@@ -1,35 +1,53 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2+{-# LANGUAGE FlexibleInstances #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE OverloadedStrings #-}
25module ProjectM36.RelationalExpression where
36import ProjectM36.Relation
47import ProjectM36.Tuple
58import ProjectM36.TupleSet
69import ProjectM36.Base
10+import qualified Data.UUID as U
711import ProjectM36.Error
812import ProjectM36.AtomType
9−import ProjectM36.Attribute (emptyAttributes)
13+import ProjectM36.Attribute (emptyAttributes, attributesFromList)
1014import ProjectM36.ScriptSession
1115import ProjectM36.DataTypes.Primitive
1216import ProjectM36.AtomFunction
1317import ProjectM36.DatabaseContextFunction
1418import ProjectM36.Arbitrary
19+import ProjectM36.GraphRefRelationalExpr
20+import ProjectM36.Transaction
1521import qualified ProjectM36.Attribute as A
1622import qualified Data.Map as M
1723import qualified Data.HashSet as HS
1824import qualified Data.Set as S
1925import Control.Monad.State hiding (join)
20−import Control.Exception
26+import Data.Bifunctor (second)
2127import Data.Maybe
2228import Data.Either
2329import Data.Char (isUpper)
30+import Data.Time
31+import qualified Data.List.NonEmpty as NE
32+import Data.Functor.Identity
2433import qualified Data.Text as T
2534import qualified Data.Vector as V
2635import qualified ProjectM36.TypeConstructorDef as TCD
27−import Control.Monad.Trans.Except
28−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
2943import Test.QuickCheck
30−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
3149import GHC.Paths
32−import Debug.Trace
50+#endif
3351
3452data DatabaseContextExprDetails = CountUpdatedTuples
3553
@@ -46,32 +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 ctx = (ctx, M.empty, False) --future work: propagate return accumulator
67+mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68+mkDatabaseContextEvalState context = DatabaseContextEvalState {
69+ dbc_context = context,
70+ dbc_accum = M.empty,
71+ dbc_dirty = False
72+ } --future work: propagate return accumulator
5173
5274-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
53−data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
54− RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
55− RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
56−
57−instance Show RelationalExprStateElems where
58− show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
59− show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
60− show (RelationalExprStateElems _) = "RelationalExprStateElems"
61−
62−mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
63−mkRelationalExprState = RelationalExprStateElems
64−
65−mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
66−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
67−mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
68−mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
69− RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
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))
7086
71−mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
72−mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
73−mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
74−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)))
75124
76125type ResultAccumName = StringType
77126
@@ -81,429 +130,403 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
81130 resultAccumResult :: Relation
82131 }
83132
84−type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
133+data DatabaseContextEvalState = DatabaseContextEvalState {
134+ dbc_context :: DatabaseContext, --new, alterable context for a new transaction
135+ dbc_accum :: M.Map ResultAccumName ResultAccum,
136+ dbc_dirty :: DirtyFlag
137+ }
85138
86−type DatabaseState a = State DatabaseStateElems a
139+data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140+ { dce_transId :: TransactionId,
141+ dce_graph :: TransactionGraph
142+ }
87143
88−getStateContext :: DatabaseState DatabaseContext
89−getStateContext = do
90− (ctx,_, _) <- get
91− pure ctx
92−
93−putStateContext :: DatabaseContext -> DatabaseState ()
94−putStateContext ctx = do
95− (_, accum, _) <- get
96− put (ctx, accum, True)
97−
98−type RelationalExprState a = Reader RelationalExprStateElems a
99−
100−stateElemsContext :: RelationalExprStateElems -> DatabaseContext
101−stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
102−stateElemsContext (RelationalExprStateElems ctx) = ctx
103−stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
104−
105−setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
106−setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
107−setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
108−setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
109−
110−--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
111−evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
112−evalRelationalExpr (RelationVariable name _) = do
113− relvarTable <- fmap (relationVariables . stateElemsContext) ask
114− return $ case M.lookup name relvarTable of
115− Just res -> Right res
116− Nothing -> Left $ RelVarNotDefinedError name
117−
118−evalRelationalExpr (Project attrNames expr) = do
119− eAttrNameSet <- evalAttributeNames attrNames expr
120− case eAttrNameSet of
121− Left err -> pure (Left err)
122− Right attrNameSet -> do
123− rel <- evalRelationalExpr expr
124− case rel of
125− Right rel2 -> pure $ project attrNameSet rel2
126− Left err -> pure $ Left err
127−
128−evalRelationalExpr (Union exprA exprB) = do
129− relA <- evalRelationalExpr exprA
130− relB <- evalRelationalExpr exprB
131− case relA of
132− Left err -> return $ Left err
133− Right relA2 -> case relB of
134− Left err -> return $ Left err
135− Right relB2 -> return $ union relA2 relB2
136−
137−evalRelationalExpr (Join exprA exprB) = do
138− relA <- evalRelationalExpr exprA
139− relB <- evalRelationalExpr exprB
140− case relA of
141− Left err -> return $ Left err
142− Right relA2 -> case relB of
143− Left err -> return $ Left err
144− Right relB2 -> return $ join relA2 relB2
145−
146−evalRelationalExpr (Difference exprA exprB) = do
147− relA <- evalRelationalExpr exprA
148− relB <- evalRelationalExpr exprB
149− case relA of
150− Left err -> return $ Left err
151− Right relA2 -> case relB of
152− Left err -> return $ Left err
153− Right relB2 -> return $ difference relA2 relB2
154−
155−evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
156− case mkRelation attributeSet tupleSet of
157− Right rel -> return $ Right rel
158− Left err -> return $ Left err
144+mkDatabaseContextEvalEnv :: TransactionId -> TransactionGraph -> DatabaseContextEvalEnv
145+mkDatabaseContextEvalEnv = DatabaseContextEvalEnv
146+
147+type DatabaseContextEvalMonad a = RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity) a
148+
149+runDatabaseContextEvalMonad :: DatabaseContext -> DatabaseContextEvalEnv -> DatabaseContextEvalMonad () -> Either RelationalError DatabaseContextEvalState
150+runDatabaseContextEvalMonad ctx env m = runIdentity (runExceptT (fst <$> execRWST m env freshEnv))
151+ where
152+ freshEnv = mkDatabaseContextEvalState ctx
159153
160−evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
161− currentContext <- fmap stateElemsContext ask
162− let tConss = typeConstructorMapping currentContext
163− -- if the mAttrExprs is Nothing, then we should attempt to infer the tuple attributes from the first tuple itself- note that this is not always possible
164− runExceptT $ do
165− mAttrs <- case mAttrExprs of
166− Just _ ->
167− Just . A.attributesFromList <$> mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
168− Nothing -> pure Nothing
169− tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
170− let attrs = fromMaybe firstTupleAttrs mAttrs
171− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
172− either throwE pure (mkRelation attrs (RelationTupleSet tuples))
154+
155+dbcTransId :: DatabaseContextEvalMonad TransactionId
156+dbcTransId = dce_transId <$> RWS.ask
157+
158+dbcGraph :: DatabaseContextEvalMonad TransactionGraph
159+dbcGraph = dce_graph <$> RWS.ask
160+
161+dbcRelationalExprEnv :: DatabaseContextEvalMonad RelationalExprEnv
162+dbcRelationalExprEnv =
163+ mkRelationalExprEnv <$> getStateContext <*> dbcGraph
164+
165+getStateContext :: DatabaseContextEvalMonad DatabaseContext
166+getStateContext = gets dbc_context
167+
168+putStateContext :: DatabaseContext -> DatabaseContextEvalMonad ()
169+putStateContext ctx' = do
170+ s <- get
171+ put (s {dbc_context = ctx', dbc_dirty = True})
172+
173+-- | The context is optionally passed down along in cases where the current context is uncommitted.
174+data GraphRefRelationalExprEnv =
175+ GraphRefRelationalExprEnv {
176+ gre_context :: Maybe DatabaseContext,
177+ gre_graph :: TransactionGraph,
178+ gre_extra :: Maybe (Either RelationTuple Attributes)
179+ }
173180
174−evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
181+type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
175182
176−evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
177− evald <- evalRelationalExpr relExpr
178− case evald of
179− Right rel -> return $ rename oldAttrName newAttrName rel
180− Left err -> return $ Left err
183+gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184+gfTransForId tid = do
185+ graph <- gfGraph
186+ lift $ except $ transactionForId tid graph
181187
182−evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
183− eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
184− case eOldAttrNameSet of
185− Left err -> pure (Left err)
186− Right oldAttrNameSet -> do
187− evald <- evalRelationalExpr relExpr
188− case evald of
189− Right rel -> return $ group oldAttrNameSet newAttrName rel
190− Left err -> return $ Left err
191−
192−evalRelationalExpr (Ungroup attrName relExpr) = do
193− evald <- evalRelationalExpr relExpr
194− case evald of
195− Right rel -> return $ ungroup attrName rel
196− Left err -> return $ Left err
197−
198−evalRelationalExpr (Restrict predicateExpr relExpr) = do
199− evald <- evalRelationalExpr relExpr
200− case evald of
201− Left err -> return $ Left err
202− Right rel -> do
203− eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
204− case eFilterFunc of
205− Left err -> return $ Left err
206− Right filterfunc ->
207− pure (restrict filterfunc rel)
208−
209−evalRelationalExpr (Equals relExprA relExprB) = do
210− evaldA <- evalRelationalExpr relExprA
211− evaldB <- evalRelationalExpr relExprB
212− case evaldA of
213− Left err -> return $ Left err
214− Right relA -> case evaldB of
215− Left err -> return $ Left err
216− Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
217−
218−--warning: copy-pasta from above- refactor
219−evalRelationalExpr (NotEquals relExprA relExprB) = do
220− evaldA <- evalRelationalExpr relExprA
221− evaldB <- evalRelationalExpr relExprB
222− case evaldA of
223− Left err -> return $ Left err
224− Right relA -> case evaldB of
225− Left err -> return $ Left err
226− Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
227−
228−-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
229−evalRelationalExpr (Extend tupleExpression relExpr) = do
230− rstate <- ask
231− let evald = runReader (evalRelationalExpr relExpr) rstate
232− case evald of
233− Left err -> pure (Left err)
234− Right rel -> do
235− tupProc <- extendTupleExpressionProcessor rel tupleExpression
236− case tupProc of
237− Left err -> pure (Left err)
238− Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
188+gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189+gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190+gfDatabaseContextForMarker UncommittedContextMarker = do
191+ mctx <- gre_context <$> askEnv
192+ case mctx of
193+ Nothing -> throwError NoUncommittedContextInEvalError
194+ Just ctx -> pure ctx
195+
196+runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197+runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
198+
199+freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200+freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
201+ gre_context = mctx,
202+ gre_graph = graph,
203+ gre_extra = Nothing
204+ }
205+
206+gfGraph :: GraphRefRelationalExprM TransactionGraph
207+gfGraph = asks gre_graph
208+
209+envContext :: RelationalExprEnv -> DatabaseContext
210+envContext = re_context
211+
212+setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213+setEnvContext e ctx = e { re_context = ctx }
239214
240215--helper function to process relation variable creation/assignment
241−setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
242−setRelVar relVarName rel = do
216+setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217+setRelVar relVarName relExpr = do
243218 currentContext <- getStateContext
244− let newRelVars = M.insert relVarName rel $ relationVariables currentContext
219+ --prevent recursive relvar definition by resolving references to relvars in previous states
220+ relExpr' <- resolve relExpr
221+ let newRelVars = M.insert relVarName relExpr' $ relationVariables currentContext
245222 potentialContext = currentContext { relationVariables = newRelVars }
246−
247− case checkConstraints potentialContext of
248− Left err -> pure (Left err)
249− Right _ -> do
250− putStateContext potentialContext
251− 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 ()
252236
253237-- 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
254−deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
238+deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
255239deleteRelVar relVarName = do
256240 currContext <- getStateContext
257241 let relVars = relationVariables currContext
258242 if M.notMember relVarName relVars then
259− pure (Right ())
243+ pure ()
260244 else do
261245 let newRelVars = M.delete relVarName relVars
262246 newContext = currContext { relationVariables = newRelVars }
263247 putStateContext newContext
264− pure (Right ())
248+ pure ()
265249
266−evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
267−evalDatabaseContextExpr NoOperation = pure (Right ())
250+evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251+evalGraphRefDatabaseContextExpr NoOperation = pure ()
268252
269−evalDatabaseContextExpr (Define relVarName attrExprs) = do
253+evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254+ context <- getStateContext
270255 relvars <- fmap relationVariables getStateContext
271256 tConss <- fmap typeConstructorMapping getStateContext
272− let eAttrs = map (evalAttrExpr tConss) attrExprs
273− attrErrs = lefts eAttrs
274− attrsList = rights eAttrs
275− if not (null attrErrs) then
276− pure (Left (someErrors attrErrs))
277− else do
278− let atomTypeErrs = lefts $ map ((`validateAtomType` tConss) . A.atomType) attrsList
279− if not (null atomTypeErrs) then
280− pure (Left (someErrors atomTypeErrs))
281− else
282− case M.member relVarName relvars of
283− True -> pure (Left (RelVarAlreadyDefinedError relVarName))
284− False -> setRelVar relVarName 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)
285267 where
286268 attrs = A.attributesFromList attrsList
287269 emptyRelation = Relation attrs emptyTupleSet
288270
289−evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
271+evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
290272
291−evalDatabaseContextExpr (Assign relVarName expr) = do
292− -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
273+evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274+ graph <- re_graph <$> dbcRelationalExprEnv
293275 context <- getStateContext
294− let existingRelVar = M.lookup relVarName relVarTable
295− relVarTable = relationVariables context
296− value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
297− case value of
298− Left err -> pure (Left err)
299− Right rel -> case existingRelVar of
300− Nothing -> setRelVar relVarName rel
301− Just existingRel -> let expectedAttributes = attributes existingRel
302− foundAttributes = attributes rel in
303− if A.attributesEqual expectedAttributes foundAttributes then
304− setRelVar relVarName rel
305− else
306− pure (Left (RelationTypeMismatchError expectedAttributes foundAttributes))
307−
308−evalDatabaseContextExpr (Insert relVarName relExpr) = do
309− context <- getStateContext
310− let unionexp = Union relExpr rv
311− rv = RelationVariable relVarName ()
312− unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
313− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
314− case unioned of
315− Left err -> pure (Left err)
316− Right unioned' -> case origRel of
317− Left err -> pure (Left err)
318− Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
319− pure (Right ())
320− else
321− evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
322−
323−evalDatabaseContextExpr (Delete relVarName predicate) = do
324− context <- getStateContext
325− let rv = RelationVariable relVarName ()
326− let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
327− origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
328− case updatedRel of
329− Left err -> pure (Left err)
330− Right updatedRel' -> case origRel of
331− Left err -> pure (Left err)
332− Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
333− pure (Right ())
334− else
335− setRelVar relVarName updatedRel'
276+ let existingRelVar = M.lookup relVarName (relationVariables context)
277+ reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278+ eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
279+ case existingRelVar of
280+ Nothing -> do
281+ case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282+ Left err -> dbErr err
283+ Right reltype -> do
284+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285+ setRelVar relVarName expr
286+ Just existingRel -> do
287+ let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
288+ case eExpectedType of
289+ Left err -> dbErr err
290+ Right expectedType ->
291+ case eNewExprType of
292+ Left err -> dbErr err
293+ Right newExprType -> do
294+ if newExprType == expectedType then do
295+ lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296+ setRelVar relVarName expr
297+ else
298+ dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
336299
300+evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301+ gfExpr <- relVarByName relVarName
302+ let optExpr = applyUnionCollapse (Union
303+ relExpr
304+ gfExpr)
305+ evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
306+
307+evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308+ gfExpr <- relVarByName relVarName
309+ let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310+ setRelVar relVarName optExpr
311+
337312--union of restricted+updated portion and the unrestricted+unupdated portion
338−evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
313+evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314+ rvExpr <- relVarByName relVarName
315+ graph <- re_graph <$> dbcRelationalExprEnv
339316 context <- getStateContext
340− let relVarTable = relationVariables context
341− case M.lookup relVarName relVarTable of
342− Nothing -> pure (Left (RelVarNotDefinedError relVarName))
343− Just rel ->
344− case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
345− Left err -> pure (Left err)
346− Right predicateFunc -> do
347− let ret = do
348− restrictedPortion <- restrict predicateFunc rel
349− if cardinality restrictedPortion == Finite 0 then
350− pure Nothing
351− else do
352− unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
353− updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
354− updatedRel <- updatedPortion `union` unrestrictedPortion
355− pure (Just updatedRel)
356− case ret of
357− Left err -> pure (Left err)
358− Right Nothing -> pure (Right ())
359− Right (Just updatedRel) -> setRelVar relVarName updatedRel
317+ let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
318+ --get the current attributes name in the relvar to ensure that we don't conflict when renaming
319+ eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
320+ exprType' <- case eExprType of
321+ Left err -> throwError err
322+ Right t -> pure t
323+ let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
324+ tmpAttr = tmpAttrC 1
325+ tmpAttrC :: Int -> AttributeName -> AttributeName
326+ tmpAttrC c attr =
327+ let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
328+ if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
329+ tmpAttrC (c+1) attr
330+ else
331+ tmpAttrName
332+ updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
333+ projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
334+ restrictedPortion = Restrict pred' rvExpr
335+ updated = foldr (\(oldname, atomExpr) accum ->
336+ let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
337+ updateAttr oldname procAtomExpr accum
338+ ) restrictedPortion (M.toList atomExprMap)
339+ -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
340+ updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341+ setRelVar relVarName (Union unrestrictedPortion updatedPortion)
360342
361−evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
343+evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
362344 currContext <- getStateContext
345+ transId <- dbcTransId
346+ graph <- dbcGraph
363347 let currDeps = inclusionDependencies currContext
364348 newDeps = M.insert newDepName newDep currDeps
365349 if M.member newDepName currDeps then
366− pure (Left (InclusionDependencyNameInUseError newDepName))
350+ dbErr (InclusionDependencyNameInUseError newDepName)
367351 else do
368352 let potentialContext = currContext { inclusionDependencies = newDeps }
369− case checkConstraints potentialContext of
370− Left err -> pure (Left err)
371− 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 _ ->
372358 putStateContext potentialContext
373− return (Right ())
374359
375−evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
360+evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
376361 currContext <- getStateContext
377362 let currDeps = inclusionDependencies currContext
378363 newDeps = M.delete depName currDeps
379364 if M.notMember depName currDeps then
380− pure (Left (InclusionDependencyNameNotInUseError depName))
381− else do
365+ dbErr (InclusionDependencyNameNotInUseError depName)
366+ else
382367 putStateContext $ currContext {inclusionDependencies = newDeps }
383− return (Right ())
384368
385369-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
386−evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
370+evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
387371 currentContext <- getStateContext
388372 let nots = notifications currentContext
389373 if M.member notName nots then
390− pure (Left (NotificationNameInUseError notName))
374+ dbErr (NotificationNameInUseError notName)
391375 else do
392376 let newNotifications = M.insert notName newNotification nots
393377 newNotification = Notification { changeExpr = triggerExpr,
394378 reportOldExpr = resultOldExpr,
395379 reportNewExpr = resultNewExpr}
396380 putStateContext $ currentContext { notifications = newNotifications }
397− return (Right ())
398381
399−evalDatabaseContextExpr (RemoveNotification notName) = do
382+evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
400383 currentContext <- getStateContext
401384 let nots = notifications currentContext
402385 if M.notMember notName nots then
403− pure (Left (NotificationNameNotInUseError notName))
386+ dbErr (NotificationNameNotInUseError notName)
404387 else do
405388 let newNotifications = M.delete notName nots
406389 putStateContext $ currentContext { notifications = newNotifications }
407− pure (Right ())
390+
408391
409392-- | Adds type and data constructors to the database context.
410393-- validate that the type *and* constructor names are unique! not yet implemented!
411−evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
394+evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
412395 currentContext <- getStateContext
413396 let oldTypes = typeConstructorMapping currentContext
414397 tConsName = TCD.name tConsDef
415398 -- validate that the constructor's types exist
416− case validateTypeConstructorDef tConsDef dConsDefList of
417− errs@(_:_) -> pure (Left (someErrors errs))
418− [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
419− | 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)
420403 | otherwise -> do
421404 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
422405 putStateContext $ currentContext { typeConstructorMapping = newTypes }
423− pure (Right ())
424406
425407-- | 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.
426−evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
408+evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
427409 currentContext <- getStateContext
428410 let oldTypes = typeConstructorMapping currentContext
429411 if isNothing (findTypeConstructor tConsName oldTypes) then
430− pure (Left (AtomTypeNameNotInUseError tConsName))
412+ dbErr (AtomTypeNameNotInUseError tConsName)
431413 else do
432414 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
433415 putStateContext $ currentContext { typeConstructorMapping = newTypes }
434− pure (Right ())
435416
436−evalDatabaseContextExpr (MultipleExpr exprs) = do
417+evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
437418 --the multiple expressions must pass the same context around- not the old unmodified context
438− evald <- forM exprs evalDatabaseContextExpr
439− --some lifting magic needed here
440− case lefts evald of
441− [] -> pure (Right ())
442− errs -> pure (Left (someErrors errs))
443−
444−evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
419+ mapM_ evalGraphRefDatabaseContextExpr exprs
420+
421+evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
445422 currentContext <- getStateContext
446423 let atomFuncs = atomFunctions currentContext
447424 case atomFunctionForName funcName atomFuncs of
448− Left err -> pure (Left err)
449− Right realFunc -> if isScriptedAtomFunction realFunc then do
450− let updatedFuncs = HS.delete realFunc atomFuncs
451− putStateContext (currentContext {atomFunctions = updatedFuncs })
452− pure (Right ())
453− else
454− 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)
455432
456−evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
433+evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
457434 context <- getStateContext
458435 let dbcFuncs = dbcFunctions context
459436 case databaseContextFunctionForName funcName dbcFuncs of
460− Left err -> pure (Left err)
461− Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
462− let updatedFuncs = HS.delete realFunc dbcFuncs
463− putStateContext (context { dbcFunctions = updatedFuncs })
464− pure (Right ())
465− else
466− 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)
467444
468−evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
445+evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
469446 context <- getStateContext
447+ graph <- dbcGraph
470448 --resolve atom arguments
471− let relExprState = mkRelationalExprState context
472− eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
449+ let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
473450 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
474452 case eFunc of
475− Left err -> pure (Left err)
453+ Left err -> dbErr err
476454 Right func -> do
477455 let expectedArgCount = length (dbcFuncType func)
478456 actualArgCount = length atomArgExprs
479457 if expectedArgCount /= actualArgCount then
480− pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
458+ dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
481459 else
482460 --check that the atom types are valid
483− case lefts eAtomTypes of
484− _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
485− [] -> do
486− let atomTypes = rights eAtomTypes
487− let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
488− Left err -> Just err
489− Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
490− typeErrors = catMaybes mValidTypes
491− 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
492471 if length (lefts eAtomArgs) > 1 then
493− pure (Left (someErrors (lefts eAtomArgs)))
472+ dbErr (someErrors (lefts eAtomArgs))
494473 else if not (null typeErrors) then
495− pure (Left (someErrors typeErrors))
474+ dbErr (someErrors typeErrors)
496475 else
497476 case evalDatabaseContextFunction func (rights eAtomArgs) context of
498− Left err -> pure (Left err)
499− Right newContext -> putStateContext newContext >> pure (Right ())
500−
501−evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
502−evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
503− case mScriptSession of
504− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
505− Just scriptSession -> do
506− 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
507530 setSession (hscEnv scriptSession)
508531 let atomFuncs = atomFunctions currentContext
509532 case extractAtomFunctionType funcType of
@@ -529,12 +552,13 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcNam
529552 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
530553 Right eContext -> case eContext of
531554 Left err -> pure (Left err)
532− Right context' -> pure (Right context')
533−
534−evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
535− case mScriptSession of
536− Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
537− 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
538562 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
539563 let last2Args = reverse (take 2 (reverse funcType))
540564 atomArgs = take (length funcType - 2) funcType
@@ -544,7 +568,7 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
544568 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
545569 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
546570 else do
547− res <- try $ runGhc (Just libdir) $ do
571+ res <- liftIO $ try $ runGhc (Just libdir) $ do
548572 setSession (hscEnv scriptSession)
549573 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
550574 pure $ case eCompiledFunc of
@@ -569,68 +593,86 @@ evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunct
569593 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
570594 Right eContext -> case eContext of
571595 Left err -> pure (Left err)
572− Right context' -> pure (Right context')
573−evalDatabaseContextIOExpr _ currentContext (LoadAtomFunctions modName funcName modPath) = do
574− 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
575600 case eLoadFunc of
576601 Left LoadSymbolError -> pure (Left LoadFunctionError)
577602 Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
578603 mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
579− in pure (Right newContext)
580−evalDatabaseContextIOExpr _ currentContext (LoadDatabaseContextFunctions modName funcName modPath) = do
581− 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
582608 case eLoadFunc of
583609 Left LoadSymbolError -> pure (Left LoadFunctionError)
584610 Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
585611 mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
586− in pure (Right newContext)
587−
588−evalDatabaseContextIOExpr _ currentContext (CreateArbitraryRelation relVarName attrExprs range) =
612+ in putDBCIOContext newContext
613+#endif
614+evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
589615 --Define
590− case runState ( evalDatabaseContextExpr (Define relVarName attrExprs)) (freshDatabaseState currentContext) of
591− (Left err,_) -> pure (Left err)
592− (Right (), elems@(ctx,_,_)) -> 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
593625 --Assign
594626 let existingRelVar = M.lookup relVarName relVarTable
595− relVarTable = relationVariables ctx
627+ relVarTable = relationVariables (dbc_context dbstate)
596628 case existingRelVar of
597629 Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
598630 Just existingRel -> do
599− let expectedAttributes = attributes existingRel
600− let tcMap = typeConstructorMapping ctx
601− eitherRel <- generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
602− case eitherRel of
603− Left err -> pure $ Left err
604− Right rel ->
605− case runState (setRelVar relVarName rel) elems of
606− (Left err,_) -> pure (Left err)
607− (Right (), (ctx',_,_)) -> pure $ Right ctx'
608−
609−updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
610−updateTupleWithAtomExprs exprMap context tupIn = do
611− --resolve all atom exprs
612− atomsAssoc <- mapM (\(attrName, atomExpr) -> do
613− atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
614− pure (attrName, atom)
615− ) (M.toList exprMap)
616− pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
631+ let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632+ case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633+ Left err -> pure (Left err)
634+ Right relType -> do
635+ let expectedAttributes = attributes relType
636+ tcMap = typeConstructorMapping (dbc_context dbstate)
637+ eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638+ case eitherRel of
639+ Left err -> pure $ Left err
640+ Right rel ->
641+ case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642+ Left err -> pure (Left err)
643+ Right dbstate' -> putDBCIOContext (dbc_context dbstate')
617644
618645--run verification on all constraints
619−checkConstraints :: DatabaseContext -> Either RelationalError ()
620−checkConstraints context = do
646+checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647+checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
621648 mapM_ (uncurry checkIncDep) (M.toList deps)
622− pure ()
623649 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+
624660 deps = inclusionDependencies context
625− eval expr = evalReader (evalRelationalExpr expr)
626− 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
627662 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663+ let process = runProcessExprM UncommittedContextMarker
664+ gfSubsetExpr = process (processRelationalExpr subsetExpr)
665+ gfSupersetExpr = process (processRelationalExpr supersetExpr)
628666 --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.
629− typeSub <- evalReader (typeForRelationalExpr subsetExpr)
630− 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)
631671 when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
632− let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
633− 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
634676 Left err -> Left err
635677 Right resultRel -> if resultRel == relationTrue then
636678 pure ()
@@ -640,88 +682,81 @@ checkConstraints context = do
640682-- 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
641683-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
642684
643−typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
685+typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
644686typeForRelationalExpr expr = do
645− rstate <- ask
646− let context = stateElemsContext rstate
647687 --replace the relationVariables context element with a cloned set of relation devoid of tuples
648− let context' = contextWithEmptyTupleSets context
649− rstate' = setStateElemsContext rstate context'
650− pure (runReader (evalRelationalExpr expr) rstate')
651−
652−--returns a database context with all tuples removed
653−--this is useful for type checking and optimization
654−contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
655−contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
656− where
657− relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
688+ --evalRelationalExpr could still return an existing relation with tuples, so strip them
689+ graph <- reGraph
690+ context <- reContext
691+ let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
692+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
693+ runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
694+ lift $ except runGf
658695
659696liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
660697liftE v = do
661698 y <- lift v
662699 case y of
663− Left err -> throwE err
700+ Left err -> throwError err
664701 Right val -> pure val
665702
666703{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
667−predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
668−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
669− runExceptT $ do
670− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
671− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
672− pure (\x -> do
673− ev1 <- expr1v x
674− ev2 <- expr2v x
675− 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))
676712
677−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
678− runExceptT $ do
679− expr1v <- liftE (predicateRestrictionFilter attrs expr1)
680− expr2v <- liftE (predicateRestrictionFilter attrs expr2)
713+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714+ expr1v <- predicateRestrictionFilter attrs expr1
715+ expr2v <- predicateRestrictionFilter attrs expr2
681716 pure (\x -> do
682717 ev1 <- expr1v x
683718 ev2 <- expr2v x
684719 pure (ev1 || ev2))
685720
686−predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
721+predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
687722
688−predicateRestrictionFilter attrs (NotPredicate expr) =
689− runExceptT $ do
690− exprv <- liftE (predicateRestrictionFilter attrs expr)
691− pure (fmap not . exprv)
723+predicateRestrictionFilter attrs (NotPredicate expr) = do
724+ exprv <- predicateRestrictionFilter attrs expr
725+ pure (fmap not . exprv)
692726
693727--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
694728predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
695− rstate <- ask
696− 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
697735 Left err -> Left err
698736 Right rel -> if arity rel /= 0 then
699737 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
700738 else
701− pure (rel == relationTrue)))
739+ pure (rel == relationTrue))
702740
703741predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
704− rstate <- ask
705− let (attrs', ctxtup') = case rstate of
706− RelationalExprStateElems _ -> (attrs, emptyTuple)
707− RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
708− RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
709− runExceptT $ do
710− atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
711− 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
712747 Right attr -> Right attr
713748 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
714749 Right ctxattr -> Right ctxattr
715750 Left err2@(NoSuchAttributeNamesError _) -> Left err2
716751 Left err -> Left err
717752 Left err -> Left err
718− if atomExprType /= A.atomType attr then
719− throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
720− else
753+ if atomExprType /= A.atomType attr then
754+ throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755+ else
721756 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
722757 Right atomCmp -> atomCmp == atomIn
723758 Left _ -> False
724− atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
759+ atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
725760 in
726761 pure $ case atomForAttributeName attrName tupleIn of
727762 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -732,243 +767,626 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
732767-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
733768predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
734769 --merge attrs into the state attributes
735− rstate <- ask
736− runExceptT $ do
737− aType <- liftE (typeFromAtomExpr attrs atomExpr)
738− if aType /= BoolAtomType then
739− throwE (AtomTypeMismatchError aType BoolAtomType)
740− else
770+ renv <- askEnv
771+ aType <- typeForGraphRefAtomExpr attrs atomExpr
772+ if aType /= BoolAtomType then
773+ throwError (AtomTypeMismatchError aType BoolAtomType)
774+ else
741775 pure (\tupleIn ->
742− pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
743− Left _ -> False
744− Right boolAtomValue -> boolAtomValue == BoolAtom True)
776+ case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777+ Left err -> Left err
778+ Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
745779
746780tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
747781tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
748− Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
782+ Left (AttributeNameInUseError attrName)
749783 else
750784 Right rel
751785
752−extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
753−extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
754− rstate <- ask
786+extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787+extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788+-- renv <- askEnv
755789 -- check that the attribute name is not in use
756790 case tupleExprCheckNewAttrName newAttrName relIn of
757− Left err -> pure (Left err)
758− Right _ -> runExceptT $ do
759− atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
760− 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
761795 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
762796 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
763− pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
764− Left err -> Left err
765− 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)
766802 )
767803
768−evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
769−evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
770− Right atom -> pure (Right atom)
771− err@(Left (NoSuchAttributeNamesError _)) -> do
772− rstate <- ask
773− case rstate of
774− RelationalExprStateElems _ -> pure err
775− RelationalExprStateAttrsElems _ _ -> pure err
776− RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
777− Left err -> pure (Left err)
778−evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
779−evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
780− argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
781− context <- fmap stateElemsContext ask
782− runExceptT $ do
783− let functions = atomFunctions context
784− func <- either throwE pure (atomFunctionForName funcName functions)
785− let expectedArgCount = length (atomFuncType func) - 1
786− actualArgCount = length argTypes
787− safeInit [_] = []
788− safeInit [] = [] -- different behavior from normal init
789− safeInit (_:xs) = safeInit xs
790− if expectedArgCount /= actualArgCount then
791− throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
792− else do
793− mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
794− evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
804+evalGraphRefAtomExpr :: RelationTuple -> GraphRefAtomExpr -> GraphRefRelationalExprM Atom
805+evalGraphRefAtomExpr tupIn (AttributeAtomExpr attrName) =
806+ case atomForAttributeName attrName tupIn of
807+ Right atom -> pure atom
808+ Left err@(NoSuchAttributeNamesError _) -> do
809+ env <- askEnv
810+ case gre_extra env of
811+ Nothing -> throwError err
812+ Just (Left ctxtup) -> lift $ except $ atomForAttributeName attrName ctxtup
813+ Just (Right _) -> throwError err
814+ Left err -> throwError err
815+evalGraphRefAtomExpr _ (NakedAtomExpr atom) = pure atom
816+evalGraphRefAtomExpr tupIn (FunctionAtomExpr funcName arguments tid) = do
817+ argTypes <- mapM (typeForGraphRefAtomExpr (tupleAttributes tupIn)) arguments
818+ context <- gfDatabaseContextForMarker tid
819+ let functions = atomFunctions context
820+ func <- lift $ except (atomFunctionForName funcName functions)
821+ let expectedArgCount = length (atomFuncType func) - 1
822+ actualArgCount = length argTypes
823+ safeInit [] = [] -- different behavior from normal init
824+ safeInit xs = init xs
825+ if expectedArgCount /= actualArgCount then
826+ throwError (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
827+ else do
828+ let zippedArgs = zip (safeInit (atomFuncType func)) argTypes
829+ mapM_ (\(expType, actType) ->
830+ lift $ except (atomTypeVerify expType actType)) zippedArgs
831+ evaldArgs <- mapM (evalGraphRefAtomExpr tupIn) arguments
795832 case evalAtomFunction func evaldArgs of
796− Left err -> throwE (AtomFunctionUserError err)
833+ Left err -> throwError (AtomFunctionUserError err)
797834 Right result -> do
798835 --validate that the result matches the expected type
799− _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
836+ _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
800837 pure result
801−evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
838+evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
802839 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
803− rstate <- ask
804− runExceptT $ do
805− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
806− relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
807− pure (RelationAtom relAtom)
808−evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
809− rstate <- lift ask
810− let newState = mergeTuplesIntoRelationalExprState tupIn rstate
811− aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
812− 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
813849 pure (ConstructedAtom dConsName aType argAtoms)
814850
815−typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
816−typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
817− rstate <- ask
851+typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852+typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853+ renv <- askEnv
818854 case A.atomTypeForAttributeName attrName attrs of
819− Right aType -> pure (Right aType)
820− Left err@(NoSuchAttributeNamesError _) -> case rstate of
821− RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
822− Left err' -> pure (Left err')
823− Right attr -> pure (Right (A.atomType attr))
824− RelationalExprStateElems _ -> pure (Left err)
825− RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
826− Left err' -> pure (Left err')
827− Right atom -> pure (Right (atomTypeForAtom atom))
828− Left err -> pure (Left err)
829−typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
830−typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
831− context <- fmap stateElemsContext ask
832− 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
833870 case atomFunctionForName funcName funcs of
834− Left err -> pure (Left err)
871+ Left err -> throwError err
835872 Right func -> do
836873 let funcRetType = last (atomFuncType func)
837874 funcArgTypes = init (atomFuncType func)
838− eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
839− case lefts eArgTypes of
840− errs@(_:_) -> pure (Left (someErrors errs))
841− [] -> do
842− let eTvMap = resolveTypeVariables funcArgTypes argTypes
843− argTypes = rights eArgTypes
844− case eTvMap of
845− Left err -> pure (Left err)
846− Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
847−typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
848− rstate <- lift ask
849− 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)
850882 pure (RelationAtomType (attributes relType))
851883-- grab the type of the data constructor, then validate that the args match the expected types
852−typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
853− runExceptT $ do
854− argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
855− context <- fmap stateElemsContext (lift ask)
856− 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
857889
858890-- | Validate that the type of the AtomExpr matches the expected type.
859−verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
860−verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
861− rstate <- lift ask
891+verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892+verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893+ env <- askEnv
862894 case A.atomTypeForAttributeName attrName (attributes relIn) of
863− Right aType -> either throwE pure (atomTypeVerify expectedType aType)
864− (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
865− RelationalExprStateTupleElems _ _ -> throwE err
866− RelationalExprStateElems _ -> throwE err
867− RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
868− Left err' -> throwE err'
869− Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
870− Left err -> throwE err
871−verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
872−verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
873− 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
874910 let functions = atomFunctions context
875− context = stateElemsContext rstate
876− runExceptT $ do
877− func <- either throwE pure (atomFunctionForName funcName functions)
878− let expectedArgTypes = atomFuncType func
879− funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
880− Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
881− Left err -> throwE err
882− Right x -> pure x
883− ) $ zip3 funcArgExprs expectedArgTypes [1..]
884− if length funcArgTypes /= length expectedArgTypes - 1 then
885− 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)
886921 else
887− either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
888−verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
889− rstate <- lift ask
890− relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
891− either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
892−verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
893− cType <- liftE (typeFromAtomExpr (attributes rel) cons)
894− 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
895931
896932-- | Look up the type's name and create a new attribute.
897−evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
898−evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
899− aType <- atomTypeForTypeConstructorValidate True tCons aTypes M.empty
900− validateAtomType aType aTypes
901− Right (Attribute attrName aType)
902−
903−evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
933+evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
934+evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
935+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
936+ aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
937+ lift $ except $ validateAtomType aType tConsMap
938+ pure $ Attribute attrName aType
904939
905−evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
906−evalTupleExpr attrs (TupleExpr tupMap) = do
907− context <- fmap stateElemsContext ask
908− 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
909992 -- 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
910993 -- 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
911− attrAtoms <- mapM (\(attrName, aExpr) -> do
912− newAtomType <- liftE (typeFromAtomExpr A.emptyAttributes aExpr)
913− newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
914− pure (attrName, newAtom, newAtomType)
915− ) (M.toList tupMap)
916− let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
917− atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
918− tup = mkRelationTuple tupAttrs atoms
919− tConss = typeConstructorMapping context
920− finalAttrs = fromMaybe tupAttrs attrs
994+ let attrs = fromMaybe A.emptyAttributes mAttrs
995+ resolveOneAtom (attrName, aExpr) =
996+ do
997+ --provided when the relation header is available
998+ let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
999+ unresolvedType <- typeForGraphRefAtomExpr attrs aExpr
1000+ resolvedType <- case eExpectedAtomType of
1001+ Left _ -> pure unresolvedType
1002+ Right typeHint -> lift $ except $ resolveAtomType typeHint unresolvedType
1003+ --resolve atom typevars based on resolvedType?
1004+ newAtom <- evalGraphRefAtomExpr emptyTuple aExpr
1005+ pure (attrName, newAtom, resolvedType)
1006+ attrAtoms <- mapM resolveOneAtom (M.toList tupMap)
1007+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
1008+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
1009+ tup = mkRelationTuple tupAttrs atoms
1010+ finalAttrs = fromMaybe tupAttrs mAttrs
9211011 --verify that the attributes match
922− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
923− tup' <- either throwE pure (resolveTypesInTuple finalAttrs (reorderTuple finalAttrs tup))
924− _ <- either throwE pure (validateTuple tup' tConss)
925− pure tup'
926−
927−evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
928−evalAttributeNames attrNames expr = do
929− eExprType <- typeForRelationalExpr expr
930− case eExprType of
931− Left err -> pure (Left err)
932− Right exprTyp -> do
933− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
934− case attrNames of
935− AttributeNames names ->
936− case A.projectionAttributesForNames names (attributes exprTyp) of
937− Left err -> pure (Left err)
938− Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1012+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
1013+ --we can't resolve types here- they have to be resolved at the atom level where the graph ref is held
1014+ --tup' <- lift $ except (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
1015+ let tup' = reorderTuple finalAttrs tup
1016+ --TODO: restore type resolution
1017+-- _ <- lift $ except (validateTuple tup' tConss)
1018+ pure tup'
1019+
1020+--temporary implementation until we have a proper planner+executor
1021+evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1022+evalGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1023+ mAttrs <- case mAttrExprs of
1024+ Just _ ->
1025+ Just . A.attributesFromList <$> mapM evalGraphRefAttrExpr (fromMaybe [] mAttrExprs)
1026+ Nothing -> pure Nothing
1027+ tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1028+ let attrs = fromMaybe firstTupleAttrs mAttrs
1029+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
1030+ lift $ except $ mkRelation attrs (RelationTupleSet tuples)
1031+evalGraphRefRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
1032+ lift $ except $ mkRelation attributeSet tupleSet
1033+evalGraphRefRelationalExpr (ExistingRelation rel) = pure rel
1034+evalGraphRefRelationalExpr (RelationVariable name tid) = do
1035+ ctx <- gfDatabaseContextForMarker tid
1036+ case M.lookup name (relationVariables ctx) of
1037+ Nothing -> throwError (RelVarNotDefinedError name)
1038+ Just rv -> evalGraphRefRelationalExpr rv
1039+evalGraphRefRelationalExpr (Project attrNames expr) = do
1040+ attrNameSet <- evalGraphRefAttributeNames attrNames expr
1041+ rel <- evalGraphRefRelationalExpr expr
1042+ lift $ except $ project attrNameSet rel
1043+evalGraphRefRelationalExpr (Union exprA exprB) = do
1044+ relA <- evalGraphRefRelationalExpr exprA
1045+ relB <- evalGraphRefRelationalExpr exprB
1046+ lift $ except $ union relA relB
1047+evalGraphRefRelationalExpr (Join exprA exprB) = do
1048+ relA <- evalGraphRefRelationalExpr exprA
1049+ relB <- evalGraphRefRelationalExpr exprB
1050+ lift $ except $ join relA relB
1051+evalGraphRefRelationalExpr (Rename oldName newName expr) = do
1052+ rel <- evalGraphRefRelationalExpr expr
1053+ lift $ except $ rename oldName newName rel
1054+evalGraphRefRelationalExpr (Difference exprA exprB) = do
1055+ relA <- evalGraphRefRelationalExpr exprA
1056+ relB <- evalGraphRefRelationalExpr exprB
1057+ lift $ except $ difference relA relB
1058+evalGraphRefRelationalExpr (Group groupAttrNames newAttrName expr) = do
1059+ groupNames <- evalGraphRefAttributeNames groupAttrNames expr
1060+ rel <- evalGraphRefRelationalExpr expr
1061+ lift $ except $ group groupNames newAttrName rel
1062+evalGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1063+ rel <- evalGraphRefRelationalExpr expr
1064+ lift $ except $ ungroup groupAttrName rel
1065+evalGraphRefRelationalExpr (Restrict predExpr expr) = do
1066+ rel <- evalGraphRefRelationalExpr expr
1067+ filt <- predicateRestrictionFilter (attributes rel) predExpr
1068+ lift $ except $ restrict filt rel
1069+evalGraphRefRelationalExpr (Equals exprA exprB) = do
1070+ relA <- evalGraphRefRelationalExpr exprA
1071+ relB <- evalGraphRefRelationalExpr exprB
1072+ pure $ if relA == relB then relationTrue else relationFalse
1073+evalGraphRefRelationalExpr (NotEquals exprA exprB) = do
1074+ relA <- evalGraphRefRelationalExpr exprA
1075+ relB <- evalGraphRefRelationalExpr exprB
1076+ pure $ if relA == relB then relationFalse else relationTrue
1077+evalGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1078+ rel <- evalGraphRefRelationalExpr expr
1079+ (newAttrs, tupProc) <- extendGraphRefTupleExpressionProcessor rel extendTupleExpr
1080+ lift $ except $ relMogrify tupProc newAttrs rel
1081+evalGraphRefRelationalExpr expr@With{} =
1082+ --strategy A: add relation variables to the contexts in the graph
1083+ --strategy B: drop in macros in place (easier programmatically)
1084+ --strategy B implementation
1085+ evalGraphRefRelationalExpr (substituteWithNameMacros [] expr)
1086+
1087+dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
1088+dbContextForTransId tid graph = do
1089+ trans <- transactionForId tid graph
1090+ pure (concreteDatabaseContext trans)
1091+
1092+transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
1093+transactionForId tid graph
1094+ | tid == U.nil =
1095+ Left RootTransactionTraversalError
1096+ | S.null matchingTrans =
1097+ Left $ NoSuchTransactionError tid
1098+ | otherwise =
1099+ Right $ head (S.toList matchingTrans)
1100+ where
1101+ matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
1102+
1103+typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1104+typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = lift $ except $ mkRelation attrs emptyTupleSet
1105+typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (emptyRelationWithAttrs (attributes rel))
1106+typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1107+ mAttrs <- case mAttrExprs of
1108+ Just attrExprs -> do
1109+ attrs <- mapM evalGraphRefAttributeExpr attrExprs
1110+ pure (Just (attributesFromList attrs))
1111+ Nothing -> pure Nothing
1112+ tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1113+ let retAttrs = case tuples of
1114+ (tup:_) -> tupleAttributes tup
1115+ [] -> fromMaybe A.emptyAttributes mAttrs
1116+ pure $ emptyRelationWithAttrs retAttrs
1117+
1118+typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119+ relVars <- relationVariables <$> gfDatabaseContextForMarker tid
1120+ case M.lookup rvName relVars of
1121+ Nothing -> throwError (RelVarNotDefinedError rvName)
1122+ Just rvExpr ->
1123+ typeForGraphRefRelationalExpr rvExpr
1124+typeForGraphRefRelationalExpr (Project attrNames expr) = do
1125+ exprType' <- typeForGraphRefRelationalExpr expr
1126+ projectionAttrs <- evalGraphRefAttributeNames attrNames expr
1127+ lift $ except $ project projectionAttrs exprType'
1128+typeForGraphRefRelationalExpr (Union exprA exprB) = do
1129+ exprA' <- typeForGraphRefRelationalExpr exprA
1130+ exprB' <- typeForGraphRefRelationalExpr exprB
1131+ lift $ except $ union exprA' exprB'
1132+typeForGraphRefRelationalExpr (Join exprA exprB) = do
1133+ exprA' <- typeForGraphRefRelationalExpr exprA
1134+ exprB' <- typeForGraphRefRelationalExpr exprB
1135+ lift $ except $ join exprA' exprB'
1136+typeForGraphRefRelationalExpr (Rename oldAttr newAttr expr) = do
1137+ expr' <- typeForGraphRefRelationalExpr expr
1138+ lift $ except $ rename oldAttr newAttr expr'
1139+typeForGraphRefRelationalExpr (Difference exprA exprB) = do
1140+ exprA' <- typeForGraphRefRelationalExpr exprA
1141+ exprB' <- typeForGraphRefRelationalExpr exprB
1142+ lift $ except $ difference exprA' exprB'
1143+typeForGraphRefRelationalExpr (Group groupNames attrName expr) = do
1144+ expr' <- typeForGraphRefRelationalExpr expr
1145+ groupNames' <- evalGraphRefAttributeNames groupNames expr
1146+ lift $ except $ group groupNames' attrName expr'
1147+typeForGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1148+ expr' <- typeForGraphRefRelationalExpr expr
1149+ lift $ except $ ungroup groupAttrName expr'
1150+typeForGraphRefRelationalExpr (Restrict pred' expr) = do
1151+ expr' <- typeForGraphRefRelationalExpr expr
1152+ filt <- predicateRestrictionFilter (attributes expr') pred'
1153+ lift $ except $ restrict filt expr'
1154+typeForGraphRefRelationalExpr Equals{} =
1155+ pure relationFalse
1156+typeForGraphRefRelationalExpr NotEquals{} =
1157+ pure relationFalse
1158+typeForGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1159+ rel <- typeForGraphRefRelationalExpr expr
1160+ evalGraphRefRelationalExpr (Extend extendTupleExpr (ExistingRelation rel))
1161+typeForGraphRefRelationalExpr expr@(With withs _) = do
1162+ let expr' = substituteWithNameMacros [] expr
1163+ checkMacroName (WithNameExpr macroName tid) = do
1164+ rvs <- relationVariables <$> gfDatabaseContextForMarker tid
1165+ case M.lookup macroName rvs of
1166+ Just _ -> lift $ except $ Left (RelVarAlreadyDefinedError macroName) --this error does not include the transaction marker, but should be good enough to identify the cause
1167+ Nothing -> pure ()
1168+ mapM_ (checkMacroName . fst) withs
1169+ typeForGraphRefRelationalExpr expr'
1170+
1171+evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1172+evalGraphRefAttributeNames attrNames expr = do
1173+ exprType' <- typeForGraphRefRelationalExpr expr
1174+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
1175+ case attrNames of
1176+ AttributeNames names ->
1177+ case A.projectionAttributesForNames names (attributes exprType') of
1178+ Left err -> throwError err
1179+ Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
9391180
940− InvertedAttributeNames names -> do
1181+ InvertedAttributeNames names -> do
9411182 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
9421183 if not (S.null nonExistentAttributeNames) then
943− pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1184+ throwError $ AttributeNamesMismatchError nonExistentAttributeNames
9441185 else
945− pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1186+ pure (A.nonMatchingAttributeNameSet names typeNameSet)
9461187
947− UnionAttributeNames namesA namesB -> do
948− eNameSetA <- evalAttributeNames namesA expr
949− case eNameSetA of
950− Left err -> pure (Left err)
951− Right nameSetA -> do
952− eNameSetB <- evalAttributeNames namesB expr
953− case eNameSetB of
954− Left err -> pure (Left err)
955− Right nameSetB ->
956− pure (Right (S.union nameSetA nameSetB))
1188+ UnionAttributeNames namesA namesB -> do
1189+ nameSetA <- evalGraphRefAttributeNames namesA expr
1190+ nameSetB <- evalGraphRefAttributeNames namesB expr
1191+ pure (S.union nameSetA nameSetB)
9571192
958− IntersectAttributeNames namesA namesB -> do
959− eNameSetA <- evalAttributeNames namesA expr
960− case eNameSetA of
961− Left err -> pure (Left err)
962− Right nameSetA -> do
963− eNameSetB <- evalAttributeNames namesB expr
964− case eNameSetB of
965− Left err -> pure (Left err)
966− Right nameSetB ->
967− pure (Right (S.intersection nameSetA nameSetB))
1193+ IntersectAttributeNames namesA namesB -> do
1194+ nameSetA <- evalGraphRefAttributeNames namesA expr
1195+ nameSetB <- evalGraphRefAttributeNames namesB expr
1196+ pure (S.intersection nameSetA nameSetB)
9681197
969− RelationalExprAttributeNames attrExpr -> do
970− eAttrExprType <- typeForRelationalExpr attrExpr
971− case eAttrExprType of
972− Left err -> pure (Left err)
973− Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
974−
1198+ RelationalExprAttributeNames attrExpr -> do
1199+ attrExprType <- typeForGraphRefRelationalExpr attrExpr
1200+ pure (A.attributeNameSet (attributes attrExprType))
1201+
1202+evalGraphRefAttributeExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
1203+evalGraphRefAttributeExpr (AttributeAndTypeNameExpr attrName tCons tid) = do
1204+ tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
1205+ case atomTypeForTypeConstructorValidate True tCons tConsMap M.empty of
1206+ Left err -> throwError err
1207+ Right aType -> do
1208+ case validateAtomType aType tConsMap of
1209+ Left err -> throwError err
1210+ Right _ -> pure (Attribute attrName aType)
1211+evalGraphRefAttributeExpr (NakedAttributeExpr attr) = pure attr
1212+
1213+mkEmptyRelVars :: RelationVariables -> RelationVariables
1214+mkEmptyRelVars = M.map mkEmptyRelVar
1215+ where
1216+ mkEmptyRelVar expr@MakeRelationFromExprs{} = expr --do not truncate here because we might lose essential type information in emptying the tuples
1217+ mkEmptyRelVar (MakeStaticRelation attrs _) = MakeStaticRelation attrs emptyTupleSet
1218+ mkEmptyRelVar (ExistingRelation rel) = ExistingRelation (emptyRelationWithAttrs (attributes rel))
1219+ mkEmptyRelVar rv@RelationVariable{} = Restrict (NotPredicate TruePredicate) rv
1220+ mkEmptyRelVar (Project attrNames expr) = Project attrNames (mkEmptyRelVar expr)
1221+ mkEmptyRelVar (Union exprA exprB) = Union (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1222+ mkEmptyRelVar (Join exprA exprB) = Join (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1223+ mkEmptyRelVar (Rename nameA nameB expr) = Rename nameA nameB (mkEmptyRelVar expr)
1224+ mkEmptyRelVar (Difference exprA exprB) = Difference (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1225+ mkEmptyRelVar (Group attrNames attrName expr) = Group attrNames attrName (mkEmptyRelVar expr)
1226+ mkEmptyRelVar (Ungroup attrName expr) = Ungroup attrName (mkEmptyRelVar expr)
1227+ mkEmptyRelVar (Restrict pred' expr) = Restrict pred' (mkEmptyRelVar expr)
1228+ mkEmptyRelVar (Equals exprA exprB) = Equals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1229+ mkEmptyRelVar (NotEquals exprA exprB) = NotEquals (mkEmptyRelVar exprA) (mkEmptyRelVar exprB)
1230+ mkEmptyRelVar (Extend extTuple expr) = Extend extTuple (mkEmptyRelVar expr)
1231+ mkEmptyRelVar (With macros expr) = With (map (second mkEmptyRelVar) macros) (mkEmptyRelVar expr)
1232+
1233+
1234+dbErr :: RelationalError -> DatabaseContextEvalMonad ()
1235+dbErr err = lift (except (Left err))
1236+
1237+-- | Return a Relation describing the relation variables.
1238+relationVariablesAsRelation :: DatabaseContext -> TransactionGraph -> Either RelationalError Relation
1239+relationVariablesAsRelation ctx graph = do
1240+ let subrelAttrs = A.attributesFromList [Attribute "attribute" TextAtomType, Attribute "type" TextAtomType]
1241+ attrs = A.attributesFromList [Attribute "name" TextAtomType,
1242+ Attribute "attributes" (RelationAtomType subrelAttrs)]
1243+ relVars = relationVariables ctx
1244+ mkRvDesc (rvName, gfExpr) = do
1245+ let gfEnv = freshGraphRefRelationalExprEnv (Just ctx) graph
1246+ gfType <- runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
1247+ pure (rvName, gfType)
1248+ relVarToAtomList (rvName, rel) = [TextAtom rvName, attributesToRel (attributesVec (attributes rel))]
1249+ attrAtoms a = [TextAtom (A.attributeName a), TextAtom (prettyAtomType (A.atomType a))]
1250+ attributesToRel attrl = case mkRelationFromList subrelAttrs (map attrAtoms (V.toList attrl)) of
1251+ Left err -> error ("relationVariablesAsRelation pooped " ++ show err)
1252+ Right rel -> RelationAtom rel
1253+ rvs <- mapM mkRvDesc (M.toList relVars)
1254+ let tups = map relVarToAtomList rvs
1255+ mkRelationFromList attrs tups
1256+
1257+-- | An unoptimized variant of evalGraphRefRelationalExpr for testing.
1258+evalRelationalExpr :: RelationalExpr -> RelationalExprM Relation
1259+evalRelationalExpr expr = do
1260+ graph <- reGraph
1261+ context <- reContext
1262+ let expr' = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
1263+ gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
1264+ case runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr expr') of
1265+ Left err -> throwError err
1266+ Right rel -> pure rel
1267+
1268+class (MonadError RelationalError m, Monad m) => DatabaseContextM m where
1269+ getContext :: m DatabaseContext
1270+
1271+instance DatabaseContextM (ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity)) where
1272+ getContext = gfDatabaseContextForMarker UncommittedContextMarker
1273+
1274+instance DatabaseContextM (RWST DatabaseContextEvalEnv () DatabaseContextEvalState (ExceptT RelationalError Identity)) where
1275+ getContext = getStateContext
1276+
1277+relVarByName :: DatabaseContextM m => RelVarName -> m GraphRefRelationalExpr
1278+relVarByName rvName = do
1279+ relvars <- relationVariables <$> getContext
1280+ case M.lookup rvName relvars of
1281+ Nothing -> throwError (RelVarNotDefinedError rvName)
1282+ Just gfexpr -> pure gfexpr
1283+
1284+-- | resolve UncommittedTransactionMarker whenever possible- this is important in the DatabaseContext in order to mitigate self-referencing loops for updates
1285+class ResolveGraphRefTransactionMarker a where
1286+ resolve :: a -> DatabaseContextEvalMonad a
1287+
1288+-- s := s union t
1289+instance ResolveGraphRefTransactionMarker GraphRefRelationalExpr where
1290+ resolve (MakeRelationFromExprs mAttrs tupleExprs) =
1291+ MakeRelationFromExprs mAttrs <$> resolve tupleExprs
1292+ resolve orig@MakeStaticRelation{} = pure orig
1293+ resolve orig@ExistingRelation{} = pure orig
1294+ resolve orig@(RelationVariable rvName UncommittedContextMarker) = do
1295+ rvMap <- relationVariables <$> getStateContext
1296+ case M.lookup rvName rvMap of
1297+ Nothing -> pure orig
1298+ Just resolvedRv -> resolve resolvedRv
1299+ resolve orig@RelationVariable{} = pure orig
1300+ resolve (Project attrNames relExpr) = Project <$> resolve attrNames <*> resolve relExpr
1301+ resolve (Union exprA exprB) = Union <$> resolve exprA <*> resolve exprB
1302+ resolve (Join exprA exprB) = Join <$> resolve exprA <*> resolve exprB
1303+ resolve (Rename attrA attrB expr) = Rename attrA attrB <$> resolve expr
1304+ resolve (Difference exprA exprB) = Difference <$> resolve exprA <*> resolve exprB
1305+ resolve (Group namesA nameB expr) = Group <$> resolve namesA <*> pure nameB <*> resolve expr
1306+ resolve (Ungroup nameA expr) = Ungroup nameA <$> resolve expr
1307+ resolve (Restrict restrictExpr relExpr) = Restrict <$> resolve restrictExpr <*> resolve relExpr
1308+ resolve (Equals exprA exprB) = Equals <$> resolve exprA <*> resolve exprB
1309+ resolve (NotEquals exprA exprB) = NotEquals <$> resolve exprA <*> resolve exprB
1310+ resolve (Extend extendExpr relExpr) = Extend <$> resolve extendExpr <*> resolve relExpr
1311+ resolve (With withExprs relExpr) = With <$> mapM (\(nam, expr) -> (,) <$> resolve nam <*> resolve expr) withExprs <*> resolve relExpr
1312+
1313+instance ResolveGraphRefTransactionMarker GraphRefTupleExprs where
1314+ resolve (TupleExprs marker tupleExprs) =
1315+ TupleExprs marker <$> mapM resolve tupleExprs
1316+
1317+instance ResolveGraphRefTransactionMarker GraphRefTupleExpr where
1318+ resolve (TupleExpr tupMap) = do
1319+ tupMap' <- mapM (\(attrName, expr) -> (,) attrName <$> resolve expr ) (M.toList tupMap)
1320+ pure (TupleExpr (M.fromList tupMap'))
1321+
1322+instance ResolveGraphRefTransactionMarker GraphRefAttributeNames where
1323+ resolve orig@AttributeNames{} = pure orig
1324+ resolve orig@InvertedAttributeNames{} = pure orig
1325+ resolve (UnionAttributeNames namesA namesB) = UnionAttributeNames <$> resolve namesA <*> resolve namesB
1326+ resolve (IntersectAttributeNames namesA namesB) = IntersectAttributeNames <$> resolve namesA <*> resolve namesB
1327+ resolve (RelationalExprAttributeNames expr) = RelationalExprAttributeNames <$> resolve expr
1328+
1329+instance ResolveGraphRefTransactionMarker GraphRefRestrictionPredicateExpr where
1330+ resolve TruePredicate = pure TruePredicate
1331+ resolve (AndPredicate exprA exprB) = AndPredicate <$> resolve exprA <*> resolve exprB
1332+ resolve (OrPredicate exprA exprB) = OrPredicate <$> resolve exprA <*> resolve exprB
1333+ resolve (NotPredicate expr) = NotPredicate <$> resolve expr
1334+ resolve (RelationalExprPredicate expr) = RelationalExprPredicate <$> resolve expr
1335+ resolve (AtomExprPredicate expr) = AtomExprPredicate <$> resolve expr
1336+ resolve (AttributeEqualityPredicate nam expr)= AttributeEqualityPredicate nam <$> resolve expr
1337+
1338+instance ResolveGraphRefTransactionMarker GraphRefExtendTupleExpr where
1339+ resolve (AttributeExtendTupleExpr nam atomExpr) = AttributeExtendTupleExpr nam <$> resolve atomExpr
1340+
1341+instance ResolveGraphRefTransactionMarker GraphRefWithNameExpr where
1342+ resolve orig@WithNameExpr{} = pure orig -- match uncommitted marker?
1343+
1344+instance ResolveGraphRefTransactionMarker GraphRefAtomExpr where
1345+ resolve orig@AttributeAtomExpr{} = pure orig
1346+ resolve orig@NakedAtomExpr{} = pure orig
1347+ resolve (FunctionAtomExpr nam atomExprs marker) =
1348+ FunctionAtomExpr nam <$> mapM resolve atomExprs <*> pure marker
1349+ resolve (RelationAtomExpr expr) = RelationAtomExpr <$> resolve expr
1350+ resolve (ConstructedAtomExpr dConsName atomExprs marker) =
1351+ ConstructedAtomExpr dConsName <$> mapM resolve atomExprs <*> pure marker
1352+
1353+--convert series of simple Union queries into MakeStaticRelation
1354+-- this is especially useful for long, nested applications of Union with simple tuples
1355+-- Union (MakeRelation x y) (MakeRelation x y') -> MakeRelation x (y + y')
1356+
1357+--MakeRelationFromExprs Nothing (TupleExprs UncommittedContextMarker [TupleExpr (fromList [("name", NakedAtomExpr (TextAtom "steve"))])])
1358+
1359+applyUnionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1360+applyUnionCollapse = Fold.cata opt
1361+ where
1362+ opt :: RelationalExprBaseF GraphRefTransactionMarker GraphRefRelationalExpr -> GraphRefRelationalExpr
1363+ opt (UnionF exprA exprB) | exprA == exprB = exprA
1364+ opt (UnionF
1365+ exprA@(MakeRelationFromExprs mAttrs1 tupExprs1)
1366+ exprB@(MakeRelationFromExprs mAttrs2 tupExprs2)) | tupExprs1 == tupExprs2 = MakeRelationFromExprs (mAttrs1 <|> mAttrs2) tupExprs1
1367+ | tupExprsNull tupExprs1 = exprB
1368+ | tupExprsNull tupExprs2 = exprA
1369+ opt x = Fold.embed x
1370+ tupExprsNull (TupleExprs _ []) = True
1371+ tupExprsNull _ = False
1372+
1373+
1374+--UPDATE optimization- find matching where clause in "lower" levels of renaming
1375+--update x where y=1 set (x:=5,z:=10); update x where y=1 set(x:=6,z:=11)
1376+-- =>
1377+-- update x where y=1 set (x:=6,z:=11)
1378+-- future opt: match individual attributes update x where y=1 set (x:=5); update x where y=1 set (z:=11) => update x where y=1 set (x:=5,z:=11)
1379+
1380+--strategy: try to collapse the top-level update (union (restrict pred MakeRelationFromExpr) expr) if it contains the same predicate and resultant relation
1381+
1382+--DELETE optimization
1383+-- if a restriction matches a previous restriction, combine them
1384+-- O(1) since it only scans at the top level, critical in benchmarks generating redundant deletions
1385+applyRestrictionCollapse :: GraphRefRelationalExpr -> GraphRefRelationalExpr
1386+applyRestrictionCollapse orig@(Restrict npred@(NotPredicate _) expr) =
1387+ case expr of
1388+ orig'@(Restrict npred'@(NotPredicate _) _) | npred == npred' -> orig'
1389+ _ -> orig
1390+applyRestrictionCollapse expr = expr
1391+
1392+