@@ -1,53 +1,35 @@
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
18import ProjectM36.Arbitrary
14import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
20−import ProjectM36.Transaction
21import qualified ProjectM36.Attribute as A
15import qualified ProjectM36.Attribute as A
22import qualified Data.Map as M
16import qualified Data.Map as M
23import qualified Data.HashSet as HS
17import qualified Data.HashSet as HS
24import qualified Data.Set as S
18import qualified Data.Set as S
25import Control.Monad.State hiding (join)
19import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
20+import Control.Exception
27import Data.Maybe
21import Data.Maybe
28import Data.Either
22import Data.Either
29import Data.Char (isUpper)
23import Data.Char (isUpper)
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
33import qualified Data.Text as T
24import qualified Data.Text as T
34import qualified Data.Vector as V
25import qualified Data.Vector as V
35import qualified ProjectM36.TypeConstructorDef as TCD
26import qualified ProjectM36.TypeConstructorDef as TCD
36−import qualified Control.Monad.RWS.Strict as RWS
27+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)
28+import Control.Monad.Trans.Reader
40−import Control.Monad.Reader as R hiding (join)
41−import ProjectM36.NormalizeExpr
42−import ProjectM36.WithNameExpr
43import Test.QuickCheck
29import Test.QuickCheck
44−import qualified Data.Functor.Foldable as Fold
30+import GHC
45−import Control.Applicative
46−#ifdef PM36_HASKELL_SCRIPTING
47−import GHC hiding (getContext)
48−import Control.Exception
49import GHC.Paths
31import GHC.Paths
50−#endif
32+import Debug.Trace
52data DatabaseContextExprDetails = CountUpdatedTuples
34data DatabaseContextExprDetails = CountUpdatedTuples
@@ -64,63 +46,32 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
64 Right ts -> ts
46 Right ts -> ts
66-- | Used to start a fresh database state for a new database context expression.
48-- | Used to start a fresh database state for a new database context expression.
67−mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
49+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
68−mkDatabaseContextEvalState context = DatabaseContextEvalState {
69− dbc_context = context,
72− } --future work: propagate return accumulator
50+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
52-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
75−data RelationalExprEnv = RelationalExprEnv {
53+data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
76− re_context :: DatabaseContext,
54+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
77− re_graph :: TransactionGraph,
55+ RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
78− re_extra :: Maybe (Either RelationTuple Attributes)
56+
79− }
57+instance Show RelationalExprStateElems where
80−
58+ show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
81−envTuple :: GraphRefRelationalExprEnv -> RelationTuple
59+ show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
82−envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
60+ show (RelationalExprStateElems _) = "RelationalExprStateElems"
84−envAttributes :: GraphRefRelationalExprEnv -> Attributes
62+mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
85−envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
63+mkRelationalExprState = RelationalExprStateElems
65+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
66+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
67+mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
68+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
69+ RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
87−instance Show RelationalExprEnv where
71+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
88− show e@RelationalExprEnv{} = "RelationalExprEnv " ++ show (re_extra e)
72+mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
89−
73+mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
90−--used to eval relationalexpr
74+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
76type ResultAccumName = StringType
@@ -130,403 +81,429 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
130 resultAccumResult :: Relation
81 resultAccumResult :: Relation
133−data DatabaseContextEvalState = DatabaseContextEvalState {
134− dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135− dbc_accum :: M.Map ResultAccumName ResultAccum,
84+type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
136− dbc_dirty :: DirtyFlag
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
144−mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
86+type DatabaseState a = State DatabaseStateElems a
145−mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
147−type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
88+getStateContext :: DatabaseState DatabaseContext
148−
89+getStateContext = do
149−runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
90+ (ctx,_, _) <- get
150−runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
91+ pure ctx
152− freshEnv = mkDatabaseContextEvalState ctx
93+putStateContext :: DatabaseContext -> DatabaseState ()
94+putStateContext ctx = do
96+ put (ctx, accum, True)
98+type RelationalExprState a = Reader RelationalExprStateElems a
100+stateElemsContext :: RelationalExprStateElems -> DatabaseContext
101+stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
102+stateElemsContext (RelationalExprStateElems ctx) = ctx
103+stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
105+setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
106+setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
107+setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
108+setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
110+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
111+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
112+evalRelationalExpr (RelationVariable name _) = do
113+ relvarTable <- fmap (relationVariables . stateElemsContext) ask
114+ return $ case M.lookup name relvarTable of
115+ Just res -> Right res
116+ Nothing -> Left $ RelVarNotDefinedError name
118+evalRelationalExpr (Project attrNames expr) = do
119+ eAttrNameSet <- evalAttributeNames attrNames expr
120+ case eAttrNameSet of
121+ Left err -> pure (Left err)
122+ Right attrNameSet -> do
123+ rel <- evalRelationalExpr expr
125+ Right rel2 -> pure $ project attrNameSet rel2
126+ Left err -> pure $ Left err
128+evalRelationalExpr (Union exprA exprB) = do
129+ relA <- evalRelationalExpr exprA
130+ relB <- evalRelationalExpr exprB
132+ Left err -> return $ Left err
133+ Right relA2 -> case relB of
134+ Left err -> return $ Left err
135+ Right relB2 -> return $ union relA2 relB2
137+evalRelationalExpr (Join exprA exprB) = do
138+ relA <- evalRelationalExpr exprA
139+ relB <- evalRelationalExpr exprB
141+ Left err -> return $ Left err
142+ Right relA2 -> case relB of
143+ Left err -> return $ Left err
144+ Right relB2 -> return $ join relA2 relB2
146+evalRelationalExpr (Difference exprA exprB) = do
147+ relA <- evalRelationalExpr exprA
148+ relB <- evalRelationalExpr exprB
150+ Left err -> return $ Left err
151+ Right relA2 -> case relB of
152+ Left err -> return $ Left err
153+ Right relB2 -> return $ difference relA2 relB2
155+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
156+ case mkRelation attributeSet tupleSet of
157+ Right rel -> return $ Right rel
158+ Left err -> return $ Left err
154−
160+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
155−dbcTransId :: DatabaseContextEvalMonad TransactionId
161+ currentContext <- fmap stateElemsContext ask
156−dbcTransId = dce_transId <$> RWS.ask
162+ let tConss = typeConstructorMapping currentContext
157−
163+ -- 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
164+ runExceptT $ do
159−dbcGraph = dce_graph <$> RWS.ask
165+ mAttrs <- case mAttrExprs of
161−dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
167+ Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
162−dbcRelationalExprEnv =
168+ Nothing -> pure Nothing
163− mkRelationalExprEnv <$> getStateContext <*> dbcGraph
169+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
164−
170+ let attrs = fromMaybe firstTupleAttrs mAttrs
165−getStateContext :: DatabaseContextEvalMonad DatabaseContext
171+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
166−getStateContext = gets dbc_context
172+ 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
174+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
207−gfGraph = asks gre_graph
209−envContext :: RelationalExprEnv -> DatabaseContext
176+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
210−envContext = re_context
177+ evald <- evalRelationalExpr relExpr
179+ Right rel -> return $ rename oldAttrName newAttrName rel
180+ Left err -> return $ Left err
212−setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
182+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
213−setEnvContext e ctx = e { re_context = ctx }
183+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
184+ case eOldAttrNameSet of
185+ Left err -> pure (Left err)
186+ Right oldAttrNameSet -> do
187+ evald <- evalRelationalExpr relExpr
189+ Right rel -> return $ group oldAttrNameSet newAttrName rel
190+ Left err -> return $ Left err
192+evalRelationalExpr (Ungroup attrName relExpr) = do
193+ evald <- evalRelationalExpr relExpr
195+ Right rel -> return $ ungroup attrName rel
196+ Left err -> return $ Left err
198+evalRelationalExpr (Restrict predicateExpr relExpr) = do
199+ evald <- evalRelationalExpr relExpr
201+ Left err -> return $ Left err
203+ eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
205+ Left err -> return $ Left err
207+ pure (restrict filterfunc rel)
209+evalRelationalExpr (Equals relExprA relExprB) = do
210+ evaldA <- evalRelationalExpr relExprA
211+ evaldB <- evalRelationalExpr relExprB
213+ Left err -> return $ Left err
214+ Right relA -> case evaldB of
215+ Left err -> return $ Left err
216+ Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
218+--warning: copy-pasta from above- refactor
219+evalRelationalExpr (NotEquals relExprA relExprB) = do
220+ evaldA <- evalRelationalExpr relExprA
221+ evaldB <- evalRelationalExpr relExprB
223+ Left err -> return $ Left err
224+ Right relA -> case evaldB of
225+ Left err -> return $ Left err
226+ Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
228+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
229+evalRelationalExpr (Extend tupleExpression relExpr) = do
231+ let evald = runReader (evalRelationalExpr relExpr) rstate
233+ Left err -> pure (Left err)
235+ tupProc <- extendTupleExpressionProcessor rel tupleExpression
237+ Left err -> pure (Left err)
238+ Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
215--helper function to process relation variable creation/assignment
240--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
241+setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
217−setRelVar relVarName relExpr = do
242+setRelVar relVarName rel = do
218 currentContext <- getStateContext
243 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
244+ let newRelVars = M.insert relVarName rel $ relationVariables currentContext
222 potentialContext = currentContext { relationVariables = newRelVars }
245 potentialContext = currentContext { relationVariables = newRelVars }
223− --optimization: if the relexpr is unchanged, skip the update
246+
224− if M.lookup relVarName (relationVariables currentContext) == Just relExpr then
227− --determine when to check constraints
230− case checkConstraints potentialContext tid graph of
247+ case checkConstraints potentialContext of
231− Left err -> dbErr err
248+ Left err -> pure (Left err)
232− Right _ -> putStateContext potentialContext
250+ putStateContext potentialContext
233−
251+ 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
253-- 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 ()
254+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239deleteRelVar relVarName = do
255deleteRelVar relVarName = do
240 currContext <- getStateContext
256 currContext <- getStateContext
241 let relVars = relationVariables currContext
257 let relVars = relationVariables currContext
242 if M.notMember relVarName relVars then
258 if M.notMember relVarName relVars then
243− pure ()
259+ pure (Right ())
245 let newRelVars = M.delete relVarName relVars
261 let newRelVars = M.delete relVarName relVars
246 newContext = currContext { relationVariables = newRelVars }
262 newContext = currContext { relationVariables = newRelVars }
247 putStateContext newContext
263 putStateContext newContext
248− pure ()
264+ pure (Right ())
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
266+evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
267+evalDatabaseContextExpr NoOperation = pure (Right ())
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
269+evalDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
255 relvars <- fmap relationVariables getStateContext
270 relvars <- fmap relationVariables getStateContext
256 tConss <- fmap typeConstructorMapping getStateContext
271 tConss <- fmap typeConstructorMapping getStateContext
257− graph <- dbcGraph
272+ let eAttrs = map (evalAttrExpr tConss) attrExprs
258− let eAttrs = runGraphRefRelationalExprM gfEnv (mapM evalGraphRefAttrExpr attrExprs)
273+ attrErrs = lefts eAttrs
259− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
274+ attrsList = rights eAttrs
260− case eAttrs of
275+ if not (null attrErrs) then
261− Left err -> dbErr err
276+ pure (Left (someErrors attrErrs))
262− Right attrsList -> do
277+ else do
263− lift $ except $ validateAttributes tConss (A.attributesFromList attrsList)
278+ let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
279+ if not (null atomTypeErrs) then
280+ pure (Left (someErrors atomTypeErrs))
264− case M.member relVarName relvars of
282+ case M.member relVarName relvars of
265− True -> dbErr (RelVarAlreadyDefinedError relVarName)
283+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
266− False -> setRelVar relVarName (ExistingRelation emptyRelation)
284+ False -> setRelVar relVarName emptyRelation >> pure (Right ())
268 attrs = A.attributesFromList attrsList
286 attrs = A.attributesFromList attrsList
269 emptyRelation = Relation attrs emptyTupleSet
287 emptyRelation = Relation attrs emptyTupleSet
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
289+evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
291+evalDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
292+ -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
275 context <- getStateContext
293 context <- getStateContext
276− let existingRelVar = M.lookup relVarName (relationVariables context)
294+ let existingRelVar = M.lookup relVarName relVarTable
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
295+ relVarTable = relationVariables context
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
296+ value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
298+ Left err -> pure (Left err)
279− case existingRelVar of
299+ 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
300+ Nothing -> setRelVar relVarName rel
286− Just existingRel -> do
301+ Just existingRel -> let expectedAttributes = attributes existingRel
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
302+ foundAttributes = attributes rel in
288− case eExpectedType of
303+ 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
304+ setRelVar relVarName rel
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
306+ pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
300−evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
308+evalDatabaseContextExpr (Insert relVarName relExpr) = do
301− gfExpr <- relVarByName relVarName
309+ context <- getStateContext
302− let optExpr = applyUnionCollapse (Union
310+ let unionexp = Union relExpr rv
303− relExpr
311+ rv = RelationVariable relVarName ()
304− gfExpr)
312+ unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
305− evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
313+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
315+ Left err -> pure (Left err)
316+ Right unioned' -> case origRel of
317+ Left err -> pure (Left err)
318+ Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
321+ evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
323+evalDatabaseContextExpr (Delete relVarName predicate) = do
324+ context <- getStateContext
325+ let rv = RelationVariable relVarName ()
326+ let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
327+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
329+ Left err -> pure (Left err)
330+ Right updatedRel' -> case origRel of
331+ Left err -> pure (Left err)
332+ Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
335+ 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
337--union of restricted+updated portion and the unrestricted+unupdated portion
313−evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
338+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
314− rvExpr <- relVarByName relVarName
315− graph <- re_graph <$> dbcRelationalExprEnv
316 context <- getStateContext
339 context <- getStateContext
317− let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
340+ let relVarTable = relationVariables context
318− --get the current attributes name in the relvar to ensure that we don't conflict when renaming
341+ case M.lookup relVarName relVarTable of
319− eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
342+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
320− exprType' <- case eExprType of
343+ Just rel ->
321− Left err -> throwError err
344+ case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
322− Right t -> pure t
345+ Left err -> pure (Left err)
323− let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
346+ Right predicateFunc -> do
324− tmpAttr = tmpAttrC 1
347+ let ret = do
325− tmpAttrC :: Int -> AttributeName -> AttributeName
348+ restrictedPortion <- restrict predicateFunc rel
326− tmpAttrC c attr =
349+ if cardinality restrictedPortion == Finite 0 then
327− let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
350+ pure Nothing
328− if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
331− tmpAttrName
352+ unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
332− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
353+ updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
333− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
354+ updatedRel <- updatedPortion `union` unrestrictedPortion
334− restrictedPortion = Restrict pred' rvExpr
355+ pure (Just updatedRel)
335− updated = foldr (\(oldname, atomExpr) accum ->
356+ case ret of
336− let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
357+ Left err -> pure (Left err)
337− updateAttr oldname procAtomExpr accum
358+ Right Nothing -> pure (Right ())
338− ) restrictedPortion (M.toList atomExprMap)
359+ 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
361+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
344 currContext <- getStateContext
362 currContext <- getStateContext
345− transId <- dbcTransId
347 let currDeps = inclusionDependencies currContext
363 let currDeps = inclusionDependencies currContext
348 newDeps = M.insert newDepName newDep currDeps
364 newDeps = M.insert newDepName newDep currDeps
349 if M.member newDepName currDeps then
365 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
366+ pure (Left (InclusionDependencyNameInUseError newDepName))
352 let potentialContext = currContext { inclusionDependencies = newDeps }
368 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
369+ case checkConstraints potentialContext of
356− Left err -> dbErr err
370+ Left err -> pure (Left err)
357− Right _ ->
371+ Right _ -> do
358 putStateContext potentialContext
372 putStateContext potentialContext
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
375+evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
361 currContext <- getStateContext
376 currContext <- getStateContext
362 let currDeps = inclusionDependencies currContext
377 let currDeps = inclusionDependencies currContext
363 newDeps = M.delete depName currDeps
378 newDeps = M.delete depName currDeps
364 if M.notMember depName currDeps then
379 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
380+ pure (Left (InclusionDependencyNameNotInUseError depName))
367 putStateContext $ currContext {inclusionDependencies = newDeps }
382 putStateContext $ currContext {inclusionDependencies = newDeps }
369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
385-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
386+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
371 currentContext <- getStateContext
387 currentContext <- getStateContext
372 let nots = notifications currentContext
388 let nots = notifications currentContext
373 if M.member notName nots then
389 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
390+ pure (Left (NotificationNameInUseError notName))
376 let newNotifications = M.insert notName newNotification nots
392 let newNotifications = M.insert notName newNotification nots
377 newNotification = Notification { changeExpr = triggerExpr,
393 newNotification = Notification { changeExpr = triggerExpr,
378 reportOldExpr = resultOldExpr,
394 reportOldExpr = resultOldExpr,
379 reportNewExpr = resultNewExpr}
395 reportNewExpr = resultNewExpr}
380 putStateContext $ currentContext { notifications = newNotifications }
396 putStateContext $ currentContext { notifications = newNotifications }
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
399+evalDatabaseContextExpr (RemoveNotification notName) = do
383 currentContext <- getStateContext
400 currentContext <- getStateContext
384 let nots = notifications currentContext
401 let nots = notifications currentContext
385 if M.notMember notName nots then
402 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
403+ pure (Left (NotificationNameNotInUseError notName))
388 let newNotifications = M.delete notName nots
405 let newNotifications = M.delete notName nots
389 putStateContext $ currentContext { notifications = newNotifications }
406 putStateContext $ currentContext { notifications = newNotifications }
392-- | Adds type and data constructors to the database context.
409-- | Adds type and data constructors to the database context.
393-- validate that the type *and* constructor names are unique! not yet implemented!
410-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
411+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
395 currentContext <- getStateContext
412 currentContext <- getStateContext
396 let oldTypes = typeConstructorMapping currentContext
413 let oldTypes = typeConstructorMapping currentContext
397 tConsName = TCD.name tConsDef
414 tConsName = TCD.name tConsDef
398 -- validate that the constructor's types exist
415 -- validate that the constructor's types exist
399− case validateTypeConstructorDef tConsDef dConsDefList oldTypes of
416+ case validateTypeConstructorDef tConsDef dConsDefList of
400− Left err -> throwError err
417+ errs@(_:_) -> pure (Left (someErrors errs))
401− Right () | T.null tConsName || not (isUpper (T.head tConsName)) -> dbErr (InvalidAtomTypeName tConsName)
418+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
402− | isJust (findTypeConstructor tConsName oldTypes) -> dbErr (AtomTypeNameInUseError tConsName)
419+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403 | otherwise -> do
420 | otherwise -> do
404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
421 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
422 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.
425-- | 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
426+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
409 currentContext <- getStateContext
427 currentContext <- getStateContext
410 let oldTypes = typeConstructorMapping currentContext
428 let oldTypes = typeConstructorMapping currentContext
411 if isNothing (findTypeConstructor tConsName oldTypes) then
429 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
430+ pure (Left (AtomTypeNameNotInUseError tConsName))
414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
432 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
433 putStateContext $ currentContext { typeConstructorMapping = newTypes }
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
436+evalDatabaseContextExpr (MultipleExpr exprs) = do
418 --the multiple expressions must pass the same context around- not the old unmodified context
437 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
438+ evald <- forM exprs evalDatabaseContextExpr
420−
439+ --some lifting magic needed here
441+ [] -> pure (Right ())
442+ errs -> pure (Left (someErrors errs))
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
444+evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
422 currentContext <- getStateContext
445 currentContext <- getStateContext
423 let atomFuncs = atomFunctions currentContext
446 let atomFuncs = atomFunctions currentContext
424 case atomFunctionForName funcName atomFuncs of
447 case atomFunctionForName funcName atomFuncs of
425− Left err -> dbErr err
448+ Left err -> pure (Left err)
427− if isScriptedAtomFunction realFunc then do
449+ Right realFunc -> if isScriptedAtomFunction realFunc then do
428− let updatedFuncs = HS.delete realFunc atomFuncs
450+ let updatedFuncs = HS.delete realFunc atomFuncs
429− putStateContext (currentContext {atomFunctions = updatedFuncs })
451+ putStateContext (currentContext {atomFunctions = updatedFuncs })
431− dbErr (PrecompiledFunctionRemoveError funcName)
454+ pure (Left (PrecompiledFunctionRemoveError funcName))
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
456+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
434 context <- getStateContext
457 context <- getStateContext
435 let dbcFuncs = dbcFunctions context
458 let dbcFuncs = dbcFunctions context
436 case databaseContextFunctionForName funcName dbcFuncs of
459 case databaseContextFunctionForName funcName dbcFuncs of
437− Left err -> dbErr err
460+ Left err -> pure (Left err)
439− if isScriptedDatabaseContextFunction realFunc then do
461+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
440− let updatedFuncs = HS.delete realFunc dbcFuncs
462+ let updatedFuncs = HS.delete realFunc dbcFuncs
441− putStateContext (context { dbcFunctions = updatedFuncs })
463+ putStateContext (context { dbcFunctions = updatedFuncs })
443− dbErr (PrecompiledFunctionRemoveError funcName)
466+ pure (Left (PrecompiledFunctionRemoveError funcName))
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
468+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
446 context <- getStateContext
469 context <- getStateContext
448 --resolve atom arguments
470 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
471+ let relExprState = mkRelationalExprState context
472+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
473 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452 case eFunc of
474 case eFunc of
453− Left err -> dbErr err
475+ Left err -> pure (Left err)
454 Right func -> do
476 Right func -> do
455 let expectedArgCount = length (dbcFuncType func)
477 let expectedArgCount = length (dbcFuncType func)
456 actualArgCount = length atomArgExprs
478 actualArgCount = length atomArgExprs
457 if expectedArgCount /= actualArgCount then
479 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
480+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
460 --check that the atom types are valid
482 --check that the atom types are valid
461− case eAtomTypes of
483+ case lefts eAtomTypes of
462− Left err -> dbErr err
484+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
463− Right atomTypes -> do
485+ [] -> do
464− let mValidTypes = zipWith (\ expType actType
486+ let atomTypes = rights eAtomTypes
465− -> case atomTypeVerify expType actType of
487+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
466− Left err -> Just err
488+ Left err -> Just err
468− (dbcFuncType func) atomTypes
489+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
469− typeErrors = catMaybes mValidTypes
490+ typeErrors = catMaybes mValidTypes
470− eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
491+ eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471 if length (lefts eAtomArgs) > 1 then
492 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
493+ pure (Left (someErrors (lefts eAtomArgs)))
473 else if not (null typeErrors) then
494 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
495+ pure (Left (someErrors typeErrors))
476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
497 case evalDatabaseContextFunction func (rights eAtomArgs) context of
477− Left err -> dbErr err
498+ Left err -> pure (Left err)
478− Right newContext -> putStateContext newContext
499+ Right newContext -> putStateContext newContext >> pure (Right ())
479−data DatabaseContextIOEvalEnv = DatabaseContextIOEvalEnv
500+
480− { dbcio_transId :: TransactionId,
501+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
502+evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
524− eScriptSession <- requireScriptSession
503+ case mScriptSession of
525− currentContext <- getDBCIOContext
504+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
526− case eScriptSession of
527− Left err -> pure (Left err)
528− Right scriptSession -> do
505+ Just scriptSession -> do
529− res <- liftIO $ try $ runGhc (Just libdir) $ do
506+ res <- try $ runGhc (Just libdir) $ do
530 setSession (hscEnv scriptSession)
507 setSession (hscEnv scriptSession)
531 let atomFuncs = atomFunctions currentContext
508 let atomFuncs = atomFunctions currentContext
532 case extractAtomFunctionType funcType of
509 case extractAtomFunctionType funcType of
@@ -552,13 +529,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
529 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553 Right eContext -> case eContext of
530 Right eContext -> case eContext of
554 Left err -> pure (Left err)
531 Left err -> pure (Left err)
555− Right context' -> putDBCIOContext context'
532+ Right context' -> pure (Right context')
556−evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType script) = do
534+evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
557− eScriptSession <- requireScriptSession
535+ case mScriptSession of
558− currentContext <- getDBCIOContext
536+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
559− case eScriptSession of
560− Left err -> pure (Left err)
561− Right scriptSession -> do
537+ Just scriptSession -> do
562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
538 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563 let last2Args = reverse (take 2 (reverse funcType))
539 let last2Args = reverse (take 2 (reverse funcType))
564 atomArgs = take (length funcType - 2) funcType
540 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +544,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
544 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
545 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
547+ res <- try $ runGhc (Just libdir) $ do
572 setSession (hscEnv scriptSession)
548 setSession (hscEnv scriptSession)
573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
549 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574 pure $ case eCompiledFunc of
550 pure $ case eCompiledFunc of
@@ -593,86 +569,68 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
569 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594 Right eContext -> case eContext of
570 Right eContext -> case eContext of
595 Left err -> pure (Left err)
571 Left err -> pure (Left err)
596− Right context' -> putDBCIOContext context'
572+ Right context' -> pure (Right context')
597−evalGraphRefDatabaseContextIOExpr (LoadAtomFunctions modName funcName modPath) = do
573+evalDatabaseContextIOExpr _ currentContext (LoadAtomFunctions modName funcName modPath) = do
598− currentContext <- getDBCIOContext
599− eLoadFunc <- liftIO $ loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
574+ eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600 case eLoadFunc of
575 case eLoadFunc of
601 Left LoadSymbolError -> pure (Left LoadFunctionError)
576 Left LoadSymbolError -> pure (Left LoadFunctionError)
602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
577 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
578 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
604− in putDBCIOContext newContext
579+ in pure (Right newContext)
605−evalGraphRefDatabaseContextIOExpr (LoadDatabaseContextFunctions modName funcName modPath) = do
580+evalDatabaseContextIOExpr _ currentContext (LoadDatabaseContextFunctions modName funcName modPath) = do
606− currentContext <- getDBCIOContext
607− eLoadFunc <- liftIO $ loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
581+ eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608 case eLoadFunc of
582 case eLoadFunc of
609 Left LoadSymbolError -> pure (Left LoadFunctionError)
583 Left LoadSymbolError -> pure (Left LoadFunctionError)
610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
584 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
585 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
586+ in pure (Right newContext)
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
588+evalDatabaseContextIOExpr _ currentContext (CreateArbitraryRelation relVarName attrExprs range) =
616− currentContext <- getDBCIOContext
590+ case runState ( evalDatabaseContextExpr (Define relVarName attrExprs)) (freshDatabaseState currentContext) of
618− --create graph ref expr
619− let gfExpr = Define relVarName attrExprs
620− evalEnv = mkDatabaseContextEvalEnv (dbcio_transId env) (dbcio_graph env)
621− graph = dbcio_graph env
622− case runDatabaseContextEvalMonad currentContext evalEnv (evalGraphRefDatabaseContextExpr gfExpr) of
623− Left err -> pure (Left err)
591+ (Left err,_) -> pure (Left err)
624− Right dbstate -> do
592+ (Right (), elems@(ctx,_,_)) -> do
626 let existingRelVar = M.lookup relVarName relVarTable
594 let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
595+ relVarTable = relationVariables ctx
628 case existingRelVar of
596 case existingRelVar of
629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
597 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630 Just existingRel -> do
598 Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
599+ let expectedAttributes = attributes existingRel
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633− Left err -> pure (Left err)
635− let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
600+ let tcMap = typeConstructorMapping ctx
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
601+ eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638− case eitherRel of
602+ case eitherRel of
639− Left err -> pure $ Left err
603+ Left err -> pure $ Left err
640− Right rel ->
604+ Right rel ->
641− case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
605+ case runState (setRelVar relVarName rel) elems of
642− Left err -> pure (Left err)
606+ (Left err,_) -> pure (Left err)
643− Right dbstate' -> putDBCIOContext (dbc_context dbstate')
607+ (Right (), (ctx',_,_)) -> pure $ Right ctx'
609+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
610+updateTupleWithAtomExprs exprMap context tupIn = do
611+ --resolve all atom exprs
612+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
613+ atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
614+ pure (attrName, atom)
615+ ) (M.toList exprMap)
616+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
645--run verification on all constraints
618--run verification on all constraints
646−checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
619+checkConstraints :: DatabaseContext -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
620+checkConstraints context = do
648 mapM_ (uncurry checkIncDep) (M.toList deps)
621 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
624 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
625+ eval expr = evalReader (evalRelationalExpr expr)
626+ evalReader f = runReader f (RelationalExprStateElems context)
662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
627 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.
628 --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
629+ typeSub <- evalReader (typeForRelationalExpr subsetExpr)
668− runGfRel = runGraphRefRelationalExprM gfEnv
630+ typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
669− typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670− typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
631 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672− let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
632+ let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
633+ case eval checkExpr of
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
676 Left err -> Left err
634 Left err -> Left err
677 Right resultRel -> if resultRel == relationTrue then
635 Right resultRel -> if resultRel == relationTrue then
@@ -682,81 +640,88 @@ 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
640-- 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
641-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
643+typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
686typeForRelationalExpr expr = do
644typeForRelationalExpr expr = do
646+ let context = stateElemsContext rstate
687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
647 --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
648+ let context' = contextWithEmptyTupleSets context
689− graph <- reGraph
649+ rstate' = setStateElemsContext rstate context'
690− context <- reContext
650+ pure (runReader (evalRelationalExpr expr) rstate')
691− let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
651+
692− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
652+--returns a database context with all tuples removed
693− runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
653+--this is useful for type checking and optimization
694− lift $ except runGf
654+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
655+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
657+ relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
659liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697liftE v = do
660liftE v = do
698 y <- lift v
661 y <- lift v
699 case y of
662 case y of
700− Left err -> throwError err
663+ Left err -> throwE err
701 Right val -> pure val
664 Right val -> pure val
703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
666{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
704−predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
667+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
705−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
668+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
706− expr1v <- predicateRestrictionFilter attrs expr1
670+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
707− expr2v <- predicateRestrictionFilter attrs expr2
671+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
708− pure (\x -> do
672+ pure (\x -> do
709− ev1 <- expr1v x
673+ ev1 <- expr1v x
710− ev2 <- expr2v x
674+ ev2 <- expr2v x
711− pure (ev1 && ev2))
675+ pure (ev1 && ev2))
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
677+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
714− expr1v <- predicateRestrictionFilter attrs expr1
679+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
715− expr2v <- predicateRestrictionFilter attrs expr2
680+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716 pure (\x -> do
681 pure (\x -> do
717 ev1 <- expr1v x
682 ev1 <- expr1v x
718 ev2 <- expr2v x
683 ev2 <- expr2v x
719 pure (ev1 || ev2))
684 pure (ev1 || ev2))
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
686+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
688+predicateRestrictionFilter attrs (NotPredicate expr) =
724− exprv <- predicateRestrictionFilter attrs expr
690+ exprv <- liftE (predicateRestrictionFilter attrs expr)
725− pure (fmap not . exprv)
691+ 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
693--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
694predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
729− renv <- askEnv
695+ rstate <- ask
730− let eval :: RelationTuple -> Either RelationalError Relation
696+ 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
697 Left err -> Left err
736 Right rel -> if arity rel /= 0 then
698 Right rel -> if arity rel /= 0 then
737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
699 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
739− pure (rel == relationTrue))
701+ pure (rel == relationTrue)))
741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
703predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
742− env <- askEnv
704+ rstate <- ask
743− let attrs' = A.union attrs (envAttributes env)
705+ let (attrs', ctxtup') = case rstate of
744− ctxtup' = envTuple env
706+ RelationalExprStateElems _ -> (attrs, emptyTuple)
707+ RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
708+ RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
745− atomExprType <- typeForGraphRefAtomExpr attrs' atomExpr
710+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
746− attr <- lift $ except $ case A.attributeForName attrName attrs of
711+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747 Right attr -> Right attr
712 Right attr -> Right attr
748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
713 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749 Right ctxattr -> Right ctxattr
714 Right ctxattr -> Right ctxattr
750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
715 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751 Left err -> Left err
716 Left err -> Left err
752 Left err -> Left err
717 Left err -> Left err
753− if atomExprType /= A.atomType attr then
718+ if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
719+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
721 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757 Right atomCmp -> atomCmp == atomIn
722 Right atomCmp -> atomCmp == atomIn
758 Left _ -> False
723 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
724+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
761 pure $ case atomForAttributeName attrName tupleIn of
726 pure $ case atomForAttributeName attrName tupleIn of
762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
727 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,626 +732,243 @@ 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
732-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
733predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769 --merge attrs into the state attributes
734 --merge attrs into the state attributes
770− renv <- askEnv
735+ rstate <- ask
771− aType <- typeForGraphRefAtomExpr attrs atomExpr
737+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
772− if aType /= BoolAtomType then
738+ if aType /= BoolAtomType then
773− throwError (AtomTypeMismatchError aType BoolAtomType)
739+ throwE (AtomTypeMismatchError aType BoolAtomType)
775 pure (\tupleIn ->
741 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
742+ pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
777− Left err -> Left err
743+ Left _ -> False
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
744+ Right boolAtomValue -> boolAtomValue == BoolAtom True)
780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
746tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
747tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
782− Left (AttributeNameInUseError attrName)
748+ Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
784 Right rel
750 Right rel
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
752+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
753+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
788−-- renv <- askEnv
754+ rstate <- ask
789 -- check that the attribute name is not in use
755 -- check that the attribute name is not in use
790 case tupleExprCheckNewAttrName newAttrName relIn of
756 case tupleExprCheckNewAttrName newAttrName relIn of
791− Left err -> throwError err
757+ Left err -> pure (Left err)
792− Right _ -> do
758+ Right _ -> runExceptT $ do
793− atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
759+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
794− atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
760+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
761 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
762 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
797− env <- ask
763+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
798− pure (newAndOldAttrs, \tup -> do
764+ Left err -> Left err
799− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup env
800− atom <- runGraphRefRelationalExprM gfEnv (evalGraphRefAtomExpr tup atomExpr)
801− Right (tupleAtomExtend newAttrName atom tup)
765+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
804−evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
768+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
805−evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806− case atomForAttributeName attrName tupIn of
769+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
807− Right atom -> pure atom
770+ Right atom -> pure (Right atom)
808− Left err@(NoSuchAttributeNamesError _) -> do
771+ err@(Left (NoSuchAttributeNamesError _)) -> do
809− env <- askEnv
772+ rstate <- ask
810− case gre_extra env of
773+ case rstate of
811− Nothing -> throwError err
774+ RelationalExprStateElems _ -> pure err
775+ RelationalExprStateAttrsElems _ _ -> pure err
812− Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
776+ RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
813− Just (Right _) -> throwError err
814− Left err -> throwError err
777+ Left err -> pure (Left err)
815−evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
778+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
816−evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
779+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
817− argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
780+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
818− context <- gfDatabaseContextForMarker tid
781+ context <- fmap stateElemsContext ask
819− let functions = atomFunctions context
783+ let functions = atomFunctions context
820− func <- lift $ except (atomFunctionForName funcName functions)
784+ func <- either throwE pure (atomFunctionForName funcName functions)
821− let expectedArgCount = length (atomFuncType func) - 1
785+ let expectedArgCount = length (atomFuncType func) - 1
822− actualArgCount = length argTypes
786+ actualArgCount = length argTypes
823− safeInit [] = [] -- different behavior from normal init
788+ safeInit [] = [] -- different behavior from normal init
824− safeInit xs = init xs
789+ safeInit (_:xs) = safeInit xs
825− if expectedArgCount /= actualArgCount then
790+ if expectedArgCount /= actualArgCount then
826− throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
791+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
828− let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
793+ 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
794+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832 case evalAtomFunction func evaldArgs of
795 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
796+ Left err -> throwE (AtomFunctionUserError err)
834 Right result -> do
797 Right result -> do
835 --validate that the result matches the expected type
798 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
799+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837 pure result
800 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
801+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
802 --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
803+ rstate <- ask
841− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn env
804+ runExceptT $ do
842− relAtom <- lift $ except $ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
805+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
806+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
843− pure (RelationAtom relAtom)
807+ pure (RelationAtom relAtom)
844−evalGraphRefAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs _) = do --why is the tid unused here? suspicious
808+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
845− let mergeEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn
809+ rstate <- lift ask
810+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
846− aType <- local mergeEnv (typeForGraphRefAtomExpr (tupleAttributes tupIn) cons)
811+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
847− argAtoms <- local mergeEnv $
812+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
848− mapM (evalGraphRefAtomExpr tupIn) dConsArgs
849 pure (ConstructedAtom dConsName aType argAtoms)
813 pure (ConstructedAtom dConsName aType argAtoms)
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
815+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
816+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
817+ rstate <- ask
854 case A.atomTypeForAttributeName attrName attrs of
818 case A.atomTypeForAttributeName attrName attrs of
855− Right aType -> pure aType
819+ Right aType -> pure (Right aType)
856− Left err@(NoSuchAttributeNamesError _) ->
820+ Left err@(NoSuchAttributeNamesError _) -> case rstate of
857− let envTup = envTuple renv
858− envAttrs = envAttributes renv in
859− case A.attributeForName attrName envAttrs of
821+ RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
822+ Left err' -> pure (Left err')
860− Right attr -> pure (A.atomType attr)
823+ Right attr -> pure (Right (A.atomType attr))
824+ RelationalExprStateElems _ -> pure (Left err)
861− Left _ -> case atomForAttributeName attrName envTup of
825+ RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
862− Right atom -> pure (atomTypeForAtom atom)
826+ Left err' -> pure (Left err')
863− Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
827+ Right atom -> pure (Right (atomTypeForAtom atom))
865− Left err -> throwError err
828+ Left err -> pure (Left err)
867−typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
829+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
868−typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
830+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
831+ context <- fmap stateElemsContext ask
869− funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
832+ let funcs = atomFunctions context
870 case atomFunctionForName funcName funcs of
833 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
834+ Left err -> pure (Left err)
872 Right func -> do
835 Right func -> do
873 let funcRetType = last (atomFuncType func)
836 let funcRetType = last (atomFuncType func)
874 funcArgTypes = init (atomFuncType func)
837 funcArgTypes = init (atomFuncType func)
875− argTypes <- mapM (typeForGraphRefAtomExpr attrs) atomArgs
838+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
839+ case lefts eArgTypes of
840+ errs@(_:_) -> pure (Left (someErrors errs))
876− let eTvMap = resolveTypeVariables funcArgTypes argTypes
842+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
843+ argTypes = rights eArgTypes
877− case eTvMap of
844+ case eTvMap of
878− Left err -> throwError err
845+ Left err -> pure (Left err)
879− Right tvMap -> lift $ except $ resolveFunctionReturnValue funcName tvMap funcRetType
846+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
880−typeForGraphRefAtomExpr attrs (RelationAtomExpr relExpr) = do
847+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
881− relType <- R.local (mergeAttributesIntoGraphRefRelationalExprEnv attrs) (typeForGraphRefRelationalExpr relExpr)
848+ rstate <- lift ask
849+ relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
882 pure (RelationAtomType (attributes relType))
850 pure (RelationAtomType (attributes relType))
883-- grab the type of the data constructor, then validate that the args match the expected types
851-- grab the type of the data constructor, then validate that the args match the expected types
884−typeForGraphRefAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs tid) =
852+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
885− do
853+ runExceptT $ do
886− argsTypes <- mapM (typeForGraphRefAtomExpr attrs) dConsArgs
854+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
887− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
855+ context <- fmap stateElemsContext (lift ask)
888− lift $ except $ atomTypeForDataConstructor tConsMap dConsName argsTypes
856+ either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
890-- | Validate that the type of the AtomExpr matches the expected type.
858-- | Validate that the type of the AtomExpr matches the expected type.
891−verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
859+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
892−verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
860+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
893− env <- askEnv
861+ rstate <- lift ask
894 case A.atomTypeForAttributeName attrName (attributes relIn) of
862 case A.atomTypeForAttributeName attrName (attributes relIn) of
895− Right aType -> lift $ except $ atomTypeVerify expectedType aType
863+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
896− (Left err@(NoSuchAttributeNamesError _)) ->
864+ (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
897− let attrs' = envAttributes env in
865+ RelationalExprStateTupleElems _ _ -> throwE err
898− if attrs' == emptyAttributes then
866+ RelationalExprStateElems _ -> throwE err
901− case A.attributeForName attrName attrs' of
867+ RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
902− Left err' -> throwError err'
868+ Left err' -> throwE err'
903− Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
869+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
904− Left err -> throwError err
870+ Left err -> throwE err
906−verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907− lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
871+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
908−verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
872+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
909− context <- gfDatabaseContextForMarker tid
873+ rstate <- ask
910 let functions = atomFunctions context
874 let functions = atomFunctions context
875+ context = stateElemsContext rstate
911− func <- lift $ except $ atomFunctionForName funcName functions
877+ func <- either throwE pure (atomFunctionForName funcName functions)
912− let expectedArgTypes = atomFuncType func
878+ let expectedArgTypes = atomFuncType func
913− funcArgVerifier (atomExpr, expectedType2, argCount) = do
879+ 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)
880+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
916− handler err = throwError err
881+ Left err -> throwE err
917− verifyGraphRefAtomExprTypes relIn atomExpr expectedType2 `catchError` handler
882+ Right x -> pure x
918− funcArgTypes <- mapM funcArgVerifier $ zip3 funcArgExprs expectedArgTypes [1..]
883+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
919− if length funcArgTypes /= length expectedArgTypes - 1 then
884+ if length funcArgTypes /= length expectedArgTypes - 1 then
920− throwError (AtomTypeCountError funcArgTypes expectedArgTypes)
885+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
922− lift $ except $ atomTypeVerify expectedType (last expectedArgTypes)
887+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
923−verifyGraphRefAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType =
888+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
924− do
889+ rstate <- lift ask
925− let mergedAttrsEnv e = mergeAttributesIntoGraphRefRelationalExprEnv (attributes relIn) e
890+ 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))
891+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
928−verifyGraphRefAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = do
892+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
929− cType <- typeForGraphRefAtomExpr (attributes rel) cons
893+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
930− lift $ except $ atomTypeVerify expectedType cType
894+ either throwE pure (atomTypeVerify expectedType cType)
932-- | Look up the type's name and create a new attribute.
896-- | Look up the type's name and create a new attribute.
933−evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
897+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
934−evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
898+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
935− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
936− aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
899+ aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
937− lift $ except $ validateAtomType aType tConsMap
900+ validateAtomType aType aTypes
938− pure $ Attribute attrName aType
901+ Right (Attribute attrName aType)
940−evalGraphRefAttrExpr (NakedAttributeExpr attr) = pure attr
903+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
905+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
906+evalTupleExpr attrs (TupleExpr tupMap) = do
907+ 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
909 -- 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
910 -- 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) =
911+ attrAtoms <- mapM (\(attrName, aExpr) -> do
996− do
912+ 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
913+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
1005− pure (attrName, newAtom, resolvedType)
914+ pure (attrName, newAtom, newAtomType)
1006− attrAtoms <- mapM resolveOneAtom (M.toList tupMap)
915+ ) (M.toList tupMap)
1007− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
916+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
1008− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
917+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
1009− tup = mkRelationTuple tupAttrs atoms
918+ tup = mkRelationTuple tupAttrs atoms
919+ tConss = typeConstructorMapping context
1010− finalAttrs = fromMaybe tupAttrs mAttrs
920+ finalAttrs = fromMaybe tupAttrs attrs
1011 --verify that the attributes match
921 --verify that the attributes match
1012− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
922+ 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))
923+ 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)
924+ _ <- either throwE pure (validateTuple tup' tConss)
1018− pure tup'
925+ pure tup'
1020−--temporary implementation until we have a proper planner+executor
927+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
928+evalAttributeNames attrNames expr = do
1173− exprType' <- typeForGraphRefRelationalExpr expr
929+ eExprType <- typeForRelationalExpr expr
931+ Left err -> pure (Left err)
1174− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
933+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
1175− case attrNames of
934+ case attrNames of
1176− AttributeNames names ->
935+ AttributeNames names ->
1177− case A.projectionAttributesForNames names (attributes exprType') of
936+ case A.projectionAttributesForNames names (attributes exprTyp) of
1178− Left err -> throwError err
937+ Left err -> pure (Left err)
1179− Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
938+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1181− InvertedAttributeNames names -> do
940+ InvertedAttributeNames names -> do
1182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
941 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1183 if not (S.null nonExistentAttributeNames) then
942 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
943+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
945+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1188− UnionAttributeNames namesA namesB -> do
947+ UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
948+ eNameSetA <- evalAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
949+ case eNameSetA of
950+ Left err -> pure (Left err)
951+ Right nameSetA -> do
952+ eNameSetB <- evalAttributeNames namesB expr
954+ Left err -> pure (Left err)
1191− pure (S.union nameSetA nameSetB)
956+ pure (Right (S.union nameSetA nameSetB))
1193− IntersectAttributeNames namesA namesB -> do
958+ IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
959+ eNameSetA <- evalAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
960+ case eNameSetA of
961+ Left err -> pure (Left err)
962+ Right nameSetA -> do
963+ eNameSetB <- evalAttributeNames namesB expr
965+ Left err -> pure (Left err)
1196− pure (S.intersection nameSetA nameSetB)
967+ pure (Right (S.intersection nameSetA nameSetB))
1198− RelationalExprAttributeNames attrExpr -> do
969+ RelationalExprAttributeNames attrExpr -> do
1199− attrExprType <- typeForGraphRefRelationalExpr attrExpr
970+ eAttrExprType <- typeForRelationalExpr attrExpr
971+ case eAttrExprType of
972+ Left err -> pure (Left err)
1200− pure (A.attributeNameSet (attributes attrExprType))
973+ 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