@@ -1,33 +1,53 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2+{-# LANGUAGE FlexibleInstances #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE OverloadedStrings #-}
25module ProjectM36.RelationalExpression where
36import ProjectM36.Relation
47import ProjectM36.Tuple
58import ProjectM36.TupleSet
69import ProjectM36.Base
10+import qualified Data.UUID as U
711import ProjectM36.Error
812import ProjectM36.AtomType
9−import ProjectM36.Attribute (emptyAttributes)
13+import ProjectM36.Attribute (emptyAttributes, attributesFromList)
1014import ProjectM36.ScriptSession
1115import ProjectM36.DataTypes.Primitive
1216import ProjectM36.AtomFunction
1317import ProjectM36.DatabaseContextFunction
18+import ProjectM36.Arbitrary
19+import ProjectM36.GraphRefRelationalExpr
20+import ProjectM36.Transaction
1421import qualified ProjectM36.Attribute as A
1522import qualified Data.Map as M
1623import qualified Data.HashSet as HS
1724import qualified Data.Set as S
1825import Control.Monad.State hiding (join)
19−import Control.Exception
26+import Data.Bifunctor (second)
2027import Data.Maybe
2128import Data.Either
2229import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2333import qualified Data.Text as T
2434import qualified Data.Vector as V
2535import qualified ProjectM36.TypeConstructorDef as TCD
26−import Control.Monad.Trans.Except
27−import Control.Monad.Trans.Reader
28−
29−import GHC
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
43+import Test.QuickCheck
44+import qualified Data.Functor.Foldable as Fold
45+import Control.Applicative
46+#ifdef PM36_HASKELL_SCRIPTING
47+import GHC hiding (getContext)
48+import Control.Exception
3049import GHC.Paths
50+#endif
3151
3252data DatabaseContextExprDetails = CountUpdatedTuples
3353
@@ -44,32 +64,63 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
4464 Right ts -> ts
4565
4666-- | Used to start a fresh database state for a new database context expression.
47−freshDatabaseState :: DatabaseContext -> DatabaseStateElems
48−freshDatabaseState ctx = (ctx, M.empty, False) --future work: propagate return accumulator
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
4973
5074-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
51−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
52− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
53− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
54−
55−instance Show RelationalExprStateElems where
56− show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
57− show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
58− show (RelationalExprStateElems _) = "RelationalExprStateElems"
59−
60−mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
61−mkRelationalExprState = RelationalExprStateElems
62−
63−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
64−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
65−mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
66−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
67− RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
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))
6886
69−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
70−mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
71−mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
72−mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
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)))
73124
74125type ResultAccumName = StringType
75126
@@ -79,423 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
79130 resultAccumResult :: Relation
80131 }
81132
82−type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
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+ }
83138
84−type DatabaseState a = State DatabaseStateElems a
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
142+ }
85143
86−getStateContext :: DatabaseState DatabaseContext
87−getStateContext = do
88− (ctx,_, _) <- get
89− pure ctx
90−
91−putStateContext :: DatabaseContext -> DatabaseState ()
92−putStateContext ctx = do
93− (_, accum, _) <- get
94− put (ctx, accum, True)
95−
96−type RelationalExprState a = Reader RelationalExprStateElems a
97−
98−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
99−stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
100−stateElemsContext (RelationalExprStateElems ctx) = ctx
101−stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
102−
103−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
104−setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
105−setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
106−setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
107−
108−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
109−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
110−evalRelationalExpr (RelationVariable name _) = do
111− relvarTable <- fmap (relationVariables . stateElemsContext) ask
112− return $ case M.lookup name relvarTable of
113− Just res -> Right res
114− Nothing -> Left $ RelVarNotDefinedError name
115−
116−evalRelationalExpr (Project attrNames expr) = do
117− eAttrNameSet <- evalAttributeNames attrNames expr
118− case eAttrNameSet of
119− Left err -> pure (Left err)
120− Right attrNameSet -> do
121− rel <- evalRelationalExpr expr
122− case rel of
123− Right rel2 -> pure $ project attrNameSet rel2
124− Left err -> pure $ Left err
125−
126−evalRelationalExpr (Union exprA exprB) = do
127− relA <- evalRelationalExpr exprA
128− relB <- evalRelationalExpr exprB
129− case relA of
130− Left err -> return $ Left err
131− Right relA2 -> case relB of
132− Left err -> return $ Left err
133− Right relB2 -> return $ union relA2 relB2
134−
135−evalRelationalExpr (Join exprA exprB) = do
136− relA <- evalRelationalExpr exprA
137− relB <- evalRelationalExpr exprB
138− case relA of
139− Left err -> return $ Left err
140− Right relA2 -> case relB of
141− Left err -> return $ Left err
142− Right relB2 -> return $ join relA2 relB2
143−
144−evalRelationalExpr (Difference exprA exprB) = do
145− relA <- evalRelationalExpr exprA
146− relB <- evalRelationalExpr exprB
147− case relA of
148− Left err -> return $ Left err
149− Right relA2 -> case relB of
150− Left err -> return $ Left err
151− Right relB2 -> return $ difference relA2 relB2
152−
153−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
154− case mkRelation attributeSet tupleSet of
155− Right rel -> return $ Right rel
156− Left err -> return $ Left err
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146+
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
148+
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151+ where
152+ freshEnv = mkDatabaseContextEvalState ctx
157153
158−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
159− currentContext <- fmap stateElemsContext ask
160− let tConss = typeConstructorMapping currentContext
161− -- if the mAttrExprs is Nothing, then we should attempt to infer the tuple attributes from the first tuple itself- note that this is not always possible
162− runExceptT $ do
163− mAttrs <- case mAttrExprs of
164− Just _ -> do
165− attrs <- mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
166− pure (Just (A.attributesFromList attrs))
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))
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+ }
172180
173−evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
181+type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
174182
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
183+gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184+gfTransForId tid = do
185+ graph <- gfGraph
186+ lift $ except $ transactionForId tid graph
180187
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
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
208+
209+envContext :: RelationalExprEnv -> DatabaseContext
210+envContext = re_context
211+
212+setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213+setEnvContext e ctx = e { re_context = ctx }
238214
239215--helper function to process relation variable creation/assignment
240−setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
241−setRelVar relVarName rel = do
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217+setRelVar relVarName relExpr = do
242218 currentContext <- getStateContext
243− let newRelVars = M.insert relVarName rel $ relationVariables currentContext
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
244222 potentialContext = currentContext { relationVariables = newRelVars }
245−
246− case checkConstraints potentialContext of
247− Left err -> pure (Left err)
248− Right _ -> do
249− putStateContext potentialContext
250− return (Right ())
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 ()
251236
252237-- it is not an error to delete a relvar which does not exist, just like it is not an error to insert a pre-existing tuple into a relation
253−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
254239deleteRelVar relVarName = do
255240 currContext <- getStateContext
256241 let relVars = relationVariables currContext
257242 if M.notMember relVarName relVars then
258− pure (Right ())
243+ pure ()
259244 else do
260245 let newRelVars = M.delete relVarName relVars
261246 newContext = currContext { relationVariables = newRelVars }
262247 putStateContext newContext
263− pure (Right ())
248+ pure ()
264249
265−evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
266−evalDatabaseContextExpr NoOperation = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
267252
268−evalDatabaseContextExpr (Define relVarName attrExprs) = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
269255 relvars <- fmap relationVariables getStateContext
270256 tConss <- fmap typeConstructorMapping getStateContext
271− let eAttrs = map (evalAttrExpr tConss) attrExprs
272− case lefts eAttrs of
273− err:_ -> pure (Left err)
274− [] -> case M.member relVarName relvars of
275− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
276− False -> setRelVar relVarName emptyRelation >> pure (Right ())
277− where
278− attrs = A.attributesFromList (rights eAttrs)
279− emptyRelation = Relation attrs emptyTupleSet
280−
281−evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
282−
283−evalDatabaseContextExpr (Assign relVarName expr) = do
284− -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
285− context <- getStateContext
286− let existingRelVar = M.lookup relVarName relVarTable
287− relVarTable = relationVariables context
288− value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
289− case value of
290− Left err -> pure (Left err)
291− Right rel -> case existingRelVar of
292− Nothing -> setRelVar relVarName rel
293− Just existingRel -> let expectedAttributes = attributes existingRel
294− foundAttributes = attributes rel in
295− if A.attributesEqual expectedAttributes foundAttributes then
296− setRelVar relVarName rel
297− else
298− pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
299−
300−evalDatabaseContextExpr (Insert relVarName relExpr) = do
301− context <- getStateContext
302− let unionexp = Union relExpr rv
303− rv = RelationVariable relVarName ()
304− unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
305− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
306− case unioned of
307− Left err -> pure (Left err)
308− Right unioned' -> case origRel of
309− Left err -> pure (Left err)
310− Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
311− pure (Right ())
312− else
313− evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
314−
315−evalDatabaseContextExpr (Delete relVarName predicate) = do
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)
267+ where
268+ attrs = A.attributesFromList attrsList
269+ emptyRelation = Relation attrs emptyTupleSet
270+
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
272+
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
316275 context <- getStateContext
317− let rv = RelationVariable relVarName ()
318− let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
319− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
320− case updatedRel of
321− Left err -> pure (Left err)
322− Right updatedRel' -> case origRel of
323− Left err -> pure (Left err)
324− Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
325− pure (Right ())
326− else
327− setRelVar relVarName updatedRel'
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))
328299
300+evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301+ gfExpr <- relVarByName relVarName
302+ let optExpr = applyUnionCollapse (Union
303+ relExpr
304+ gfExpr)
305+ evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
306+
307+evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308+ gfExpr <- relVarByName relVarName
309+ let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310+ setRelVar relVarName optExpr
311+
329312--union of restricted+updated portion and the unrestricted+unupdated portion
330−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
331316 context <- getStateContext
332− let relVarTable = relationVariables context
333− case M.lookup relVarName relVarTable of
334− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
335− Just rel ->
336− case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
337− Left err -> pure (Left err)
338− Right predicateFunc -> do
339− let ret = do
340− restrictedPortion <- restrict predicateFunc rel
341− if cardinality restrictedPortion == Finite 0 then
342− pure Nothing
343− else do
344− unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
345− updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
346− updatedRel <- updatedPortion `union` unrestrictedPortion
347− pure (Just updatedRel)
348− case ret of
349− Left err -> pure (Left err)
350− Right Nothing -> pure (Right ())
351− Right (Just updatedRel) -> setRelVar relVarName updatedRel
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)
352342
353−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
354344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
355347 let currDeps = inclusionDependencies currContext
356348 newDeps = M.insert newDepName newDep currDeps
357349 if M.member newDepName currDeps then
358− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
359351 else do
360352 let potentialContext = currContext { inclusionDependencies = newDeps }
361− case checkConstraints potentialContext of
362− Left err -> pure (Left err)
363− Right _ -> do
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 _ ->
364358 putStateContext potentialContext
365− return (Right ())
366359
367−evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
368361 currContext <- getStateContext
369362 let currDeps = inclusionDependencies currContext
370363 newDeps = M.delete depName currDeps
371364 if M.notMember depName currDeps then
372− pure (Left (InclusionDependencyNameNotInUseError depName))
373− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
374367 putStateContext $ currContext {inclusionDependencies = newDeps }
375− return (Right ())
376368
377369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
378−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
379371 currentContext <- getStateContext
380372 let nots = notifications currentContext
381373 if M.member notName nots then
382− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
383375 else do
384376 let newNotifications = M.insert notName newNotification nots
385377 newNotification = Notification { changeExpr = triggerExpr,
386378 reportOldExpr = resultOldExpr,
387379 reportNewExpr = resultNewExpr}
388380 putStateContext $ currentContext { notifications = newNotifications }
389− return (Right ())
390381
391−evalDatabaseContextExpr (RemoveNotification notName) = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
392383 currentContext <- getStateContext
393384 let nots = notifications currentContext
394385 if M.notMember notName nots then
395− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
396387 else do
397388 let newNotifications = M.delete notName nots
398389 putStateContext $ currentContext { notifications = newNotifications }
399− pure (Right ())
390+
400391
401392-- | Adds type and data constructors to the database context.
402393-- validate that the type *and* constructor names are unique! not yet implemented!
403−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
404395 currentContext <- getStateContext
405396 let oldTypes = typeConstructorMapping currentContext
406397 tConsName = TCD.name tConsDef
407398 -- validate that the constructor's types exist
408− case validateTypeConstructorDef tConsDef dConsDefList of
409− errs@(_:_) -> pure (Left (someErrors errs))
410− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
411− | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
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)
412403 | otherwise -> do
413404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
414405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
415− pure (Right ())
416406
417407-- | 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.
418−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
419409 currentContext <- getStateContext
420410 let oldTypes = typeConstructorMapping currentContext
421411 if isNothing (findTypeConstructor tConsName oldTypes) then
422− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
423413 else do
424414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
425415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
426− pure (Right ())
427416
428−evalDatabaseContextExpr (MultipleExpr exprs) = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
429418 --the multiple expressions must pass the same context around- not the old unmodified context
430− evald <- forM exprs evalDatabaseContextExpr
431− --some lifting magic needed here
432− case lefts evald of
433− [] -> pure (Right ())
434− errs -> pure (Left (someErrors errs))
435−
436−evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
437422 currentContext <- getStateContext
438423 let atomFuncs = atomFunctions currentContext
439424 case atomFunctionForName funcName atomFuncs of
440− Left err -> pure (Left err)
441− Right realFunc -> if isScriptedAtomFunction realFunc then do
442− let updatedFuncs = HS.delete realFunc atomFuncs
443− putStateContext (currentContext {atomFunctions = updatedFuncs })
444− pure (Right ())
445− else
446− pure (Left (PrecompiledFunctionRemoveError funcName))
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)
447432
448−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
449434 context <- getStateContext
450435 let dbcFuncs = dbcFunctions context
451436 case databaseContextFunctionForName funcName dbcFuncs of
452− Left err -> pure (Left err)
453− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
454− let updatedFuncs = HS.delete realFunc dbcFuncs
455− putStateContext (context { dbcFunctions = updatedFuncs })
456− pure (Right ())
457− else
458− pure (Left (PrecompiledFunctionRemoveError funcName))
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)
459444
460−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
461446 context <- getStateContext
447+ graph <- dbcGraph
462448 --resolve atom arguments
463− let relExprState = mkRelationalExprState context
464− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
465450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
466452 case eFunc of
467− Left err -> pure (Left err)
453+ Left err -> dbErr err
468454 Right func -> do
469455 let expectedArgCount = length (dbcFuncType func)
470456 actualArgCount = length atomArgExprs
471457 if expectedArgCount /= actualArgCount then
472− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
473459 else
474460 --check that the atom types are valid
475− case lefts eAtomTypes of
476− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
477− [] -> do
478− let atomTypes = rights eAtomTypes
479− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
480− Left err -> Just err
481− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
482− typeErrors = catMaybes mValidTypes
483− eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
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
484471 if length (lefts eAtomArgs) > 1 then
485− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
486473 else if not (null typeErrors) then
487− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
488475 else
489476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
490− Left err -> pure (Left err)
491− Right newContext -> putStateContext newContext >> pure (Right ())
492−
493−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
494−evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
495− case mScriptSession of
496− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
497− Just scriptSession -> do
498− res <- try $ runGhc (Just libdir) $ do
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
499530 setSession (hscEnv scriptSession)
500531 let atomFuncs = atomFunctions currentContext
501532 case extractAtomFunctionType funcType of
@@ -506,7 +537,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcNam
506537 pure $ case eCompiledFunc of
507538 Left err -> Left (ScriptError err)
508539 Right compiledFunc -> do
509− funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructor funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
540+ funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructorValidate False funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
510541 let updatedFuncs = HS.insert newAtomFunc atomFuncs
511542 newContext = currentContext { atomFunctions = updatedFuncs }
512543 newAtomFunc = AtomFunction { atomFuncName = funcName,
@@ -521,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcNam
521552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
522553 Right eContext -> case eContext of
523554 Left err -> pure (Left err)
524− Right context' -> pure (Right context')
525−
526−evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
527− case mScriptSession of
528− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
529− Just scriptSession -> do
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
530562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
531563 let last2Args = reverse (take 2 (reverse funcType))
532564 atomArgs = take (length funcType - 2) funcType
@@ -536,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
536568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
537569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
538570 else do
539− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
540572 setSession (hscEnv scriptSession)
541573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
542574 pure $ case eCompiledFunc of
@@ -561,34 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
561593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
562594 Right eContext -> case eContext of
563595 Left err -> pure (Left err)
564− Right context' -> pure (Right context')
565−
566−
567−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
568−updateTupleWithAtomExprs exprMap context tupIn = do
569− --resolve all atom exprs
570− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
571− atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
572− pure (attrName, atom)
573− ) (M.toList exprMap)
574− pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
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
600+ case eLoadFunc of
601+ Left LoadSymbolError -> pure (Left LoadFunctionError)
602+ Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603+ 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
608+ case eLoadFunc of
609+ Left LoadSymbolError -> pure (Left LoadFunctionError)
610+ Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611+ mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
615+ --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
625+ --Assign
626+ let existingRelVar = M.lookup relVarName relVarTable
627+ relVarTable = relationVariables (dbc_context dbstate)
628+ case existingRelVar of
629+ Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630+ Just existingRel -> do
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633+ Left err -> pure (Left err)
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')
575644
576645--run verification on all constraints
577−checkConstraints :: DatabaseContext -> Either RelationalError ()
578−checkConstraints context = do
646+checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
579648 mapM_ (uncurry checkIncDep) (M.toList deps)
580− pure ()
581649 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+
582660 deps = inclusionDependencies context
583− eval expr = evalReader (evalRelationalExpr expr)
584− evalReader f = runReader f (RelationalExprStateElems 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
585662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
586666 --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.
587− typeSub <- evalReader (typeForRelationalExpr subsetExpr)
588− typeSuper <- evalReader (typeForRelationalExpr supersetExpr)
667+ let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668+ runGfRel = runGraphRefRelationalExprM gfEnv
669+ typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670+ typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
589671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
590− let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
591− case eval checkExpr of
672+ let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673+ gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674+ gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675+ case gfEvald of
592676 Left err -> Left err
593677 Right resultRel -> if resultRel == relationTrue then
594678 pure ()
@@ -598,90 +682,81 @@ checkConstraints context = do
598682-- 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
599683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
600684
601−typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
602686typeForRelationalExpr expr = do
603− rstate <- ask
604− let context = stateElemsContext rstate
605687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
606− let context' = contextWithEmptyTupleSets context
607− rstate' = setStateElemsContext rstate context'
608− pure (runReader (evalRelationalExpr expr) rstate')
609−
610−--returns a database context with all tuples removed
611−--this is useful for type checking and optimization
612−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
613−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
614− where
615− relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
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
616695
617696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
618697liftE v = do
619698 y <- lift v
620699 case y of
621− Left err -> throwE err
700+ Left err -> throwError err
622701 Right val -> pure val
623702
624703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
625−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
626−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
627− runExceptT $ do
628− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
629− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
630− pure (\x -> do
631− ev1 <- expr1v x
632− ev2 <- expr2v x
633− pure (ev1 && ev2))
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))
634712
635−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
636− runExceptT $ do
637− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
638− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
713+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714+ expr1v <- predicateRestrictionFilter attrs expr1
715+ expr2v <- predicateRestrictionFilter attrs expr2
639716 pure (\x -> do
640717 ev1 <- expr1v x
641718 ev2 <- expr2v x
642719 pure (ev1 || ev2))
643720
644−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
645722
646−predicateRestrictionFilter attrs (NotPredicate expr) =
647− runExceptT $ do
648− exprv <- liftE (predicateRestrictionFilter attrs expr)
649− pure (\x -> do
650− ev <- exprv x
651− pure (not ev))
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
652726
653727--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
654728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
655− rstate <- ask
656− pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
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
657735 Left err -> Left err
658736 Right rel -> if arity rel /= 0 then
659737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
660738 else
661− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
662740
663741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
664− rstate <- ask
665− let (attrs', ctxtup') = case rstate of
666− RelationalExprStateElems _ -> (attrs, emptyTuple)
667− RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
668− RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
669− runExceptT $ do
670− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
671− attr <- either throwE pure $ case A.attributeForName attrName attrs of
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
672747 Right attr -> Right attr
673748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
674749 Right ctxattr -> Right ctxattr
675750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
676751 Left err -> Left err
677752 Left err -> Left err
678− if atomExprType /= A.atomType attr then
679− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
680− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
681756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
682757 Right atomCmp -> atomCmp == atomIn
683758 Left _ -> False
684− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
685760 in
686761 pure $ case atomForAttributeName attrName tupleIn of
687762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -692,244 +767,626 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
692767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
693768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
694769 --merge attrs into the state attributes
695− rstate <- ask
696− runExceptT $ do
697− aType <- liftE (typeFromAtomExpr attrs atomExpr)
698− if aType /= BoolAtomType then
699− throwE (AtomTypeMismatchError aType BoolAtomType)
700− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
701775 pure (\tupleIn ->
702− pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
703− Left _ -> False
704− Right boolAtomValue -> boolAtomValue == BoolAtom True)
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
705779
706780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
707781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
708− Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
782+ Left (AttributeNameInUseError attrName)
709783 else
710784 Right rel
711785
712−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
713−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
714− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
715789 -- check that the attribute name is not in use
716790 case tupleExprCheckNewAttrName newAttrName relIn of
717− Left err -> pure (Left err)
718− Right _ -> runExceptT $ do
719− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
720− atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
791+ Left err -> throwError err
792+ Right _ -> do
793+ atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
794+ atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
721795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
722796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
723− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
724− Left err -> Left err
725− Right atom -> Right (tupleAtomExtend newAttrName atom tup)
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)
726802 )
727803
728−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
729−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
730− Right atom -> pure (Right atom)
731− err@(Left (NoSuchAttributeNamesError _)) -> do
732− rstate <- ask
733− case rstate of
734− RelationalExprStateElems _ -> pure err
735− RelationalExprStateAttrsElems _ _ -> pure err
736− RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
737− Left err -> pure (Left err)
738−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
739−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
740− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
741− context <- fmap stateElemsContext ask
742− runExceptT $ do
743− let functions = atomFunctions context
744− func <- either throwE pure (atomFunctionForName funcName functions)
745− let expectedArgCount = length (atomFuncType func) - 1
746− actualArgCount = length argTypes
747− safeInit [_] = []
748− safeInit [] = [] -- different behavior from normal init
749− safeInit (_:xs) = safeInit xs
750− if expectedArgCount /= actualArgCount then
751− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
752− else do
753− mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
754− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
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
755832 case evalAtomFunction func evaldArgs of
756− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
757834 Right result -> do
758835 --validate that the result matches the expected type
759− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
760837 pure result
761−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
762839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
763− rstate <- ask
764− runExceptT $ do
765− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
766− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
767− pure (RelationAtom relAtom)
768−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
769− rstate <- lift ask
770− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
771− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
772− argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
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
773849 pure (ConstructedAtom dConsName aType argAtoms)
774850
775−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
776−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
777− rstate <- ask
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
778854 case A.atomTypeForAttributeName attrName attrs of
779− Right aType -> pure (Right aType)
780− Left err@(NoSuchAttributeNamesError _) -> case rstate of
781− RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
782− Left err' -> pure (Left err')
783− Right attr -> pure (Right (A.atomType attr))
784− RelationalExprStateElems _ -> pure (Left err)
785− RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
786− Left err' -> pure (Left err')
787− Right atom -> pure (Right (atomTypeForAtom atom))
788− Left err -> pure (Left err)
789−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
790−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
791− context <- fmap stateElemsContext ask
792− let funcs = atomFunctions context
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
793870 case atomFunctionForName funcName funcs of
794− Left err -> pure (Left err)
871+ Left err -> throwError err
795872 Right func -> do
796873 let funcRetType = last (atomFuncType func)
797874 funcArgTypes = init (atomFuncType func)
798− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
799− case lefts eArgTypes of
800− errs@(_:_) -> pure (Left (someErrors errs))
801− [] -> do
802− let eTvMap = resolveTypeVariables funcArgTypes argTypes
803− argTypes = rights eArgTypes
804− case eTvMap of
805− Left err -> pure (Left err)
806− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
807−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
808− rstate <- lift ask
809− relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
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)
810882 pure (RelationAtomType (attributes relType))
811883-- grab the type of the data constructor, then validate that the args match the expected types
812−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
813− runExceptT $ do
814− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
815− context <- fmap stateElemsContext (lift ask)
816− aType <- either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
817− pure aType
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
818889
819890-- | Validate that the type of the AtomExpr matches the expected type.
820−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
821−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
822− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
823894 case A.atomTypeForAttributeName attrName (attributes relIn) of
824− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
825− (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
826− RelationalExprStateTupleElems _ _ -> throwE err
827− RelationalExprStateElems _ -> throwE err
828− RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
829− Left err' -> throwE err'
830− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
831− Left err -> throwE err
832−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
833−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
834− rstate <- ask
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
835910 let functions = atomFunctions context
836− context = stateElemsContext rstate
837− runExceptT $ do
838− func <- either throwE pure (atomFunctionForName funcName functions)
839− let expectedArgTypes = atomFuncType func
840− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
841− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
842− Left err -> throwE err
843− Right x -> pure x
844− ) $ zip3 funcArgExprs expectedArgTypes [1..]
845− if length funcArgTypes /= length expectedArgTypes - 1 then
846− throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
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)
847921 else
848− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
849−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
850− rstate <- lift ask
851− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
852− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
853−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
854− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
855− either throwE pure (atomTypeVerify expectedType cType)
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
856931
857932-- | Look up the type's name and create a new attribute.
858−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
859−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
860− aType <- atomTypeForTypeConstructor tCons aTypes M.empty
861− Right (Attribute attrName aType)
862−
863−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
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
864939
865−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
866−evalTupleExpr attrs (TupleExpr tupMap) = do
867− context <- fmap stateElemsContext ask
868− runExceptT $ do
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
869992 -- 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
870993 -- 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
871− attrAtoms <- mapM (\(attrName, aExpr) -> do
872− newAtomType <- liftE (typeFromAtomExpr A.emptyAttributes aExpr)
873− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
874− pure (attrName, newAtom, newAtomType)
875− ) (M.toList tupMap)
876− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
877− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
878− tup = mkRelationTuple tupAttrs atoms
879− tConss = typeConstructorMapping context
880− finalAttrs = fromMaybe tupAttrs attrs
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
1001+ Left _ -> pure unresolvedType
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
1003+ --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
8811011 --verify that the attributes match
882− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
883− tup' <- either throwE pure (resolveTypesInTuple finalAttrs (reorderTuple finalAttrs tup))
884− _ <- either throwE pure (validateTuple tup' tConss)
885− pure tup'
886−
887−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
888−evalAttributeNames attrNames expr = do
889− eExprType <- typeForRelationalExpr expr
890− case eExprType of
891− Left err -> pure (Left err)
892− Right exprTyp -> do
893− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
894− case attrNames of
895− AttributeNames names ->
896− case A.projectionAttributesForNames names (attributes exprTyp) of
897− Left err -> pure (Left err)
898− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
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)))
8991180
900− InvertedAttributeNames names -> do
1181+ InvertedAttributeNames names -> do
9011182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
9021183 if not (S.null nonExistentAttributeNames) then
903− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
9041185 else
905− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
9061187
907− UnionAttributeNames namesA namesB -> do
908− eNameSetA <- evalAttributeNames namesA expr
909− case eNameSetA of
910− Left err -> pure (Left err)
911− Right nameSetA -> do
912− eNameSetB <- evalAttributeNames namesB expr
913− case eNameSetB of
914− Left err -> pure (Left err)
915− Right nameSetB ->
916− pure (Right (S.union nameSetA nameSetB))
1188+ UnionAttributeNames namesA namesB -> do
1189+ nameSetA <- evalGraphRefAttributeNames namesA expr
1190+ nameSetB <- evalGraphRefAttributeNames namesB expr
1191+ pure (S.union nameSetA nameSetB)
9171192
918− IntersectAttributeNames namesA namesB -> do
919− eNameSetA <- evalAttributeNames namesA expr
920− case eNameSetA of
921− Left err -> pure (Left err)
922− Right nameSetA -> do
923− eNameSetB <- evalAttributeNames namesB expr
924− case eNameSetB of
925− Left err -> pure (Left err)
926− Right nameSetB ->
927− pure (Right (S.intersection nameSetA nameSetB))
1193+ IntersectAttributeNames namesA namesB -> do
1194+ nameSetA <- evalGraphRefAttributeNames namesA expr
1195+ nameSetB <- evalGraphRefAttributeNames namesB expr
1196+ pure (S.intersection nameSetA nameSetB)
9281197
929− RelationalExprAttributeNames attrExpr -> do
930− eAttrExprType <- typeForRelationalExpr attrExpr
931− case eAttrExprType of
932− Left err -> pure (Left err)
933− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
934−
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
9351287
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+