $ loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
565+ eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600 case eLoadFunc of
566 case eLoadFunc of
601 Left LoadSymbolError -> pure (Left LoadFunctionError)
567 Left LoadSymbolError -> pure (Left LoadFunctionError)
602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
568 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
569 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
604− in putDBCIOContext newContext
570+ in pure (Right newContext)
605−evalGraphRefDatabaseContextIOExpr (LoadDatabaseContextFunctions modName funcName modPath) = do
571+evalDatabaseContextIOExpr _ currentContext (LoadDatabaseContextFunctions modName funcName modPath) = do
606− currentContext <- getDBCIOContext
607− eLoadFunc <- liftIO $ loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
572+ eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608 case eLoadFunc of
573 case eLoadFunc of
609 Left LoadSymbolError -> pure (Left LoadFunctionError)
574 Left LoadSymbolError -> pure (Left LoadFunctionError)
610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
575 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
576 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
577+ in pure (Right newContext)
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
579+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
615− --Define
580+updateTupleWithAtomExprs exprMap context tupIn = do
616− currentContext <- getDBCIOContext
581+ --resolve all atom exprs
617− env <- RWS.ask
582+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
618− --create graph ref expr
583+ atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
619− let gfExpr = Define relVarName attrExprs
584+ pure (attrName, atom)
620− evalEnv = mkDatabaseContextEvalEnv (dbcio_transId env) (dbcio_graph env)
585+ ) (M.toList exprMap)
621− graph = dbcio_graph env
586+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
622− case runDatabaseContextEvalMonad currentContext evalEnv (evalGraphRefDatabaseContextExpr gfExpr) of
623− Left err -> pure (Left err)
626− let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
628− case existingRelVar of
629− Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630− Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633− Left err -> pure (Left err)
635− let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
639− Left err -> pure $ Left err
641− case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642− Left err -> pure (Left err)
643− Right dbstate' -> putDBCIOContext (dbc_context dbstate')
645--run verification on all constraints
588--run verification on all constraints
646−checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
589+checkConstraints :: DatabaseContext -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
590+checkConstraints context = do
648 mapM_ (uncurry checkIncDep) (M.toList deps)
591 mapM_ (uncurry checkIncDep) (M.toList deps)
650− potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
651− tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
652− utctDayTime = secondsToDiffTime 0 }
653− tempSchemas = Schemas context M.empty
654− tempTrans = Transaction U.nil tempTransInfo tempSchemas
655− tempTransInfo = TransactionInfo { parents = transId NE.:| [],
660 deps = inclusionDependencies context
594 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
595+ eval expr = evalReader (evalRelationalExpr expr)
596+ evalReader f = runReader f (RelationalExprStateElems context)
662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
597 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663− let process = runProcessExprM UncommittedContextMarker
664− gfSubsetExpr = process (processRelationalExpr subsetExpr)
665− gfSupersetExpr = process (processRelationalExpr supersetExpr)
666 --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.
598 --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
599+ typeSub <- evalReader (typeForRelationalExpr subsetExpr)
668− runGfRel = runGraphRefRelationalExprM gfEnv
600+ typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
669− typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670− typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
601 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672− let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
602+ let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
603+ case eval checkExpr of
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
676 Left err -> Left err
604 Left err -> Left err
677 Right resultRel -> if resultRel == relationTrue then
605 Right resultRel -> if resultRel == relationTrue then
@@ -682,81 +610,88 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
682-- 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
610-- 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
683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
611-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
613+typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
686typeForRelationalExpr expr = do
614typeForRelationalExpr expr = do
616+ let context = stateElemsContext rstate
687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
617 --replace the relationVariables context element with a cloned set of relation devoid of tuples
688− --evalRelationalExpr could still return an existing relation with tuples, so strip them
618+ let context' = contextWithEmptyTupleSets context
689− graph <- reGraph
619+ rstate' = setStateElemsContext rstate context'
690− context <- reContext
620+ pure (runReader (evalRelationalExpr expr) rstate')
691− let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
621+
692− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
622+--returns a database context with all tuples removed
693− runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
623+--this is useful for type checking and optimization
694− lift $ except runGf
624+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
625+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
627+ relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
629liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697liftE v = do
630liftE v = do
698 y <- lift v
631 y <- lift v
699 case y of
632 case y of
700− Left err -> throwError err
633+ Left err -> throwE err
701 Right val -> pure val
634 Right val -> pure val
703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
636{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
704−predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
637+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
705−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
638+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
706− expr1v <- predicateRestrictionFilter attrs expr1
640+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
707− expr2v <- predicateRestrictionFilter attrs expr2
641+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
708− pure (\x -> do
642+ pure (\x -> do
709− ev1 <- expr1v x
643+ ev1 <- expr1v x
710− ev2 <- expr2v x
644+ ev2 <- expr2v x
711− pure (ev1 && ev2))
645+ pure (ev1 && ev2))
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
647+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
714− expr1v <- predicateRestrictionFilter attrs expr1
649+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
715− expr2v <- predicateRestrictionFilter attrs expr2
650+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716 pure (\x -> do
651 pure (\x -> do
717 ev1 <- expr1v x
652 ev1 <- expr1v x
718 ev2 <- expr2v x
653 ev2 <- expr2v x
719 pure (ev1 || ev2))
654 pure (ev1 || ev2))
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
656+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
658+predicateRestrictionFilter attrs (NotPredicate expr) =
724− exprv <- predicateRestrictionFilter attrs expr
660+ exprv <- liftE (predicateRestrictionFilter attrs expr)
725− pure (fmap not . exprv)
661+ pure (fmap not . exprv)
727--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
663--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
728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
664predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
729− renv <- askEnv
665+ rstate <- ask
730− let eval :: RelationTuple -> Either RelationalError Relation
666+ pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
732− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup renv in
733− runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
734− pure (\tup -> case eval tup of
735 Left err -> Left err
667 Left err -> Left err
736 Right rel -> if arity rel /= 0 then
668 Right rel -> if arity rel /= 0 then
737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
669 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
739− pure (rel == relationTrue))
671+ pure (rel == relationTrue)))
741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
673predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
742− env <- askEnv
674+ rstate <- ask
743− let attrs' = A.union attrs (envAttributes env)
675+ let (attrs', ctxtup') = case rstate of
744− ctxtup' = envTuple env
676+ RelationalExprStateElems _ -> (attrs, emptyTuple)
677+ RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
678+ RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
745− atomExprType <- typeForGraphRefAtomExpr attrs' atomExpr
680+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
746− attr <- lift $ except $ case A.attributeForName attrName attrs of
681+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747 Right attr -> Right attr
682 Right attr -> Right attr
748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
683 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749 Right ctxattr -> Right ctxattr
684 Right ctxattr -> Right ctxattr
750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
685 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751 Left err -> Left err
686 Left err -> Left err
752 Left err -> Left err
687 Left err -> Left err
753− if atomExprType /= A.atomType attr then
688+ if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
689+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
691 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757 Right atomCmp -> atomCmp == atomIn
692 Right atomCmp -> atomCmp == atomIn
758 Left _ -> False
693 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
694+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
761 pure $ case atomForAttributeName attrName tupleIn of
696 pure $ case atomForAttributeName attrName tupleIn of
762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
697 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,626 +702,243 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
702-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
703predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769 --merge attrs into the state attributes
704 --merge attrs into the state attributes
770− renv <- askEnv
705+ rstate <- ask
771− aType <- typeForGraphRefAtomExpr attrs atomExpr
707+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
772− if aType /= BoolAtomType then
708+ if aType /= BoolAtomType then
773− throwError (AtomTypeMismatchError aType BoolAtomType)
709+ throwE (AtomTypeMismatchError aType BoolAtomType)
775 pure (\tupleIn ->
711 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
712+ pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
777− Left err -> Left err
713+ Left _ -> False
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
714+ Right boolAtomValue -> boolAtomValue == BoolAtom True)
780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
716tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
717tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
782− Left (AttributeNameInUseError attrName)
718+ Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
784 Right rel
720 Right rel
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
722+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
723+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
788−-- renv <- askEnv
724+ rstate <- ask
789 -- check that the attribute name is not in use
725 -- check that the attribute name is not in use
790 case tupleExprCheckNewAttrName newAttrName relIn of
726 case tupleExprCheckNewAttrName newAttrName relIn of
791− Left err -> throwError err
727+ Left err -> pure (Left err)
792− Right _ -> do
728+ Right _ -> runExceptT $ do
793− atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
729+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
794− atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
730+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
731 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
732 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
797− env <- ask
733+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
798− pure (newAndOldAttrs, \tup -> do
734+ Left err -> Left err
799− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup env
800− atom <- runGraphRefRelationalExprM gfEnv (evalGraphRefAtomExpr tup atomExpr)
801− Right (tupleAtomExtend newAttrName atom tup)
735+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
804−evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
738+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
805−evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806− case atomForAttributeName attrName tupIn of
739+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
807− Right atom -> pure atom
740+ Right atom -> pure (Right atom)
808− Left err@(NoSuchAttributeNamesError _) -> do
741+ err@(Left (NoSuchAttributeNamesError _)) -> do
809− env <- askEnv
742+ rstate <- ask
810− case gre_extra env of
743+ case rstate of
811− Nothing -> throwError err
744+ RelationalExprStateElems _ -> pure err
745+ RelationalExprStateAttrsElems _ _ -> pure err
812− Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
746+ RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
813− Just (Right _) -> throwError err
814− Left err -> throwError err
747+ Left err -> pure (Left err)
815−evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
748+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
816−evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
749+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
817− argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
750+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
818− context <- gfDatabaseContextForMarker tid
751+ context <- fmap stateElemsContext ask
819− let functions = atomFunctions context
753+ let functions = atomFunctions context
820− func <- lift $ except (atomFunctionForName funcName functions)
754+ func <- either throwE pure (atomFunctionForName funcName functions)
821− let expectedArgCount = length (atomFuncType func) - 1
755+ let expectedArgCount = length (atomFuncType func) - 1
822− actualArgCount = length argTypes
756+ actualArgCount = length argTypes
823− safeInit [] = [] -- different behavior from normal init
758+ safeInit [] = [] -- different behavior from normal init
824− safeInit xs = init xs
759+ safeInit (_:xs) = safeInit xs
825− if expectedArgCount /= actualArgCount then
760+ if expectedArgCount /= actualArgCount then
826− throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
761+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
828− let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
763+ mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
829− mapM_ (\(expType, actType) ->
830− lift $ except (atomTypeVerify expType actType)) zippedArgs
831− evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
764+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832 case evalAtomFunction func evaldArgs of
765 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
766+ Left err -> throwE (AtomFunctionUserError err)
834 Right result -> do
767 Right result -> do
835 --validate that the result matches the expected type
768 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
769+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837 pure result
770 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
771+evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
772 --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
773+ rstate <- ask
841− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn env
774+ runExceptT $ do
842− relAtom <- lift $ except $ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
775+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
776+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
843− pure (RelationAtom relAtom)
777+ pure (RelationAtom relAtom)
844−evalGraphRefAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs _) = do --why is the tid unused here? suspicious
778+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
845− let mergeEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn
779+ rstate <- lift ask
780+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
846− aType <- local mergeEnv (typeForGraphRefAtomExpr (tupleAttributes tupIn) cons)
781+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
847− argAtoms <- local mergeEnv $
782+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
848− mapM (evalGraphRefAtomExpr tupIn) dConsArgs
849 pure (ConstructedAtom dConsName aType argAtoms)
783 pure (ConstructedAtom dConsName aType argAtoms)
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
785+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
786+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
787+ rstate <- ask
854 case A.atomTypeForAttributeName attrName attrs of
788 case A.atomTypeForAttributeName attrName attrs of
855− Right aType -> pure aType
789+ Right aType -> pure (Right aType)
856− Left err@(NoSuchAttributeNamesError _) ->
790+ Left err@(NoSuchAttributeNamesError _) -> case rstate of
857− let envTup = envTuple renv
858− envAttrs = envAttributes renv in
859− case A.attributeForName attrName envAttrs of
791+ RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
792+ Left err' -> pure (Left err')
860− Right attr -> pure (A.atomType attr)
793+ Right attr -> pure (Right (A.atomType attr))
794+ RelationalExprStateElems _ -> pure (Left err)
861− Left _ -> case atomForAttributeName attrName envTup of
795+ RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
862− Right atom -> pure (atomTypeForAtom atom)
796+ Left err' -> pure (Left err')
863− Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
797+ Right atom -> pure (Right (atomTypeForAtom atom))
865− Left err -> throwError err
798+ Left err -> pure (Left err)
867−typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
799+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
868−typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
800+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
801+ context <- fmap stateElemsContext ask
869− funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
802+ let funcs = atomFunctions context
870 case atomFunctionForName funcName funcs of
803 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
804+ Left err -> pure (Left err)
872 Right func -> do
805 Right func -> do
873 let funcRetType = last (atomFuncType func)
806 let funcRetType = last (atomFuncType func)
874 funcArgTypes = init (atomFuncType func)
807 funcArgTypes = init (atomFuncType func)
875− argTypes <- mapM (typeForGraphRefAtomExpr attrs) atomArgs
808+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
809+ case lefts eArgTypes of
810+ errs@(_:_) -> pure (Left (someErrors errs))
876− let eTvMap = resolveTypeVariables funcArgTypes argTypes
812+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
813+ argTypes = rights eArgTypes
877− case eTvMap of
814+ case eTvMap of
878− Left err -> throwError err
815+ Left err -> pure (Left err)
879− Right tvMap -> lift $ except $ resolveFunctionReturnValue funcName tvMap funcRetType
816+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
880−typeForGraphRefAtomExpr attrs (RelationAtomExpr relExpr) = do
817+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
881− relType <- R.local (mergeAttributesIntoGraphRefRelationalExprEnv attrs) (typeForGraphRefRelationalExpr relExpr)
818+ rstate <- lift ask
819+ relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
882 pure (RelationAtomType (attributes relType))
820 pure (RelationAtomType (attributes relType))
883-- grab the type of the data constructor, then validate that the args match the expected types
821-- grab the type of the data constructor, then validate that the args match the expected types
884−typeForGraphRefAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs tid) =
822+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
885− do
823+ runExceptT $ do
886− argsTypes <- mapM (typeForGraphRefAtomExpr attrs) dConsArgs
824+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
887− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
825+ context <- fmap stateElemsContext (lift ask)
888− lift $ except $ atomTypeForDataConstructor tConsMap dConsName argsTypes
826+ either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
890-- | Validate that the type of the AtomExpr matches the expected type.
828-- | Validate that the type of the AtomExpr matches the expected type.
891−verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
829+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
892−verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
830+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
893− env <- askEnv
831+ rstate <- lift ask
894 case A.atomTypeForAttributeName attrName (attributes relIn) of
832 case A.atomTypeForAttributeName attrName (attributes relIn) of
895− Right aType -> lift $ except $ atomTypeVerify expectedType aType
833+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
896− (Left err@(NoSuchAttributeNamesError _)) ->
834+ (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
897− let attrs' = envAttributes env in
835+ RelationalExprStateTupleElems _ _ -> throwE err
898− if attrs' == emptyAttributes then
836+ RelationalExprStateElems _ -> throwE err
901− case A.attributeForName attrName attrs' of
837+ RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
902− Left err' -> throwError err'
838+ Left err' -> throwE err'
903− Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
839+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
904− Left err -> throwError err
840+ Left err -> throwE err
906−verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907− lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
841+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
908−verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
842+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
909− context <- gfDatabaseContextForMarker tid
843+ rstate <- ask
910 let functions = atomFunctions context
844 let functions = atomFunctions context
845+ context = stateElemsContext rstate
911− func <- lift $ except $ atomFunctionForName funcName functions
847+ func <- either throwE pure (atomFunctionForName funcName functions)
912− let expectedArgTypes = atomFuncType func
848+ let expectedArgTypes = atomFuncType func
913− funcArgVerifier (atomExpr, expectedType2, argCount) = do
849+ funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
914− let handler :: RelationalError -> GraphRefRelationalExprM AtomType
915− handler (AtomTypeMismatchError expSubType actSubType) = throwError (AtomFunctionTypeError funcName argCount expSubType actSubType)
850+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
916− handler err = throwError err
851+ Left err -> throwE err
917− verifyGraphRefAtomExprTypes relIn atomExpr expectedType2 `catchError` handler
852+ Right x -> pure x
918− funcArgTypes <- mapM funcArgVerifier $ zip3 funcArgExprs expectedArgTypes [1..]
853+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
919− if length funcArgTypes /= length expectedArgTypes - 1 then
854+ if length funcArgTypes /= length expectedArgTypes - 1 then
920− throwError (AtomTypeCountError funcArgTypes expectedArgTypes)
855+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
922− lift $ except $ atomTypeVerify expectedType (last expectedArgTypes)
857+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
923−verifyGraphRefAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType =
858+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
924− do
859+ rstate <- lift ask
925− let mergedAttrsEnv e = mergeAttributesIntoGraphRefRelationalExprEnv (attributes relIn) e
860+ relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
926− relType <- R.local mergedAttrsEnv (typeForGraphRefRelationalExpr relationExpr)
927− lift $ except $ atomTypeVerify expectedType (RelationAtomType (attributes relType))
861+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
928−verifyGraphRefAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = do
862+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
929− cType <- typeForGraphRefAtomExpr (attributes rel) cons
863+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
930− lift $ except $ atomTypeVerify expectedType cType
864+ either throwE pure (atomTypeVerify expectedType cType)
932-- | Look up the type's name and create a new attribute.
866-- | Look up the type's name and create a new attribute.
933−evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
867+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
934−evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
868+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
935− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
869+ aType <- atomTypeForTypeConstructor tCons aTypes M.empty
936− aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
937− lift $ except $ validateAtomType aType tConsMap
938− pure $ Attribute attrName aType
870+ Right (Attribute attrName aType)
940−evalGraphRefAttrExpr (NakedAttributeExpr attr) = pure attr
872+evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
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
874+evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
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
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])
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
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
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
988−--resolveAttributes (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",IntegerAtomType),("b",TypeVariableType "b")]))) (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",TypeVariableType "a"),("b",TextAtomType)])))
990−evalGraphRefTupleExpr :: Maybe Attributes -> GraphRefTupleExpr -> GraphRefRelationalExprM RelationTuple
991−evalGraphRefTupleExpr mAttrs (TupleExpr tupMap) = do
875+evalTupleExpr attrs (TupleExpr tupMap) = do
876+ context <- fmap stateElemsContext ask
992 -- 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
878 -- 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
993 -- 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
879 -- 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) =
880+ attrAtoms <- mapM (\(attrName, aExpr) -> do
996− do
881+ newAtomType <- liftE (typeFromAtomExpr A.emptyAttributes aExpr)
997− --provided when the relation header is available
998− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
999− unresolvedType <- typeForGraphRefAtomExpr attrs aExpr
1000− resolvedType <- case eExpectedAtomType of
1001− Left _ -> pure unresolvedType
1002− Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
1003− --resolve atom typevars based on resolvedType?
1004− newAtom <- evalGraphRefAtomExpr emptyTuple aExpr
882+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
1005− pure (attrName, newAtom, resolvedType)
883+ pure (attrName, newAtom, newAtomType)
1006− attrAtoms <- mapM resolveOneAtom (M.toList tupMap)
884+ ) (M.toList tupMap)
1007− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
885+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
1008− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
886+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
1009− tup = mkRelationTuple tupAttrs atoms
887+ tup = mkRelationTuple tupAttrs atoms
888+ tConss = typeConstructorMapping context
1010− finalAttrs = fromMaybe tupAttrs mAttrs
889+ finalAttrs = fromMaybe tupAttrs attrs
1011 --verify that the attributes match
890 --verify that the attributes match
1012− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
891+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (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))
892+ tup' <- either throwE pure (resolveTypesInTuple finalAttrs (reorderTuple finalAttrs tup))
1015− let tup' = reorderTuple finalAttrs tup
1016− --TODO: restore type resolution
1017−-- _ <- lift $ except (validateTuple tup' tConss)
893+ _ <- either throwE pure (validateTuple tup' tConss)
1018− pure tup'
894+ pure tup'
1020−--temporary implementation until we have a proper planner+executor
896+evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
1021−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1022−evalGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1023− mAttrs <- case mAttrExprs of
1025− Just . A.attributesFromList <$> mapM evalGraphRefAttrExpr (fromMaybe [] mAttrExprs)
1026− Nothing -> pure Nothing
1027− tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1028− let attrs = fromMaybe firstTupleAttrs mAttrs
1029− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
1030− lift $ except $ mkRelation attrs (RelationTupleSet tuples)
1031−evalGraphRefRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
1032− lift $ except $ mkRelation attributeSet tupleSet
1033−evalGraphRefRelationalExpr (ExistingRelation rel) = pure rel
1034−evalGraphRefRelationalExpr (RelationVariable name tid) = do
1035− ctx <- gfDatabaseContextForMarker tid
1036− case M.lookup name (relationVariables ctx) of
1037− Nothing -> throwError (RelVarNotDefinedError name)
1038− Just rv -> evalGraphRefRelationalExpr rv
1039−evalGraphRefRelationalExpr (Project attrNames expr) = do
1040− attrNameSet <- evalGraphRefAttributeNames attrNames expr
1041− rel <- evalGraphRefRelationalExpr expr
1042− lift $ except $ project attrNameSet rel
1043−evalGraphRefRelationalExpr (Union exprA exprB) = do
1044− relA <- evalGraphRefRelationalExpr exprA
1045− relB <- evalGraphRefRelationalExpr exprB
1046− lift $ except $ union relA relB
1047−evalGraphRefRelationalExpr (Join exprA exprB) = do
1048− relA <- evalGraphRefRelationalExpr exprA
1049− relB <- evalGraphRefRelationalExpr exprB
1050− lift $ except $ join relA relB
1051−evalGraphRefRelationalExpr (Rename oldName newName expr) = do
1052− rel <- evalGraphRefRelationalExpr expr
1053− lift $ except $ rename oldName newName rel
1054−evalGraphRefRelationalExpr (Difference exprA exprB) = do
1055− relA <- evalGraphRefRelationalExpr exprA
1056− relB <- evalGraphRefRelationalExpr exprB
1057− lift $ except $ difference relA relB
1058−evalGraphRefRelationalExpr (Group groupAttrNames newAttrName expr) = do
1059− groupNames <- evalGraphRefAttributeNames groupAttrNames expr
1060− rel <- evalGraphRefRelationalExpr expr
1061− lift $ except $ group groupNames newAttrName rel
1062−evalGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1063− rel <- evalGraphRefRelationalExpr expr
1064− lift $ except $ ungroup groupAttrName rel
1065−evalGraphRefRelationalExpr (Restrict predExpr expr) = do
1066− rel <- evalGraphRefRelationalExpr expr
1067− filt <- predicateRestrictionFilter (attributes rel) predExpr
1068− lift $ except $ restrict filt rel
1069−evalGraphRefRelationalExpr (Equals exprA exprB) = do
1070− relA <- evalGraphRefRelationalExpr exprA
1071− relB <- evalGraphRefRelationalExpr exprB
1072− pure $ if relA == relB then relationTrue else relationFalse
1073−evalGraphRefRelationalExpr (NotEquals exprA exprB) = do
1074− relA <- evalGraphRefRelationalExpr exprA
1075− relB <- evalGraphRefRelationalExpr exprB
1076− pure $ if relA == relB then relationFalse else relationTrue
1077−evalGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1078− rel <- evalGraphRefRelationalExpr expr
1079− (newAttrs, tupProc) <- extendGraphRefTupleExpressionProcessor rel extendTupleExpr
1080− lift $ except $ relMogrify tupProc newAttrs rel
1081−evalGraphRefRelationalExpr expr@With{} =
1082− --strategy A: add relation variables to the contexts in the graph
1083− --strategy B: drop in macros in place (easier programmatically)
1084− --strategy B implementation
1085− evalGraphRefRelationalExpr (substituteWithNameMacros [] expr)
1087−dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
1088−dbContextForTransId tid graph = do
1089− trans <- transactionForId tid graph
1090− pure (concreteDatabaseContext trans)
1092−transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
1093−transactionForId tid graph
1095− Left RootTransactionTraversalError
1096− | S.null matchingTrans =
1097− Left $ NoSuchTransactionError tid
1099− Right $ head (S.toList matchingTrans)
1101− matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
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
1118−typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119− relVars <- relationVariables <$> gfDatabaseContextForMarker tid
1120− case M.lookup rvName relVars of
1121− Nothing -> throwError (RelVarNotDefinedError rvName)
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{} =
1156−typeForGraphRefRelationalExpr NotEquals{} =
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
1168− mapM_ (checkMacroName . fst) withs
1169− typeForGraphRefRelationalExpr expr'
1171−evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1172−evalGraphRefAttributeNames attrNames expr = do
897+evalAttributeNames attrNames expr = do
1173− exprType' <- typeForGraphRefRelationalExpr expr
898+ eExprType <- typeForRelationalExpr expr
900+ Left err -> pure (Left err)
1174− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
902+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
1175− case attrNames of
903+ case attrNames of
1176− AttributeNames names ->
904+ AttributeNames names ->
1177− case A.projectionAttributesForNames names (attributes exprType') of
905+ case A.projectionAttributesForNames names (attributes exprTyp) of
1178− Left err -> throwError err
906+ Left err -> pure (Left err)
1179− Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
907+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1181− InvertedAttributeNames names -> do
909+ InvertedAttributeNames names -> do
1182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
910 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1183 if not (S.null nonExistentAttributeNames) then
911 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
912+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
914+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1188− UnionAttributeNames namesA namesB -> do
916+ UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
917+ eNameSetA <- evalAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
918+ case eNameSetA of
919+ Left err -> pure (Left err)
920+ Right nameSetA -> do
921+ eNameSetB <- evalAttributeNames namesB expr
923+ Left err -> pure (Left err)
1191− pure (S.union nameSetA nameSetB)
925+ pure (Right (S.union nameSetA nameSetB))
1193− IntersectAttributeNames namesA namesB -> do
927+ IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
928+ eNameSetA <- evalAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
929+ case eNameSetA of
930+ Left err -> pure (Left err)
931+ Right nameSetA -> do
932+ eNameSetB <- evalAttributeNames namesB expr
934+ Left err -> pure (Left err)
1196− pure (S.intersection nameSetA nameSetB)
936+ pure (Right (S.intersection nameSetA nameSetB))
1198− RelationalExprAttributeNames attrExpr -> do
938+ RelationalExprAttributeNames attrExpr -> do
1199− attrExprType <- typeForGraphRefRelationalExpr attrExpr
939+ eAttrExprType <- typeForRelationalExpr attrExpr
940+ case eAttrExprType of
941+ Left err -> pure (Left err)
1200− pure (A.attributeNameSet (attributes attrExprType))
942+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
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
1208− case validateAtomType aType tConsMap of
1209− Left err -> throwError err
1210− Right _ -> pure (Attribute attrName aType)
1211−evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1213−mkEmptyRelVars :: RelationVariables -> RelationVariables
1214−mkEmptyRelVars = M.map mkEmptyRelVar
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)
1234−dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235−dbErr err = lift (except (Left err))
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
1257−-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258−evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259−evalRelationalExpr expr = do
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
1268−class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269− getContext :: m DatabaseContext
1271−instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272− getContext = gfDatabaseContextForMarker UncommittedContextMarker
1274−instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275− getContext = getStateContext
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
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
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) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1313−instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314− resolve (TupleExprs marker tupleExprs) =
1315− TupleExprs marker <$> mapM resolve tupleExprs
1317−instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318− resolve (TupleExpr tupMap) = do
1319− tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320− pure (TupleExpr (M.fromList tupMap'))
1322−instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323− resolve orig@AttributeNames{} = pure orig
1324− resolve orig@InvertedAttributeNames{} = pure orig
1325− resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326− resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327− resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
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
1338−instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339− resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1341−instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342− resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1344−instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345− resolve orig@AttributeAtomExpr{} = pure orig
1346− resolve orig@NakedAtomExpr{} = pure orig
1347− resolve (FunctionAtomExpr nam atomExprs marker) =
1348− FunctionAtomExpr nam <$> 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
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')
1357−--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1359−applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360−applyUnionCollapse = Fold.cata opt
1362− opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363− opt (UnionF exprA exprB) | exprA == exprB = exprA
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
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)
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)
1380−--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
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) =
1388− orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1390−applyRestrictionCollapse expr = expr