@@ -1,4 +1,7 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2+{-# LANGUAGE FlexibleInstances #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE OverloadedStrings #-}
25module ProjectM36.RelationalExpression where
36import ProjectM36.Relation
47import ProjectM36.Tuple
@@ -7,29 +10,44 @@ import ProjectM36.Base
710import qualified Data.UUID as U
811import ProjectM36.Error
912import ProjectM36.AtomType
10−import ProjectM36.Attribute (emptyAttributes)
13+import ProjectM36.Attribute (emptyAttributes, attributesFromList)
1114import ProjectM36.ScriptSession
1215import ProjectM36.DataTypes.Primitive
1316import ProjectM36.AtomFunction
1417import ProjectM36.DatabaseContextFunction
1518import ProjectM36.Arbitrary
19+import ProjectM36.GraphRefRelationalExpr
20+import ProjectM36.Transaction
1621import qualified ProjectM36.Attribute as A
1722import qualified Data.Map as M
1823import qualified Data.HashSet as HS
1924import qualified Data.Set as S
2025import Control.Monad.State hiding (join)
21−import Control.Exception
26+import Data.Bifunctor (second)
2227import Data.Maybe
2328import Data.Either
2429import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2533import qualified Data.Text as T
2634import qualified Data.Vector as V
2735import qualified ProjectM36.TypeConstructorDef as TCD
28−import Control.Monad.Trans.Except
29−import Control.Monad.Trans.Reader
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
3043import Test.QuickCheck
31−import GHC
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
3249import GHC.Paths
50+#endif
3351
3452data DatabaseContextExprDetails = CountUpdatedTuples
3553
@@ -46,36 +64,63 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
4664 Right ts -> ts
4765
4866-- | Used to start a fresh database state for a new database context expression.
49−freshDatabaseState :: DatabaseContext -> DatabaseStateElems
50−freshDatabaseState context = DatabaseStateElems {
51− context = context,
52− accum = M.empty,
53− dirty = False
67+mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68+mkDatabaseContextEvalState context = DatabaseContextEvalState {
69+ dbc_context = context,
70+ dbc_accum = M.empty,
71+ dbc_dirty = False
5472 } --future work: propagate return accumulator
5573
5674-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
57−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
58− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
59− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
60−
61−instance Show RelationalExprStateElems where
62− show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
63− show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
64− show (RelationalExprStateElems _) = "RelationalExprStateElems"
65−
66−mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
67−mkRelationalExprState = RelationalExprStateElems
68−
69−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
70−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
71−mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
72−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
73− 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))
7486
75−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
76−mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
77−mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
78−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)))
79124
80125type ResultAccumName = StringType
81126
@@ -85,443 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
85130 resultAccumResult :: Relation
86131 }
87132
88−data DatabaseStateElems = DatabaseStateElems {
89− context :: DatabaseContext, --new, alterable context for a new transaction
90− accum :: M.Map ResultAccumName ResultAccum,
91− dirty :: 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+ }
138+
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
92142 }
93143
94−type DatabaseState a = State DatabaseStateElems a
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
95146
96−getStateContext :: DatabaseState DatabaseContext
97−getStateContext = context <$> get
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
98148
99−putStateContext :: DatabaseContext -> DatabaseState ()
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151+ where
152+ freshEnv = mkDatabaseContextEvalState ctx
153+
154+
155+dbcTransId :: DatabaseContextEvalMonad TransactionId
156+dbcTransId = dce_transId <$> RWS.ask
157+
158+dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159+dbcGraph = dce_graph <$> RWS.ask
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 ()
100169putStateContext ctx' = do
101170 s <- get
102− put (s {context = ctx'})
103−
104−type RelationalExprState a = Reader RelationalExprStateElems a
105−
106−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
107−stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
108−stateElemsContext (RelationalExprStateElems ctx) = ctx
109−stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
110−
111−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
112−setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
113−setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
114−setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
115−
116−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
117−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError GraphRefRelationalExpr)
118−evalRelationalExpr (RelationVariable name _) = do
119− relvarTable <- fmap (relationVariables . stateElemsContext) ask
120− return $ case M.lookup name relvarTable of
121− Just res -> Right res
122− Nothing -> Left $ RelVarNotDefinedError name
123−
124−evalRelationalExpr (Project attrNames expr) = do
125− eAttrNameSet <- evalAttributeNames attrNames expr
126− case eAttrNameSet of
127− Left err -> pure (Left err)
128− Right attrNameSet -> do
129− rel <- evalRelationalExpr expr
130− case rel of
131− Right rel2 -> pure $ Right (Project (AttributeNames attrNameSet) rel2)
132− Left err -> pure $ Left err
133−
134−evalRelationalExpr (Union exprA exprB) = do
135− relA <- evalRelationalExpr exprA
136− relB <- evalRelationalExpr exprB
137− case relA of
138− Left err -> return $ Left err
139− Right relA2 -> case relB of
140− Left err -> return $ Left err
141− Right relB2 -> return $ Right (Union relA2 relB2)
142−
143−evalRelationalExpr (Join exprA exprB) = do
144− relA <- evalRelationalExpr exprA
145− relB <- evalRelationalExpr exprB
146− case relA of
147− Left err -> return $ Left err
148− Right relA2 -> case relB of
149− Left err -> return $ Left err
150− Right relB2 -> return $ Right (Join relA2 relB2)
151−
152−evalRelationalExpr (Difference exprA exprB) = do
153− relA <- evalRelationalExpr exprA
154− relB <- evalRelationalExpr exprB
155− case relA of
156− Left err -> return $ Left err
157− Right relA2 -> case relB of
158− Left err -> return $ Left err
159− Right relB2 -> return $ Right (Difference relA2 relB2)
160−
161−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
162− case mkRelation attributeSet tupleSet of
163− Right rel -> return $ Right (ExistingRelation rel)
164− Left err -> return $ Left err
165−
166−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
167− currentContext <- fmap stateElemsContext ask
168− let tConss = typeConstructorMapping currentContext
169− -- 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
170− runExceptT $ do
171− mAttrs <- case mAttrExprs of
172− Just _ ->
173− Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
174− Nothing -> pure Nothing
175− tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
176− let attrs = fromMaybe firstTupleAttrs mAttrs
177− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
178− expr <- either throwE pure (mkRelation attrs (RelationTupleSet tuples))
179− pure (ExistingRelation expr)
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+ }
180180
181−evalRelationalExpr (ExistingRelation rel) = pure (Right (ExistingRelation rel))
181+type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
182182
183−evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
184− evald <- evalRelationalExpr relExpr
185− case evald of
186− Right expr -> return $ Right (Rename oldAttrName newAttrName expr)
187− Left err -> return $ Left err
183+gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184+gfTransForId tid = do
185+ graph <- gfGraph
186+ lift $ except $ transactionForId tid graph
188187
189−evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
190− eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
191− case eOldAttrNameSet of
192− Left err -> pure (Left err)
193− Right oldAttrNameSet -> do
194− evald <- evalRelationalExpr relExpr
195− case evald of
196− Right expr -> return $ Right (Group (AttributeNames oldAttrNameSet) newAttrName expr)
197− Left err -> return $ Left err
198−
199−evalRelationalExpr (Ungroup attrName relExpr) = do
200− evald <- evalRelationalExpr relExpr
201− case evald of
202− Right expr -> return $ Right (Ungroup attrName expr)
203− Left err -> return $ Left err
204−
205−evalRelationalExpr (Restrict predicateExpr relExpr) = do
206− evald <- evalRelationalExpr relExpr
207− ePred <- processRestrictionPredicateExpr predicateExpr
208− case evald of
209− Left err -> return $ Left err
210− Right expr -> case ePred of
211− Left err -> pure (Left err)
212− Right pred -> pure $ Right (Restrict pred expr)
213−
214−evalRelationalExpr (Equals relExprA relExprB) = do
215− evaldA <- evalRelationalExpr relExprA
216− evaldB <- evalRelationalExpr relExprB
217− case evaldA of
218− Left err -> return $ Left err
219− Right exprA -> case evaldB of
220− Left err -> return $ Left err
221− Right exprB -> return $ Right (Equals exprA exprB)
222−{-
223−evalRelationalExpr (With views mainExpr) = do
224− rstate <- ask
225−
226− let addScopedView ctx (vname,vexpr) = if vname `M.member` relationVariables ctx then
227− Left (RelVarAlreadyDefinedError vname)
228− else
229− case runState (evalDatabaseContextExpr (Assign vname vexpr)) (freshDatabaseState ctx) of
230− (Left err,_) -> Left err
231− (Right (), (ctx',_,_)) -> Right ctx'
232−
233− case foldM addScopedView (stateElemsContext rstate) views of
234− Left err -> return $ Left err
235− Right ctx'' -> do
236− let evalMainExpr expr = runReader (evalRelationalExpr expr) (RelationalExprStateElems ctx'')
237− case evalMainExpr mainExpr of
238− Left err -> return $ Left err
239− Right rel -> return $ Right rel
240−-}
241−--warning: copy-pasta from above- refactor
242−evalRelationalExpr (NotEquals relExprA relExprB) = do
243− evaldA <- evalRelationalExpr relExprA
244− evaldB <- evalRelationalExpr relExprB
245− case evaldA of
246− Left err -> return $ Left err
247− Right exprA -> case evaldB of
248− Left err -> return $ Left err
249− Right exprB -> return $ Right (NotEquals exprA exprB)
250−
251−-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
252−evalRelationalExpr (Extend tupleExpression relExpr) = do
253− eExpr <- evalRelationalExpr relExpr
254− case eExpr of
255− Left err -> pure (Left err)
256− Right expr -> do
257− eTupProc <- processExtendTupleExpr tupleExpression
258− case eTupProc of
259− Left err -> pure (Left err)
260− Right tupProc -> pure (Right (Extend tupProc expr))
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 }
261214
262215--helper function to process relation variable creation/assignment
263−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseState (Either RelationalError ())
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
264217setRelVar relVarName relExpr = do
265218 currentContext <- getStateContext
266− let newRelVars = M.insert relVarName relExpr $ 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
267222 potentialContext = currentContext { relationVariables = newRelVars }
268− --determine when to check constraints
269−
270− case checkConstraints potentialContext of
271− Left err -> pure (Left err)
272− Right _ -> do
273− putStateContext potentialContext
274− 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 ()
275236
276237-- 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
277−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
278239deleteRelVar relVarName = do
279240 currContext <- getStateContext
280241 let relVars = relationVariables currContext
281242 if M.notMember relVarName relVars then
282− pure (Right ())
243+ pure ()
283244 else do
284245 let newRelVars = M.delete relVarName relVars
285246 newContext = currContext { relationVariables = newRelVars }
286247 putStateContext newContext
287− pure (Right ())
248+ pure ()
288249
289−evalDatabaseContextExpr :: DatabaseContextExpr -> TransactionId -> TransactionGraph -> DatabaseState (Either RelationalError ())
290−evalDatabaseContextExpr NoOperation _ _ = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
291252
292−evalDatabaseContextExpr (Define relVarName attrExprs) _ _ = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
293255 relvars <- fmap relationVariables getStateContext
294256 tConss <- fmap typeConstructorMapping getStateContext
295− let eAttrs = map (evalAttrExpr tConss) attrExprs
296− attrErrs = lefts eAttrs
297− attrsList = rights eAttrs
298− if not (null attrErrs) then
299− pure (Left (someErrors attrErrs))
300− else do
301− let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
302− if not (null atomTypeErrs) then
303− pure (Left (someErrors atomTypeErrs))
304− else
305− case M.member relVarName relvars of
306− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
307− False -> setRelVar relVarName (ExistingRelation emptyRelation) >> pure (Right ())
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)
308267 where
309268 attrs = A.attributesFromList attrsList
310269 emptyRelation = Relation attrs emptyTupleSet
311270
312−evalDatabaseContextExpr (Undefine relVarName) _ _ = deleteRelVar relVarName
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
313272
314−evalDatabaseContextExpr (Assign relVarName expr) transId graph = do
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
315275 context <- getStateContext
316276 let existingRelVar = M.lookup relVarName (relationVariables context)
317− relExprState = mkRelationalExprState context
277+ reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278+ eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
318279 case existingRelVar of
319280 Nothing -> do
320− let ervExpr = runReader (evalRelationalExpr expr) relExprState
321− case ervExpr of
322− Left err -> pure (Left err)
323− Right rvExpr -> setRelVar relVarName rvExpr
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
324286 Just existingRel -> do
325− let eExpectedType = typeForGraphRefRelationalExpr existingRel transId graph
326− eNewExprType = runReader (typeForRelationalExpr expr) relExprState
287+ let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
327288 case eExpectedType of
328− Left err -> pure (Left err)
289+ Left err -> dbErr err
329290 Right expectedType ->
330291 case eNewExprType of
331− Left err -> pure (Left err)
292+ Left err -> dbErr err
332293 Right newExprType -> do
333294 if newExprType == expectedType then do
334− let ervExpr = runReader (evalRelationalExpr expr) relExprState
335− case ervExpr of
336− Left err -> pure (Left err)
337− Right rvExpr -> setRelVar relVarName rvExpr
295+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296+ setRelVar relVarName expr
338297 else
339− pure (Left (RelationTypeMismatchError (attributes expectedType) (attributes newExprType)))
298+ dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
340299
341−evalDatabaseContextExpr (Insert relVarName relExpr) tid graph =
342− evalDatabaseContextExpr (Assign relVarName (Union (RelationVariable relVarName ())
343− relExpr)) tid graph
300+evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301+ gfExpr <- relVarByName relVarName
302+ let optExpr = applyUnionCollapse (Union
303+ relExpr
304+ gfExpr)
305+ evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
344306
345−evalDatabaseContextExpr (Delete relVarName predicate) transId _ = do
346− ctx <- getStateContext
347− let rv = RelationVariable relVarName transId
348− rvState = mkRelationalExprState ctx
349− case runReader (processRestrictionPredicateExpr predicate) rvState of
350− Left err -> pure (Left err)
351− Right graphRefPredicate ->
352− setRelVar relVarName (Restrict (NotPredicate graphRefPredicate) rv)
307+evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308+ gfExpr <- relVarByName relVarName
309+ let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310+ setRelVar relVarName optExpr
353311
354312--union of restricted+updated portion and the unrestricted+unupdated portion
355−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) transId _ = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
356316 context <- getStateContext
357− let rvState = mkRelationalExprState context
358− relVarTable = relationVariables context
359− case runReader (processRestrictionPredicateExpr restrictionPredicateExpr) rvState of
360− Left err -> pure (Left err)
361− Right graphRefPredicate ->
362− case M.lookup relVarName relVarTable of
363− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
364− Just existingRvExpr -> do
365− let unrestrictedPortion = Restrict (NotPredicate graphRefPredicate) rv
366− rv = RelationVariable relVarName transId
367− tmpAttr attr = "_tmp_" <> attr --this could certainly be improved to verify that there is no attribute name conflict
368− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
369− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
370− restrictedPortion = Restrict graphRefPredicate
371− updated = foldr (\(oldname, atomExpr) accum ->
372− let procAtomExpr = processAtomExpr atomExpr transId in
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
373337 updateAttr oldname procAtomExpr accum
374− ) rv (M.toList atomExprMap)
338+ ) restrictedPortion (M.toList atomExprMap)
375339 -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
376− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
377− setRelVar relVarName (Union unrestrictedPortion updatedPortion)
340+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341+ setRelVar relVarName (Union unrestrictedPortion updatedPortion)
378342
379−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) _ _ = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
380344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
381347 let currDeps = inclusionDependencies currContext
382348 newDeps = M.insert newDepName newDep currDeps
383349 if M.member newDepName currDeps then
384− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
385351 else do
386352 let potentialContext = currContext { inclusionDependencies = newDeps }
387− case checkConstraints potentialContext of
388− Left err -> pure (Left err)
389− 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 _ ->
390358 putStateContext potentialContext
391− return (Right ())
392359
393−evalDatabaseContextExpr (RemoveInclusionDependency depName) _ _ = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
394361 currContext <- getStateContext
395362 let currDeps = inclusionDependencies currContext
396363 newDeps = M.delete depName currDeps
397364 if M.notMember depName currDeps then
398− pure (Left (InclusionDependencyNameNotInUseError depName))
399− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
400367 putStateContext $ currContext {inclusionDependencies = newDeps }
401− return (Right ())
402368
403369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
404−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) _ _ = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
405371 currentContext <- getStateContext
406372 let nots = notifications currentContext
407373 if M.member notName nots then
408− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
409375 else do
410376 let newNotifications = M.insert notName newNotification nots
411377 newNotification = Notification { changeExpr = triggerExpr,
412378 reportOldExpr = resultOldExpr,
413379 reportNewExpr = resultNewExpr}
414380 putStateContext $ currentContext { notifications = newNotifications }
415− return (Right ())
416381
417−evalDatabaseContextExpr (RemoveNotification notName) _ _ = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
418383 currentContext <- getStateContext
419384 let nots = notifications currentContext
420385 if M.notMember notName nots then
421− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
422387 else do
423388 let newNotifications = M.delete notName nots
424389 putStateContext $ currentContext { notifications = newNotifications }
425− pure (Right ())
390+
426391
427392-- | Adds type and data constructors to the database context.
428393-- validate that the type *and* constructor names are unique! not yet implemented!
429−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) _ _ = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
430395 currentContext <- getStateContext
431396 let oldTypes = typeConstructorMapping currentContext
432397 tConsName = TCD.name tConsDef
433398 -- validate that the constructor's types exist
434− case validateTypeConstructorDef tConsDef dConsDefList of
435− errs@(_:_) -> pure (Left (someErrors errs))
436− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
437− | 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)
438403 | otherwise -> do
439404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
440405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
441− pure (Right ())
442406
443407-- | 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.
444−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) _ _ = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
445409 currentContext <- getStateContext
446410 let oldTypes = typeConstructorMapping currentContext
447411 if isNothing (findTypeConstructor tConsName oldTypes) then
448− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
449413 else do
450414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
451415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
452− pure (Right ())
453416
454−evalDatabaseContextExpr (MultipleExpr exprs) transId graph = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
455418 --the multiple expressions must pass the same context around- not the old unmodified context
456− evald <- forM exprs (\expr -> evalDatabaseContextExpr expr transId graph)
457− --some lifting magic needed here
458− case lefts evald of
459− [] -> pure (Right ())
460− errs -> pure (Left (someErrors errs))
461−
462−evalDatabaseContextExpr (RemoveAtomFunction funcName) _ _ = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
463422 currentContext <- getStateContext
464423 let atomFuncs = atomFunctions currentContext
465424 case atomFunctionForName funcName atomFuncs of
466− Left err -> pure (Left err)
467− Right realFunc -> if isScriptedAtomFunction realFunc then do
468− let updatedFuncs = HS.delete realFunc atomFuncs
469− putStateContext (currentContext {atomFunctions = updatedFuncs })
470− pure (Right ())
471− else
472− 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)
473432
474−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) _ _ = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
475434 context <- getStateContext
476435 let dbcFuncs = dbcFunctions context
477436 case databaseContextFunctionForName funcName dbcFuncs of
478− Left err -> pure (Left err)
479− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
480− let updatedFuncs = HS.delete realFunc dbcFuncs
481− putStateContext (context { dbcFunctions = updatedFuncs })
482− pure (Right ())
483− else
484− 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)
485444
486−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) _ _ = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
487446 context <- getStateContext
447+ graph <- dbcGraph
488448 --resolve atom arguments
489− let relExprState = mkRelationalExprState context
490− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
491450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
492452 case eFunc of
493− Left err -> pure (Left err)
453+ Left err -> dbErr err
494454 Right func -> do
495455 let expectedArgCount = length (dbcFuncType func)
496456 actualArgCount = length atomArgExprs
497457 if expectedArgCount /= actualArgCount then
498− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
499459 else
500460 --check that the atom types are valid
501− case lefts eAtomTypes of
502− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
503− [] -> do
504− let atomTypes = rights eAtomTypes
505− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
506− Left err -> Just err
507− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
508− typeErrors = catMaybes mValidTypes
509− 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
510471 if length (lefts eAtomArgs) > 1 then
511− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
512473 else if not (null typeErrors) then
513− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
514475 else
515476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
516− Left err -> pure (Left err)
517− Right newContext -> putStateContext newContext >> pure (Right ())
518−
519−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> TransactionId -> TransactionGraph -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
520−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction funcName funcType script) =
521− case mScriptSession of
522− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
523− Just scriptSession -> do
524− 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
525530 setSession (hscEnv scriptSession)
526531 let atomFuncs = atomFunctions currentContext
527532 case extractAtomFunctionType funcType of
@@ -547,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddAtomFunction fun
547552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
548553 Right eContext -> case eContext of
549554 Left err -> pure (Left err)
550− Right context' -> pure (Right context')
551−
552−evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextFunction funcName funcType script) =
553− case mScriptSession of
554− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
555− 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
556562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
557563 let last2Args = reverse (take 2 (reverse funcType))
558564 atomArgs = take (length funcType - 2) funcType
@@ -562,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
562568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
563569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
564570 else do
565− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
566572 setSession (hscEnv scriptSession)
567573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
568574 pure $ case eCompiledFunc of
@@ -587,70 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext _ _ (AddDatabaseContextF
587593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
588594 Right eContext -> case eContext of
589595 Left err -> pure (Left err)
590− Right context' -> pure (Right context')
591−evalDatabaseContextIOExpr _ currentContext _ _ (LoadAtomFunctions modName funcName modPath) = do
592− eLoadFunc <- loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
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
593600 case eLoadFunc of
594601 Left LoadSymbolError -> pure (Left LoadFunctionError)
595602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
596603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
597− in pure (Right newContext)
598−evalDatabaseContextIOExpr _ currentContext _ _ (LoadDatabaseContextFunctions modName funcName modPath) = do
599− eLoadFunc <- loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
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
600608 case eLoadFunc of
601609 Left LoadSymbolError -> pure (Left LoadFunctionError)
602610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
603611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
604− in pure (Right newContext)
605−
606−evalDatabaseContextIOExpr _ currentContext transId graph (CreateArbitraryRelation relVarName attrExprs range) =
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
607615 --Define
608− case runState (evalDatabaseContextExpr (Define relVarName attrExprs) transId graph) (freshDatabaseState currentContext) of
609− (Left err,_) -> pure (Left err)
610− (Right (), elems) -> do
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
611625 --Assign
612626 let existingRelVar = M.lookup relVarName relVarTable
613− relVarTable = relationVariables (context elems)
627+ relVarTable = relationVariables (dbc_context dbstate)
614628 case existingRelVar of
615629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
616630 Just existingRel -> do
617− case typeForGraphRefRelationalExpr existingRel transId graph of
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
618633 Left err -> pure (Left err)
619634 Right relType -> do
620635 let expectedAttributes = attributes relType
621− tcMap = typeConstructorMapping (context elems)
622− eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
636+ tcMap = typeConstructorMapping (dbc_context dbstate)
637+ eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
623638 case eitherRel of
624639 Left err -> pure $ Left err
625640 Right rel ->
626− case runState (setRelVar relVarName (ExistingRelation rel)) elems of
627− (Left err,_) -> pure (Left err)
628− (Right (), elems') -> pure $ Right (context elems)
629−
630−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
631−updateTupleWithAtomExprs exprMap context tupIn = do
632− --resolve all atom exprs
633− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
634− atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
635− pure (attrName, atom)
636− ) (M.toList exprMap)
637− pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
641+ case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642+ Left err -> pure (Left err)
643+ Right dbstate' -> putDBCIOContext (dbc_context dbstate')
638644
639645--run verification on all constraints
640−checkConstraints :: DatabaseContext -> Either RelationalError ()
641−checkConstraints context =
646+checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
642648 mapM_ (uncurry checkIncDep) (M.toList deps)
643649 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+
644660 deps = inclusionDependencies context
645− eval expr = evalReader (evalRelationalExpr expr)
646− 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
647662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
648666 --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.
649− typeSub <- evalReader (typeForRelationalExpr subsetExpr)
650− 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)
651671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
652− let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
653− 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
654676 Left err -> Left err
655677 Right resultRel -> if resultRel == relationTrue then
656678 pure ()
@@ -660,91 +682,81 @@ checkConstraints context =
660682-- 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
661683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
662684
663−typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
664686typeForRelationalExpr expr = do
665− rstate <- ask
666− let context = stateElemsContext rstate
667687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
668− let context' = contextWithEmptyTupleSets context
669− rstate' = setStateElemsContext rstate context'
670688 --evalRelationalExpr could still return an existing relation with tuples, so strip them
671− pure $ case runReader (evalRelationalExpr expr) rstate' of
672− Left err -> Left err
673− Right typeRel -> Right (relationWithEmptyTupleSet typeRel)
674−
675−--returns a database context with all tuples removed
676−--this is useful for type checking and optimization
677−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
678−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
679− where
680− relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
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
681695
682696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
683697liftE v = do
684698 y <- lift v
685699 case y of
686− Left err -> throwE err
700+ Left err -> throwError err
687701 Right val -> pure val
688702
689703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
690−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExprBase a -> RelationalExprState (Either RelationalError RestrictionFilter)
691−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
692− runExceptT $ do
693− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
694− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
695− pure (\x -> do
696− ev1 <- expr1v x
697− ev2 <- expr2v x
698− 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))
699712
700−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
701− runExceptT $ do
702− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
703− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
713+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714+ expr1v <- predicateRestrictionFilter attrs expr1
715+ expr2v <- predicateRestrictionFilter attrs expr2
704716 pure (\x -> do
705717 ev1 <- expr1v x
706718 ev2 <- expr2v x
707719 pure (ev1 || ev2))
708720
709−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
710722
711−predicateRestrictionFilter attrs (NotPredicate expr) =
712− runExceptT $ do
713− exprv <- liftE (predicateRestrictionFilter attrs expr)
714− pure (fmap not . exprv)
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
715726
716727--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
717728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
718− rstate <- ask
719− 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
720735 Left err -> Left err
721736 Right rel -> if arity rel /= 0 then
722737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
723738 else
724− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
725740
726741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
727− rstate <- ask
728− let (attrs', ctxtup') = case rstate of
729− RelationalExprStateElems _ -> (attrs, emptyTuple)
730− RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
731− RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
732− runExceptT $ do
733− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
734− 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
735747 Right attr -> Right attr
736748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
737749 Right ctxattr -> Right ctxattr
738750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
739751 Left err -> Left err
740752 Left err -> Left err
741− if atomExprType /= A.atomType attr then
742− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
743− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
744756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
745757 Right atomCmp -> atomCmp == atomIn
746758 Left _ -> False
747− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
748760 in
749761 pure $ case atomForAttributeName attrName tupleIn of
750762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -755,16 +767,15 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
755767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
756768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
757769 --merge attrs into the state attributes
758− rstate <- ask
759− runExceptT $ do
760− aType <- liftE (typeFromAtomExpr attrs atomExpr)
761− if aType /= BoolAtomType then
762− throwE (AtomTypeMismatchError aType BoolAtomType)
763− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
764775 pure (\tupleIn ->
765− case runReader (evalAtomExpr tupleIn atomExpr) rstate of
766− Left err -> Left err
767− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
768779
769780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
770781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
@@ -772,249 +783,311 @@ tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName r
772783 else
773784 Right rel
774785
775−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
776−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
777− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
778789 -- check that the attribute name is not in use
779790 case tupleExprCheckNewAttrName newAttrName relIn of
780− Left err -> pure (Left err)
781− Right _ -> runExceptT $ do
782− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
783− 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
784795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
785796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
786− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
787− Left err -> Left err
788− 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)
789802 )
790803
791−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
792−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
793− Right atom -> pure (Right atom)
794− err@(Left (NoSuchAttributeNamesError _)) -> do
795− rstate <- ask
796− case rstate of
797− RelationalExprStateElems _ -> pure err
798− RelationalExprStateAttrsElems _ _ -> pure err
799− RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
800− Left err -> pure (Left err)
801−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
802−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
803− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
804− context <- fmap stateElemsContext ask
805− runExceptT $ do
806− let functions = atomFunctions context
807− func <- either throwE pure (atomFunctionForName funcName functions)
808− let expectedArgCount = length (atomFuncType func) - 1
809− actualArgCount = length argTypes
810− safeInit [] = [] -- different behavior from normal init
811− safeInit xs = init xs
812− if expectedArgCount /= actualArgCount then
813− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
814− else do
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
815828 let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
816− mapM_ (\(expType, eActType) -> do
817− actType <- either throwE pure eActType
818− either throwE pure (atomTypeVerify expType actType)) zippedArgs
819− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
829+ mapM_ (\(expType, actType) ->
830+ lift $ except (atomTypeVerify expType actType)) zippedArgs
831+ evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
820832 case evalAtomFunction func evaldArgs of
821− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
822834 Right result -> do
823835 --validate that the result matches the expected type
824− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
825837 pure result
826−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
827839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
828− rstate <- ask
829− runExceptT $ do
830− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
831− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
832− pure (RelationAtom relAtom)
833−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
834− rstate <- lift ask
835− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
836− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
837− 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
838849 pure (ConstructedAtom dConsName aType argAtoms)
839850
840−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
841−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
842− rstate <- ask
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
843854 case A.atomTypeForAttributeName attrName attrs of
844− Right aType -> pure (Right aType)
845− Left err@(NoSuchAttributeNamesError _) -> case rstate of
846− RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
847− Left err' -> pure (Left err')
848− Right attr -> pure (Right (A.atomType attr))
849− RelationalExprStateElems _ -> pure (Left err)
850− RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
851− Left err' -> pure (Left err')
852− Right atom -> pure (Right (atomTypeForAtom atom))
853− Left err -> pure (Left err)
854−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
855−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
856− context <- fmap stateElemsContext ask
857− 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
858870 case atomFunctionForName funcName funcs of
859− Left err -> pure (Left err)
871+ Left err -> throwError err
860872 Right func -> do
861873 let funcRetType = last (atomFuncType func)
862874 funcArgTypes = init (atomFuncType func)
863− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
864− case lefts eArgTypes of
865− errs@(_:_) -> pure (Left (someErrors errs))
866− [] -> do
867− let eTvMap = resolveTypeVariables funcArgTypes argTypes
868− argTypes = rights eArgTypes
869− case eTvMap of
870− Left err -> pure (Left err)
871− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
872−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
873− rstate <- lift ask
874− 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)
875882 pure (RelationAtomType (attributes relType))
876883-- grab the type of the data constructor, then validate that the args match the expected types
877−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
878− runExceptT $ do
879− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
880− context <- fmap stateElemsContext (lift ask)
881− either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
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
882889
883890-- | Validate that the type of the AtomExpr matches the expected type.
884−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
885−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
886− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
887894 case A.atomTypeForAttributeName attrName (attributes relIn) of
888− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
889− (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
890− RelationalExprStateTupleElems _ _ -> throwE err
891− RelationalExprStateElems _ -> throwE err
892− RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
893− Left err' -> throwE err'
894− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
895− Left err -> throwE err
896−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
897−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
898− 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
899910 let functions = atomFunctions context
900− context = stateElemsContext rstate
901− runExceptT $ do
902− func <- either throwE pure (atomFunctionForName funcName functions)
903− let expectedArgTypes = atomFuncType func
904− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
905− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
906− Left err -> throwE err
907− Right x -> pure x
908− ) $ zip3 funcArgExprs expectedArgTypes [1..]
909− if length funcArgTypes /= length expectedArgTypes - 1 then
910− 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)
911921 else
912− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
913−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
914− rstate <- lift ask
915− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
916− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
917−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
918− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
919− 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
920931
921932-- | Look up the type's name and create a new attribute.
922−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
923−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
924− aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
925− validateAtomType aType aTypes
926− Right (Attribute attrName aType)
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
927939
928−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
929−
930−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
931−evalTupleExpr mAttrs (TupleExpr tupMap) = do
932− context <- fmap stateElemsContext ask
933− 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
934992 -- 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
935993 -- 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
936− let attrs = fromMaybe A.emptyAttributes mAttrs
937− attrAtoms <- mapM (\(attrName, aExpr) -> do
938− --provided when the relation header is available
939− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
940− unresolvedType <- liftE (typeFromAtomExpr attrs aExpr)
941− resolvedType <- case eExpectedAtomType of
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
9421001 Left _ -> pure unresolvedType
943− Right typeHint -> either throwE pure (resolveAtomType typeHint unresolvedType)
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
9441003 --resolve atom typevars based on resolvedType?
945− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
946− pure (attrName, newAtom, resolvedType)
947− ) (M.toList tupMap)
948− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
949− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
950− tup = mkRelationTuple tupAttrs atoms
951− tConss = typeConstructorMapping context
952− finalAttrs = fromMaybe tupAttrs mAttrs
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
9531011 --verify that the attributes match
954− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
955− tup' <- either throwE pure (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
956− _ <- either throwE pure (validateTuple tup' tConss)
957− pure tup'
958−
959−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
960−evalAttributeNames attrNames expr = do
961− eExprType <- typeForRelationalExpr expr
962− case eExprType of
963− Left err -> pure (Left err)
964− Right exprTyp -> do
965− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
966− case attrNames of
967− AttributeNames names ->
968− case A.projectionAttributesForNames names (attributes exprTyp) of
969− Left err -> pure (Left err)
970− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
971−
972− InvertedAttributeNames names -> do
973− let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
974− if not (S.null nonExistentAttributeNames) then
975− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
976− else
977− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
978−
979− UnionAttributeNames namesA namesB -> do
980− eNameSetA <- evalAttributeNames namesA expr
981− case eNameSetA of
982− Left err -> pure (Left err)
983− Right nameSetA -> do
984− eNameSetB <- evalAttributeNames namesB expr
985− case eNameSetB of
986− Left err -> pure (Left err)
987− Right nameSetB ->
988− pure (Right (S.union nameSetA nameSetB))
989−
990− IntersectAttributeNames namesA namesB -> do
991− eNameSetA <- evalAttributeNames namesA expr
992− case eNameSetA of
993− Left err -> pure (Left err)
994− Right nameSetA -> do
995− eNameSetB <- evalAttributeNames namesB expr
996− case eNameSetB of
997− Left err -> pure (Left err)
998− Right nameSetB ->
999− pure (Right (S.intersection nameSetA nameSetB))
1000−
1001− RelationalExprAttributeNames attrExpr -> do
1002− eAttrExprType <- typeForRelationalExpr attrExpr
1003− case eAttrExprType of
1004− Left err -> pure (Left err)
1005− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
1006−
1007−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionGraph -> Either RelationalError Relation
1008−evalGraphRefRelationalExpr (RelationVariable name tid) graph = do
1009− ctx <- dbContextForTransId tid graph
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
10101036 case M.lookup name (relationVariables ctx) of
1011− Nothing -> Left (RelVarNotDefinedError name)
1012− Just rv -> evalGraphRefRelationalExpr rv graph
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)
10131086
10141087dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
10151088dbContextForTransId tid graph = do
10161089 trans <- transactionForId tid graph
1017− pure (concreteDatabaseContext ctx)
1090+ pure (concreteDatabaseContext trans)
10181091
10191092transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
10201093transactionForId tid graph
@@ -1027,26 +1100,293 @@ transactionForId tid graph
10271100 where
10281101 matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
10291102
1030−processRestrictionPredicateExpr :: RestrictionPredicateExpr -> RelationalExprState (Either RelationalError GraphRefRestrictionPredicateExpr)
1031−processRestrictionPredicateExpr TruePredicate = TruePredicate
1032−processRestrictionPredicateExpr (AndPredicate a b) = pure $ AndPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1033−processRestrictionPredicateExpr (OrPredicate a b) = OrPredicate <$> processRestrictionPredicateExpr a <*> processRestrictionPredicateExpr b
1034−processRestrictionPredicateExpr (NotPredicate a) = pure $ NotPredicate <$> processRestrictionPredicateExpr a
1035−processRestrictionPredicateExpr (RelationalExprPredicate expr) = pure $ RelationalExprPredicate <$> evalRelationalExpr expr
1036−processRestrictionPredicateExpr (AtomExprPredicate expr) = AtomExprPredicate <$> evalAtomExpr expr
1037−processRestrictionPredicateExpr (AttributeEqualityPredicate nam expr) = AttributeEqualityPredicate nam <$> evalAtomExpr expr
1038−
1039−processExtendTupleExpr :: ExtendTupleExpr -> RelationalExprState (Either RelationalError (ExtendTupleExprBase a))
1040−processExtendTupleExpr (AttributeExtendTupleExpr nam atomExpr) = do
1041− eExpr <- evalAtomExpr atomExpr
1042− case eExpr of
1043− Left err -> pure (Left err)
1044− Right expr -> pure (Right (AttributeExtendTupleExpr nam expr))
1045−
1046−typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> TransactionId -> TransactionGraph -> Either RelationalError Relation
1047−typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = mkRelation attrs emptyTupleSet
1103+typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1104+typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = lift $ except $ mkRelation attrs emptyTupleSet
10481105typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (emptyRelationWithAttrs (attributes rel))
1049−typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrs tupleExprs) = unimplemented
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)))
1180+
1181+ InvertedAttributeNames names -> do
1182+ let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1183+ if not (S.null nonExistentAttributeNames) then
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
1185+ else
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
1187+
1188+ UnionAttributeNames namesA namesB -> do
1189+ nameSetA <- evalGraphRefAttributeNames namesA expr
1190+ nameSetB <- evalGraphRefAttributeNames namesB expr
1191+ pure (S.union nameSetA nameSetB)
1192+
1193+ IntersectAttributeNames namesA namesB -> do
1194+ nameSetA <- evalGraphRefAttributeNames namesA expr
1195+ nameSetB <- evalGraphRefAttributeNames namesB expr
1196+ pure (S.intersection nameSetA nameSetB)
1197+
1198+ RelationalExprAttributeNames attrExpr -> do
1199+ attrExprType <- typeForGraphRefRelationalExpr attrExpr
1200+ pure (A.attributeNameSet (attributes attrExprType))
10501201
1051−processAtomExpr :: AtomExpr -> TransactionId -> GraphRefAtomExpr
1052−processAtomExpr = unimplemented
1202+evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
1203+evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) = do
1204+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
1205+ case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1206+ Left err -> throwError err
1207+ Right aType -> do
1208+ case validateAtomType aType tConsMap of
1209+ Left err -> throwError err
1210+ Right _ -> pure (Attribute attrName aType)
1211+evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1212+
1213+mkEmptyRelVars :: RelationVariables -> RelationVariables
1214+mkEmptyRelVars = M.map mkEmptyRelVar
1215+ where
1216+ mkEmptyRelVar expr@MakeRelationFromExprs{} = expr --do not truncate here because we might lose essential type information in emptying the tuples
1217+ mkEmptyRelVar (MakeStaticRelation attrs _) = MakeStaticRelation attrs emptyTupleSet
1218+ mkEmptyRelVar (ExistingRelation rel) = ExistingRelation (emptyRelationWithAttrs (attributes rel))
1219+ mkEmptyRelVar rv@RelationVariable{} = Restrict (NotPredicate TruePredicate) rv
1220+ mkEmptyRelVar (Project attrNames expr) = Project attrNames (mkEmptyRelVar expr)
1221+ mkEmptyRelVar (Union exprA exprB) = Union (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1222+ mkEmptyRelVar (Join exprA exprB) = Join (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1223+ mkEmptyRelVar (Rename nameA nameB expr) = Rename nameA nameB (mkEmptyRelVar expr)
1224+ mkEmptyRelVar (Difference exprA exprB) = Difference (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1225+ mkEmptyRelVar (Group attrNames attrName expr) = Group attrNames attrName (mkEmptyRelVar expr)
1226+ mkEmptyRelVar (Ungroup attrName expr) = Ungroup attrName (mkEmptyRelVar expr)
1227+ mkEmptyRelVar (Restrict pred' expr) = Restrict pred' (mkEmptyRelVar expr)
1228+ mkEmptyRelVar (Equals exprA exprB) = Equals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1229+ mkEmptyRelVar (NotEquals exprA exprB) = NotEquals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1230+ mkEmptyRelVar (Extend extTuple expr) = Extend extTuple (mkEmptyRelVar expr)
1231+ mkEmptyRelVar (With macros expr) = With (map (second mkEmptyRelVar) macros) (mkEmptyRelVar expr)
1232+
1233+
1234+dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235+dbErr err = lift (except (Left err))
1236+
1237+-- | Return a Relation describing the relation variables.
1238+relationVariablesAsRelation :: DatabaseContext -> TransactionGraph -> Either RelationalError Relation
1239+relationVariablesAsRelation ctx graph = do
1240+ let subrelAttrs = A.attributesFromList [Attribute "attribute" TextAtomType, Attribute "type" TextAtomType]
1241+ attrs = A.attributesFromList [Attribute "name" TextAtomType,
1242+ Attribute "attributes" (RelationAtomType subrelAttrs)]
1243+ relVars = relationVariables ctx
1244+ mkRvDesc (rvName, gfExpr) = do
1245+ let gfEnv = freshGraphRefRelationalExprEnv (Just ctx) graph
1246+ gfType <- runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
1247+ pure (rvName, gfType)
1248+ relVarToAtomList (rvName, rel) = [TextAtom rvName, attributesToRel (attributesVec (attributes rel))]
1249+ attrAtoms a = [TextAtom (A.attributeName a), TextAtom (prettyAtomType (A.atomType a))]
1250+ attributesToRel attrl = case mkRelationFromList subrelAttrs (map attrAtoms (V.toList attrl)) of
1251+ Left err -> error ("relationVariablesAsRelation pooped " ++ show err)
1252+ Right rel -> RelationAtom rel
1253+ rvs <- mapM mkRvDesc (M.toList relVars)
1254+ let tups = map relVarToAtomList rvs
1255+ mkRelationFromList attrs tups
1256+
1257+-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258+evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259+evalRelationalExpr expr = do
1260+ graph <- reGraph
1261+ context <- reContext
1262+ let expr' = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
1263+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
1264+ case runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr expr') of
1265+ Left err -> throwError err
1266+ Right rel -> pure rel
1267+
1268+class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269+ getContext :: m DatabaseContext
1270+
1271+instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272+ getContext = gfDatabaseContextForMarker UncommittedContextMarker
1273+
1274+instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275+ getContext = getStateContext
1276+
1277+relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278+relVarByName rvName = do
1279+ relvars <- relationVariables <$> getContext
1280+ case M.lookup rvName relvars of
1281+ Nothing -> throwError (RelVarNotDefinedError rvName)
1282+ Just gfexpr -> pure gfexpr
1283+
1284+-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285+class ResolveGraphRefTransactionMarker a where
1286+ resolve :: a -> DatabaseContextEvalMonad a
1287+
1288+-- s := s union t
1289+instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290+ resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291+ MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292+ resolve orig@MakeStaticRelation{} = pure orig
1293+ resolve orig@ExistingRelation{} = pure orig
1294+ resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295+ rvMap <- relationVariables <$> getStateContext
1296+ case M.lookup rvName rvMap of
1297+ Nothing -> pure orig
1298+ Just resolvedRv -> resolve resolvedRv
1299+ resolve orig@RelationVariable{} = pure orig
1300+ resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301+ resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302+ resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303+ resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304+ resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305+ resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306+ resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307+ resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308+ resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309+ resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310+ resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311+ resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312+
1313+instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314+ resolve (TupleExprs marker tupleExprs) =
1315+ TupleExprs marker <$> mapM resolve tupleExprs
1316+
1317+instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318+ resolve (TupleExpr tupMap) = do
1319+ tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320+ pure (TupleExpr (M.fromList tupMap'))
1321+
1322+instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323+ resolve orig@AttributeNames{} = pure orig
1324+ resolve orig@InvertedAttributeNames{} = pure orig
1325+ resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326+ resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327+ resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328+
1329+instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330+ resolve TruePredicate = pure TruePredicate
1331+ resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332+ resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333+ resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334+ resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335+ resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336+ resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337+
1338+instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339+ resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340+
1341+instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342+ resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343+
1344+instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345+ resolve orig@AttributeAtomExpr{} = pure orig
1346+ resolve orig@NakedAtomExpr{} = pure orig
1347+ resolve (FunctionAtomExpr nam atomExprs marker) =
1348+ FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349+ resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350+ resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351+ ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352+
1353+--convert series of simple Union queries into MakeStaticRelation
1354+-- this is especially useful for long, nested applications of Union with simple tuples
1355+-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356+
1357+--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358+
1359+applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360+applyUnionCollapse = Fold.cata opt
1361+ where
1362+ opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363+ opt (UnionF exprA exprB) | exprA == exprB = exprA
1364+ opt (UnionF
1365+ exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366+ exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367+ | tupExprsNull tupExprs1 = exprB
1368+ | tupExprsNull tupExprs2 = exprA
1369+ opt x = Fold.embed x
1370+ tupExprsNull (TupleExprs _ []) = True
1371+ tupExprsNull _ = False
1372+
1373+
1374+--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375+--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376+-- =>
1377+-- update x where y=1 set (x:=6,z:=11)
1378+-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379+
1380+--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381+
1382+--DELETE optimization
1383+-- if a restriction matches a previous restriction, combine them
1384+-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385+applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386+applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387+ case expr of
1388+ orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389+ _ -> orig
1390+applyRestrictionCollapse expr = expr
1391+
1392+