@@ -1,53 +1,34 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FlexibleContexts #-}
4−{-# LANGUAGE OverloadedStrings #-}
52module ProjectM36.RelationalExpression where
63import ProjectM36.Relation
74import ProjectM36.Tuple
85import ProjectM36.TupleSet
96import ProjectM36.Base
10−import qualified Data.UUID as U
117import ProjectM36.Error
128import ProjectM36.AtomType
13−import ProjectM36.Attribute (emptyAttributes, attributesFromList)
9+import ProjectM36.Attribute (emptyAttributes)
1410import ProjectM36.ScriptSession
1511import ProjectM36.DataTypes.Primitive
1612import ProjectM36.AtomFunction
1713import ProjectM36.DatabaseContextFunction
1814import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
20−import ProjectM36.Transaction
2115import qualified ProjectM36.Attribute as A
2216import qualified Data.Map as M
2317import qualified Data.HashSet as HS
2418import qualified Data.Set as S
2519import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
20+import Control.Exception
2721import Data.Maybe
2822import Data.Either
2923import Data.Char (isUpper)
30−import Data.Time
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
3324import qualified Data.Text as T
3425import qualified Data.Vector as V
3526import 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
27+import Control.Monad.Trans.Except
28+import Control.Monad.Trans.Reader
4329import 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
30+import GHC
4931import GHC.Paths
50−#endif
5132
5233data DatabaseContextExprDetails = CountUpdatedTuples
5334
@@ -64,63 +45,32 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
6445 Right ts -> ts
6546
6647-- | 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
72− } --future work: propagate return accumulator
48+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
49+freshDatabaseState ctx = (ctx, M.empty, False) --future work: propagate return accumulator
7350
7451-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
75−data RelationalExprEnv = RelationalExprEnv {
76− re_context :: DatabaseContext,
77− re_graph :: TransactionGraph,
78− re_extra :: Maybe (Either RelationTuple Attributes)
79− }
80−
81−envTuple :: GraphRefRelationalExprEnv -> RelationTuple
82−envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
83−
84−envAttributes :: GraphRefRelationalExprEnv -> Attributes
85−envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
52+data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
53+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
54+ RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
55+
56+instance Show RelationalExprStateElems where
57+ show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
58+ show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
59+ show (RelationalExprStateElems _) = "RelationalExprStateElems"
60+
61+mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
62+mkRelationalExprState = RelationalExprStateElems
63+
64+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
65+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
66+mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
67+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
68+ RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
8669
87−instance Show RelationalExprEnv where
88− show e@RelationalExprEnv{} = "RelationalExprEnv " ++ show (re_extra e)
89−
90−--used to eval relationalexpr
91−type RelationalExprM a = ReaderT RelationalExprEnv (ExceptT RelationalError Identity) a
92−
93−runRelationalExprM :: RelationalExprEnv -> RelationalExprM a -> Either RelationalError a
94−runRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
95−
96−reGraph :: RelationalExprM TransactionGraph
97−reGraph = asks re_graph
98−
99−reContext :: RelationalExprM DatabaseContext
100−reContext = asks re_context
101−
102−mkRelationalExprEnv :: DatabaseContext -> TransactionGraph -> RelationalExprEnv
103−mkRelationalExprEnv ctx graph =
104− RelationalExprEnv
105− { re_context = ctx,
106− re_graph = graph,
107− re_extra = Nothing }
108−
109−askEnv :: GraphRefRelationalExprM GraphRefRelationalExprEnv
110−askEnv = R.ask
111−
112−mergeTuplesIntoGraphRefRelationalExprEnv :: RelationTuple -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
113−mergeTuplesIntoGraphRefRelationalExprEnv tupIn env =
114− env { gre_extra = new_elems }
115− where
116− new_elems = Just (Left newTuple)
117− mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap (envTuple env))
118− newTuple = mkRelationTupleFromMap mergedTupMap
119−
120−mergeAttributesIntoGraphRefRelationalExprEnv :: Attributes -> GraphRefRelationalExprEnv -> GraphRefRelationalExprEnv
121−mergeAttributesIntoGraphRefRelationalExprEnv attrsIn e = e { gre_extra = newattrs }
122− where
123− newattrs = Just (Right (A.union attrsIn (envAttributes e)))
70+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
71+mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
72+mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
73+mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
12474
12575type ResultAccumName = StringType
12676
@@ -130,403 +80,429 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
13080 resultAccumResult :: Relation
13181 }
13282
133−data DatabaseContextEvalState = DatabaseContextEvalState {
134− dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135− dbc_accum :: M.Map ResultAccumName ResultAccum,
136− dbc_dirty :: DirtyFlag
137− }
138−
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
142− }
83+type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
14384
144−mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145−mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
85+type DatabaseState a = State DatabaseStateElems a
14686
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
87+getStateContext :: DatabaseState DatabaseContext
88+getStateContext = do
89+ (ctx,_, _) <- get
90+ pure ctx
91+
92+putStateContext :: DatabaseContext -> DatabaseState ()
93+putStateContext ctx = do
94+ (_, accum, _) <- get
95+ put (ctx, accum, True)
96+
97+type RelationalExprState a = Reader RelationalExprStateElems a
98+
99+stateElemsContext :: RelationalExprStateElems -> DatabaseContext
100+stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
101+stateElemsContext (RelationalExprStateElems ctx) = ctx
102+stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
103+
104+setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
105+setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
106+setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
107+setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
108+
109+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
110+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
111+evalRelationalExpr (RelationVariable name _) = do
112+ relvarTable <- fmap (relationVariables . stateElemsContext) ask
113+ return $ case M.lookup name relvarTable of
114+ Just res -> Right res
115+ Nothing -> Left $ RelVarNotDefinedError name
116+
117+evalRelationalExpr (Project attrNames expr) = do
118+ eAttrNameSet <- evalAttributeNames attrNames expr
119+ case eAttrNameSet of
120+ Left err -> pure (Left err)
121+ Right attrNameSet -> do
122+ rel <- evalRelationalExpr expr
123+ case rel of
124+ Right rel2 -> pure $ project attrNameSet rel2
125+ Left err -> pure $ Left err
126+
127+evalRelationalExpr (Union exprA exprB) = do
128+ relA <- evalRelationalExpr exprA
129+ relB <- evalRelationalExpr exprB
130+ case relA of
131+ Left err -> return $ Left err
132+ Right relA2 -> case relB of
133+ Left err -> return $ Left err
134+ Right relB2 -> return $ union relA2 relB2
135+
136+evalRelationalExpr (Join exprA exprB) = do
137+ relA <- evalRelationalExpr exprA
138+ relB <- evalRelationalExpr exprB
139+ case relA of
140+ Left err -> return $ Left err
141+ Right relA2 -> case relB of
142+ Left err -> return $ Left err
143+ Right relB2 -> return $ join relA2 relB2
144+
145+evalRelationalExpr (Difference exprA exprB) = do
146+ relA <- evalRelationalExpr exprA
147+ relB <- evalRelationalExpr exprB
148+ case relA of
149+ Left err -> return $ Left err
150+ Right relA2 -> case relB of
151+ Left err -> return $ Left err
152+ Right relB2 -> return $ difference relA2 relB2
153+
154+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
155+ case mkRelation attributeSet tupleSet of
156+ Right rel -> return $ Right rel
157+ Left err -> return $ Left err
153158
154−
155−dbcTransId :: DatabaseContextEvalMonad TransactionId
156−dbcTransId = dce_transId <$> RWS.ask
157−
158−dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159−dbcGraph = dce_graph <$> RWS.ask
160−
161−dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162−dbcRelationalExprEnv =
163− mkRelationalExprEnv <$> getStateContext <*> dbcGraph
164−
165−getStateContext :: DatabaseContextEvalMonad DatabaseContext
166−getStateContext = gets dbc_context
167−
168−putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
169−putStateContext ctx' = do
170− s <- get
171− put (s {dbc_context = ctx', dbc_dirty = True})
172−
173−-- | The context is optionally passed down along in cases where the current context is uncommitted.
174−data GraphRefRelationalExprEnv =
175− GraphRefRelationalExprEnv {
176− gre_context :: Maybe DatabaseContext,
177− gre_graph :: TransactionGraph,
178− gre_extra :: Maybe (Either RelationTuple Attributes)
179− }
159+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
160+ currentContext <- fmap stateElemsContext ask
161+ let tConss = typeConstructorMapping currentContext
162+ -- if the mAttrExprs is Nothing, then we should attempt to infer the tuple attributes from the first tuple itself- note that this is not always possible
163+ runExceptT $ do
164+ mAttrs <- case mAttrExprs of
165+ Just _ ->
166+ Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
167+ Nothing -> pure Nothing
168+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
169+ let attrs = fromMaybe firstTupleAttrs mAttrs
170+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
171+ either throwE pure (mkRelation attrs (RelationTupleSet tuples))
180172
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
173+evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
208174
209−envContext :: RelationalExprEnv -> DatabaseContext
210−envContext = re_context
175+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
176+ evald <- evalRelationalExpr relExpr
177+ case evald of
178+ Right rel -> return $ rename oldAttrName newAttrName rel
179+ Left err -> return $ Left err
211180
212−setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213−setEnvContext e ctx = e { re_context = ctx }
181+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
182+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
183+ case eOldAttrNameSet of
184+ Left err -> pure (Left err)
185+ Right oldAttrNameSet -> do
186+ evald <- evalRelationalExpr relExpr
187+ case evald of
188+ Right rel -> return $ group oldAttrNameSet newAttrName rel
189+ Left err -> return $ Left err
190+
191+evalRelationalExpr (Ungroup attrName relExpr) = do
192+ evald <- evalRelationalExpr relExpr
193+ case evald of
194+ Right rel -> return $ ungroup attrName rel
195+ Left err -> return $ Left err
196+
197+evalRelationalExpr (Restrict predicateExpr relExpr) = do
198+ evald <- evalRelationalExpr relExpr
199+ case evald of
200+ Left err -> return $ Left err
201+ Right rel -> do
202+ eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
203+ case eFilterFunc of
204+ Left err -> return $ Left err
205+ Right filterfunc ->
206+ pure (restrict filterfunc rel)
207+
208+evalRelationalExpr (Equals relExprA relExprB) = do
209+ evaldA <- evalRelationalExpr relExprA
210+ evaldB <- evalRelationalExpr relExprB
211+ case evaldA of
212+ Left err -> return $ Left err
213+ Right relA -> case evaldB of
214+ Left err -> return $ Left err
215+ Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
216+
217+--warning: copy-pasta from above- refactor
218+evalRelationalExpr (NotEquals relExprA relExprB) = do
219+ evaldA <- evalRelationalExpr relExprA
220+ evaldB <- evalRelationalExpr relExprB
221+ case evaldA of
222+ Left err -> return $ Left err
223+ Right relA -> case evaldB of
224+ Left err -> return $ Left err
225+ Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
226+
227+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
228+evalRelationalExpr (Extend tupleExpression relExpr) = do
229+ rstate <- ask
230+ let evald = runReader (evalRelationalExpr relExpr) rstate
231+ case evald of
232+ Left err -> pure (Left err)
233+ Right rel -> do
234+ tupProc <- extendTupleExpressionProcessor rel tupleExpression
235+ case tupProc of
236+ Left err -> pure (Left err)
237+ Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
214238
215239--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217−setRelVar relVarName relExpr = do
240+setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
241+setRelVar relVarName rel = do
218242 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
243+ let newRelVars = M.insert relVarName rel $ relationVariables currentContext
222244 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 ()
245+
246+ case checkConstraints potentialContext of
247+ Left err -> pure (Left err)
248+ Right _ -> do
249+ putStateContext potentialContext
250+ return (Right ())
236251
237252-- 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 ()
253+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239254deleteRelVar relVarName = do
240255 currContext <- getStateContext
241256 let relVars = relationVariables currContext
242257 if M.notMember relVarName relVars then
243− pure ()
258+ pure (Right ())
244259 else do
245260 let newRelVars = M.delete relVarName relVars
246261 newContext = currContext { relationVariables = newRelVars }
247262 putStateContext newContext
248− pure ()
263+ pure (Right ())
249264
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
265+evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
266+evalDatabaseContextExpr NoOperation = pure (Right ())
252267
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
268+evalDatabaseContextExpr (Define relVarName attrExprs) = do
255269 relvars <- fmap relationVariables getStateContext
256270 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)
271+ let eAttrs = map (evalAttrExpr tConss) attrExprs
272+ attrErrs = lefts eAttrs
273+ attrsList = rights eAttrs
274+ if not (null attrErrs) then
275+ pure (Left (someErrors attrErrs))
276+ else do
277+ let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
278+ if not (null atomTypeErrs) then
279+ pure (Left (someErrors atomTypeErrs))
280+ else
281+ case M.member relVarName relvars of
282+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
283+ False -> setRelVar relVarName emptyRelation >> pure (Right ())
267284 where
268285 attrs = A.attributesFromList attrsList
269286 emptyRelation = Relation attrs emptyTupleSet
270287
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
288+evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
272289
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
290+evalDatabaseContextExpr (Assign relVarName expr) = do
291+ -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
275292 context <- getStateContext
276− let existingRelVar = M.lookup relVarName (relationVariables context)
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
279− case existingRelVar of
280− Nothing -> do
281− case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282− Left err -> dbErr err
283− Right reltype -> do
284− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285− setRelVar relVarName expr
286− Just existingRel -> do
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
288− case eExpectedType of
289− Left err -> dbErr err
290− Right expectedType ->
291− case eNewExprType of
292− Left err -> dbErr err
293− Right newExprType -> do
294− if newExprType == expectedType then do
295− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296− setRelVar relVarName expr
297− else
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
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)
293+ let existingRelVar = M.lookup relVarName relVarTable
294+ relVarTable = relationVariables context
295+ value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
296+ case value of
297+ Left err -> pure (Left err)
298+ Right rel -> case existingRelVar of
299+ Nothing -> setRelVar relVarName rel
300+ Just existingRel -> let expectedAttributes = attributes existingRel
301+ foundAttributes = attributes rel in
302+ if A.attributesEqual expectedAttributes foundAttributes then
303+ setRelVar relVarName rel
304+ else
305+ pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
306+
307+evalDatabaseContextExpr (Insert relVarName relExpr) = do
308+ context <- getStateContext
309+ let unionexp = Union relExpr rv
310+ rv = RelationVariable relVarName ()
311+ unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
312+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
313+ case unioned of
314+ Left err -> pure (Left err)
315+ Right unioned' -> case origRel of
316+ Left err -> pure (Left err)
317+ Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
318+ pure (Right ())
319+ else
320+ evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
321+
322+evalDatabaseContextExpr (Delete relVarName predicate) = do
323+ context <- getStateContext
324+ let rv = RelationVariable relVarName ()
325+ let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
326+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
327+ case updatedRel of
328+ Left err -> pure (Left err)
329+ Right updatedRel' -> case origRel of
330+ Left err -> pure (Left err)
331+ Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
332+ pure (Right ())
333+ else
334+ setRelVar relVarName updatedRel'
306335
307−evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308− gfExpr <- relVarByName relVarName
309− let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310− setRelVar relVarName optExpr
311−
312336--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
337+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
316338 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
337− updateAttr oldname procAtomExpr accum
338− ) restrictedPortion (M.toList atomExprMap)
339− -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
340− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341− setRelVar relVarName (Union unrestrictedPortion updatedPortion)
339+ let relVarTable = relationVariables context
340+ case M.lookup relVarName relVarTable of
341+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
342+ Just rel ->
343+ case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
344+ Left err -> pure (Left err)
345+ Right predicateFunc -> do
346+ let ret = do
347+ restrictedPortion <- restrict predicateFunc rel
348+ if cardinality restrictedPortion == Finite 0 then
349+ pure Nothing
350+ else do
351+ unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
352+ updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
353+ updatedRel <- updatedPortion `union` unrestrictedPortion
354+ pure (Just updatedRel)
355+ case ret of
356+ Left err -> pure (Left err)
357+ Right Nothing -> pure (Right ())
358+ Right (Just updatedRel) -> setRelVar relVarName updatedRel
342359
343−evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
360+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
344361 currContext <- getStateContext
345− transId <- dbcTransId
346− graph <- dbcGraph
347362 let currDeps = inclusionDependencies currContext
348363 newDeps = M.insert newDepName newDep currDeps
349364 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
365+ pure (Left (InclusionDependencyNameInUseError newDepName))
351366 else do
352367 let potentialContext = currContext { inclusionDependencies = newDeps }
353− -- if the potential context passes all constraints, then save it
354− -- potential optimization: validate only the new constraint- all old constraints must already hold
355− case checkConstraints potentialContext transId graph of
356− Left err -> dbErr err
357− Right _ ->
368+ case checkConstraints potentialContext of
369+ Left err -> pure (Left err)
370+ Right _ -> do
358371 putStateContext potentialContext
372+ return (Right ())
359373
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
374+evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
361375 currContext <- getStateContext
362376 let currDeps = inclusionDependencies currContext
363377 newDeps = M.delete depName currDeps
364378 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
366− else
379+ pure (Left (InclusionDependencyNameNotInUseError depName))
380+ else do
367381 putStateContext $ currContext {inclusionDependencies = newDeps }
382+ return (Right ())
368383
369384-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
385+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
371386 currentContext <- getStateContext
372387 let nots = notifications currentContext
373388 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
389+ pure (Left (NotificationNameInUseError notName))
375390 else do
376391 let newNotifications = M.insert notName newNotification nots
377392 newNotification = Notification { changeExpr = triggerExpr,
378393 reportOldExpr = resultOldExpr,
379394 reportNewExpr = resultNewExpr}
380395 putStateContext $ currentContext { notifications = newNotifications }
396+ return (Right ())
381397
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
398+evalDatabaseContextExpr (RemoveNotification notName) = do
383399 currentContext <- getStateContext
384400 let nots = notifications currentContext
385401 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
402+ pure (Left (NotificationNameNotInUseError notName))
387403 else do
388404 let newNotifications = M.delete notName nots
389405 putStateContext $ currentContext { notifications = newNotifications }
390−
406+ pure (Right ())
391407
392408-- | Adds type and data constructors to the database context.
393409-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
410+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
395411 currentContext <- getStateContext
396412 let oldTypes = typeConstructorMapping currentContext
397413 tConsName = TCD.name tConsDef
398414 -- 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)
415+ case validateTypeConstructorDef tConsDef dConsDefList of
416+ errs@(_:_) -> pure (Left (someErrors errs))
417+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
418+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403419 | otherwise -> do
404420 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405421 putStateContext $ currentContext { typeConstructorMapping = newTypes }
422+ pure (Right ())
406423
407424-- | 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
425+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
409426 currentContext <- getStateContext
410427 let oldTypes = typeConstructorMapping currentContext
411428 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
429+ pure (Left (AtomTypeNameNotInUseError tConsName))
413430 else do
414431 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415432 putStateContext $ currentContext { typeConstructorMapping = newTypes }
433+ pure (Right ())
416434
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
435+evalDatabaseContextExpr (MultipleExpr exprs) = do
418436 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
420−
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
437+ evald <- forM exprs evalDatabaseContextExpr
438+ --some lifting magic needed here
439+ case lefts evald of
440+ [] -> pure (Right ())
441+ errs -> pure (Left (someErrors errs))
442+
443+evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
422444 currentContext <- getStateContext
423445 let atomFuncs = atomFunctions currentContext
424446 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)
447+ Left err -> pure (Left err)
448+ Right realFunc -> if isScriptedAtomFunction realFunc then do
449+ let updatedFuncs = HS.delete realFunc atomFuncs
450+ putStateContext (currentContext {atomFunctions = updatedFuncs })
451+ pure (Right ())
452+ else
453+ pure (Left (PrecompiledFunctionRemoveError funcName))
432454
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
455+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
434456 context <- getStateContext
435457 let dbcFuncs = dbcFunctions context
436458 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)
459+ Left err -> pure (Left err)
460+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
461+ let updatedFuncs = HS.delete realFunc dbcFuncs
462+ putStateContext (context { dbcFunctions = updatedFuncs })
463+ pure (Right ())
464+ else
465+ pure (Left (PrecompiledFunctionRemoveError funcName))
444466
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
467+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
446468 context <- getStateContext
447− graph <- dbcGraph
448469 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
470+ let relExprState = mkRelationalExprState context
471+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450472 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452473 case eFunc of
453− Left err -> dbErr err
474+ Left err -> pure (Left err)
454475 Right func -> do
455476 let expectedArgCount = length (dbcFuncType func)
456477 actualArgCount = length atomArgExprs
457478 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
479+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
459480 else
460481 --check that the atom types are valid
461− case eAtomTypes of
462− Left err -> dbErr err
463− Right atomTypes -> do
464− let mValidTypes = zipWith (\ expType actType
465− -> case atomTypeVerify expType actType of
466− Left err -> Just err
467− Right _ -> Nothing)
468− (dbcFuncType func) atomTypes
469− typeErrors = catMaybes mValidTypes
470− eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
482+ case lefts eAtomTypes of
483+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
484+ [] -> do
485+ let atomTypes = rights eAtomTypes
486+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
487+ Left err -> Just err
488+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
489+ typeErrors = catMaybes mValidTypes
490+ eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471491 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
492+ pure (Left (someErrors (lefts eAtomArgs)))
473493 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
494+ pure (Left (someErrors typeErrors))
475495 else
476496 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
497+ Left err -> pure (Left err)
498+ Right newContext -> putStateContext newContext >> pure (Right ())
499+
500+evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
501+evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
502+ case mScriptSession of
503+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
504+ Just scriptSession -> do
505+ res <- try $ runGhc (Just libdir) $ do
530506 setSession (hscEnv scriptSession)
531507 let atomFuncs = atomFunctions currentContext
532508 case extractAtomFunctionType funcType of
@@ -552,13 +528,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552528 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553529 Right eContext -> case eContext of
554530 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
531+ Right context' -> pure (Right context')
532+
533+evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
534+ case mScriptSession of
535+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
536+ Just scriptSession -> do
562537 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563538 let last2Args = reverse (take 2 (reverse funcType))
564539 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +543,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568543 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569544 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
570545 else do
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
546+ res <- try $ runGhc (Just libdir) $ do
572547 setSession (hscEnv scriptSession)
573548 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574549 pure $ case eCompiledFunc of
@@ -593,86 +568,68 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593568 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594569 Right eContext -> case eContext of
595570 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
571+ Right context' -> pure (Right context')
572+evalDatabaseContextIOExpr _ currentContext (LoadAtomFunctions modName funcName modPath) = do
573+ eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600574 case eLoadFunc of
601575 Left LoadSymbolError -> pure (Left LoadFunctionError)
602576 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603577 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
578+ in pure (Right newContext)
579+evalDatabaseContextIOExpr _ currentContext (LoadDatabaseContextFunctions modName funcName modPath) = do
580+ eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608581 case eLoadFunc of
609582 Left LoadSymbolError -> pure (Left LoadFunctionError)
610583 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611584 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
613−#endif
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
585+ in pure (Right newContext)
586+
587+evalDatabaseContextIOExpr _ currentContext (CreateArbitraryRelation relVarName attrExprs range) =
615588 --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
589+ case runState ( evalDatabaseContextExpr (Define relVarName attrExprs)) (freshDatabaseState currentContext) of
590+ (Left err,_) -> pure (Left err)
591+ (Right (), elems@(ctx,_,_)) -> do
625592 --Assign
626593 let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
594+ relVarTable = relationVariables ctx
628595 case existingRelVar of
629596 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630597 Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633− Left err -> pure (Left err)
634− Right relType -> do
635− let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638− case eitherRel of
639− Left err -> pure $ Left err
640− Right rel ->
641− case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642− Left err -> pure (Left err)
643− Right dbstate' -> putDBCIOContext (dbc_context dbstate')
598+ let expectedAttributes = attributes existingRel
599+ let tcMap = typeConstructorMapping ctx
600+ eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
601+ case eitherRel of
602+ Left err -> pure $ Left err
603+ Right rel ->
604+ case runState (setRelVar relVarName rel) elems of
605+ (Left err,_) -> pure (Left err)
606+ (Right (), (ctx',_,_)) -> pure $ Right ctx'
607+
608+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
609+updateTupleWithAtomExprs exprMap context tupIn = do
610+ --resolve all atom exprs
611+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
612+ atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
613+ pure (attrName, atom)
614+ ) (M.toList exprMap)
615+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
644616
645617--run verification on all constraints
646−checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
618+checkConstraints :: DatabaseContext -> Either RelationalError ()
619+checkConstraints context = do
648620 mapM_ (uncurry checkIncDep) (M.toList deps)
621+ pure ()
649622 where
650− potentialGraph = TransactionGraph graphHeads (S.insert tempTrans transSet)
651− tempStamp = UTCTime { utctDay = fromGregorian 2000 1 1,
652− utctDayTime = secondsToDiffTime 0 }
653− tempSchemas = Schemas context M.empty
654− tempTrans = Transaction U.nil tempTransInfo tempSchemas
655− tempTransInfo = TransactionInfo { parents = transId NE.:| [],
656− stamp = tempStamp,
657− merkleHash = mempty
658− }
659−
660623 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
624+ eval expr = evalReader (evalRelationalExpr expr)
625+ evalReader f = runReader f (RelationalExprStateElems context)
662626 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663− let process = runProcessExprM UncommittedContextMarker
664− gfSubsetExpr = process (processRelationalExpr subsetExpr)
665− gfSupersetExpr = process (processRelationalExpr supersetExpr)
666627 --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)
628+ typeSub <- evalReader (typeForRelationalExpr subsetExpr)
629+ typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
671630 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672− let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675− case gfEvald of
631+ let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
632+ case eval checkExpr of
676633 Left err -> Left err
677634 Right resultRel -> if resultRel == relationTrue then
678635 pure ()
@@ -682,81 +639,88 @@ checkConstraints context transId graph@(TransactionGraph graphHeads transSet) =
682639-- 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
683640-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
684641
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
642+typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
686643typeForRelationalExpr expr = do
644+ rstate <- ask
645+ let context = stateElemsContext rstate
687646 --replace the relationVariables context element with a cloned set of relation devoid of tuples
688− --evalRelationalExpr could still return an existing relation with tuples, so strip them
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
647+ let context' = contextWithEmptyTupleSets context
648+ rstate' = setStateElemsContext rstate context'
649+ pure (runReader (evalRelationalExpr expr) rstate')
650+
651+--returns a database context with all tuples removed
652+--this is useful for type checking and optimization
653+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
654+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
655+ where
656+ relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
695657
696658liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697659liftE v = do
698660 y <- lift v
699661 case y of
700− Left err -> throwError err
662+ Left err -> throwE err
701663 Right val -> pure val
702664
703665{- 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))
666+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
667+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
668+ runExceptT $ do
669+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
670+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
671+ pure (\x -> do
672+ ev1 <- expr1v x
673+ ev2 <- expr2v x
674+ pure (ev1 && ev2))
712675
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714− expr1v <- predicateRestrictionFilter attrs expr1
715− expr2v <- predicateRestrictionFilter attrs expr2
676+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
677+ runExceptT $ do
678+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
679+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716680 pure (\x -> do
717681 ev1 <- expr1v x
718682 ev2 <- expr2v x
719683 pure (ev1 || ev2))
720684
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
685+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
722686
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
724− exprv <- predicateRestrictionFilter attrs expr
725− pure (fmap not . exprv)
687+predicateRestrictionFilter attrs (NotPredicate expr) =
688+ runExceptT $ do
689+ exprv <- liftE (predicateRestrictionFilter attrs expr)
690+ pure (fmap not . exprv)
726691
727692--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
728693predicateRestrictionFilter _ (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
694+ rstate <- ask
695+ pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
735696 Left err -> Left err
736697 Right rel -> if arity rel /= 0 then
737698 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
738699 else
739− pure (rel == relationTrue))
700+ pure (rel == relationTrue)))
740701
741702predicateRestrictionFilter 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
703+ rstate <- ask
704+ let (attrs', ctxtup') = case rstate of
705+ RelationalExprStateElems _ -> (attrs, emptyTuple)
706+ RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
707+ RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
708+ runExceptT $ do
709+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
710+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747711 Right attr -> Right attr
748712 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749713 Right ctxattr -> Right ctxattr
750714 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751715 Left err -> Left err
752716 Left err -> Left err
753− if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755− else
717+ if atomExprType /= A.atomType attr then
718+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
719+ else
756720 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757721 Right atomCmp -> atomCmp == atomIn
758722 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
723+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
760724 in
761725 pure $ case atomForAttributeName attrName tupleIn of
762726 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,626 +731,250 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
767731-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768732predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769733 --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
734+ rstate <- ask
735+ runExceptT $ do
736+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
737+ if aType /= BoolAtomType then
738+ throwE (AtomTypeMismatchError aType BoolAtomType)
739+ else
775740 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777− Left err -> Left err
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
741+ pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
742+ Left _ -> False
743+ Right boolAtomValue -> boolAtomValue == BoolAtom True)
779744
780745tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781746tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
782− Left (AttributeNameInUseError attrName)
747+ Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
783748 else
784749 Right rel
785750
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788−-- renv <- askEnv
751+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
752+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
753+ rstate <- ask
789754 -- check that the attribute name is not in use
790755 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
756+ Left err -> pure (Left err)
757+ Right _ -> runExceptT $ do
758+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
759+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795760 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796761 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)
762+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
763+ Left err -> Left err
764+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
802765 )
803766
804−evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
805−evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806− case atomForAttributeName attrName tupIn of
807− Right atom -> pure atom
808− Left err@(NoSuchAttributeNamesError _) -> do
809− env <- askEnv
810− case gre_extra env of
811− Nothing -> throwError err
812− Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
813− Just (Right _) -> throwError err
814− Left err -> throwError err
815−evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
816−evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
817− argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
818− context <- gfDatabaseContextForMarker tid
819− let functions = atomFunctions context
820− func <- lift $ except (atomFunctionForName funcName functions)
821− let expectedArgCount = length (atomFuncType func) - 1
822− actualArgCount = length argTypes
823− safeInit [] = [] -- different behavior from normal init
824− safeInit xs = init xs
825− if expectedArgCount /= actualArgCount then
826− throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
827− else do
828− let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
829− mapM_ (\(expType, actType) ->
830− lift $ except (atomTypeVerify expType actType)) zippedArgs
831− evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
767+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
768+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
769+ Right atom -> pure (Right atom)
770+ err@(Left (NoSuchAttributeNamesError _)) -> do
771+ rstate <- ask
772+ case rstate of
773+ RelationalExprStateElems _ -> pure err
774+ RelationalExprStateAttrsElems _ _ -> pure err
775+ RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
776+ Left err -> pure (Left err)
777+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
778+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
779+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
780+ context <- fmap stateElemsContext ask
781+ runExceptT $ do
782+ let functions = atomFunctions context
783+ func <- either throwE pure (atomFunctionForName funcName functions)
784+ let expectedArgCount = length (atomFuncType func) - 1
785+ actualArgCount = length argTypes
786+ safeInit [_] = []
787+ safeInit [] = [] -- different behavior from normal init
788+ safeInit (_:xs) = safeInit xs
789+ if expectedArgCount /= actualArgCount then
790+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
791+ else do
792+ mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
793+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832794 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
795+ Left err -> throwE (AtomFunctionUserError err)
834796 Right result -> do
835797 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
798+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837799 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
800+evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
839801 --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
802+ rstate <- ask
803+ runExceptT $ do
804+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
805+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
806+ pure (RelationAtom relAtom)
807+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
808+ rstate <- lift ask
809+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
810+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
811+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
849812 pure (ConstructedAtom dConsName aType argAtoms)
850813
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
814+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
815+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
816+ rstate <- ask
854817 case A.atomTypeForAttributeName attrName attrs of
855− Right aType -> pure aType
856− Left err@(NoSuchAttributeNamesError _) ->
857− let envTup = envTuple renv
858− envAttrs = envAttributes renv in
859− case A.attributeForName attrName envAttrs of
860− Right attr -> pure (A.atomType attr)
861− Left _ -> case atomForAttributeName attrName envTup of
862− Right atom -> pure (atomTypeForAtom atom)
863− Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
864− throwError err
865− Left err -> throwError err
866−
867−typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
868−typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
869− funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
818+ Right aType -> pure (Right aType)
819+ Left err@(NoSuchAttributeNamesError _) -> case rstate of
820+ RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
821+ Left err' -> pure (Left err')
822+ Right attr -> pure (Right (A.atomType attr))
823+ RelationalExprStateElems _ -> pure (Left err)
824+ RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
825+ Left err' -> pure (Left err')
826+ Right atom -> pure (Right (atomTypeForAtom atom))
827+ Left err -> pure (Left err)
828+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
829+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
830+ context <- fmap stateElemsContext ask
831+ let funcs = atomFunctions context
870832 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
833+ Left err -> pure (Left err)
872834 Right func -> do
873835 let funcRetType = last (atomFuncType func)
874836 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)
837+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
838+ case lefts eArgTypes of
839+ errs@(_:_) -> pure (Left (someErrors errs))
840+ [] -> do
841+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
842+ argTypes = rights eArgTypes
843+ case eTvMap of
844+ Left err -> pure (Left err)
845+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
846+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
847+ rstate <- lift ask
848+ relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
882849 pure (RelationAtomType (attributes relType))
883850-- 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
851+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
852+ runExceptT $ do
853+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
854+ context <- fmap stateElemsContext (lift ask)
855+ either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
889856
890857-- | 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
858+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
859+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
860+ rstate <- lift ask
894861 case A.atomTypeForAttributeName attrName (attributes relIn) of
895− Right aType -> lift $ except $ atomTypeVerify expectedType aType
896− (Left err@(NoSuchAttributeNamesError _)) ->
897− let attrs' = envAttributes env in
898− if attrs' == emptyAttributes then
899− throwError err
900− else
901− case A.attributeForName attrName attrs' of
902− Left err' -> throwError err'
903− Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
904− Left err -> throwError err
905−
906−verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907− lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
908−verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
909− context <- gfDatabaseContextForMarker tid
862+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
863+ (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
864+ RelationalExprStateTupleElems _ _ -> throwE err
865+ RelationalExprStateElems _ -> throwE err
866+ RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
867+ Left err' -> throwE err'
868+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
869+ Left err -> throwE err
870+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
871+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
872+ rstate <- ask
910873 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)
874+ context = stateElemsContext rstate
875+ runExceptT $ do
876+ func <- either throwE pure (atomFunctionForName funcName functions)
877+ let expectedArgTypes = atomFuncType func
878+ funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
879+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
880+ Left err -> throwE err
881+ Right x -> pure x
882+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
883+ if length funcArgTypes /= length expectedArgTypes - 1 then
884+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
921885 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
886+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
887+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
888+ rstate <- lift ask
889+ relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
890+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
891+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
892+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
893+ either throwE pure (atomTypeVerify expectedType cType)
931894
932895-- | 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
896+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
897+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
898+ aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
899+ validateAtomType aType aTypes
900+ Right (Attribute attrName aType)
939901
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
902+evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
903+
904+evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
905+evalTupleExpr mAttrs (TupleExpr tupMap) = do
906+ context <- fmap stateElemsContext ask
907+ runExceptT $ do
992908 -- 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
993909 -- 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
910+ let attrs = fromMaybe A.emptyAttributes mAttrs
911+ attrAtoms <- mapM (\(attrName, aExpr) -> do
912+ --provided when the relation header is available
913+ let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
914+ unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
915+ resolvedType <- case eExpectedAtomType of
1001916 Left _ -> pure unresolvedType
1002− Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
917+ Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1003918 --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
919+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
920+ pure (attrName, newAtom, resolvedType)
921+ ) (M.toList tupMap)
922+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
923+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
924+ tup = mkRelationTuple tupAttrs atoms
925+ tConss = typeConstructorMapping context
926+ finalAttrs = fromMaybe tupAttrs mAttrs
1011927 --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
1036− case M.lookup name (relationVariables ctx) of
1037− Nothing -> throwError (RelVarNotDefinedError name)
1038− Just rv -> evalGraphRefRelationalExpr rv
1039−evalGraphRefRelationalExpr (Project attrNames expr) = do
1040− attrNameSet <- evalGraphRefAttributeNames attrNames expr
1041− rel <- evalGraphRefRelationalExpr expr
1042− lift $ except $ project attrNameSet rel
1043−evalGraphRefRelationalExpr (Union exprA exprB) = do
1044− relA <- evalGraphRefRelationalExpr exprA
1045− relB <- evalGraphRefRelationalExpr exprB
1046− lift $ except $ union relA relB
1047−evalGraphRefRelationalExpr (Join exprA exprB) = do
1048− relA <- evalGraphRefRelationalExpr exprA
1049− relB <- evalGraphRefRelationalExpr exprB
1050− lift $ except $ join relA relB
1051−evalGraphRefRelationalExpr (Rename oldName newName expr) = do
1052− rel <- evalGraphRefRelationalExpr expr
1053− lift $ except $ rename oldName newName rel
1054−evalGraphRefRelationalExpr (Difference exprA exprB) = do
1055− relA <- evalGraphRefRelationalExpr exprA
1056− relB <- evalGraphRefRelationalExpr exprB
1057− lift $ except $ difference relA relB
1058−evalGraphRefRelationalExpr (Group groupAttrNames newAttrName expr) = do
1059− groupNames <- evalGraphRefAttributeNames groupAttrNames expr
1060− rel <- evalGraphRefRelationalExpr expr
1061− lift $ except $ group groupNames newAttrName rel
1062−evalGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1063− rel <- evalGraphRefRelationalExpr expr
1064− lift $ except $ ungroup groupAttrName rel
1065−evalGraphRefRelationalExpr (Restrict predExpr expr) = do
1066− rel <- evalGraphRefRelationalExpr expr
1067− filt <- predicateRestrictionFilter (attributes rel) predExpr
1068− lift $ except $ restrict filt rel
1069−evalGraphRefRelationalExpr (Equals exprA exprB) = do
1070− relA <- evalGraphRefRelationalExpr exprA
1071− relB <- evalGraphRefRelationalExpr exprB
1072− pure $ if relA == relB then relationTrue else relationFalse
1073−evalGraphRefRelationalExpr (NotEquals exprA exprB) = do
1074− relA <- evalGraphRefRelationalExpr exprA
1075− relB <- evalGraphRefRelationalExpr exprB
1076− pure $ if relA == relB then relationFalse else relationTrue
1077−evalGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1078− rel <- evalGraphRefRelationalExpr expr
1079− (newAttrs, tupProc) <- extendGraphRefTupleExpressionProcessor rel extendTupleExpr
1080− lift $ except $ relMogrify tupProc newAttrs rel
1081−evalGraphRefRelationalExpr expr@With{} =
1082− --strategy A: add relation variables to the contexts in the graph
1083− --strategy B: drop in macros in place (easier programmatically)
1084− --strategy B implementation
1085− evalGraphRefRelationalExpr (substituteWithNameMacros [] expr)
1086−
1087−dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
1088−dbContextForTransId tid graph = do
1089− trans <- transactionForId tid graph
1090− pure (concreteDatabaseContext trans)
1091−
1092−transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
1093−transactionForId tid graph
1094− | tid == U.nil =
1095− Left RootTransactionTraversalError
1096− | S.null matchingTrans =
1097− Left $ NoSuchTransactionError tid
1098− | otherwise =
1099− Right $ head (S.toList matchingTrans)
1100− where
1101− matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
1102−
1103−typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1104−typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = lift $ except $ mkRelation attrs emptyTupleSet
1105−typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (emptyRelationWithAttrs (attributes rel))
1106−typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1107− mAttrs <- case mAttrExprs of
1108− Just attrExprs -> do
1109− attrs <- mapM evalGraphRefAttributeExpr attrExprs
1110− pure (Just (attributesFromList attrs))
1111− Nothing -> pure Nothing
1112− tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1113− let retAttrs = case tuples of
1114− (tup:_) -> tupleAttributes tup
1115− [] -> fromMaybe A.emptyAttributes mAttrs
1116− pure $ emptyRelationWithAttrs retAttrs
1117−
1118−typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119− relVars <- relationVariables <$> gfDatabaseContextForMarker tid
1120− case M.lookup rvName relVars of
1121− Nothing -> throwError (RelVarNotDefinedError rvName)
1122− Just rvExpr ->
1123− typeForGraphRefRelationalExpr rvExpr
1124−typeForGraphRefRelationalExpr (Project attrNames expr) = do
1125− exprType' <- typeForGraphRefRelationalExpr expr
1126− projectionAttrs <- evalGraphRefAttributeNames attrNames expr
1127− lift $ except $ project projectionAttrs exprType'
1128−typeForGraphRefRelationalExpr (Union exprA exprB) = do
1129− exprA' <- typeForGraphRefRelationalExpr exprA
1130− exprB' <- typeForGraphRefRelationalExpr exprB
1131− lift $ except $ union exprA' exprB'
1132−typeForGraphRefRelationalExpr (Join exprA exprB) = do
1133− exprA' <- typeForGraphRefRelationalExpr exprA
1134− exprB' <- typeForGraphRefRelationalExpr exprB
1135− lift $ except $ join exprA' exprB'
1136−typeForGraphRefRelationalExpr (Rename oldAttr newAttr expr) = do
1137− expr' <- typeForGraphRefRelationalExpr expr
1138− lift $ except $ rename oldAttr newAttr expr'
1139−typeForGraphRefRelationalExpr (Difference exprA exprB) = do
1140− exprA' <- typeForGraphRefRelationalExpr exprA
1141− exprB' <- typeForGraphRefRelationalExpr exprB
1142− lift $ except $ difference exprA' exprB'
1143−typeForGraphRefRelationalExpr (Group groupNames attrName expr) = do
1144− expr' <- typeForGraphRefRelationalExpr expr
1145− groupNames' <- evalGraphRefAttributeNames groupNames expr
1146− lift $ except $ group groupNames' attrName expr'
1147−typeForGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1148− expr' <- typeForGraphRefRelationalExpr expr
1149− lift $ except $ ungroup groupAttrName expr'
1150−typeForGraphRefRelationalExpr (Restrict pred' expr) = do
1151− expr' <- typeForGraphRefRelationalExpr expr
1152− filt <- predicateRestrictionFilter (attributes expr') pred'
1153− lift $ except $ restrict filt expr'
1154−typeForGraphRefRelationalExpr Equals{} =
1155− pure relationFalse
1156−typeForGraphRefRelationalExpr NotEquals{} =
1157− pure relationFalse
1158−typeForGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1159− rel <- typeForGraphRefRelationalExpr expr
1160− evalGraphRefRelationalExpr (Extend extendTupleExpr (ExistingRelation rel))
1161−typeForGraphRefRelationalExpr expr@(With withs _) = do
1162− let expr' = substituteWithNameMacros [] expr
1163− checkMacroName (WithNameExpr macroName tid) = do
1164− rvs <- relationVariables <$> gfDatabaseContextForMarker tid
1165− case M.lookup macroName rvs of
1166− Just _ -> lift $ except $ Left (RelVarAlreadyDefinedError macroName) --this error does not include the transaction marker, but should be good enough to identify the cause
1167− Nothing -> pure ()
1168− mapM_ (checkMacroName . fst) withs
1169− typeForGraphRefRelationalExpr expr'
1170−
1171−evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1172−evalGraphRefAttributeNames attrNames expr = do
1173− exprType' <- typeForGraphRefRelationalExpr expr
1174− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
1175− case attrNames of
1176− AttributeNames names ->
1177− case A.projectionAttributesForNames names (attributes exprType') of
1178− Left err -> throwError err
1179− Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
928+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
929+ tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
930+ _ <- either throwE pure (validateTuple tup' tConss)
931+ pure tup'
932+
933+evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
934+evalAttributeNames attrNames expr = do
935+ eExprType <- typeForRelationalExpr expr
936+ case eExprType of
937+ Left err -> pure (Left err)
938+ Right exprTyp -> do
939+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
940+ case attrNames of
941+ AttributeNames names ->
942+ case A.projectionAttributesForNames names (attributes exprTyp) of
943+ Left err -> pure (Left err)
944+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1180945
1181− InvertedAttributeNames names -> do
946+ InvertedAttributeNames names -> do
1182947 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1183948 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
949+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1185950 else
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
951+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1187952
1188− UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
1191− pure (S.union nameSetA nameSetB)
953+ UnionAttributeNames namesA namesB -> do
954+ eNameSetA <- evalAttributeNames namesA expr
955+ case eNameSetA of
956+ Left err -> pure (Left err)
957+ Right nameSetA -> do
958+ eNameSetB <- evalAttributeNames namesB expr
959+ case eNameSetB of
960+ Left err -> pure (Left err)
961+ Right nameSetB ->
962+ pure (Right (S.union nameSetA nameSetB))
1192963
1193− IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
1196− pure (S.intersection nameSetA nameSetB)
964+ IntersectAttributeNames namesA namesB -> do
965+ eNameSetA <- evalAttributeNames namesA expr
966+ case eNameSetA of
967+ Left err -> pure (Left err)
968+ Right nameSetA -> do
969+ eNameSetB <- evalAttributeNames namesB expr
970+ case eNameSetB of
971+ Left err -> pure (Left err)
972+ Right nameSetB ->
973+ pure (Right (S.intersection nameSetA nameSetB))
1197974
1198− RelationalExprAttributeNames attrExpr -> do
1199− attrExprType <- typeForGraphRefRelationalExpr attrExpr
1200− pure (A.attributeNameSet (attributes attrExprType))
1201−
1202−evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
1203−evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) = do
1204− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
1205− case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1206− Left err -> throwError err
1207− Right aType -> do
1208− case validateAtomType aType tConsMap of
1209− Left err -> throwError err
1210− Right _ -> pure (Attribute attrName aType)
1211−evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1212−
1213−mkEmptyRelVars :: RelationVariables -> RelationVariables
1214−mkEmptyRelVars = M.map mkEmptyRelVar
1215− where
1216− mkEmptyRelVar expr@MakeRelationFromExprs{} = expr --do not truncate here because we might lose essential type information in emptying the tuples
1217− mkEmptyRelVar (MakeStaticRelation attrs _) = MakeStaticRelation attrs emptyTupleSet
1218− mkEmptyRelVar (ExistingRelation rel) = ExistingRelation (emptyRelationWithAttrs (attributes rel))
1219− mkEmptyRelVar rv@RelationVariable{} = Restrict (NotPredicate TruePredicate) rv
1220− mkEmptyRelVar (Project attrNames expr) = Project attrNames (mkEmptyRelVar expr)
1221− mkEmptyRelVar (Union exprA exprB) = Union (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1222− mkEmptyRelVar (Join exprA exprB) = Join (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1223− mkEmptyRelVar (Rename nameA nameB expr) = Rename nameA nameB (mkEmptyRelVar expr)
1224− mkEmptyRelVar (Difference exprA exprB) = Difference (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1225− mkEmptyRelVar (Group attrNames attrName expr) = Group attrNames attrName (mkEmptyRelVar expr)
1226− mkEmptyRelVar (Ungroup attrName expr) = Ungroup attrName (mkEmptyRelVar expr)
1227− mkEmptyRelVar (Restrict pred' expr) = Restrict pred' (mkEmptyRelVar expr)
1228− mkEmptyRelVar (Equals exprA exprB) = Equals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1229− mkEmptyRelVar (NotEquals exprA exprB) = NotEquals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1230− mkEmptyRelVar (Extend extTuple expr) = Extend extTuple (mkEmptyRelVar expr)
1231− mkEmptyRelVar (With macros expr) = With (map (second mkEmptyRelVar) macros) (mkEmptyRelVar expr)
1232−
1233−
1234−dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235−dbErr err = lift (except (Left err))
1236−
1237−-- | Return a Relation describing the relation variables.
1238−relationVariablesAsRelation :: DatabaseContext -> TransactionGraph -> Either RelationalError Relation
1239−relationVariablesAsRelation ctx graph = do
1240− let subrelAttrs = A.attributesFromList [Attribute "attribute" TextAtomType, Attribute "type" TextAtomType]
1241− attrs = A.attributesFromList [Attribute "name" TextAtomType,
1242− Attribute "attributes" (RelationAtomType subrelAttrs)]
1243− relVars = relationVariables ctx
1244− mkRvDesc (rvName, gfExpr) = do
1245− let gfEnv = freshGraphRefRelationalExprEnv (Just ctx) graph
1246− gfType <- runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
1247− pure (rvName, gfType)
1248− relVarToAtomList (rvName, rel) = [TextAtom rvName, attributesToRel (attributesVec (attributes rel))]
1249− attrAtoms a = [TextAtom (A.attributeName a), TextAtom (prettyAtomType (A.atomType a))]
1250− attributesToRel attrl = case mkRelationFromList subrelAttrs (map attrAtoms (V.toList attrl)) of
1251− Left err -> error ("relationVariablesAsRelation pooped " ++ show err)
1252− Right rel -> RelationAtom rel
1253− rvs <- mapM mkRvDesc (M.toList relVars)
1254− let tups = map relVarToAtomList rvs
1255− mkRelationFromList attrs tups
1256−
1257−-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258−evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259−evalRelationalExpr expr = do
1260− graph <- reGraph
1261− context <- reContext
1262− let expr' = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
1263− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
1264− case runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr expr') of
1265− Left err -> throwError err
1266− Right rel -> pure rel
1267−
1268−class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269− getContext :: m DatabaseContext
1270−
1271−instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272− getContext = gfDatabaseContextForMarker UncommittedContextMarker
1273−
1274−instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275− getContext = getStateContext
1276−
1277−relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278−relVarByName rvName = do
1279− relvars <- relationVariables <$> getContext
1280− case M.lookup rvName relvars of
1281− Nothing -> throwError (RelVarNotDefinedError rvName)
1282− Just gfexpr -> pure gfexpr
1283−
1284−-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285−class ResolveGraphRefTransactionMarker a where
1286− resolve :: a -> DatabaseContextEvalMonad a
1287−
1288−-- s := s union t
1289−instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290− resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291− MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292− resolve orig@MakeStaticRelation{} = pure orig
1293− resolve orig@ExistingRelation{} = pure orig
1294− resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295− rvMap <- relationVariables <$> getStateContext
1296− case M.lookup rvName rvMap of
1297− Nothing -> pure orig
1298− Just resolvedRv -> resolve resolvedRv
1299− resolve orig@RelationVariable{} = pure orig
1300− resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301− resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302− resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303− resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304− resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305− resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306− resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307− resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308− resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309− resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310− resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311− resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312−
1313−instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314− resolve (TupleExprs marker tupleExprs) =
1315− TupleExprs marker <$> mapM resolve tupleExprs
1316−
1317−instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318− resolve (TupleExpr tupMap) = do
1319− tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320− pure (TupleExpr (M.fromList tupMap'))
1321−
1322−instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323− resolve orig@AttributeNames{} = pure orig
1324− resolve orig@InvertedAttributeNames{} = pure orig
1325− resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326− resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327− resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328−
1329−instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330− resolve TruePredicate = pure TruePredicate
1331− resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332− resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333− resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334− resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335− resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336− resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337−
1338−instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339− resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340−
1341−instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342− resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343−
1344−instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345− resolve orig@AttributeAtomExpr{} = pure orig
1346− resolve orig@NakedAtomExpr{} = pure orig
1347− resolve (FunctionAtomExpr nam atomExprs marker) =
1348− FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349− resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350− resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351− ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352−
1353−--convert series of simple Union queries into MakeStaticRelation
1354−-- this is especially useful for long, nested applications of Union with simple tuples
1355−-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356−
1357−--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358−
1359−applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360−applyUnionCollapse = Fold.cata opt
1361− where
1362− opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363− opt (UnionF exprA exprB) | exprA == exprB = exprA
1364− opt (UnionF
1365− exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366− exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367− | tupExprsNull tupExprs1 = exprB
1368− | tupExprsNull tupExprs2 = exprA
1369− opt x = Fold.embed x
1370− tupExprsNull (TupleExprs _ []) = True
1371− tupExprsNull _ = False
1372−
1373−
1374−--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375−--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376−-- =>
1377−-- update x where y=1 set (x:=6,z:=11)
1378−-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379−
1380−--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381−
1382−--DELETE optimization
1383−-- if a restriction matches a previous restriction, combine them
1384−-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385−applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386−applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387− case expr of
1388− orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389− _ -> orig
1390−applyRestrictionCollapse expr = expr
1391−
1392−
975+ RelationalExprAttributeNames attrExpr -> do
976+ eAttrExprType <- typeForRelationalExpr attrExpr
977+ case eAttrExprType of
978+ Left err -> pure (Left err)
979+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
980+