@@ -1,7 +1,4 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FlexibleContexts #-}
4−{-# LANGUAGE OverloadedStrings #-}
52module ProjectM36.RelationalExpression where
63import ProjectM36.Relation
74import ProjectM36.Tuple
@@ -16,38 +13,27 @@ import ProjectM36.DataTypes.Primitive
1613import ProjectM36.AtomFunction
1714import ProjectM36.DatabaseContextFunction
1815import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
2016import ProjectM36.Transaction
2117import qualified ProjectM36.Attribute as A
2218import qualified Data.Map as M
2319import qualified Data.HashSet as HS
2420import qualified Data.Set as S
2521import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
22+import Control.Exception
2723import Data.Maybe
2824import Data.Either
2925import Data.Char (isUpper)
30−import Data.Time
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
3326import qualified Data.Text as T
3427import qualified Data.Vector as V
3528import qualified ProjectM36.TypeConstructorDef as TCD
36−import qualified Control.Monad.RWS.Strict as RWS
37−import Control.Monad.RWS.Strict (RWST, execRWST, runRWST)
38−import Control.Monad.Except hiding (join)
39−import Control.Monad.Trans.Except (except)
40−import Control.Monad.Reader as R hiding (join)
41−import ProjectM36.NormalizeExpr
42−import ProjectM36.WithNameExpr
29+import Control.Monad.Trans.Except
30+import Control.Monad.Trans.Reader
4331import Test.QuickCheck
44−import qualified Data.Functor.Foldable as Fold
45−import Control.Applicative
46−#ifdef PM36_HASKELL_SCRIPTING
47−import GHC hiding (getContext)
48−import Control.Exception
32+import GHC
4933import GHC.Paths
50−#endif
34+import Data.Time.Clock
35+import Data.Time.Calendar
36+import qualified Data.List.NonEmpty as NE
5137
5238data DatabaseContextExprDetails = CountUpdatedTuples
5339
@@ -64,63 +50,61 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
6450 Right ts -> ts
6551
6652-- | Used to start a fresh database state for a new database context expression.
67−mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68−mkDatabaseContextEvalState context = DatabaseContextEvalState {
69− dbc_context = context,
70− dbc_accum = M.empty,
71− dbc_dirty = False
53+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
54+freshDatabaseState context = DatabaseStateElems {
55+ context = context,
56+ accum = M.empty,
57+ dirty = False
7258 } --future work: propagate return accumulator
7359
7460-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
7561data RelationalExprEnv = RelationalExprEnv {
7662 re_context :: DatabaseContext,
7763 re_graph :: TransactionGraph,
64+ re_currentTransId :: TransactionId,
7865 re_extra :: Maybe (Either RelationTuple Attributes)
7966 }
8067
81−envTuple :: GraphRefRelationalExprEnv -> RelationTuple
82−envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
68+stateTuple :: RelationalExprEnv -> RelationTuple
69+stateTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (re_extra e))
8370
84−envAttributes :: GraphRefRelationalExprEnv -> Attributes
85−envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
71+stateAttributes :: RelationalExprEnv -> Attributes
72+stateAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (re_extra e))
73+{-
74+data RelationalExprEnv = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
75+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
76+ RelationalExprEnv DatabaseContext --used by default at the top level of evaluation
77+ -}
8678
8779instance Show RelationalExprEnv where
8880 show e@RelationalExprEnv{} = "RelationalExprEnv " ++ show (re_extra e)
8981
90−--used to eval relationalexpr
91−type RelationalExprM a = ReaderT RelationalExprEnv (ExceptT RelationalError Identity) a
92−
93−runRelationalExprM :: RelationalExprEnv -> RelationalExprM a -> Either RelationalError a
94−runRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
95−
96−reGraph :: RelationalExprM TransactionGraph
97−reGraph = asks re_graph
98−
99−reContext :: RelationalExprM DatabaseContext
100−reContext = asks re_context
101−
102−mkRelationalExprEnv :: DatabaseContext -> TransactionGraph -> RelationalExprEnv
103−mkRelationalExprEnv ctx graph =
82+mkRelationalExprState :: DatabaseContext -> TransactionId -> TransactionGraph -> RelationalExprEnv
83+mkRelationalExprState ctx currentTransId graph =
10484 RelationalExprEnv
10585 { re_context = ctx,
10686 re_graph = graph,
87+ re_currentTransId = currentTransId,
10788 re_extra = Nothing }
10889
109−askEnv :: GraphRefRelationalExprM GraphRefRelationalExprEnv
110−askEnv = R.ask
111−
112−mergeTuplesIntoGraphRefRelationalExprEnv :: RelationTuple -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
113−mergeTuplesIntoGraphRefRelationalExprEnv tupIn env =
114− env { gre_extra = new_elems }
90+currentTrans :: RelationalExprState (Either RelationalError Transaction)
91+currentTrans = do
92+ tid <- re_currentTransId <$> ask
93+ graph <- re_graph <$> ask
94+ pure (transactionForId tid graph)
95+
96+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprEnv -> RelationalExprEnv
97+mergeTuplesIntoRelationalExprState tupIn e@RelationalExprEnv{} =
98+ e{re_extra = new_elems }
11599 where
116100 new_elems = Just (Left newTuple)
117− mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (envTuple env))
101+ mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (stateTuple e))
118102 newTuple = mkRelationTupleFromMap mergedTupMap
119−
120−mergeAttributesIntoGraphRefRelationalExprEnv :: Attributes -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
121−mergeAttributesIntoGraphRefRelationalExprEnv attrsIn e = e { gre_extra = newattrs }
103+
104+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprEnv -> RelationalExprEnv
105+mergeAttributesIntoRelationalExprState attrsIn e@RelationalExprEnv{} = e{re_extra = newattrs }
122106 where
123− newattrs = Just (Right (A.union attrsIn (envAttributes e)))
107+ newattrs = Just (Right (A.union attrsIn (stateAttributes e)))
124108
125109type ResultAccumName = StringType
126110
@@ -130,81 +114,23 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
130114 resultAccumResult :: Relation
131115 }
132116
133−data DatabaseContextEvalState = DatabaseContextEvalState {
134− dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135− dbc_accum :: M.Map ResultAccumName ResultAccum,
136− dbc_dirty :: DirtyFlag
117+data DatabaseStateElems = DatabaseStateElems {
118+ context :: DatabaseContext, --new, alterable context for a new transaction
119+ accum :: M.Map ResultAccumName ResultAccum,
120+ dirty :: DirtyFlag
137121 }
138122
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
142− }
143−
144−mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145−mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146−
147−type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
148−
149−runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150−runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151− where
152− freshEnv = mkDatabaseContextEvalState ctx
153−
154−
155−dbcTransId :: DatabaseContextEvalMonad TransactionId
156−dbcTransId = dce_transId <$> RWS.ask
157−
158−dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159−dbcGraph = dce_graph <$> RWS.ask
123+type DatabaseState a = State DatabaseStateElems a
160124
161−dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162−dbcRelationalExprEnv =
163− mkRelationalExprEnv <$> getStateContext <*> dbcGraph
125+getStateContext :: DatabaseState DatabaseContext
126+getStateContext = context <$> get
164127
165−getStateContext :: DatabaseContextEvalMonad DatabaseContext
166−getStateContext = gets dbc_context
167−
168−putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
128+putStateContext :: DatabaseContext -> DatabaseState ()
169129putStateContext ctx' = do
170130 s <- get
171− put (s {dbc_context = ctx', dbc_dirty = True})
172−
173−-- | The context is optionally passed down along in cases where the current context is uncommitted.
174−data GraphRefRelationalExprEnv =
175− GraphRefRelationalExprEnv {
176− gre_context :: Maybe DatabaseContext,
177− gre_graph :: TransactionGraph,
178− gre_extra :: Maybe (Either RelationTuple Attributes)
179− }
131+ put (s {context = ctx'})
180132
181−type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
182−
183−gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184−gfTransForId tid = do
185− graph <- gfGraph
186− lift $ except $ transactionForId tid graph
187−
188−gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189−gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190−gfDatabaseContextForMarker UncommittedContextMarker = do
191− mctx <- gre_context <$> askEnv
192− case mctx of
193− Nothing -> throwError NoUncommittedContextInEvalError
194− Just ctx -> pure ctx
195−
196−runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197−runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
198−
199−freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200−freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
201− gre_context = mctx,
202− gre_graph = graph,
203− gre_extra = Nothing
204− }
205−
206−gfGraph :: GraphRefRelationalExprM TransactionGraph
207−gfGraph = asks gre_graph
133+type RelationalExprState a = Reader RelationalExprEnv a
208134
209135envContext :: RelationalExprEnv -> DatabaseContext
210136envContext = re_context
@@ -212,321 +138,416 @@ envContext = re_context
212138setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213139setEnvContext e ctx = e { re_context = ctx }
214140
141+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
142+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError GraphRefRelationalExpr)
143+evalRelationalExpr (RelationVariable name _) = do
144+ relvarTable <- fmap (relationVariables . envContext) ask
145+ return $ case M.lookup name relvarTable of
146+ Just res -> Right res
147+ Nothing -> Left $ RelVarNotDefinedError name
148+
149+evalRelationalExpr (Project attrNames expr) = do
150+ eAttrNameSet <- evalAttributeNames attrNames expr
151+ case eAttrNameSet of
152+ Left err -> pure (Left err)
153+ Right attrNameSet -> do
154+ rel <- evalRelationalExpr expr
155+ case rel of
156+ Right rel2 -> pure $ Right (Project (AttributeNames attrNameSet) rel2)
157+ Left err -> pure $ Left err
158+
159+evalRelationalExpr (Union exprA exprB) = do
160+ relA <- evalRelationalExpr exprA
161+ relB <- evalRelationalExpr exprB
162+ case relA of
163+ Left err -> return $ Left err
164+ Right relA2 -> case relB of
165+ Left err -> return $ Left err
166+ Right relB2 -> return $ Right (Union relA2 relB2)
167+
168+evalRelationalExpr (Join exprA exprB) = do
169+ relA <- evalRelationalExpr exprA
170+ relB <- evalRelationalExpr exprB
171+ case relA of
172+ Left err -> return $ Left err
173+ Right relA2 -> case relB of
174+ Left err -> return $ Left err
175+ Right relB2 -> return $ Right (Join relA2 relB2)
176+
177+evalRelationalExpr (Difference exprA exprB) = do
178+ relA <- evalRelationalExpr exprA
179+ relB <- evalRelationalExpr exprB
180+ case relA of
181+ Left err -> return $ Left err
182+ Right relA2 -> case relB of
183+ Left err -> return $ Left err
184+ Right relB2 -> return $ Right (Difference relA2 relB2)
185+
186+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
187+ case mkRelation attributeSet tupleSet of
188+ Right rel -> return $ Right (ExistingRelation rel)
189+ Left err -> return $ Left err
190+
191+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
192+ currentContext <- fmap envContext ask
193+ let tConss = typeConstructorMapping currentContext
194+ -- 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
195+ runExceptT $ do
196+ mAttrs <- case mAttrExprs of
197+ Just _ ->
198+ Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
199+ Nothing -> pure Nothing
200+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
201+ let attrs = fromMaybe firstTupleAttrs mAttrs
202+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
203+ expr <- either throwE pure (mkRelation attrs (RelationTupleSet tuples))
204+ pure (ExistingRelation expr)
205+
206+evalRelationalExpr (ExistingRelation rel) = pure (Right (ExistingRelation rel))
207+
208+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
209+ evald <- evalRelationalExpr relExpr
210+ case evald of
211+ Right expr -> return $ Right (Rename oldAttrName newAttrName expr)
212+ Left err -> return $ Left err
213+
214+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
215+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
216+ case eOldAttrNameSet of
217+ Left err -> pure (Left err)
218+ Right oldAttrNameSet -> do
219+ evald <- evalRelationalExpr relExpr
220+ case evald of
221+ Right expr -> return $ Right (Group (AttributeNames oldAttrNameSet) newAttrName expr)
222+ Left err -> return $ Left err
223+
224+evalRelationalExpr (Ungroup attrName relExpr) = do
225+ evald <- evalRelationalExpr relExpr
226+ case evald of
227+ Right expr -> return $ Right (Ungroup attrName expr)
228+ Left err -> return $ Left err
229+
230+evalRelationalExpr (Restrict predicateExpr relExpr) = do
231+ evald <- evalRelationalExpr relExpr
232+ ePred <- processRestrictionPredicateExpr predicateExpr
233+ case evald of
234+ Left err -> return $ Left err
235+ Right expr -> case ePred of
236+ Left err -> pure (Left err)
237+ Right pred -> pure $ Right (Restrict pred expr)
238+
239+evalRelationalExpr (Equals relExprA relExprB) = do
240+ evaldA <- evalRelationalExpr relExprA
241+ evaldB <- evalRelationalExpr relExprB
242+ case evaldA of
243+ Left err -> return $ Left err
244+ Right exprA -> case evaldB of
245+ Left err -> return $ Left err
246+ Right exprB -> return $ Right (Equals exprA exprB)
247+{-
248+evalRelationalExpr (With views mainExpr) = do
249+ rstate <- ask
250+
251+ let addScopedView ctx (vname,vexpr) = if vname `M.member` relationVariables ctx then
252+ Left (RelVarAlreadyDefinedError vname)
253+ else
254+ case runState (evalDatabaseContextExpr (Assign vname vexpr)) (freshDatabaseState ctx) of
255+ (Left err,_) -> Left err
256+ (Right (), (ctx',_,_)) -> Right ctx'
257+
258+ case foldM addScopedView (stateElemsContext rstate) views of
259+ Left err -> return $ Left err
260+ Right ctx'' -> do
261+ let evalMainExpr expr = runReader (evalRelationalExpr expr) (RelationalExprEnv ctx'')
262+ case evalMainExpr mainExpr of
263+ Left err -> return $ Left err
264+ Right rel -> return $ Right rel
265+-}
266+--warning: copy-pasta from above- refactor
267+evalRelationalExpr (NotEquals relExprA relExprB) = do
268+ evaldA <- evalRelationalExpr relExprA
269+ evaldB <- evalRelationalExpr relExprB
270+ case evaldA of
271+ Left err -> return $ Left err
272+ Right exprA -> case evaldB of
273+ Left err -> return $ Left err
274+ Right exprB -> return $ Right (NotEquals exprA exprB)
275+
276+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
277+evalRelationalExpr (Extend tupleExpression relExpr) = do
278+ eExpr <- evalRelationalExpr relExpr
279+ case eExpr of
280+ Left err -> pure (Left err)
281+ Right expr -> do
282+ eTupProc <- processExtendTupleExpr tupleExpression
283+ case eTupProc of
284+ Left err -> pure (Left err)
285+ Right tupProc -> pure (Right (Extend tupProc expr))
286+
215287--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217−setRelVar relVarName relExpr = do
288+setRelVar :: RelVarName -> GraphRefRelationalExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
289+setRelVar relVarName relExpr transId graph = do
218290 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
291+ let newRelVars = M.insert relVarName relExpr $ relationVariables currentContext
222292 potentialContext = currentContext { relationVariables = newRelVars }
223− --optimization: if the relexpr is unchanged, skip the update
224− if M.lookup relVarName (relationVariables currentContext) == Just relExpr then
225− pure ()
226− else do
227− --determine when to check constraints
228− graph <- dbcGraph
229− tid <- dbcTransId
230− case checkConstraints potentialContext tid graph of
231− Left err -> dbErr err
232− Right _ -> putStateContext potentialContext
233−
234−--fast-path insertion- we already know that the previous relvar validated correctly, so we can validate just the relation that is being inserted for attribute matches- without this, even a single tuple relation inserted causes the entire relation to be re-validated unnecessarily
235−--insertIntoRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
293+ --determine when to check constraints
294+
295+ case checkConstraints potentialContext transId graph of
296+ Left err -> pure (Left err)
297+ Right _ -> do
298+ putStateContext potentialContext
299+ return (Right ())
236300
237301-- 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 ()
302+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239303deleteRelVar relVarName = do
240304 currContext <- getStateContext
241305 let relVars = relationVariables currContext
242306 if M.notMember relVarName relVars then
243− pure ()
307+ pure (Right ())
244308 else do
245309 let newRelVars = M.delete relVarName relVars
246310 newContext = currContext { relationVariables = newRelVars }
247311 putStateContext newContext
248− pure ()
312+ pure (Right ())
249313
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
314+evalDatabaseContextExpr :: DatabaseContextExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
315+evalDatabaseContextExpr NoOperation _ _ = pure (Right ())
252316
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
317+evalDatabaseContextExpr (Define relVarName attrExprs) transId graph = do
255318 relvars <- fmap relationVariables getStateContext
256319 tConss <- fmap typeConstructorMapping getStateContext
257− graph <- dbcGraph
258− let eAttrs = runGraphRefRelationalExprM gfEnv (mapM evalGraphRefAttrExpr attrExprs)
259− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
260− case eAttrs of
261− Left err -> dbErr err
262− Right attrsList -> do
263− lift $ except $ validateAttributes tConss (A.attributesFromList attrsList)
264− case M.member relVarName relvars of
265− True -> dbErr (RelVarAlreadyDefinedError relVarName)
266− False -> setRelVar relVarName (ExistingRelation emptyRelation)
320+ let eAttrs = map (evalAttrExpr tConss) attrExprs
321+ attrErrs = lefts eAttrs
322+ attrsList = rights eAttrs
323+ if not (null attrErrs) then
324+ pure (Left (someErrors attrErrs))
325+ else do
326+ let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
327+ if not (null atomTypeErrs) then
328+ pure (Left (someErrors atomTypeErrs))
329+ else
330+ case M.member relVarName relvars of
331+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
332+ False -> setRelVar relVarName (ExistingRelation emptyRelation) transId graph >> pure (Right ())
267333 where
268334 attrs = A.attributesFromList attrsList
269335 emptyRelation = Relation attrs emptyTupleSet
270336
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
337+evalDatabaseContextExpr (Undefine relVarName) _ _ = deleteRelVar relVarName
272338
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
339+evalDatabaseContextExpr (Assign relVarName expr) transId graph = do
275340 context <- getStateContext
276341 let existingRelVar = M.lookup relVarName (relationVariables context)
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
342+ relExprState = mkRelationalExprState context transId graph
279343 case existingRelVar of
280344 Nothing -> do
281− case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282− Left err -> dbErr err
283− Right reltype -> do
284− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285− setRelVar relVarName expr
345+ let ervExpr = runReader (evalRelationalExpr expr) relExprState
346+ case ervExpr of
347+ Left err -> pure (Left err)
348+ Right rvExpr -> setRelVar relVarName rvExpr transId graph
286349 Just existingRel -> do
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
350+ let eExpectedType = runReader (typeForGraphRefRelationalExpr existingRel) (mkRelationalExprState context transId graph)
351+ eNewExprType = runReader (typeForRelationalExpr expr) relExprState
288352 case eExpectedType of
289− Left err -> dbErr err
353+ Left err -> pure (Left err)
290354 Right expectedType ->
291355 case eNewExprType of
292− Left err -> dbErr err
356+ Left err -> pure (Left err)
293357 Right newExprType -> do
294358 if newExprType == expectedType then do
295− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296− setRelVar relVarName expr
359+ let ervExpr = runReader (evalRelationalExpr expr) relExprState
360+ case ervExpr of
361+ Left err -> pure (Left err)
362+ Right rvExpr -> setRelVar relVarName rvExpr transId graph
297363 else
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
299−
300−evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301− gfExpr <- relVarByName relVarName
302− let optExpr = applyUnionCollapse (Union
303− relExpr
304− gfExpr)
305− evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
306−
307−evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308− gfExpr <- relVarByName relVarName
309− let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310− setRelVar relVarName optExpr
364+ pure (Left (RelationTypeMismatchError (attributes expectedType) (attributes newExprType)))
365+
366+evalDatabaseContextExpr (Insert relVarName relExpr) tid graph =
367+ evalDatabaseContextExpr (Assign relVarName (Union (RelationVariable relVarName ())
368+ relExpr)) tid graph
369+
370+evalDatabaseContextExpr (Delete relVarName predicate) transId graph = do
371+ ctx <- getStateContext
372+ let rv = RelationVariable relVarName transId
373+ rvState = mkRelationalExprState ctx transId graph
374+ case runReader (processRestrictionPredicateExpr predicate) rvState of
375+ Left err -> pure (Left err)
376+ Right graphRefPredicate ->
377+ setRelVar relVarName (Restrict (NotPredicate graphRefPredicate) rv) transId graph
311378
312379--union of restricted+updated portion and the unrestricted+unupdated portion
313−evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314− rvExpr <- relVarByName relVarName
315− graph <- re_graph <$> dbcRelationalExprEnv
380+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) transId graph = do
316381 context <- getStateContext
317− let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
318− --get the current attributes name in the relvar to ensure that we don't conflict when renaming
319− eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
320− exprType' <- case eExprType of
321− Left err -> throwError err
322− Right t -> pure t
323− let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
324− tmpAttr = tmpAttrC 1
325− tmpAttrC :: Int -> AttributeName -> AttributeName
326− tmpAttrC c attr =
327− let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
328− if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
329− tmpAttrC (c+1) attr
330− else
331− tmpAttrName
332− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
333− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
334− restrictedPortion = Restrict pred' rvExpr
335− updated = foldr (\(oldname, atomExpr) accum ->
336− let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
382+ let rvState = mkRelationalExprState context transId graph
383+ relVarTable = relationVariables context
384+ case runReader (processRestrictionPredicateExpr restrictionPredicateExpr) rvState of
385+ Left err -> pure (Left err)
386+ Right graphRefPredicate ->
387+ case M.lookup relVarName relVarTable of
388+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
389+ Just existingRvExpr -> do
390+ let unrestrictedPortion = Restrict (NotPredicate graphRefPredicate) rv
391+ rv = RelationVariable relVarName transId
392+ tmpAttr attr = "_tmp_" <> attr --this could certainly be improved to verify that there is no attribute name conflict
393+ updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
394+ projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
395+ restrictedPortion = Restrict graphRefPredicate
396+ updated = foldr (\(oldname, atomExpr) accum ->
397+ let procAtomExpr = runReader (processAtomExpr atomExpr) rvState in
337398 updateAttr oldname procAtomExpr accum
338− ) restrictedPortion (M.toList atomExprMap)
399+ ) rv (M.toList atomExprMap)
339400 -- 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)
401+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
402+ setRelVar relVarName (Union unrestrictedPortion updatedPortion) transId graph
342403
343−evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
404+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) transId graph = do
344405 currContext <- getStateContext
345− transId <- dbcTransId
346− graph <- dbcGraph
347406 let currDeps = inclusionDependencies currContext
348407 newDeps = M.insert newDepName newDep currDeps
349408 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
409+ pure (Left (InclusionDependencyNameInUseError newDepName))
351410 else do
352411 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
355412 case checkConstraints potentialContext transId graph of
356− Left err -> dbErr err
357− Right _ ->
413+ Left err -> pure (Left err)
414+ Right _ -> do
358415 putStateContext potentialContext
416+ return (Right ())
359417
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
418+evalDatabaseContextExpr (RemoveInclusionDependency depName) _ _ = do
361419 currContext <- getStateContext
362420 let currDeps = inclusionDependencies currContext
363421 newDeps = M.delete depName currDeps
364422 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
366− else
423+ pure (Left (InclusionDependencyNameNotInUseError depName))
424+ else do
367425 putStateContext $ currContext {inclusionDependencies = newDeps }
426+ return (Right ())
368427
369428-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
429+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) _ _ = do
371430 currentContext <- getStateContext
372431 let nots = notifications currentContext
373432 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
433+ pure (Left (NotificationNameInUseError notName))
375434 else do
376435 let newNotifications = M.insert notName newNotification nots
377436 newNotification = Notification { changeExpr = triggerExpr,
378437 reportOldExpr = resultOldExpr,
379438 reportNewExpr = resultNewExpr}
380439 putStateContext $ currentContext { notifications = newNotifications }
440+ return (Right ())
381441
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
442+evalDatabaseContextExpr (RemoveNotification notName) _ _ = do
383443 currentContext <- getStateContext
384444 let nots = notifications currentContext
385445 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
446+ pure (Left (NotificationNameNotInUseError notName))
387447 else do
388448 let newNotifications = M.delete notName nots
389449 putStateContext $ currentContext { notifications = newNotifications }
390−
450+ pure (Right ())
391451
392452-- | Adds type and data constructors to the database context.
393453-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
454+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) _ _ = do
395455 currentContext <- getStateContext
396456 let oldTypes = typeConstructorMapping currentContext
397457 tConsName = TCD.name tConsDef
398458 -- validate that the constructor's types exist
399− case validateTypeConstructorDef tConsDef dConsDefList oldTypes of
400− Left err -> throwError err
401− Right () | T.null tConsName || not (isUpper (T.head tConsName)) -> dbErr (InvalidAtomTypeName tConsName)
402− | isJust (findTypeConstructor tConsName oldTypes) -> dbErr (AtomTypeNameInUseError tConsName)
459+ case validateTypeConstructorDef tConsDef dConsDefList of
460+ errs@(_:_) -> pure (Left (someErrors errs))
461+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
462+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403463 | otherwise -> do
404464 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405465 putStateContext $ currentContext { typeConstructorMapping = newTypes }
466+ pure (Right ())
406467
407468-- | 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
469+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) _ _ = do
409470 currentContext <- getStateContext
410471 let oldTypes = typeConstructorMapping currentContext
411472 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
473+ pure (Left (AtomTypeNameNotInUseError tConsName))
413474 else do
414475 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415476 putStateContext $ currentContext { typeConstructorMapping = newTypes }
477+ pure (Right ())
416478
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
479+evalDatabaseContextExpr (MultipleExpr exprs) transId graph = do
418480 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
420−
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
481+ evald <- forM exprs (\expr -> evalDatabaseContextExpr expr transId graph)
482+ --some lifting magic needed here
483+ case lefts evald of
484+ [] -> pure (Right ())
485+ errs -> pure (Left (someErrors errs))
486+
487+evalDatabaseContextExpr (RemoveAtomFunction funcName) _ _ = do
422488 currentContext <- getStateContext
423489 let atomFuncs = atomFunctions currentContext
424490 case atomFunctionForName funcName atomFuncs of
425− Left err -> dbErr err
426− Right realFunc ->
427− if isScriptedAtomFunction realFunc then do
428− let updatedFuncs = HS.delete realFunc atomFuncs
429− putStateContext (currentContext {atomFunctions = updatedFuncs })
430− else
431− dbErr (PrecompiledFunctionRemoveError funcName)
491+ Left err -> pure (Left err)
492+ Right realFunc -> if isScriptedAtomFunction realFunc then do
493+ let updatedFuncs = HS.delete realFunc atomFuncs
494+ putStateContext (currentContext {atomFunctions = updatedFuncs })
495+ pure (Right ())
496+ else
497+ pure (Left (PrecompiledFunctionRemoveError funcName))
432498
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
499+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) _ _ = do
434500 context <- getStateContext
435501 let dbcFuncs = dbcFunctions context
436502 case databaseContextFunctionForName funcName dbcFuncs of
437− Left err -> dbErr err
438− Right realFunc ->
439− if isScriptedDatabaseContextFunction realFunc then do
440− let updatedFuncs = HS.delete realFunc dbcFuncs
441− putStateContext (context { dbcFunctions = updatedFuncs })
442− else
443− dbErr (PrecompiledFunctionRemoveError funcName)
503+ Left err -> pure (Left err)
504+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
505+ let updatedFuncs = HS.delete realFunc dbcFuncs
506+ putStateContext (context { dbcFunctions = updatedFuncs })
507+ pure (Right ())
508+ else
509+ pure (Left (PrecompiledFunctionRemoveError funcName))
444510
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
511+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) transId graph = do
446512 context <- getStateContext
447− graph <- dbcGraph
448513 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
514+ let relExprState = mkRelationalExprState context transId graph
515+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450516 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452517 case eFunc of
453− Left err -> dbErr err
518+ Left err -> pure (Left err)
454519 Right func -> do
455520 let expectedArgCount = length (dbcFuncType func)
456521 actualArgCount = length atomArgExprs
457522 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
523+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
459524 else
460525 --check that the atom types are valid
461− case eAtomTypes of
462− Left err -> dbErr err
463− Right atomTypes -> do
464− let mValidTypes = zipWith (\ expType actType
465− -> case atomTypeVerify expType actType of
466− Left err -> Just err
467− Right _ -> Nothing)
468− (dbcFuncType func) atomTypes
526+ case lefts eAtomTypes of
527+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
528+ [] -> do
529+ let atomTypes = rights eAtomTypes
530+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
531+ Left err -> Just err
532+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
469533 typeErrors = catMaybes mValidTypes
470− eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
534+ eAtomArgs = unimplemented
535+ --eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471536 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
537+ pure (Left (someErrors (lefts eAtomArgs)))
473538 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
539+ pure (Left (someErrors typeErrors))
475540 else
476541 case evalDatabaseContextFunction func (rights eAtomArgs) context of
477− Left err -> dbErr err
478− Right newContext -> putStateContext newContext
479−data DatabaseContextIOEvalEnv = DatabaseContextIOEvalEnv
480− { dbcio_transId :: TransactionId,
481− dbcio_graph :: TransactionGraph,
482− dbcio_mScriptSession :: Maybe ScriptSession
483− }
484−
485−type DatabaseContextIOEvalMonad a = RWST DatabaseContextIOEvalEnv () DatabaseContextEvalState IO a
486−
487−runDatabaseContextIOEvalMonad :: DatabaseContextIOEvalEnv -> DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ()) -> IO (Either RelationalError DatabaseContextEvalState)
488−runDatabaseContextIOEvalMonad env ctx m = do
489− res <- runRWST m env freshState
490− case res of
491− (Left err,_,_) -> pure (Left err)
492− (Right (),s,_) -> pure (Right s)
493− where
494− freshState = mkDatabaseContextEvalState ctx
495−
496−requireScriptSession :: DatabaseContextIOEvalMonad (Either RelationalError ScriptSession)
497−requireScriptSession = do
498− env <- RWS.ask
499− case dbcio_mScriptSession env of
500− Nothing -> pure $ Left $ ScriptError ScriptCompilationDisabledError
501− Just ss -> pure (Right ss)
502−
503−putDBCIOContext :: DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ())
504−putDBCIOContext ctx = do
505− RWS.modify (\dbstate -> dbstate { dbc_context = ctx})
506− pure (Right ())
507−
508−getDBCIOContext :: DatabaseContextIOEvalMonad DatabaseContext
509−getDBCIOContext = dbc_context <$> RWS.get
510−
511−getDBCIORelationalExprEnv :: DatabaseContextIOEvalMonad RelationalExprEnv
512−getDBCIORelationalExprEnv = do
513− context <- getDBCIOContext
514− mkRelationalExprEnv context . dbcio_graph <$> RWS.ask
515−
516−evalGraphRefDatabaseContextIOExpr :: GraphRefDatabaseContextIOExpr -> DatabaseContextIOEvalMonad (Either RelationalError ())
517−#if !defined(PM36_HASKELL_SCRIPTING)
518−evalGraphRefDatabaseContextIOExpr AddAtomFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
519−evalGraphRefDatabaseContextIOExpr AddDatabaseContextFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
520−evalGraphRefDatabaseContextIOExpr LoadAtomFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
521−evalGraphRefDatabaseContextIOExpr LoadDatabaseContextFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
522−#else
523−evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = do
524− eScriptSession <- requireScriptSession
525− currentContext <- getDBCIOContext
526− case eScriptSession of
527− Left err -> pure (Left err)
528− Right scriptSession -> do
529− res <- liftIO $ try $ runGhc (Just libdir) $ do
542+ Left err -> pure (Left err)
543+ Right newContext -> putStateContext newContext >> pure (Right ())
544+
545+evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> TransactionId -> TransactionGraph -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
546+evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction funcName funcType script) =
547+ case mScriptSession of
548+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
549+ Just scriptSession -> do
550+ res <- try $ runGhc (Just libdir) $ do
530551 setSession (hscEnv scriptSession)
531552 let atomFuncs = atomFunctions currentContext
532553 case extractAtomFunctionType funcType of
@@ -552,13 +573,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552573 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553574 Right eContext -> case eContext of
554575 Left err -> pure (Left err)
555− Right context' -> putDBCIOContext context'
556−evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType script) = do
557− eScriptSession <- requireScriptSession
558− currentContext <- getDBCIOContext
559− case eScriptSession of
560− Left err -> pure (Left err)
561− Right scriptSession -> do
576+ Right context' -> pure (Right context')
577+
578+evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextFunction funcName funcType script) =
579+ case mScriptSession of
580+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
581+ Just scriptSession -> do
562582 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563583 let last2Args = reverse (take 2 (reverse funcType))
564584 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +588,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568588 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569589 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
570590 else do
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
591+ res <- try $ runGhc (Just libdir) $ do
572592 setSession (hscEnv scriptSession)
573593 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574594 pure $ case eCompiledFunc of
@@ -593,86 +613,79 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593613 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594614 Right eContext -> case eContext of
595615 Left err -> pure (Left err)
596− Right context' -> putDBCIOContext context'
597−evalGraphRefDatabaseContextIOExpr (LoadAtomFunctions modName funcName modPath) = do
598− currentContext <- getDBCIOContext
599− eLoadFunc <- liftIO $ loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
616+ Right context' -> pure (Right context')
617+evalDatabaseContextIOExpr _ currentContext _ _ (LoadAtomFunctions modName funcName modPath) = do
618+ eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600619 case eLoadFunc of
601620 Left LoadSymbolError -> pure (Left LoadFunctionError)
602621 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603622 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
604− in putDBCIOContext newContext
605−evalGraphRefDatabaseContextIOExpr (LoadDatabaseContextFunctions modName funcName modPath) = do
606− currentContext <- getDBCIOContext
607− eLoadFunc <- liftIO $ loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
623+ in pure (Right newContext)
624+evalDatabaseContextIOExpr _ currentContext _ _ (LoadDatabaseContextFunctions modName funcName modPath) = do
625+ eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608626 case eLoadFunc of
609627 Left LoadSymbolError -> pure (Left LoadFunctionError)
610628 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611629 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
613−#endif
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
630+ in pure (Right newContext)
631+
632+evalDatabaseContextIOExpr _ currentContext transId graph (CreateArbitraryRelation relVarName attrExprs range) =
615633 --Define
616− currentContext <- getDBCIOContext
617− env <- RWS.ask
618− --create graph ref expr
619− let gfExpr = Define relVarName attrExprs
620− evalEnv = mkDatabaseContextEvalEnv (dbcio_transId env) (dbcio_graph env)
621− graph = dbcio_graph env
622− case runDatabaseContextEvalMonad currentContext evalEnv (evalGraphRefDatabaseContextExpr gfExpr) of
623− Left err -> pure (Left err)
624− Right dbstate -> do
634+ case runState (evalDatabaseContextExpr (Define relVarName attrExprs) transId graph) (freshDatabaseState currentContext) of
635+ (Left err,_) -> pure (Left err)
636+ (Right (), elems) -> do
625637 --Assign
626638 let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
639+ relVarTable = relationVariables (context elems)
628640 case existingRelVar of
629641 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630642 Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
643+ case runReader (typeForGraphRefRelationalExpr existingRel) (mkRelationalExprState currentContext transId graph) of
633644 Left err -> pure (Left err)
634645 Right relType -> do
635646 let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
647+ tcMap = typeConstructorMapping (context elems)
648+ eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638649 case eitherRel of
639650 Left err -> pure $ Left err
640651 Right rel ->
641− case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642− Left err -> pure (Left err)
643− Right dbstate' -> putDBCIOContext (dbc_context dbstate')
652+ case runState (setRelVar relVarName (ExistingRelation rel) transId graph) elems of
653+ (Left err,_) -> pure (Left err)
654+ (Right (), elems') -> pure $ Right (context elems)
655+
656+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> TransactionGraph -> RelationTuple -> Either RelationalError RelationTuple
657+updateTupleWithAtomExprs exprMap context graph tupIn = do
658+ --resolve all atom exprs
659+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
660+ let atom = unimplemented
661+ --atom <- runReader (evalAtomExpr tupIn atomExpr) (mkRelationalExprState context graph)
662+ pure (attrName, atom)
663+ ) (M.toList exprMap)
664+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
644665
645666--run verification on all constraints
646667checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
668+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
648669 mapM_ (uncurry checkIncDep) (M.toList deps)
649670 where
650671 potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
651672 tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
652673 utctDayTime = secondsToDiffTime 0 }
653674 tempSchemas = Schemas context M.empty
654− tempTrans = Transaction U.nil tempTransInfo tempSchemas
655− tempTransInfo = TransactionInfo { parents = transId NE.:| [],
656− stamp = tempStamp,
657− merkleHash = mempty
658− }
675+ tempTrans = Transaction U.nil (TransactionInfo (transId NE.:| []) tempStamp) tempSchemas
659676
660677 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
678+ eval expr = evalReader (evalRelationalExpr expr)
679+ evalReader f = runReader f (mkRelationalExprState context transId graph)
662680 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663− let process = runProcessExprM UncommittedContextMarker
664− gfSubsetExpr = process (processRelationalExpr subsetExpr)
665− gfSupersetExpr = process (processRelationalExpr supersetExpr)
681+ let gfSubsetExpr = evalReader (processRelationalExpr subsetExpr)
682+ gfSupersetExpr = evalReader (processRelationalExpr supersetExpr)
666683 --if both expressions are of a single-attribute (such as with a simple foreign key), the names of the attributes are irrelevant (they need not match) because the expression is unambiguous, but special-casing this to rename the attribute automatically would not be orthogonal behavior and probably cause confusion. Instead, special case the error to make it clear.
667− let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668− runGfRel = runGraphRefRelationalExprM gfEnv
669− typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670− typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
684+ typeSub <- evalReader (typeForRelationalExpr subsetExpr)
685+ typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
671686 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672687 let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675− case gfEvald of
688+ case evalGraphRefRelationalExpr checkExpr potentialGraph of
676689 Left err -> Left err
677690 Right resultRel -> if resultRel == relationTrue then
678691 pure ()
@@ -682,81 +695,87 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
682695-- 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
683696-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
684697
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
698+typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
686699typeForRelationalExpr expr = do
687700 --replace the relationVariables context element with a cloned set of relation devoid of tuples
688701 --evalRelationalExpr could still return an existing relation with tuples, so strip them
689− graph <- reGraph
690− context <- reContext
691− let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
692− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
693− runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
694− lift $ except runGf
702+ gfExpr <- processRelationalExpr expr
703+ typeForGraphRefRelationalExpr gfExpr
704+
705+--returns a database context with all tuples removed
706+--this is useful for type checking and optimization
707+{-
708+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
709+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
710+ where
711+ relVars = M.map (\rel -> ExistingRelation (Relation (attributes rel) emptyTupleSet)) (relationVariables contextIn)
712+-}
695713
696714liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697715liftE v = do
698716 y <- lift v
699717 case y of
700− Left err -> throwError err
718+ Left err -> throwE err
701719 Right val -> pure val
702720
703721{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
704−predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
705−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
706− expr1v <- predicateRestrictionFilter attrs expr1
707− expr2v <- predicateRestrictionFilter attrs expr2
708− pure (\x -> do
709− ev1 <- expr1v x
710− ev2 <- expr2v x
711− pure (ev1 && ev2))
712−
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714− expr1v <- predicateRestrictionFilter attrs expr1
715− expr2v <- predicateRestrictionFilter attrs expr2
722+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExprBase a -> RelationalExprState (Either RelationalError RestrictionFilter)
723+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
724+ runExceptT $ do
725+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
726+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
727+ pure (\x -> do
728+ ev1 <- expr1v x
729+ ev2 <- expr2v x
730+ pure (ev1 && ev2))
731+
732+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
733+ runExceptT $ do
734+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
735+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716736 pure (\x -> do
717737 ev1 <- expr1v x
718738 ev2 <- expr2v x
719739 pure (ev1 || ev2))
720740
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
741+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
722742
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
724− exprv <- predicateRestrictionFilter attrs expr
725− pure (fmap not . exprv)
743+predicateRestrictionFilter attrs (NotPredicate expr) =
744+ runExceptT $ do
745+ exprv <- liftE (predicateRestrictionFilter attrs expr)
746+ pure (fmap not . exprv)
726747
727748--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
749+{-
728750predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
729− renv <- askEnv
730− let eval :: RelationTuple -> Either RelationalError Relation
731− eval tup =
732− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup renv in
733− runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
734− pure (\tup -> case eval tup of
751+ rstate <- ask
752+ pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
735753 Left err -> Left err
736754 Right rel -> if arity rel /= 0 then
737755 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
738756 else
739− pure (rel == relationTrue))
757+ pure (rel == relationTrue)))
740758
741759predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
742− env <- askEnv
743− let attrs' = A.union attrs (envAttributes env)
744− ctxtup' = envTuple env
745− atomExprType <- typeForGraphRefAtomExpr attrs' atomExpr
746− attr <- lift $ except $ case A.attributeForName attrName attrs of
760+ rstate <- ask
761+ let attrs' = stateAttributes rstate
762+ ctxtup' = stateTuple rstate
763+ runExceptT $ do
764+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
765+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747766 Right attr -> Right attr
748767 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749768 Right ctxattr -> Right ctxattr
750769 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751770 Left err -> Left err
752771 Left err -> Left err
753− if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755− else
772+ if atomExprType /= A.atomType attr then
773+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
774+ else
756775 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757776 Right atomCmp -> atomCmp == atomIn
758777 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
778+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
760779 in
761780 pure $ case atomForAttributeName attrName tupleIn of
762781 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,322 +786,267 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
767786-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768787predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769788 --merge attrs into the state attributes
770− renv <- askEnv
771− aType <- typeForGraphRefAtomExpr attrs atomExpr
772− if aType /= BoolAtomType then
773− throwError (AtomTypeMismatchError aType BoolAtomType)
774− else
789+ rstate <- ask
790+ runExceptT $ do
791+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
792+ if aType /= BoolAtomType then
793+ throwE (AtomTypeMismatchError aType BoolAtomType)
794+ else
775795 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777− Left err -> Left err
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
779−
796+ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
797+ Left err -> Left err
798+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
799+-}
780800tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781801tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
782802 Left (AttributeNameInUseError attrName)
783803 else
784804 Right rel
785805
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788−-- renv <- askEnv
806+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
807+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
808+ rstate <- ask
789809 -- check that the attribute name is not in use
790810 case tupleExprCheckNewAttrName newAttrName relIn of
791− Left err -> throwError err
792− Right _ -> do
793− atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
794− atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
811+ Left err -> pure (Left err)
812+ Right _ -> runExceptT $ do
813+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
814+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795815 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796816 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
797− env <- ask
798− pure (newAndOldAttrs, \tup -> do
799− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup env
800− atom <- runGraphRefRelationalExprM gfEnv (evalGraphRefAtomExpr tup atomExpr)
801− Right (tupleAtomExtend newAttrName atom tup)
817+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in
818+ case unimplemented {-runReader (evalAtomExpr tup atomExpr) substate-} of
819+ Left err -> Left err
820+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
802821 )
803822
804−evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
805−evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806− case atomForAttributeName attrName tupIn of
807− Right atom -> pure atom
808− Left err@(NoSuchAttributeNamesError _) -> do
809− env <- askEnv
810− case gre_extra env of
811− Nothing -> throwError err
812− Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
813− Just (Right _) -> throwError err
814− Left err -> throwError err
815−evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
816−evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
817− argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
818− context <- gfDatabaseContextForMarker tid
819− let functions = atomFunctions context
820− func <- lift $ except (atomFunctionForName funcName functions)
821− let expectedArgCount = length (atomFuncType func) - 1
822− actualArgCount = length argTypes
823− safeInit [] = [] -- different behavior from normal init
824− safeInit xs = init xs
825− if expectedArgCount /= actualArgCount then
826− throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
827− else do
823+
824+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
825+evalAtomExpr = undefined
826+{-
827+
828+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
829+ Right atom -> pure (Right atom)
830+ err@(Left (NoSuchAttributeNamesError _)) -> do
831+ rstate <- ask
832+ let stateTup = stateTuple rstate
833+ pure (atomForAttributeName attrName stateTup)
834+ Left err -> pure (Left err)
835+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
836+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
837+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
838+ context <- fmap stateElemsContext ask
839+ runExceptT $ do
840+ let functions = atomFunctions context
841+ func <- either throwE pure (atomFunctionForName funcName functions)
842+ let expectedArgCount = length (atomFuncType func) - 1
843+ actualArgCount = length argTypes
844+ safeInit [] = [] -- different behavior from normal init
845+ safeInit xs = init xs
846+ if expectedArgCount /= actualArgCount then
847+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
848+ else do
828849 let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
829− mapM_ (\(expType, actType) ->
830− lift $ except (atomTypeVerify expType actType)) zippedArgs
831− evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
850+ mapM_ (\(expType, eActType) -> do
851+ actType <- either throwE pure eActType
852+ either throwE pure (atomTypeVerify expType actType)) zippedArgs
853+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832854 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
855+ Left err -> throwE (AtomFunctionUserError err)
834856 Right result -> do
835857 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
858+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837859 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
860+evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
839861 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
840− env <- ask
841− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn env
842− relAtom <- lift $ except $ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
843− pure (RelationAtom relAtom)
844−evalGraphRefAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs _) = do --why is the tid unused here? suspicious
845− let mergeEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn
846− aType <- local mergeEnv (typeForGraphRefAtomExpr (tupleAttributes tupIn) cons)
847− argAtoms <- local mergeEnv $
848− mapM (evalGraphRefAtomExpr tupIn) dConsArgs
862+ rstate <- ask
863+ runExceptT $ do
864+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
865+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
866+ pure (RelationAtom relAtom)
867+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
868+ rstate <- lift ask
869+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
870+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
871+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
849872 pure (ConstructedAtom dConsName aType argAtoms)
850−
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
873+-}
874+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
875+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
876+ rstate <- ask
854877 case A.atomTypeForAttributeName attrName attrs of
855− Right aType -> pure aType
878+ Right aType -> pure (Right aType)
856879 Left err@(NoSuchAttributeNamesError _) ->
857− let envTup = envTuple renv
858− envAttrs = envAttributes renv in
859− case A.attributeForName attrName envAttrs of
860− Right attr -> pure (A.atomType attr)
861− Left _ -> case atomForAttributeName attrName envTup of
862− Right atom -> pure (atomTypeForAtom atom)
863− Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
864− throwError err
865− Left err -> throwError err
866−
867−typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
868−typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
869− funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
880+ let stateTup = stateTuple rstate
881+ stateAttrs = stateAttributes rstate in
882+ case A.attributeForName attrName stateAttrs of
883+ Right attr -> pure (Right (A.atomType attr))
884+ Left _ -> case atomForAttributeName attrName stateTup of
885+ Right atom -> pure (Right (atomTypeForAtom atom))
886+ Left _ -> pure (Left err)
887+
888+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
889+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
890+ context <- fmap envContext ask
891+ let funcs = atomFunctions context
870892 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
893+ Left err -> pure (Left err)
872894 Right func -> do
873895 let funcRetType = last (atomFuncType func)
874896 funcArgTypes = init (atomFuncType func)
875− argTypes <- mapM (typeForGraphRefAtomExpr attrs) atomArgs
876− let eTvMap = resolveTypeVariables funcArgTypes argTypes
877− case eTvMap of
878− Left err -> throwError err
879− Right tvMap -> lift $ except $ resolveFunctionReturnValue funcName tvMap funcRetType
880−typeForGraphRefAtomExpr attrs (RelationAtomExpr relExpr) = do
881− relType <- R.local (mergeAttributesIntoGraphRefRelationalExprEnv attrs) (typeForGraphRefRelationalExpr relExpr)
882− pure (RelationAtomType (attributes relType))
897+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
898+ case lefts eArgTypes of
899+ errs@(_:_) -> pure (Left (someErrors errs))
900+ [] -> do
901+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
902+ argTypes = rights eArgTypes
903+ case eTvMap of
904+ Left err -> pure (Left err)
905+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
906+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = do
907+ relType <- local (mergeAttributesIntoRelationalExprState attrs) (typeForRelationalExpr relExpr)
908+ case relType of
909+ Left err -> pure (Left err)
910+ Right relType' ->
911+ pure (pure (RelationAtomType (attributes relType')))
883912-- grab the type of the data constructor, then validate that the args match the expected types
884−typeForGraphRefAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs tid) =
885− do
886− argsTypes <- mapM (typeForGraphRefAtomExpr attrs) dConsArgs
887− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
888− lift $ except $ atomTypeForDataConstructor tConsMap dConsName argsTypes
913+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
914+ runExceptT $ do
915+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
916+ context <- fmap envContext (lift ask)
917+ either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
889918
890919-- | Validate that the type of the AtomExpr matches the expected type.
891−verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892−verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893− env <- askEnv
920+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
921+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
922+ rstate <- lift ask
894923 case A.atomTypeForAttributeName attrName (attributes relIn) of
895− Right aType -> lift $ except $ atomTypeVerify expectedType aType
924+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
896925 (Left err@(NoSuchAttributeNamesError _)) ->
897− let attrs' = envAttributes env in
926+ let attrs' = stateAttributes rstate in
898927 if attrs' == emptyAttributes then
899− throwError err
928+ throwE err
900929 else
901930 case A.attributeForName attrName attrs' of
902− Left err' -> throwError err'
903− Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
904− Left err -> throwError err
905−
906−verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907− lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
908−verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
909− context <- gfDatabaseContextForMarker tid
931+ Left err' -> throwE err'
932+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
933+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
934+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
935+ rstate <- ask
910936 let functions = atomFunctions context
911− func <- lift $ except $ atomFunctionForName funcName functions
912− let expectedArgTypes = atomFuncType func
913− funcArgVerifier (atomExpr, expectedType2, argCount) = do
914− let handler :: RelationalError -> GraphRefRelationalExprM AtomType
915− handler (AtomTypeMismatchError expSubType actSubType) = throwError (AtomFunctionTypeError funcName argCount expSubType actSubType)
916− handler err = throwError err
917− verifyGraphRefAtomExprTypes relIn atomExpr expectedType2 `catchError` handler
918− funcArgTypes <- mapM funcArgVerifier $ zip3 funcArgExprs expectedArgTypes [1..]
919− if length funcArgTypes /= length expectedArgTypes - 1 then
920− throwError (AtomTypeCountError funcArgTypes expectedArgTypes)
937+ context = envContext rstate
938+ runExceptT $ do
939+ func <- either throwE pure (atomFunctionForName funcName functions)
940+ let expectedArgTypes = atomFuncType func
941+ funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
942+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
943+ Left err -> throwE err
944+ Right x -> pure x
945+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
946+ if length funcArgTypes /= length expectedArgTypes - 1 then
947+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
921948 else
922− lift $ except $ atomTypeVerify expectedType (last expectedArgTypes)
923−verifyGraphRefAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType =
924− do
925− let mergedAttrsEnv e = mergeAttributesIntoGraphRefRelationalExprEnv (attributes relIn) e
926− relType <- R.local mergedAttrsEnv (typeForGraphRefRelationalExpr relationExpr)
927− lift $ except $ atomTypeVerify expectedType (RelationAtomType (attributes relType))
928−verifyGraphRefAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = do
929− cType <- typeForGraphRefAtomExpr (attributes rel) cons
930− lift $ except $ atomTypeVerify expectedType cType
949+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
950+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
951+ rstate <- lift ask
952+ relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
953+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
954+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
955+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
956+ either throwE pure (atomTypeVerify expectedType cType)
931957
932958-- | Look up the type's name and create a new attribute.
933−evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
934−evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
935− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
936− aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
937− lift $ except $ validateAtomType aType tConsMap
938− pure $ Attribute attrName aType
959+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
960+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
961+ aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
962+ validateAtomType aType aTypes
963+ Right (Attribute attrName aType)
939964
940−evalGraphRefAttrExpr (NakedAttributeExpr attr) = pure attr
941−
942−-- for tuple type concrete resolution (Nothing ==> Maybe Int) when the attributes hint is Nothing, we need to first process all the tuples, then extract the concrete types on a per-attribute basis, then reprocess the tuples to include the concrete types
943−evalGraphRefTupleExprs :: Maybe Attributes -> GraphRefTupleExprs -> GraphRefRelationalExprM [RelationTuple]
944−evalGraphRefTupleExprs _ (TupleExprs _ []) = pure []
945−evalGraphRefTupleExprs mAttrs (TupleExprs fixedMarker tupleExprL) = do
946− tuples <- mapM (evalGraphRefTupleExpr mAttrs) tupleExprL
947− finalAttrs <- case mAttrs of
948− Just attrs -> pure attrs
949− Nothing ->
950− case tuples of
951− [] -> pure emptyAttributes
952− (headTuple:tailTuples) -> do
953− --gather up resolved atom types or throw an error if an attribute cannot be made concrete from the inferred types- this could still fail if the type cannot be inferred (e.g. from [Nothing, Nothing])
954− let
955− processTupleAttrs (tupAttr, accAttr) =
956− --if the attribute is a constructedatomtype, we can recurse into it to potentially resolve type variables
957− if isResolvedAttribute accAttr && tupAttr == accAttr then
958− pure accAttr
959− else
960− lift $ except $ resolveAttributes accAttr tupAttr
961− mostResolvedTypes <-
962− foldM (\acc tup -> do
963− let zipped = zip (V.toList . attributesVec $ tupleAttributes tup) acc
964− accNames = S.fromList $ map A.attributeName acc
965− tupNames = A.attributeNameSet (tupleAttributes tup)
966− attrNamesDiff = S.union (S.difference accNames tupNames) (S.difference tupNames accNames)
967− unless (null attrNamesDiff) (throwError (AttributeNamesMismatchError attrNamesDiff))
968− nextTupleAttrs <- mapM processTupleAttrs zipped
969− let diff = A.attributesDifference (A.attributesFromList nextTupleAttrs) (A.attributesFromList acc)
970− if diff == A.emptyAttributes then
971− pure nextTupleAttrs
972− else
973− throwError (TupleAttributeTypeMismatchError diff)
974− ) (V.toList . attributesVec $ tupleAttributes headTuple) tailTuples
975− pure (A.attributesFromList mostResolvedTypes)
976− --strategy: if all the tuple expr transaction markers refer to one location, then we can pass the type constructor mapping from that location, otherwise, we cannot assume that the types are the same
977− tConsMap <- case singularTransactions tupleExprL of
978− SingularTransactionRef commonTransId ->
979− typeConstructorMapping <$> gfDatabaseContextForMarker commonTransId
980− NoTransactionsRef ->
981− typeConstructorMapping <$> gfDatabaseContextForMarker fixedMarker
982− -- if there are multiple transaction markers in the TupleExprs, then we can't assume a single type constructor mapping- this could be improved in the future, but if all the tuples are fully resolved, then we don't need further resolution
983− _ -> throwError TupleExprsReferenceMultipleMarkersError
984− lift $ except $ validateAttributes tConsMap finalAttrs
985− mapM (lift . except . resolveTypesInTuple finalAttrs tConsMap) tuples
986−
987−
988−--resolveAttributes (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",IntegerAtomType),("b",TypeVariableType "b")]))) (Attribute "gonk" (ConstructedAtomType "Either" (fromList [("a",TypeVariableType "a"),("b",TextAtomType)])))
989−
990−evalGraphRefTupleExpr :: Maybe Attributes -> GraphRefTupleExpr -> GraphRefRelationalExprM RelationTuple
991−evalGraphRefTupleExpr mAttrs (TupleExpr tupMap) = do
965+evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
966+
967+evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
968+evalTupleExpr mAttrs (TupleExpr tupMap) = do
969+ context <- fmap envContext ask
970+ runExceptT $ do
992971 -- 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
993972 -- I could adjust this logic so that when the attributes are not specified (Nothing), then I can attempt to extract the attributes from the tuple- the type resolution will blow up if an ambiguous data constructor is used (Left 4) and this should allow simple cases to "relation{tuple{a 4}}" to be processed
994− let attrs = fromMaybe A.emptyAttributes mAttrs
995− resolveOneAtom (attrName, aExpr) =
996− do
997− --provided when the relation header is available
998− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
999− unresolvedType <- typeForGraphRefAtomExpr attrs aExpr
1000− resolvedType <- case eExpectedAtomType of
973+ let attrs = fromMaybe A.emptyAttributes mAttrs
974+ attrAtoms <- mapM (\(attrName, aExpr) -> do
975+ --provided when the relation header is available
976+ let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
977+ unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
978+ resolvedType <- case eExpectedAtomType of
1001979 Left _ -> pure unresolvedType
1002− Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
980+ Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1003981 --resolve atom typevars based on resolvedType?
1004− newAtom <- evalGraphRefAtomExpr emptyTuple aExpr
1005− pure (attrName, newAtom, resolvedType)
1006− attrAtoms <- mapM resolveOneAtom (M.toList tupMap)
1007− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
1008− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
1009− tup = mkRelationTuple tupAttrs atoms
1010− finalAttrs = fromMaybe tupAttrs mAttrs
982+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
983+ pure (attrName, newAtom, resolvedType)
984+ ) (M.toList tupMap)
985+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
986+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
987+ tup = mkRelationTuple tupAttrs atoms
988+ tConss = typeConstructorMapping context
989+ finalAttrs = fromMaybe tupAttrs mAttrs
1011990 --verify that the attributes match
1012− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
1013− --we can't resolve types here- they have to be resolved at the atom level where the graph ref is held
1014− --tup' <- lift $ except (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
1015− let tup' = reorderTuple finalAttrs tup
1016− --TODO: restore type resolution
1017−-- _ <- lift $ except (validateTuple tup' tConss)
1018− pure tup'
1019−
1020−--temporary implementation until we have a proper planner+executor
1021−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1022−evalGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1023− mAttrs <- case mAttrExprs of
1024− Just _ ->
1025− Just . A.attributesFromList <$> mapM evalGraphRefAttrExpr (fromMaybe [] mAttrExprs)
1026− Nothing -> pure Nothing
1027− tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1028− let attrs = fromMaybe firstTupleAttrs mAttrs
1029− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
1030− lift $ except $ mkRelation attrs (RelationTupleSet tuples)
1031−evalGraphRefRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
1032− lift $ except $ mkRelation attributeSet tupleSet
1033−evalGraphRefRelationalExpr (ExistingRelation rel) = pure rel
1034−evalGraphRefRelationalExpr (RelationVariable name tid) = do
1035− ctx <- gfDatabaseContextForMarker tid
991+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
992+ tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
993+ _ <- either throwE pure (validateTuple tup' tConss)
994+ pure tup'
995+
996+evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
997+evalAttributeNames attrNames expr = do
998+ eExprType <- typeForRelationalExpr expr
999+ case eExprType of
1000+ Left err -> pure (Left err)
1001+ Right exprTyp -> do
1002+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
1003+ case attrNames of
1004+ AttributeNames names ->
1005+ case A.projectionAttributesForNames names (attributes exprTyp) of
1006+ Left err -> pure (Left err)
1007+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1008+
1009+ InvertedAttributeNames names -> do
1010+ let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1011+ if not (S.null nonExistentAttributeNames) then
1012+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1013+ else
1014+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1015+
1016+ UnionAttributeNames namesA namesB -> do
1017+ eNameSetA <- evalAttributeNames namesA expr
1018+ case eNameSetA of
1019+ Left err -> pure (Left err)
1020+ Right nameSetA -> do
1021+ eNameSetB <- evalAttributeNames namesB expr
1022+ case eNameSetB of
1023+ Left err -> pure (Left err)
1024+ Right nameSetB ->
1025+ pure (Right (S.union nameSetA nameSetB))
1026+
1027+ IntersectAttributeNames namesA namesB -> do
1028+ eNameSetA <- evalAttributeNames namesA expr
1029+ case eNameSetA of
1030+ Left err -> pure (Left err)
1031+ Right nameSetA -> do
1032+ eNameSetB <- evalAttributeNames namesB expr
1033+ case eNameSetB of
1034+ Left err -> pure (Left err)
1035+ Right nameSetB ->
1036+ pure (Right (S.intersection nameSetA nameSetB))
1037+
1038+ RelationalExprAttributeNames attrExpr -> do
1039+ eAttrExprType <- typeForRelationalExpr attrExpr
1040+ case eAttrExprType of
1041+ Left err -> pure (Left err)
1042+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1043+
1044+evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1045+evalGraphRefRelationalExpr (RelationVariable name tid) graph = do
1046+ ctx <- dbContextForTransId tid graph
10361047 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)
1048+ Nothing -> Left (RelVarNotDefinedError name)
1049+ Just rv -> evalGraphRefRelationalExpr rv graph
10861050
10871051dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
10881052dbContextForTransId tid graph = do
@@ -1100,120 +1064,176 @@ transactionForId tid graph
11001064 where
11011065 matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
11021066
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
1067+processRestrictionPredicateExpr :: RestrictionPredicateExpr -> RelationalExprState (Either RelationalError GraphRefRestrictionPredicateExpr)
1068+processRestrictionPredicateExpr TruePredicate = pure (Right TruePredicate)
1069+processRestrictionPredicateExpr (AndPredicate a b) = do
1070+ a' <- processRestrictionPredicateExpr a
1071+ b' <- processRestrictionPredicateExpr b
1072+ case a' of
1073+ Left err -> pure (Left err)
1074+ Right a'' -> case b' of
1075+ Left err -> pure (Left err)
1076+ Right b'' ->
1077+ pure (Right (AndPredicate a'' b''))
1078+processRestrictionPredicateExpr (OrPredicate a b) = do
1079+ a' <- processRestrictionPredicateExpr a
1080+ b' <- processRestrictionPredicateExpr b
1081+ case a' of
1082+ Left err -> pure (Left err)
1083+ Right a'' -> case b' of
1084+ Left err -> pure (Left err)
1085+ Right b'' ->
1086+ pure (Right (OrPredicate a'' b''))
1087+processRestrictionPredicateExpr (NotPredicate a) = do
1088+ a' <- processRestrictionPredicateExpr a
1089+ case a' of
1090+ Left err -> pure (Left err)
1091+ Right a'' ->
1092+ pure (Right (NotPredicate a''))
1093+processRestrictionPredicateExpr (RelationalExprPredicate expr) = do
1094+ e <- evalRelationalExpr expr
1095+ pure $ case e of
1096+ Left err -> Left err
1097+ Right e' -> Right (RelationalExprPredicate e')
1098+processRestrictionPredicateExpr (AtomExprPredicate expr) = do
1099+ e <- processAtomExpr expr
1100+ pure (Right (AtomExprPredicate e))
1101+processRestrictionPredicateExpr (AttributeEqualityPredicate nam expr) = do
1102+ e <- processAtomExpr expr
1103+ pure (Right (AttributeEqualityPredicate nam e))
11171104
1105+processExtendTupleExpr :: ExtendTupleExpr -> RelationalExprState (Either RelationalError GraphRefExtendTupleExpr)
1106+processExtendTupleExpr (AttributeExtendTupleExpr nam atomExpr) = do
1107+ e <- processAtomExpr atomExpr
1108+ pure (Right (AttributeExtendTupleExpr nam e))
1109+
1110+typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> RelationalExprState (Either RelationalError Relation)
1111+typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = pure $ mkRelation attrs emptyTupleSet
1112+typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (Right (emptyRelationWithAttrs (attributes rel)))
1113+typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) =
1114+ case mAttrExprs of
1115+ Just attrExprs -> do
1116+ eAttrs <- mapM (\e -> evalGraphRefAttributeExpr e) attrExprs
1117+ case lefts eAttrs of
1118+ [] -> pure (Right (emptyRelationWithAttrs (attributesFromList (rights eAttrs))))
1119+ _ -> pure (Left (someErrors (lefts eAttrs)))
11181120typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119− relVars <- relationVariables <$> gfDatabaseContextForMarker tid
1120− case M.lookup rvName relVars of
1121− Nothing -> throwError (RelVarNotDefinedError rvName)
1122− Just rvExpr ->
1123− typeForGraphRefRelationalExpr rvExpr
1121+ eTrans <- currentTrans
1122+ case eTrans of
1123+ Left err -> pure (Left err)
1124+ Right trans -> do
1125+ let relVars = relationVariables (concreteDatabaseContext trans)
1126+ case M.lookup rvName relVars of
1127+ Nothing -> pure (Left (RelVarNotDefinedError rvName))
1128+ Just rvExpr -> typeForGraphRefRelationalExpr rvExpr
11241129typeForGraphRefRelationalExpr (Project attrNames expr) = do
1125− exprType' <- typeForGraphRefRelationalExpr expr
1126− projectionAttrs <- evalGraphRefAttributeNames attrNames expr
1127− lift $ except $ project projectionAttrs exprType'
1128−typeForGraphRefRelationalExpr (Union exprA exprB) = do
1129− exprA' <- typeForGraphRefRelationalExpr exprA
1130− exprB' <- typeForGraphRefRelationalExpr exprB
1131− lift $ except $ union exprA' exprB'
1132−typeForGraphRefRelationalExpr (Join exprA exprB) = do
1133− exprA' <- typeForGraphRefRelationalExpr exprA
1134− exprB' <- typeForGraphRefRelationalExpr exprB
1135− lift $ except $ join exprA' exprB'
1136−typeForGraphRefRelationalExpr (Rename oldAttr newAttr expr) = do
1137− expr' <- typeForGraphRefRelationalExpr expr
1138− lift $ except $ rename oldAttr newAttr expr'
1139−typeForGraphRefRelationalExpr (Difference exprA exprB) = do
1140− exprA' <- typeForGraphRefRelationalExpr exprA
1141− exprB' <- typeForGraphRefRelationalExpr exprB
1142− lift $ except $ difference exprA' exprB'
1143−typeForGraphRefRelationalExpr (Group groupNames attrName expr) = do
1144− expr' <- typeForGraphRefRelationalExpr expr
1145− groupNames' <- evalGraphRefAttributeNames groupNames expr
1146− lift $ except $ group groupNames' attrName expr'
1147−typeForGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1148− expr' <- typeForGraphRefRelationalExpr expr
1149− lift $ except $ ungroup groupAttrName expr'
1150−typeForGraphRefRelationalExpr (Restrict pred' expr) = do
1151− expr' <- typeForGraphRefRelationalExpr expr
1152− filt <- predicateRestrictionFilter (attributes expr') pred'
1153− lift $ except $ restrict filt expr'
1154−typeForGraphRefRelationalExpr Equals{} =
1155− pure relationFalse
1156−typeForGraphRefRelationalExpr NotEquals{} =
1157− pure relationFalse
1158−typeForGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1159− rel <- typeForGraphRefRelationalExpr expr
1160− evalGraphRefRelationalExpr (Extend extendTupleExpr (ExistingRelation rel))
1161−typeForGraphRefRelationalExpr expr@(With withs _) = do
1162− let expr' = substituteWithNameMacros [] expr
1163− checkMacroName (WithNameExpr macroName tid) = do
1164− rvs <- relationVariables <$> gfDatabaseContextForMarker tid
1165− case M.lookup macroName rvs of
1166− Just _ -> lift $ except $ Left (RelVarAlreadyDefinedError macroName) --this error does not include the transaction marker, but should be good enough to identify the cause
1167− Nothing -> pure ()
1168− mapM_ (checkMacroName . fst) withs
1169− typeForGraphRefRelationalExpr expr'
1170−
1171−evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1130+ eExprType <- typeForGraphRefRelationalExpr expr
1131+ case eExprType of
1132+ Left err -> pure (Left err)
1133+ Right exprType -> do
1134+ eProjectionAttrs <- evalGraphRefAttributeNames attrNames expr
1135+ pure $ case eProjectionAttrs of
1136+ Left err -> Left err
1137+ Right projectionAttrs -> project projectionAttrs exprType
1138+
1139+evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
11721140evalGraphRefAttributeNames attrNames expr = do
1173− exprType' <- typeForGraphRefRelationalExpr expr
1174− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
1175− case attrNames of
1176− AttributeNames names ->
1177− case A.projectionAttributesForNames names (attributes exprType') of
1178− Left err -> throwError err
1179− Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
1141+ eExprType <- typeForGraphRefRelationalExpr expr
1142+ case eExprType of
1143+ Left err -> pure (Left err)
1144+ Right exprTyp -> do
1145+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
1146+ case attrNames of
1147+ AttributeNames names ->
1148+ case A.projectionAttributesForNames names (attributes exprTyp) of
1149+ Left err -> pure (Left err)
1150+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
11801151
1181− InvertedAttributeNames names -> do
1152+ InvertedAttributeNames names -> do
11821153 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
11831154 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
1155+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
11851156 else
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
1157+ pure (pure (A.nonMatchingAttributeNameSet names typeNameSet))
1158+
1159+ UnionAttributeNames namesA namesB -> do
1160+ eNameSetA <- evalGraphRefAttributeNames namesA expr
1161+ case eNameSetA of
1162+ Left err -> pure (Left err)
1163+ Right nameSetA -> do
1164+ eNameSetB <- evalGraphRefAttributeNames namesB expr
1165+ case eNameSetB of
1166+ Left err -> pure (Left err)
1167+ Right nameSetB ->
1168+ pure (Right (S.union nameSetA nameSetB))
11871169
1188− UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
1191− pure (S.union nameSetA nameSetB)
1170+ IntersectAttributeNames namesA namesB -> do
1171+ eNameSetA <- evalGraphRefAttributeNames namesA expr
1172+ case eNameSetA of
1173+ Left err -> pure (Left err)
1174+ Right nameSetA -> do
1175+ eNameSetB <- evalGraphRefAttributeNames namesB expr
1176+ case eNameSetB of
1177+ Left err -> pure (Left err)
1178+ Right nameSetB ->
1179+ pure (Right (S.intersection nameSetA nameSetB))
11921180
1193− IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
1196− pure (S.intersection nameSetA nameSetB)
1181+ RelationalExprAttributeNames attrExpr -> do
1182+ eAttrExprType <- typeForGraphRefRelationalExpr attrExpr
1183+ case eAttrExprType of
1184+ Left err -> pure (Left err)
1185+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
11971186
1198− RelationalExprAttributeNames attrExpr -> do
1199− attrExprType <- typeForGraphRefRelationalExpr attrExpr
1200− pure (A.attributeNameSet (attributes attrExprType))
12011187
1202−evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
1188+
1189+
1190+processAtomExpr :: AtomExpr -> RelationalExprState GraphRefAtomExpr
1191+processAtomExpr (AttributeAtomExpr nam) = pure $ AttributeAtomExpr nam
1192+processAtomExpr (NakedAtomExpr atom) = pure $ NakedAtomExpr atom
1193+processAtomExpr (FunctionAtomExpr fName atomExprs ()) = do
1194+ tid <- re_currentTransId <$> ask
1195+ FunctionAtomExpr fName <$> mapM processAtomExpr atomExprs <*> pure tid
1196+processAtomExpr (RelationAtomExpr expr) = RelationAtomExpr <$> processRelationalExpr expr
1197+processAtomExpr (ConstructedAtomExpr dConsName atomExprs ()) = ConstructedAtomExpr dConsName <$> mapM processAtomExpr atomExprs <*> (re_currentTransId <$> ask)
1198+
1199+processTupleExpr :: TupleExpr -> RelationalExprState GraphRefTupleExpr
1200+processTupleExpr (TupleExpr tMap) =
1201+ TupleExpr . M.fromList <$> mapM (\(k,v) -> (,) k <$> processAtomExpr v) (M.toList tMap)
1202+
1203+evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> RelationalExprState (Either RelationalError Attribute)
12031204evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) = do
1204− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
1205− case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1206− Left err -> throwError err
1207− Right aType -> do
1208− case validateAtomType aType tConsMap of
1209− Left err -> throwError err
1210− Right _ -> pure (Attribute attrName aType)
1211−evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1205+ graph <- re_graph <$> ask
1206+ case transactionForId tid graph of
1207+ Left err -> pure (Left err)
1208+ Right trans -> do
1209+ let tConsMap = typeConstructorMapping (concreteDatabaseContext trans)
1210+ case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1211+ Left err -> pure (Left err)
1212+ Right aType -> do
1213+ case validateAtomType aType tConsMap of
1214+ Left err -> pure (Left err)
1215+ Right _ -> pure (Right (Attribute attrName aType))
1216+
1217+--convert AttributeExpr to GraphRefAttributeExpr
1218+processAttributeExpr :: AttributeExpr -> RelationalExprState GraphRefAttributeExpr
1219+processAttributeExpr (AttributeAndTypeNameExpr nam tCons ()) = do
1220+ tid <- re_currentTransId <$> ask
1221+ pure $ AttributeAndTypeNameExpr nam tCons tid
1222+processAttributeExpr (NakedAttributeExpr attr) = pure $ NakedAttributeExpr attr
1223+
1224+-- convert a RelationalExpr into a GraphRefRelationalExpr
1225+processRelationalExpr :: RelationalExpr -> RelationalExprState GraphRefRelationalExpr
1226+processRelationalExpr (MakeRelationFromExprs mAttrs tupleExprs) = do
1227+ mAttrs' <- case mAttrs of
1228+ Nothing -> pure Nothing
1229+ Just mAttrs'' -> Just <$> mapM processAttributeExpr mAttrs''
1230+ MakeRelationFromExprs mAttrs' <$> mapM processTupleExpr tupleExprs
1231+
12121232
12131233mkEmptyRelVars :: RelationVariables -> RelationVariables
1214−mkEmptyRelVars = M.map mkEmptyRelVar
1234+mkEmptyRelVars rvMap = M.map mkEmptyRelVar rvMap
12151235 where
1216− mkEmptyRelVar expr@MakeRelationFromExprs{} = expr --do not truncate here because we might lose essential type information in emptying the tuples
1236+ mkEmptyRelVar (MakeRelationFromExprs mAttrs _) = MakeRelationFromExprs mAttrs []
12171237 mkEmptyRelVar (MakeStaticRelation attrs _) = MakeStaticRelation attrs emptyTupleSet
12181238 mkEmptyRelVar (ExistingRelation rel) = ExistingRelation (emptyRelationWithAttrs (attributes rel))
12191239 mkEmptyRelVar rv@RelationVariable{} = Restrict (NotPredicate TruePredicate) rv
@@ -1224,169 +1244,14 @@ mkEmptyRelVars = M.map mkEmptyRelVar
12241244 mkEmptyRelVar (Difference exprA exprB) = Difference (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
12251245 mkEmptyRelVar (Group attrNames attrName expr) = Group attrNames attrName (mkEmptyRelVar expr)
12261246 mkEmptyRelVar (Ungroup attrName expr) = Ungroup attrName (mkEmptyRelVar expr)
1227− mkEmptyRelVar (Restrict pred' expr) = Restrict pred' (mkEmptyRelVar expr)
1247+ mkEmptyRelVar (Restrict pred expr) = Restrict pred (mkEmptyRelVar expr)
12281248 mkEmptyRelVar (Equals exprA exprB) = Equals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
12291249 mkEmptyRelVar (NotEquals exprA exprB) = NotEquals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
12301250 mkEmptyRelVar (Extend extTuple expr) = Extend extTuple (mkEmptyRelVar expr)
1231− mkEmptyRelVar (With macros expr) = With (map (second mkEmptyRelVar) macros) (mkEmptyRelVar expr)
1251+ mkEmptyRelVar (With macros expr) = With (map (\(rv, expr) -> (rv, mkEmptyRelVar expr)) macros) (mkEmptyRelVar expr)
12321252
1233−
1234−dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235−dbErr err = lift (except (Left err))
1236−
1237−-- | Return a Relation describing the relation variables.
1238−relationVariablesAsRelation :: DatabaseContext -> TransactionGraph -> Either RelationalError Relation
1239−relationVariablesAsRelation ctx graph = do
1240− let subrelAttrs = A.attributesFromList [Attribute "attribute" TextAtomType, Attribute "type" TextAtomType]
1241− attrs = A.attributesFromList [Attribute "name" TextAtomType,
1242− Attribute "attributes" (RelationAtomType subrelAttrs)]
1243− relVars = relationVariables ctx
1244− mkRvDesc (rvName, gfExpr) = do
1245− let gfEnv = freshGraphRefRelationalExprEnv (Just ctx) graph
1246− gfType <- runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
1247− pure (rvName, gfType)
1248− relVarToAtomList (rvName, rel) = [TextAtom rvName, attributesToRel (attributesVec (attributes rel))]
1249− attrAtoms a = [TextAtom (A.attributeName a), TextAtom (prettyAtomType (A.atomType a))]
1250− attributesToRel attrl = case mkRelationFromList subrelAttrs (map attrAtoms (V.toList attrl)) of
1251− Left err -> error ("relationVariablesAsRelation pooped " ++ show err)
1252− Right rel -> RelationAtom rel
1253− rvs <- mapM mkRvDesc (M.toList relVars)
1254− let tups = map relVarToAtomList rvs
1255− mkRelationFromList attrs tups
1256−
1257−-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258−evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259−evalRelationalExpr expr = do
1260− graph <- reGraph
1261− context <- reContext
1262− let expr' = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
1263− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
1264− case runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr expr') of
1265− Left err -> throwError err
1266− Right rel -> pure rel
1267−
1268−class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269− getContext :: m DatabaseContext
1270−
1271−instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272− getContext = gfDatabaseContextForMarker UncommittedContextMarker
1273−
1274−instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275− getContext = getStateContext
1276−
1277−relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278−relVarByName rvName = do
1279− relvars <- relationVariables <$> getContext
1280− case M.lookup rvName relvars of
1281− Nothing -> throwError (RelVarNotDefinedError rvName)
1282− Just gfexpr -> pure gfexpr
1283−
1284−-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285−class ResolveGraphRefTransactionMarker a where
1286− resolve :: a -> DatabaseContextEvalMonad a
1287−
1288−-- s := s union t
1289−instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290− resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291− MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292− resolve orig@MakeStaticRelation{} = pure orig
1293− resolve orig@ExistingRelation{} = pure orig
1294− resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295− rvMap <- relationVariables <$> getStateContext
1296− case M.lookup rvName rvMap of
1297− Nothing -> pure orig
1298− Just resolvedRv -> resolve resolvedRv
1299− resolve orig@RelationVariable{} = pure orig
1300− resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301− resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302− resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303− resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304− resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305− resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306− resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307− resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308− resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309− resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310− resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311− resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312−
1313−instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314− resolve (TupleExprs marker tupleExprs) =
1315− TupleExprs marker <$> mapM resolve tupleExprs
1316−
1317−instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318− resolve (TupleExpr tupMap) = do
1319− tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320− pure (TupleExpr (M.fromList tupMap'))
1321−
1322−instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323− resolve orig@AttributeNames{} = pure orig
1324− resolve orig@InvertedAttributeNames{} = pure orig
1325− resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326− resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327− resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328−
1329−instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330− resolve TruePredicate = pure TruePredicate
1331− resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332− resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333− resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334− resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335− resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336− resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337−
1338−instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339− resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340−
1341−instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342− resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343−
1344−instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345− resolve orig@AttributeAtomExpr{} = pure orig
1346− resolve orig@NakedAtomExpr{} = pure orig
1347− resolve (FunctionAtomExpr nam atomExprs marker) =
1348− FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349− resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350− resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351− ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352−
1353−--convert series of simple Union queries into MakeStaticRelation
1354−-- this is especially useful for long, nested applications of Union with simple tuples
1355−-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356−
1357−--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358−
1359−applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360−applyUnionCollapse = Fold.cata opt
1361− where
1362− opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363− opt (UnionF exprA exprB) | exprA == exprB = exprA
1364− opt (UnionF
1365− exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366− exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367− | tupExprsNull tupExprs1 = exprB
1368− | tupExprsNull tupExprs2 = exprA
1369− opt x = Fold.embed x
1370− tupExprsNull (TupleExprs _ []) = True
1371− tupExprsNull _ = False
1372−
1373−
1374−--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375−--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376−-- =>
1377−-- update x where y=1 set (x:=6,z:=11)
1378−-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379−
1380−--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381−
1382−--DELETE optimization
1383−-- if a restriction matches a previous restriction, combine them
1384−-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385−applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386−applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387− case expr of
1388− orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389− _ -> orig
1390−applyRestrictionCollapse expr = expr
1391−
1392−
1253+processAttributeNames :: AttributeNames -> RelationalExprState GraphRefAttributeNames
1254+processAttributeNames (AttributeNames nameSet) = pure $ AttributeNames nameSet
1255+processAttributeNames (UnionAttributeNames attrNamesA attrNamesB) = UnionAttributeNames <$> processAttributeNames attrNamesA <*> processAttributeNames attrNamesB
1256+processAttributeNames (IntersectAttributeNames attrNamesA attrNamesB) = IntersectAttributeNames <$> processAttributeNames attrNamesA <*> processAttributeNames attrNamesB
1257+processAttributeNames (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> processRelationalExpr expr