@@ -1,53 +1,33 @@
11{-# LANGUAGE ScopedTypeVariables #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FlexibleContexts #-}
4−{-# LANGUAGE OverloadedStrings #-}
52module ProjectM36.RelationalExpression where
63import ProjectM36.Relation
74import ProjectM36.Tuple
85import ProjectM36.TupleSet
96import ProjectM36.Base
10−import qualified Data.UUID as U
117import ProjectM36.Error
128import ProjectM36.AtomType
13−import ProjectM36.Attribute (emptyAttributes, attributesFromList)
9+import ProjectM36.Attribute (emptyAttributes)
1410import ProjectM36.ScriptSession
1511import ProjectM36.DataTypes.Primitive
1612import ProjectM36.AtomFunction
1713import ProjectM36.DatabaseContextFunction
18−import ProjectM36.Arbitrary
19−import ProjectM36.GraphRefRelationalExpr
20−import ProjectM36.Transaction
2114import qualified ProjectM36.Attribute as A
2215import qualified Data.Map as M
2316import qualified Data.HashSet as HS
2417import qualified Data.Set as S
2518import Control.Monad.State hiding (join)
26−import Data.Bifunctor (second)
19+import Control.Exception
2720import Data.Maybe
2821import Data.Either
2922import Data.Char (isUpper)
30−import Data.Time
31−import qualified Data.List.NonEmpty as NE
32−import Data.Functor.Identity
3323import qualified Data.Text as T
3424import qualified Data.Vector as V
3525import qualified ProjectM36.TypeConstructorDef as TCD
36−import qualified Control.Monad.RWS.Strict as RWS
37−import Control.Monad.RWS.Strict (RWST, execRWST, runRWST)
38−import Control.Monad.Except hiding (join)
39−import Control.Monad.Trans.Except (except)
40−import Control.Monad.Reader as R hiding (join)
41−import ProjectM36.NormalizeExpr
42−import ProjectM36.WithNameExpr
43−import Test.QuickCheck
44−import qualified Data.Functor.Foldable as Fold
45−import Control.Applicative
46−#ifdef PM36_HASKELL_SCRIPTING
47−import GHC hiding (getContext)
48−import Control.Exception
26+import Control.Monad.Trans.Except
27+import Control.Monad.Trans.Reader
28+
29+import GHC
4930import GHC.Paths
50−#endif
5131
5232data DatabaseContextExprDetails = CountUpdatedTuples
5333
@@ -64,63 +44,32 @@ databaseContextExprDetailsFunc CountUpdatedTuples _ relIn = Relation attrs newTu
6444 Right ts -> ts
6545
6646-- | Used to start a fresh database state for a new database context expression.
67−mkDatabaseContextEvalState :: DatabaseContext -> DatabaseContextEvalState
68−mkDatabaseContextEvalState context = DatabaseContextEvalState {
69− dbc_context = context,
70− dbc_accum = M.empty,
71− dbc_dirty = False
72− } --future work: propagate return accumulator
47+freshDatabaseState :: DatabaseContext -> DatabaseStateElems
48+freshDatabaseState ctx = (ctx, M.empty, False) --future work: propagate return accumulator
7349
7450-- we need to pass around a higher level RelationTuple and Attributes in order to solve #52
75−data RelationalExprEnv = RelationalExprEnv {
76− re_context :: DatabaseContext,
77− re_graph :: TransactionGraph,
78− re_extra :: Maybe (Either RelationTuple Attributes)
79− }
80−
81−envTuple :: GraphRefRelationalExprEnv -> RelationTuple
82−envTuple e = fromLeft emptyTuple (fromMaybe (Left emptyTuple) (gre_extra e))
83−
84−envAttributes :: GraphRefRelationalExprEnv -> Attributes
85−envAttributes e = fromRight emptyAttributes (fromMaybe (Right emptyAttributes) (gre_extra e))
51+data RelationalExprStateElems = RelationalExprStateTupleElems DatabaseContext RelationTuple | -- used when fully evaluating a relexpr
52+ RelationalExprStateAttrsElems DatabaseContext Attributes | --used when evaluating the type of a relexpr
53+ RelationalExprStateElems DatabaseContext --used by default at the top level of evaluation
54+
55+instance Show RelationalExprStateElems where
56+ show (RelationalExprStateTupleElems _ tup) = "RelationalExprStateTupleElems " ++ show tup
57+ show (RelationalExprStateAttrsElems _ attrs) = "RelationalExprStateAttrsElems" ++ show attrs
58+ show (RelationalExprStateElems _) = "RelationalExprStateElems"
59+
60+mkRelationalExprState :: DatabaseContext -> RelationalExprStateElems
61+mkRelationalExprState = RelationalExprStateElems
62+
63+mergeTuplesIntoRelationalExprState :: RelationTuple -> RelationalExprStateElems -> RelationalExprStateElems
64+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateElems ctx) = RelationalExprStateTupleElems ctx tupIn
65+mergeTuplesIntoRelationalExprState _ st@(RelationalExprStateAttrsElems _ _) = st
66+mergeTuplesIntoRelationalExprState tupIn (RelationalExprStateTupleElems ctx existingTuple) = let mergedTupMap = M.union (tupleToMap tupIn) (tupleToMap existingTuple) in
67+ RelationalExprStateTupleElems ctx (mkRelationTupleFromMap mergedTupMap)
8668
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)))
69+mergeAttributesIntoRelationalExprState :: Attributes -> RelationalExprStateElems -> RelationalExprStateElems
70+mergeAttributesIntoRelationalExprState attrs (RelationalExprStateElems ctx) = RelationalExprStateAttrsElems ctx attrs
71+mergeAttributesIntoRelationalExprState _ st@(RelationalExprStateTupleElems _ _) = st
72+mergeAttributesIntoRelationalExprState attrsIn (RelationalExprStateAttrsElems ctx attrs) = RelationalExprStateAttrsElems ctx (A.union attrsIn attrs)
12473
12574type ResultAccumName = StringType
12675
@@ -130,403 +79,423 @@ data ResultAccum = ResultAccum { resultAccumFunc :: ResultAccumFunc,
13079 resultAccumResult :: Relation
13180 }
13281
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− }
82+type DatabaseStateElems = (DatabaseContext, M.Map ResultAccumName ResultAccum, DirtyFlag)
13883
139−data DatabaseContextEvalEnv = DatabaseContextEvalEnv
140− { dce_transId :: TransactionId,
141− dce_graph :: TransactionGraph
142− }
84+type DatabaseState a = State DatabaseStateElems a
14385
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
86+getStateContext :: DatabaseState DatabaseContext
87+getStateContext = do
88+ (ctx,_, _) <- get
89+ pure ctx
90+
91+putStateContext :: DatabaseContext -> DatabaseState ()
92+putStateContext ctx = do
93+ (_, accum, _) <- get
94+ put (ctx, accum, True)
95+
96+type RelationalExprState a = Reader RelationalExprStateElems a
97+
98+stateElemsContext :: RelationalExprStateElems -> DatabaseContext
99+stateElemsContext (RelationalExprStateTupleElems ctx _) = ctx
100+stateElemsContext (RelationalExprStateElems ctx) = ctx
101+stateElemsContext (RelationalExprStateAttrsElems ctx _) = ctx
102+
103+setStateElemsContext :: RelationalExprStateElems -> DatabaseContext -> RelationalExprStateElems
104+setStateElemsContext (RelationalExprStateTupleElems _ tup) ctx = RelationalExprStateTupleElems ctx tup
105+setStateElemsContext (RelationalExprStateElems _) ctx = RelationalExprStateElems ctx
106+setStateElemsContext (RelationalExprStateAttrsElems _ attrs) ctx = RelationalExprStateAttrsElems ctx attrs
107+
108+--relvar state is needed in evaluation of relational expression but only as read-only in order to extract current relvar values
109+evalRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
110+evalRelationalExpr (RelationVariable name _) = do
111+ relvarTable <- fmap (relationVariables . stateElemsContext) ask
112+ return $ case M.lookup name relvarTable of
113+ Just res -> Right res
114+ Nothing -> Left $ RelVarNotDefinedError name
115+
116+evalRelationalExpr (Project attrNames expr) = do
117+ eAttrNameSet <- evalAttributeNames attrNames expr
118+ case eAttrNameSet of
119+ Left err -> pure (Left err)
120+ Right attrNameSet -> do
121+ rel <- evalRelationalExpr expr
122+ case rel of
123+ Right rel2 -> pure $ project attrNameSet rel2
124+ Left err -> pure $ Left err
125+
126+evalRelationalExpr (Union exprA exprB) = do
127+ relA <- evalRelationalExpr exprA
128+ relB <- evalRelationalExpr exprB
129+ case relA of
130+ Left err -> return $ Left err
131+ Right relA2 -> case relB of
132+ Left err -> return $ Left err
133+ Right relB2 -> return $ union relA2 relB2
134+
135+evalRelationalExpr (Join exprA exprB) = do
136+ relA <- evalRelationalExpr exprA
137+ relB <- evalRelationalExpr exprB
138+ case relA of
139+ Left err -> return $ Left err
140+ Right relA2 -> case relB of
141+ Left err -> return $ Left err
142+ Right relB2 -> return $ join relA2 relB2
143+
144+evalRelationalExpr (Difference exprA exprB) = do
145+ relA <- evalRelationalExpr exprA
146+ relB <- evalRelationalExpr exprB
147+ case relA of
148+ Left err -> return $ Left err
149+ Right relA2 -> case relB of
150+ Left err -> return $ Left err
151+ Right relB2 -> return $ difference relA2 relB2
152+
153+evalRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
154+ case mkRelation attributeSet tupleSet of
155+ Right rel -> return $ Right rel
156+ Left err -> return $ Left err
153157
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− }
158+evalRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
159+ currentContext <- fmap stateElemsContext ask
160+ let tConss = typeConstructorMapping currentContext
161+ -- if the mAttrExprs is Nothing, then we should attempt to infer the tuple attributes from the first tuple itself- note that this is not always possible
162+ runExceptT $ do
163+ mAttrs <- case mAttrExprs of
164+ Just _ -> do
165+ attrs <- mapM (either throwE pure . evalAttrExpr tConss) (fromMaybe [] mAttrExprs)
166+ pure (Just (A.attributesFromList attrs))
167+ Nothing -> pure Nothing
168+ tuples <- mapM (liftE . evalTupleExpr mAttrs) tupleExprs
169+ let attrs = fromMaybe firstTupleAttrs mAttrs
170+ firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
171+ either throwE pure (mkRelation attrs (RelationTupleSet tuples))
180172
181−type GraphRefRelationalExprM a = ReaderT GraphRefRelationalExprEnv (ExceptT RelationalError Identity) a
182−
183−gfTransForId :: TransactionId -> GraphRefRelationalExprM Transaction
184−gfTransForId tid = do
185− graph <- gfGraph
186− lift $ except $ transactionForId tid graph
187−
188−gfDatabaseContextForMarker :: GraphRefTransactionMarker -> GraphRefRelationalExprM DatabaseContext
189−gfDatabaseContextForMarker (TransactionMarker transId) = concreteDatabaseContext <$> gfTransForId transId
190−gfDatabaseContextForMarker UncommittedContextMarker = do
191− mctx <- gre_context <$> askEnv
192− case mctx of
193− Nothing -> throwError NoUncommittedContextInEvalError
194− Just ctx -> pure ctx
195−
196−runGraphRefRelationalExprM :: GraphRefRelationalExprEnv -> GraphRefRelationalExprM a -> Either RelationalError a
197−runGraphRefRelationalExprM env m = runIdentity (runExceptT (runReaderT m env))
198−
199−freshGraphRefRelationalExprEnv :: Maybe DatabaseContext -> TransactionGraph -> GraphRefRelationalExprEnv
200−freshGraphRefRelationalExprEnv mctx graph = GraphRefRelationalExprEnv {
201− gre_context = mctx,
202− gre_graph = graph,
203− gre_extra = Nothing
204− }
173+evalRelationalExpr (ExistingRelation rel) = pure (Right rel)
205174
206−gfGraph :: GraphRefRelationalExprM TransactionGraph
207−gfGraph = asks gre_graph
175+evalRelationalExpr (Rename oldAttrName newAttrName relExpr) = do
176+ evald <- evalRelationalExpr relExpr
177+ case evald of
178+ Right rel -> return $ rename oldAttrName newAttrName rel
179+ Left err -> return $ Left err
208180
209−envContext :: RelationalExprEnv -> DatabaseContext
210−envContext = re_context
211−
212−setEnvContext :: RelationalExprEnv -> DatabaseContext -> RelationalExprEnv
213−setEnvContext e ctx = e { re_context = ctx }
181+evalRelationalExpr (Group oldAttrNames newAttrName relExpr) = do
182+ eOldAttrNameSet <- evalAttributeNames oldAttrNames relExpr
183+ case eOldAttrNameSet of
184+ Left err -> pure (Left err)
185+ Right oldAttrNameSet -> do
186+ evald <- evalRelationalExpr relExpr
187+ case evald of
188+ Right rel -> return $ group oldAttrNameSet newAttrName rel
189+ Left err -> return $ Left err
190+
191+evalRelationalExpr (Ungroup attrName relExpr) = do
192+ evald <- evalRelationalExpr relExpr
193+ case evald of
194+ Right rel -> return $ ungroup attrName rel
195+ Left err -> return $ Left err
196+
197+evalRelationalExpr (Restrict predicateExpr relExpr) = do
198+ evald <- evalRelationalExpr relExpr
199+ case evald of
200+ Left err -> return $ Left err
201+ Right rel -> do
202+ eFilterFunc <- predicateRestrictionFilter (attributes rel) predicateExpr
203+ case eFilterFunc of
204+ Left err -> return $ Left err
205+ Right filterfunc ->
206+ pure (restrict filterfunc rel)
207+
208+evalRelationalExpr (Equals relExprA relExprB) = do
209+ evaldA <- evalRelationalExpr relExprA
210+ evaldB <- evalRelationalExpr relExprB
211+ case evaldA of
212+ Left err -> return $ Left err
213+ Right relA -> case evaldB of
214+ Left err -> return $ Left err
215+ Right relB -> return $ Right $ if relA == relB then relationTrue else relationFalse
216+
217+--warning: copy-pasta from above- refactor
218+evalRelationalExpr (NotEquals relExprA relExprB) = do
219+ evaldA <- evalRelationalExpr relExprA
220+ evaldB <- evalRelationalExpr relExprB
221+ case evaldA of
222+ Left err -> return $ Left err
223+ Right relA -> case evaldB of
224+ Left err -> return $ Left err
225+ Right relB -> return $ Right $ if relA /= relB then relationTrue else relationFalse
226+
227+-- extending a relation adds a single attribute with the results of the per-tuple expression evaluated
228+evalRelationalExpr (Extend tupleExpression relExpr) = do
229+ rstate <- ask
230+ let evald = runReader (evalRelationalExpr relExpr) rstate
231+ case evald of
232+ Left err -> pure (Left err)
233+ Right rel -> do
234+ tupProc <- extendTupleExpressionProcessor rel tupleExpression
235+ case tupProc of
236+ Left err -> pure (Left err)
237+ Right (newAttrs, tupProc') -> pure $ relMogrify tupProc' newAttrs rel
214238
215239--helper function to process relation variable creation/assignment
216−setRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
217−setRelVar relVarName relExpr = do
240+setRelVar :: RelVarName -> Relation -> DatabaseState (Either RelationalError ())
241+setRelVar relVarName rel = do
218242 currentContext <- getStateContext
219− --prevent recursive relvar definition by resolving references to relvars in previous states
220− relExpr' <- resolve relExpr
221− let newRelVars = M.insert relVarName relExpr' $ relationVariables currentContext
243+ let newRelVars = M.insert relVarName rel $ relationVariables currentContext
222244 potentialContext = currentContext { relationVariables = newRelVars }
223− --optimization: if the relexpr is unchanged, skip the update
224− if M.lookup relVarName (relationVariables currentContext) == Just relExpr then
225− pure ()
226− else do
227− --determine when to check constraints
228− graph <- dbcGraph
229− tid <- dbcTransId
230− case checkConstraints potentialContext tid graph of
231− Left err -> dbErr err
232− Right _ -> putStateContext potentialContext
233−
234−--fast-path insertion- we already know that the previous relvar validated correctly, so we can validate just the relation that is being inserted for attribute matches- without this, even a single tuple relation inserted causes the entire relation to be re-validated unnecessarily
235−--insertIntoRelVar :: RelVarName -> GraphRefRelationalExpr -> DatabaseContextEvalMonad ()
245+
246+ case checkConstraints potentialContext of
247+ Just err -> pure (Left err)
248+ Nothing -> do
249+ putStateContext potentialContext
250+ return (Right ())
236251
237252-- it is not an error to delete a relvar which does not exist, just like it is not an error to insert a pre-existing tuple into a relation
238−deleteRelVar :: RelVarName -> DatabaseContextEvalMonad ()
253+deleteRelVar :: RelVarName -> DatabaseState (Either RelationalError ())
239254deleteRelVar relVarName = do
240255 currContext <- getStateContext
241256 let relVars = relationVariables currContext
242257 if M.notMember relVarName relVars then
243− pure ()
258+ pure (Right ())
244259 else do
245260 let newRelVars = M.delete relVarName relVars
246261 newContext = currContext { relationVariables = newRelVars }
247262 putStateContext newContext
248− pure ()
263+ pure (Right ())
249264
250−evalGraphRefDatabaseContextExpr :: GraphRefDatabaseContextExpr -> DatabaseContextEvalMonad ()
251−evalGraphRefDatabaseContextExpr NoOperation = pure ()
265+evalDatabaseContextExpr :: DatabaseContextExpr -> DatabaseState (Either RelationalError ())
266+evalDatabaseContextExpr NoOperation = pure (Right ())
252267
253−evalGraphRefDatabaseContextExpr (Define relVarName attrExprs) = do
254− context <- getStateContext
268+evalDatabaseContextExpr (Define relVarName attrExprs) = do
255269 relvars <- fmap relationVariables getStateContext
256270 tConss <- fmap typeConstructorMapping getStateContext
257− graph <- dbcGraph
258− let eAttrs = runGraphRefRelationalExprM gfEnv (mapM evalGraphRefAttrExpr attrExprs)
259− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
260− case eAttrs of
261− Left err -> dbErr err
262− Right attrsList -> do
263− lift $ except $ validateAttributes tConss (A.attributesFromList attrsList)
264− case M.member relVarName relvars of
265− True -> dbErr (RelVarAlreadyDefinedError relVarName)
266− False -> setRelVar relVarName (ExistingRelation emptyRelation)
267− where
268− attrs = A.attributesFromList attrsList
269− emptyRelation = Relation attrs emptyTupleSet
270−
271−evalGraphRefDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
272−
273−evalGraphRefDatabaseContextExpr (Assign relVarName expr) = do
274− graph <- re_graph <$> dbcRelationalExprEnv
271+ let eAttrs = map (evalAttrExpr tConss) attrExprs
272+ case lefts eAttrs of
273+ err:_ -> pure (Left err)
274+ [] -> case M.member relVarName relvars of
275+ True -> pure (Left (RelVarAlreadyDefinedError relVarName))
276+ False -> setRelVar relVarName emptyRelation >> pure (Right ())
277+ where
278+ attrs = A.attributesFromList (rights eAttrs)
279+ emptyRelation = Relation attrs emptyTupleSet
280+
281+evalDatabaseContextExpr (Undefine relVarName) = deleteRelVar relVarName
282+
283+evalDatabaseContextExpr (Assign relVarName expr) = do
284+ -- in the future, it would be nice to get types from the RelationalExpr instead of needing to evaluate it
275285 context <- getStateContext
276− let existingRelVar = M.lookup relVarName (relationVariables context)
277− reEnv = freshGraphRefRelationalExprEnv (Just context) graph
278− eNewExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr)
279− case existingRelVar of
280− Nothing -> do
281− case runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr expr) of
282− Left err -> dbErr err
283− Right reltype -> do
284− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes reltype)
285− setRelVar relVarName expr
286− Just existingRel -> do
287− let eExpectedType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr existingRel)
288− case eExpectedType of
289− Left err -> dbErr err
290− Right expectedType ->
291− case eNewExprType of
292− Left err -> dbErr err
293− Right newExprType -> do
294− if newExprType == expectedType then do
295− lift $ except $ validateAttributes (typeConstructorMapping context) (attributes newExprType)
296− setRelVar relVarName expr
297− else
298− dbErr (RelationTypeMismatchError (attributes expectedType) (attributes newExprType))
299−
300−evalGraphRefDatabaseContextExpr (Insert relVarName relExpr) = do
301− gfExpr <- relVarByName relVarName
302− let optExpr = applyUnionCollapse (Union
303− relExpr
304− gfExpr)
305− evalGraphRefDatabaseContextExpr (Assign relVarName optExpr)
286+ let existingRelVar = M.lookup relVarName relVarTable
287+ relVarTable = relationVariables context
288+ value = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
289+ case value of
290+ Left err -> pure (Left err)
291+ Right rel -> case existingRelVar of
292+ Nothing -> setRelVar relVarName rel
293+ Just existingRel -> let expectedAttributes = attributes existingRel
294+ foundAttributes = attributes rel in
295+ if A.attributesEqual expectedAttributes foundAttributes then
296+ setRelVar relVarName rel
297+ else
298+ pure (Left (RelVarAssignmentTypeMismatchError expectedAttributes foundAttributes))
299+
300+evalDatabaseContextExpr (Insert relVarName relExpr) = do
301+ context <- getStateContext
302+ let unionexp = Union relExpr rv
303+ rv = RelationVariable relVarName ()
304+ unioned = runReader (evalRelationalExpr unionexp) (RelationalExprStateElems context)
305+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
306+ case unioned of
307+ Left err -> pure (Left err)
308+ Right unioned' -> case origRel of
309+ Left err -> pure (Left err)
310+ Right origRel' -> if cardinality unioned' == cardinality origRel' then --no tuples actually inserted
311+ pure (Right ())
312+ else
313+ evalDatabaseContextExpr $ Assign relVarName (ExistingRelation unioned')
314+
315+evalDatabaseContextExpr (Delete relVarName predicate) = do
316+ context <- getStateContext
317+ let rv = RelationVariable relVarName ()
318+ let updatedRel = runReader (evalRelationalExpr (Restrict (NotPredicate predicate) rv)) (RelationalExprStateElems context)
319+ origRel = runReader (evalRelationalExpr rv) (RelationalExprStateElems context)
320+ case updatedRel of
321+ Left err -> pure (Left err)
322+ Right updatedRel' -> case origRel of
323+ Left err -> pure (Left err)
324+ Right origRel' -> if cardinality origRel' == cardinality updatedRel' then
325+ pure (Right ())
326+ else
327+ setRelVar relVarName updatedRel'
306328
307−evalGraphRefDatabaseContextExpr (Delete relVarName predicate) = do
308− gfExpr <- relVarByName relVarName
309− let optExpr = applyRestrictionCollapse (Restrict (NotPredicate predicate) gfExpr)
310− setRelVar relVarName optExpr
311−
312329--union of restricted+updated portion and the unrestricted+unupdated portion
313−evalGraphRefDatabaseContextExpr (Update relVarName atomExprMap pred') = do
314− rvExpr <- relVarByName relVarName
315− graph <- re_graph <$> dbcRelationalExprEnv
330+evalDatabaseContextExpr (Update relVarName atomExprMap restrictionPredicateExpr) = do
316331 context <- getStateContext
317− let reEnv = freshGraphRefRelationalExprEnv (Just context) graph
318− --get the current attributes name in the relvar to ensure that we don't conflict when renaming
319− eExprType = runGraphRefRelationalExprM reEnv (typeForGraphRefRelationalExpr rvExpr)
320− exprType' <- case eExprType of
321− Left err -> throwError err
322− Right t -> pure t
323− let unrestrictedPortion = Restrict (NotPredicate pred') rvExpr
324− tmpAttr = tmpAttrC 1
325− tmpAttrC :: Int -> AttributeName -> AttributeName
326− tmpAttrC c attr =
327− let tmpAttrName = "_tmp_" <> T.pack (show c) <> attr in
328− if tmpAttrName `S.member` A.attributeNameSet (attributes exprType') then
329− tmpAttrC (c+1) attr
330− else
331− tmpAttrName
332− updateAttr nam atomExpr = Extend (AttributeExtendTupleExpr (tmpAttr nam) atomExpr)
333− projectAndRename attr expr = Rename (tmpAttr attr) attr (Project (InvertedAttributeNames (S.singleton attr)) expr)
334− restrictedPortion = Restrict pred' rvExpr
335− updated = foldr (\(oldname, atomExpr) accum ->
336− let procAtomExpr = runProcessExprM UncommittedContextMarker (processAtomExpr atomExpr) in
337− updateAttr oldname procAtomExpr accum
338− ) restrictedPortion (M.toList atomExprMap)
339− -- the atomExprMap could reference other attributes, so we must perform multi-pass folds
340− updatedPortion = foldr projectAndRename updated (M.keys atomExprMap)
341− setRelVar relVarName (Union unrestrictedPortion updatedPortion)
332+ let relVarTable = relationVariables context
333+ case M.lookup relVarName relVarTable of
334+ Nothing -> pure (Left (RelVarNotDefinedError relVarName))
335+ Just rel ->
336+ case runReader (predicateRestrictionFilter (attributes rel) restrictionPredicateExpr) (RelationalExprStateElems context) of
337+ Left err -> pure (Left err)
338+ Right predicateFunc -> do
339+ let ret = do
340+ restrictedPortion <- restrict predicateFunc rel
341+ if cardinality restrictedPortion == Finite 0 then
342+ pure Nothing
343+ else do
344+ unrestrictedPortion <- restrict (predicateFunc >=> (pure . not)) rel
345+ updatedPortion <- relMap (updateTupleWithAtomExprs atomExprMap context) restrictedPortion
346+ updatedRel <- updatedPortion `union` unrestrictedPortion
347+ pure (Just updatedRel)
348+ case ret of
349+ Left err -> pure (Left err)
350+ Right Nothing -> pure (Right ())
351+ Right (Just updatedRel) -> setRelVar relVarName updatedRel
342352
343−evalGraphRefDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
353+evalDatabaseContextExpr (AddInclusionDependency newDepName newDep) = do
344354 currContext <- getStateContext
345− transId <- dbcTransId
346− graph <- dbcGraph
347355 let currDeps = inclusionDependencies currContext
348356 newDeps = M.insert newDepName newDep currDeps
349357 if M.member newDepName currDeps then
350− dbErr (InclusionDependencyNameInUseError newDepName)
358+ pure (Left (InclusionDependencyNameInUseError newDepName))
351359 else do
352360 let potentialContext = currContext { inclusionDependencies = newDeps }
353− -- if the potential context passes all constraints, then save it
354− -- potential optimization: validate only the new constraint- all old constraints must already hold
355− case checkConstraints potentialContext transId graph of
356− Left err -> dbErr err
357− Right _ ->
361+ case checkConstraints potentialContext of
362+ Just err -> pure (Left err)
363+ Nothing -> do
358364 putStateContext potentialContext
365+ return (Right ())
359366
360−evalGraphRefDatabaseContextExpr (RemoveInclusionDependency depName) = do
367+evalDatabaseContextExpr (RemoveInclusionDependency depName) = do
361368 currContext <- getStateContext
362369 let currDeps = inclusionDependencies currContext
363370 newDeps = M.delete depName currDeps
364371 if M.notMember depName currDeps then
365− dbErr (InclusionDependencyNameNotInUseError depName)
366− else
372+ pure (Left (InclusionDependencyNameNotInUseError depName))
373+ else do
367374 putStateContext $ currContext {inclusionDependencies = newDeps }
375+ return (Right ())
368376
369377-- | Add a notification which will send the resultExpr when triggerExpr changes between commits.
370−evalGraphRefDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
378+evalDatabaseContextExpr (AddNotification notName triggerExpr resultOldExpr resultNewExpr) = do
371379 currentContext <- getStateContext
372380 let nots = notifications currentContext
373381 if M.member notName nots then
374− dbErr (NotificationNameInUseError notName)
382+ pure (Left (NotificationNameInUseError notName))
375383 else do
376384 let newNotifications = M.insert notName newNotification nots
377385 newNotification = Notification { changeExpr = triggerExpr,
378386 reportOldExpr = resultOldExpr,
379387 reportNewExpr = resultNewExpr}
380388 putStateContext $ currentContext { notifications = newNotifications }
389+ return (Right ())
381390
382−evalGraphRefDatabaseContextExpr (RemoveNotification notName) = do
391+evalDatabaseContextExpr (RemoveNotification notName) = do
383392 currentContext <- getStateContext
384393 let nots = notifications currentContext
385394 if M.notMember notName nots then
386− dbErr (NotificationNameNotInUseError notName)
395+ pure (Left (NotificationNameNotInUseError notName))
387396 else do
388397 let newNotifications = M.delete notName nots
389398 putStateContext $ currentContext { notifications = newNotifications }
390−
399+ pure (Right ())
391400
392401-- | Adds type and data constructors to the database context.
393402-- validate that the type *and* constructor names are unique! not yet implemented!
394−evalGraphRefDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
403+evalDatabaseContextExpr (AddTypeConstructor tConsDef dConsDefList) = do
395404 currentContext <- getStateContext
396405 let oldTypes = typeConstructorMapping currentContext
397406 tConsName = TCD.name tConsDef
398407 -- validate that the constructor's types exist
399− case validateTypeConstructorDef tConsDef dConsDefList oldTypes of
400− Left err -> throwError err
401− Right () | T.null tConsName || not (isUpper (T.head tConsName)) -> dbErr (InvalidAtomTypeName tConsName)
402− | isJust (findTypeConstructor tConsName oldTypes) -> dbErr (AtomTypeNameInUseError tConsName)
408+ case validateTypeConstructorDef tConsDef dConsDefList of
409+ errs@(_:_) -> pure (Left (someErrors errs))
410+ [] | T.null tConsName || not (isUpper (T.head tConsName)) -> pure (Left (InvalidAtomTypeName tConsName))
411+ | isJust (findTypeConstructor tConsName oldTypes) -> pure (Left (AtomTypeNameInUseError tConsName))
403412 | otherwise -> do
404413 let newTypes = oldTypes ++ [(tConsDef, dConsDefList)]
405414 putStateContext $ currentContext { typeConstructorMapping = newTypes }
415+ pure (Right ())
406416
407417-- | Removing the atom constructor prevents new atoms of the type from being created. Existing atoms of the type remain. Thus, the atomTypes list in the DatabaseContext need not be all-inclusive.
408−evalGraphRefDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
418+evalDatabaseContextExpr (RemoveTypeConstructor tConsName) = do
409419 currentContext <- getStateContext
410420 let oldTypes = typeConstructorMapping currentContext
411421 if isNothing (findTypeConstructor tConsName oldTypes) then
412− dbErr (AtomTypeNameNotInUseError tConsName)
422+ pure (Left (AtomTypeNameNotInUseError tConsName))
413423 else do
414424 let newTypes = filter (\(tCons, _) -> TCD.name tCons /= tConsName) oldTypes
415425 putStateContext $ currentContext { typeConstructorMapping = newTypes }
426+ pure (Right ())
416427
417−evalGraphRefDatabaseContextExpr (MultipleExpr exprs) =
428+evalDatabaseContextExpr (MultipleExpr exprs) = do
418429 --the multiple expressions must pass the same context around- not the old unmodified context
419− mapM_ evalGraphRefDatabaseContextExpr exprs
420−
421−evalGraphRefDatabaseContextExpr (RemoveAtomFunction funcName) = do
430+ evald <- forM exprs evalDatabaseContextExpr
431+ --some lifting magic needed here
432+ case lefts evald of
433+ [] -> pure (Right ())
434+ errs -> pure (Left (someErrors errs))
435+
436+evalDatabaseContextExpr (RemoveAtomFunction funcName) = do
422437 currentContext <- getStateContext
423438 let atomFuncs = atomFunctions currentContext
424439 case atomFunctionForName funcName atomFuncs of
425− Left err -> dbErr err
426− Right realFunc ->
427− if isScriptedAtomFunction realFunc then do
428− let updatedFuncs = HS.delete realFunc atomFuncs
429− putStateContext (currentContext {atomFunctions = updatedFuncs })
430− else
431− dbErr (PrecompiledFunctionRemoveError funcName)
440+ Left err -> pure (Left err)
441+ Right realFunc -> if isScriptedAtomFunction realFunc then do
442+ let updatedFuncs = HS.delete realFunc atomFuncs
443+ putStateContext (currentContext {atomFunctions = updatedFuncs })
444+ pure (Right ())
445+ else
446+ pure (Left (PrecompiledFunctionRemoveError funcName))
432447
433−evalGraphRefDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
448+evalDatabaseContextExpr (RemoveDatabaseContextFunction funcName) = do
434449 context <- getStateContext
435450 let dbcFuncs = dbcFunctions context
436451 case databaseContextFunctionForName funcName dbcFuncs of
437− Left err -> dbErr err
438− Right realFunc ->
439− if isScriptedDatabaseContextFunction realFunc then do
440− let updatedFuncs = HS.delete realFunc dbcFuncs
441− putStateContext (context { dbcFunctions = updatedFuncs })
442− else
443− dbErr (PrecompiledFunctionRemoveError funcName)
452+ Left err -> pure (Left err)
453+ Right realFunc -> if isScriptedDatabaseContextFunction realFunc then do
454+ let updatedFuncs = HS.delete realFunc dbcFuncs
455+ putStateContext (context { dbcFunctions = updatedFuncs })
456+ pure (Right ())
457+ else
458+ pure (Left (PrecompiledFunctionRemoveError funcName))
444459
445−evalGraphRefDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
460+evalDatabaseContextExpr (ExecuteDatabaseContextFunction funcName atomArgExprs) = do
446461 context <- getStateContext
447− graph <- dbcGraph
448462 --resolve atom arguments
449− let eAtomTypes = mapM (runGraphRefRelationalExprM gfEnv . typeForGraphRefAtomExpr emptyAttributes) atomArgExprs
463+ let relExprState = mkRelationalExprState context
464+ eAtomTypes = map (\atomExpr -> runReader (typeFromAtomExpr emptyAttributes atomExpr) relExprState) atomArgExprs
450465 eFunc = databaseContextFunctionForName funcName (dbcFunctions context)
451− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
452466 case eFunc of
453− Left err -> dbErr err
467+ Left err -> pure (Left err)
454468 Right func -> do
455469 let expectedArgCount = length (dbcFuncType func)
456470 actualArgCount = length atomArgExprs
457471 if expectedArgCount /= actualArgCount then
458− dbErr (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
472+ pure (Left (FunctionArgumentCountMismatchError expectedArgCount actualArgCount))
459473 else
460474 --check that the atom types are valid
461− case eAtomTypes of
462− Left err -> dbErr err
463− Right atomTypes -> do
464− let mValidTypes = zipWith (\ expType actType
465− -> case atomTypeVerify expType actType of
466− Left err -> Just err
467− Right _ -> Nothing)
468− (dbcFuncType func) atomTypes
469− typeErrors = catMaybes mValidTypes
470− eAtomArgs = map (runGraphRefRelationalExprM gfEnv . evalGraphRefAtomExpr emptyTuple) atomArgExprs
475+ case lefts eAtomTypes of
476+ _:_ -> pure (Left (someErrors (lefts eAtomTypes)))
477+ [] -> do
478+ let atomTypes = rights eAtomTypes
479+ let mValidTypes = map (\(expType, actType) -> case atomTypeVerify expType actType of
480+ Left err -> Just err
481+ Right _ -> Nothing) (zip (dbcFuncType func) atomTypes)
482+ typeErrors = catMaybes mValidTypes
483+ eAtomArgs = map (\arg -> runReader (evalAtomExpr emptyTuple arg) relExprState) atomArgExprs
471484 if length (lefts eAtomArgs) > 1 then
472− dbErr (someErrors (lefts eAtomArgs))
485+ pure (Left (someErrors (lefts eAtomArgs)))
473486 else if not (null typeErrors) then
474− dbErr (someErrors typeErrors)
487+ pure (Left (someErrors typeErrors))
475488 else
476489 case evalDatabaseContextFunction func (rights eAtomArgs) context of
477− Left err -> dbErr err
478− Right newContext -> putStateContext newContext
479−data DatabaseContextIOEvalEnv = DatabaseContextIOEvalEnv
480− { dbcio_transId :: TransactionId,
481− dbcio_graph :: TransactionGraph,
482− dbcio_mScriptSession :: Maybe ScriptSession
483− }
484−
485−type DatabaseContextIOEvalMonad a = RWST DatabaseContextIOEvalEnv () DatabaseContextEvalState IO a
486−
487−runDatabaseContextIOEvalMonad :: DatabaseContextIOEvalEnv -> DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ()) -> IO (Either RelationalError DatabaseContextEvalState)
488−runDatabaseContextIOEvalMonad env ctx m = do
489− res <- runRWST m env freshState
490− case res of
491− (Left err,_,_) -> pure (Left err)
492− (Right (),s,_) -> pure (Right s)
493− where
494− freshState = mkDatabaseContextEvalState ctx
495−
496−requireScriptSession :: DatabaseContextIOEvalMonad (Either RelationalError ScriptSession)
497−requireScriptSession = do
498− env <- RWS.ask
499− case dbcio_mScriptSession env of
500− Nothing -> pure $ Left $ ScriptError ScriptCompilationDisabledError
501− Just ss -> pure (Right ss)
502−
503−putDBCIOContext :: DatabaseContext -> DatabaseContextIOEvalMonad (Either RelationalError ())
504−putDBCIOContext ctx = do
505− RWS.modify (\dbstate -> dbstate { dbc_context = ctx})
506− pure (Right ())
507−
508−getDBCIOContext :: DatabaseContextIOEvalMonad DatabaseContext
509−getDBCIOContext = dbc_context <$> RWS.get
510−
511−getDBCIORelationalExprEnv :: DatabaseContextIOEvalMonad RelationalExprEnv
512−getDBCIORelationalExprEnv = do
513− context <- getDBCIOContext
514− mkRelationalExprEnv context . dbcio_graph <$> RWS.ask
515−
516−evalGraphRefDatabaseContextIOExpr :: GraphRefDatabaseContextIOExpr -> DatabaseContextIOEvalMonad (Either RelationalError ())
517−#if !defined(PM36_HASKELL_SCRIPTING)
518−evalGraphRefDatabaseContextIOExpr AddAtomFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
519−evalGraphRefDatabaseContextIOExpr AddDatabaseContextFunction{} = pure (Left (ScriptError ScriptCompilationDisabledError))
520−evalGraphRefDatabaseContextIOExpr LoadAtomFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
521−evalGraphRefDatabaseContextIOExpr LoadDatabaseContextFunctions{} = pure (Left (ScriptError ScriptCompilationDisabledError))
522−#else
523−evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = do
524− eScriptSession <- requireScriptSession
525− currentContext <- getDBCIOContext
526− case eScriptSession of
527− Left err -> pure (Left err)
528− Right scriptSession -> do
529− res <- liftIO $ try $ runGhc (Just libdir) $ do
490+ Left err -> pure (Left err)
491+ Right newContext -> putStateContext newContext >> pure (Right ())
492+
493+evalDatabaseContextIOExpr :: Maybe ScriptSession -> DatabaseContext -> DatabaseContextIOExpr -> IO (Either RelationalError DatabaseContext)
494+evalDatabaseContextIOExpr mScriptSession currentContext (AddAtomFunction funcName funcType script) =
495+ case mScriptSession of
496+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
497+ Just scriptSession -> do
498+ res <- try $ runGhc (Just libdir) $ do
530499 setSession (hscEnv scriptSession)
531500 let atomFuncs = atomFunctions currentContext
532501 case extractAtomFunctionType funcType of
@@ -537,7 +506,7 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
537506 pure $ case eCompiledFunc of
538507 Left err -> Left (ScriptError err)
539508 Right compiledFunc -> do
540− funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructorValidate False funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
509+ funcAtomType <- mapM (\funcTypeArg -> atomTypeForTypeConstructor funcTypeArg (typeConstructorMapping currentContext) M.empty) adjustedAtomTypeCons
541510 let updatedFuncs = HS.insert newAtomFunc atomFuncs
542511 newContext = currentContext { atomFunctions = updatedFuncs }
543512 newAtomFunc = AtomFunction { atomFuncName = funcName,
@@ -552,13 +521,12 @@ evalGraphRefDatabaseContextIOExpr (AddAtomFunction funcName funcType script) = d
552521 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
553522 Right eContext -> case eContext of
554523 Left err -> pure (Left err)
555− Right context' -> putDBCIOContext context'
556−evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType script) = do
557− eScriptSession <- requireScriptSession
558− currentContext <- getDBCIOContext
559− case eScriptSession of
560− Left err -> pure (Left err)
561− Right scriptSession -> do
524+ Right context' -> pure (Right context')
525+
526+evalDatabaseContextIOExpr mScriptSession currentContext (AddDatabaseContextFunction funcName funcType script) =
527+ case mScriptSession of
528+ Nothing -> pure (Left (ScriptError ScriptCompilationDisabledError))
529+ Just scriptSession -> do
562530 --validate that the function signature is of the form x -> y -> ... -> DatabaseContext -> DatabaseContext
563531 let last2Args = reverse (take 2 (reverse funcType))
564532 atomArgs = take (length funcType - 2) funcType
@@ -568,7 +536,7 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
568536 if last2Args /= [ADTypeConstructor "DatabaseContext" [], dbContextTypeCons] then
569537 pure (Left (ScriptError (TypeCheckCompilationError expectedType actualType)))
570538 else do
571− res <- liftIO $ try $ runGhc (Just libdir) $ do
539+ res <- try $ runGhc (Just libdir) $ do
572540 setSession (hscEnv scriptSession)
573541 eCompiledFunc <- compileScript (dbcFunctionBodyType scriptSession) script
574542 pure $ case eCompiledFunc of
@@ -593,170 +561,123 @@ evalGraphRefDatabaseContextIOExpr (AddDatabaseContextFunction funcName funcType
593561 Left (exc :: SomeException) -> pure $ Left (ScriptError (OtherScriptCompilationError (show exc)))
594562 Right eContext -> case eContext of
595563 Left err -> pure (Left err)
596− Right context' -> putDBCIOContext context'
597−evalGraphRefDatabaseContextIOExpr (LoadAtomFunctions modName funcName modPath) = do
598− currentContext <- getDBCIOContext
599− eLoadFunc <- liftIO $ loadAtomFunctions (T.unpack modName) (T.unpack funcName) modPath
600− case eLoadFunc of
601− Left LoadSymbolError -> pure (Left LoadFunctionError)
602− Right atomFunctionListFunc -> let newContext = currentContext { atomFunctions = mergedFuncs }
603− mergedFuncs = HS.union (atomFunctions currentContext) (HS.fromList atomFunctionListFunc)
604− in putDBCIOContext newContext
605−evalGraphRefDatabaseContextIOExpr (LoadDatabaseContextFunctions modName funcName modPath) = do
606− currentContext <- getDBCIOContext
607− eLoadFunc <- liftIO $ loadDatabaseContextFunctions (T.unpack modName) (T.unpack funcName) modPath
608− case eLoadFunc of
609− Left LoadSymbolError -> pure (Left LoadFunctionError)
610− Right dbcListFunc -> let newContext = currentContext { dbcFunctions = mergedFuncs }
611− mergedFuncs = HS.union (dbcFunctions currentContext) (HS.fromList dbcListFunc)
612− in putDBCIOContext newContext
613−#endif
614−evalGraphRefDatabaseContextIOExpr (CreateArbitraryRelation relVarName attrExprs range) = do
615− --Define
616− currentContext <- getDBCIOContext
617− env <- RWS.ask
618− --create graph ref expr
619− let gfExpr = Define relVarName attrExprs
620− evalEnv = mkDatabaseContextEvalEnv (dbcio_transId env) (dbcio_graph env)
621− graph = dbcio_graph env
622− case runDatabaseContextEvalMonad currentContext evalEnv (evalGraphRefDatabaseContextExpr gfExpr) of
623− Left err -> pure (Left err)
624− Right dbstate -> do
625− --Assign
626− let existingRelVar = M.lookup relVarName relVarTable
627− relVarTable = relationVariables (dbc_context dbstate)
628− case existingRelVar of
629− Nothing -> pure $ Left (RelVarNotDefinedError relVarName)
630− Just existingRel -> do
631− let gfEnv = freshGraphRefRelationalExprEnv (Just currentContext) graph
632− case runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr existingRel) of
633− Left err -> pure (Left err)
634− Right relType -> do
635− let expectedAttributes = attributes relType
636− tcMap = typeConstructorMapping (dbc_context dbstate)
637− eitherRel <- liftIO $ generate $ runReaderT (arbitraryRelation expectedAttributes range) tcMap
638− case eitherRel of
639− Left err -> pure $ Left err
640− Right rel ->
641− case runDatabaseContextEvalMonad currentContext evalEnv (setRelVar relVarName (ExistingRelation rel)) of
642− Left err -> pure (Left err)
643− Right dbstate' -> putDBCIOContext (dbc_context dbstate')
564+ Right context' -> pure (Right context')
565+
566+
567+updateTupleWithAtomExprs :: M.Map AttributeName AtomExpr -> DatabaseContext -> RelationTuple -> Either RelationalError RelationTuple
568+updateTupleWithAtomExprs exprMap context tupIn = do
569+ --resolve all atom exprs
570+ atomsAssoc <- mapM (\(attrName, atomExpr) -> do
571+ atom <- runReader (evalAtomExpr tupIn atomExpr) (RelationalExprStateElems context)
572+ pure (attrName, atom)
573+ ) (M.toList exprMap)
574+ pure (updateTupleWithAtoms (M.fromList atomsAssoc) tupIn)
644575
645576--run verification on all constraints
646−checkConstraints :: DatabaseContext -> TransactionId -> TransactionGraph -> Either RelationalError ()
647−checkConstraints context transId graph@(TransactionGraph graphHeads transSet) = do
648− mapM_ (uncurry checkIncDep) (M.toList deps)
577+checkConstraints :: DatabaseContext -> Maybe RelationalError
578+checkConstraints context = case failures of
579+ [] -> Nothing
580+ l:_ -> Just l
649581 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−
582+ failures = M.elems $ M.mapMaybeWithKey checkIncDep deps
660583 deps = inclusionDependencies context
661− -- no optimization available here, really? perhaps the optimizer should be passed down to here or the eval function should be passed through the environment
584+ eval expr = runReader (evalRelationalExpr expr) (RelationalExprStateElems context)
662585 checkIncDep depName (InclusionDependency subsetExpr supersetExpr) = do
663− let process = runProcessExprM UncommittedContextMarker
664− gfSubsetExpr = process (processRelationalExpr subsetExpr)
665− gfSupersetExpr = process (processRelationalExpr supersetExpr)
666− --if both expressions are of a single-attribute (such as with a simple foreign key), the names of the attributes are irrelevant (they need not match) because the expression is unambiguous, but special-casing this to rename the attribute automatically would not be orthogonal behavior and probably cause confusion. Instead, special case the error to make it clear.
667− let gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
668− runGfRel = runGraphRefRelationalExprM gfEnv
669− typeSub <- runGfRel (typeForGraphRefRelationalExpr gfSubsetExpr)
670− typeSuper <- runGfRel (typeForGraphRefRelationalExpr gfSupersetExpr)
671− when (typeSub /= typeSuper) (Left (RelationTypeMismatchError (attributes typeSub) (attributes typeSuper)))
672− let checkExpr = Equals gfSupersetExpr (Union gfSubsetExpr gfSupersetExpr)
673− gfEvald = runGraphRefRelationalExprM gfEnv' (evalGraphRefRelationalExpr checkExpr)
674− gfEnv' = freshGraphRefRelationalExprEnv (Just context) potentialGraph
675− case gfEvald of
676− Left err -> Left err
586+ let checkExpr = Equals supersetExpr (Union subsetExpr supersetExpr)
587+ case eval checkExpr of
588+ Left err -> Just err
677589 Right resultRel -> if resultRel == relationTrue then
678− pure ()
590+ Nothing
679591 else
680− Left (InclusionDependencyCheckError depName)
592+ Just $ InclusionDependencyCheckError depName
681593
682594-- 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
683595-- furthermore, the type of a relational expression is the resultant header of the evaluated empty-tupled relation
684596
685−typeForRelationalExpr :: RelationalExpr -> RelationalExprM Relation
597+typeForRelationalExpr :: RelationalExpr -> RelationalExprState (Either RelationalError Relation)
686598typeForRelationalExpr expr = do
599+ rstate <- ask
600+ let context = stateElemsContext rstate
687601 --replace the relationVariables context element with a cloned set of relation devoid of tuples
688− --evalRelationalExpr could still return an existing relation with tuples, so strip them
689− graph <- reGraph
690− context <- reContext
691− let gfExpr = runProcessExprM UncommittedContextMarker (processRelationalExpr expr)
692− gfEnv = freshGraphRefRelationalExprEnv (Just context) graph
693− runGf = runGraphRefRelationalExprM gfEnv (typeForGraphRefRelationalExpr gfExpr)
694− lift $ except runGf
602+ let context' = contextWithEmptyTupleSets context
603+ rstate' = setStateElemsContext rstate context'
604+ pure (runReader (evalRelationalExpr expr) rstate')
605+
606+--returns a database context with all tuples removed
607+--this is useful for type checking and optimization
608+contextWithEmptyTupleSets :: DatabaseContext -> DatabaseContext
609+contextWithEmptyTupleSets contextIn = contextIn { relationVariables = relVars }
610+ where
611+ relVars = M.map (\rel -> Relation (attributes rel) emptyTupleSet) (relationVariables contextIn)
695612
696613liftE :: (Monad m) => m (Either a b) -> ExceptT a m b
697614liftE v = do
698615 y <- lift v
699616 case y of
700− Left err -> throwError err
617+ Left err -> throwE err
701618 Right val -> pure val
702619
703620{- used for restrictions- take the restrictionpredicate and return the corresponding filter function -}
704−predicateRestrictionFilter :: Attributes -> GraphRefRestrictionPredicateExpr -> GraphRefRelationalExprM RestrictionFilter
705−predicateRestrictionFilter attrs (AndPredicate expr1 expr2) = do
706− expr1v <- predicateRestrictionFilter attrs expr1
707− expr2v <- predicateRestrictionFilter attrs expr2
708− pure (\x -> do
709− ev1 <- expr1v x
710− ev2 <- expr2v x
711− pure (ev1 && ev2))
621+predicateRestrictionFilter :: Attributes -> RestrictionPredicateExpr -> RelationalExprState (Either RelationalError RestrictionFilter)
622+predicateRestrictionFilter attrs (AndPredicate expr1 expr2) =
623+ runExceptT $ do
624+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
625+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
626+ pure (\x -> do
627+ ev1 <- expr1v x
628+ ev2 <- expr2v x
629+ pure (ev1 && ev2))
712630
713−predicateRestrictionFilter attrs (OrPredicate expr1 expr2) = do
714− expr1v <- predicateRestrictionFilter attrs expr1
715− expr2v <- predicateRestrictionFilter attrs expr2
631+predicateRestrictionFilter attrs (OrPredicate expr1 expr2) =
632+ runExceptT $ do
633+ expr1v <- liftE (predicateRestrictionFilter attrs expr1)
634+ expr2v <- liftE (predicateRestrictionFilter attrs expr2)
716635 pure (\x -> do
717636 ev1 <- expr1v x
718637 ev2 <- expr2v x
719638 pure (ev1 || ev2))
720639
721−predicateRestrictionFilter _ TruePredicate = pure (\_ -> pure True)
640+predicateRestrictionFilter _ TruePredicate = pure (Right (\_ -> pure True))
722641
723−predicateRestrictionFilter attrs (NotPredicate expr) = do
724− exprv <- predicateRestrictionFilter attrs expr
725− pure (fmap not . exprv)
642+predicateRestrictionFilter attrs (NotPredicate expr) =
643+ runExceptT $ do
644+ exprv <- liftE (predicateRestrictionFilter attrs expr)
645+ pure (\x -> do
646+ ev <- exprv x
647+ pure (not ev))
726648
727649--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
728650predicateRestrictionFilter _ (RelationalExprPredicate relExpr) = do
729− renv <- askEnv
730− let eval :: RelationTuple -> Either RelationalError Relation
731− eval tup =
732− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup renv in
733− runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
734− pure (\tup -> case eval tup of
651+ rstate <- ask
652+ pure (Right (\tup -> case runReader (evalRelationalExpr relExpr) (mergeTuplesIntoRelationalExprState tup rstate) of
735653 Left err -> Left err
736654 Right rel -> if arity rel /= 0 then
737655 Left (PredicateExpressionError "Relational restriction filter must evaluate to 'true' or 'false'")
738656 else
739− pure (rel == relationTrue))
657+ pure (rel == relationTrue)))
740658
741659predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr) = do
742− env <- askEnv
743− let attrs' = A.union attrs (envAttributes env)
744− ctxtup' = envTuple env
745− atomExprType <- typeForGraphRefAtomExpr attrs' atomExpr
746− attr <- lift $ except $ case A.attributeForName attrName attrs of
660+ rstate <- ask
661+ let (attrs', ctxtup') = case rstate of
662+ RelationalExprStateElems _ -> (attrs, emptyTuple)
663+ RelationalExprStateAttrsElems _ _ -> (attrs, emptyTuple)
664+ RelationalExprStateTupleElems _ ctxtup -> (A.union attrs (tupleAttributes ctxtup), ctxtup)
665+ runExceptT $ do
666+ atomExprType <- liftE (typeFromAtomExpr attrs' atomExpr)
667+ attr <- either throwE pure $ case A.attributeForName attrName attrs of
747668 Right attr -> Right attr
748669 Left (NoSuchAttributeNamesError _) -> case A.attributeForName attrName (tupleAttributes ctxtup') of
749670 Right ctxattr -> Right ctxattr
750671 Left err2@(NoSuchAttributeNamesError _) -> Left err2
751672 Left err -> Left err
752673 Left err -> Left err
753− if atomExprType /= A.atomType attr then
754− throwError (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
755− else
674+ if atomExprType /= A.atomType attr then
675+ throwE (TupleAttributeTypeMismatchError (A.attributesFromList [attr]))
676+ else
756677 pure $ \tupleIn -> let evalAndCmp atomIn = case atomEvald of
757678 Right atomCmp -> atomCmp == atomIn
758679 Left _ -> False
759− atomEvald = runGraphRefRelationalExprM env (evalGraphRefAtomExpr tupleIn atomExpr)
680+ atomEvald = runReader (evalAtomExpr tupleIn atomExpr) rstate
760681 in
761682 pure $ case atomForAttributeName attrName tupleIn of
762683 Left (NoSuchAttributeNamesError _) -> case atomForAttributeName attrName ctxtup' of
@@ -767,626 +688,244 @@ predicateRestrictionFilter attrs (AttributeEqualityPredicate attrName atomExpr)
767688-- in the future, it would be useful to do typechecking on the attribute and atom expr filters in advance
768689predicateRestrictionFilter attrs (AtomExprPredicate atomExpr) = do
769690 --merge attrs into the state attributes
770− renv <- askEnv
771− aType <- typeForGraphRefAtomExpr attrs atomExpr
772− if aType /= BoolAtomType then
773− throwError (AtomTypeMismatchError aType BoolAtomType)
774− else
691+ rstate <- ask
692+ runExceptT $ do
693+ aType <- liftE (typeFromAtomExpr attrs atomExpr)
694+ if aType /= BoolAtomType then
695+ throwE (AtomTypeMismatchError aType BoolAtomType)
696+ else
775697 pure (\tupleIn ->
776− case runGraphRefRelationalExprM renv (evalGraphRefAtomExpr tupleIn atomExpr) of
777− Left err -> Left err
778− Right boolAtomValue -> pure (boolAtomValue == BoolAtom True))
698+ pure $ case runReader (evalAtomExpr tupleIn atomExpr) rstate of
699+ Left _ -> False
700+ Right boolAtomValue -> boolAtomValue == BoolAtom True)
779701
780702tupleExprCheckNewAttrName :: AttributeName -> Relation -> Either RelationalError Relation
781703tupleExprCheckNewAttrName attrName rel = if isRight (attributeForName attrName rel) then
782− Left (AttributeNameInUseError attrName)
704+ Left (error "SPAMMIT" $ AttributeNameInUseError attrName)
783705 else
784706 Right rel
785707
786−extendGraphRefTupleExpressionProcessor :: Relation -> GraphRefExtendTupleExpr -> GraphRefRelationalExprM (Attributes, RelationTuple -> Either RelationalError RelationTuple)
787−extendGraphRefTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) =
788−-- renv <- askEnv
708+extendTupleExpressionProcessor :: Relation -> ExtendTupleExpr -> RelationalExprState (Either RelationalError (Attributes, RelationTuple -> Either RelationalError RelationTuple))
709+extendTupleExpressionProcessor relIn (AttributeExtendTupleExpr newAttrName atomExpr) = do
710+ rstate <- ask
789711 -- check that the attribute name is not in use
790712 case tupleExprCheckNewAttrName newAttrName relIn of
791− Left err -> throwError err
792− Right _ -> do
793− atomExprType <- typeForGraphRefAtomExpr (attributes relIn) atomExpr
794− atomExprType' <- verifyGraphRefAtomExprTypes relIn atomExpr atomExprType
713+ Left err -> pure (Left err)
714+ Right _ -> runExceptT $ do
715+ atomExprType <- liftE (typeFromAtomExpr (attributes relIn) atomExpr)
716+ atomExprType' <- liftE (verifyAtomExprTypes relIn atomExpr atomExprType)
795717 let newAttrs = A.attributesFromList [Attribute newAttrName atomExprType']
796718 newAndOldAttrs = A.addAttributes (attributes relIn) newAttrs
797− env <- ask
798− pure (newAndOldAttrs, \tup -> do
799− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tup env
800− atom <- runGraphRefRelationalExprM gfEnv (evalGraphRefAtomExpr tup atomExpr)
801− Right (tupleAtomExtend newAttrName atom tup)
719+ pure (newAndOldAttrs, \tup -> let substate = mergeTuplesIntoRelationalExprState tup rstate in case runReader (evalAtomExpr tup atomExpr) substate of
720+ Left err -> Left err
721+ Right atom -> Right (tupleAtomExtend newAttrName atom tup)
802722 )
803723
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
724+evalAtomExpr :: RelationTuple -> AtomExpr -> RelationalExprState (Either RelationalError Atom)
725+evalAtomExpr tupIn (AttributeAtomExpr attrName) = case atomForAttributeName attrName tupIn of
726+ Right atom -> pure (Right atom)
727+ err@(Left (NoSuchAttributeNamesError _)) -> do
728+ rstate <- ask
729+ case rstate of
730+ RelationalExprStateElems _ -> pure err
731+ RelationalExprStateAttrsElems _ _ -> pure err
732+ RelationalExprStateTupleElems _ ctxtup -> pure (atomForAttributeName attrName ctxtup)
733+ Left err -> pure (Left err)
734+evalAtomExpr _ (NakedAtomExpr atom) = pure (Right atom)
735+evalAtomExpr tupIn (FunctionAtomExpr funcName arguments ()) = do
736+ argTypes <- mapM (typeFromAtomExpr (tupleAttributes tupIn)) arguments
737+ context <- fmap stateElemsContext ask
738+ runExceptT $ do
739+ let functions = atomFunctions context
740+ func <- either throwE pure (atomFunctionForName funcName functions)
741+ let expectedArgCount = length (atomFuncType func) - 1
742+ actualArgCount = length argTypes
743+ safeInit [_] = []
744+ safeInit [] = [] -- different behavior from normal init
745+ safeInit (_:xs) = safeInit xs
746+ if expectedArgCount /= actualArgCount then
747+ throwE (FunctionArgumentCountMismatchError expectedArgCount actualArgCount)
748+ else do
749+ mapM_ (\(expType, actType) -> either throwE pure (atomTypeVerify expType actType)) (safeInit (zip (atomFuncType func) argTypes))
750+ evaldArgs <- mapM (liftE . evalAtomExpr tupIn) arguments
832751 case evalAtomFunction func evaldArgs of
833− Left err -> throwError (AtomFunctionUserError err)
752+ Left err -> throwE (AtomFunctionUserError err)
834753 Right result -> do
835754 --validate that the result matches the expected type
836− _ <- lift $ except (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
755+ _ <- either throwE pure (atomTypeVerify (last (atomFuncType func)) (atomTypeForAtom result))
837756 pure result
838−evalGraphRefAtomExpr tupIn (RelationAtomExpr relExpr) = do
757+evalAtomExpr tupIn (RelationAtomExpr relExpr) = do
839758 --merge existing state tuple context into new state tuple context to support an arbitrary number of levels, but new attributes trounce old attributes
840− env <- ask
841− let gfEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn env
842− relAtom <- lift $ except $ runGraphRefRelationalExprM gfEnv (evalGraphRefRelationalExpr relExpr)
843− pure (RelationAtom relAtom)
844−evalGraphRefAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs _) = do --why is the tid unused here? suspicious
845− let mergeEnv = mergeTuplesIntoGraphRefRelationalExprEnv tupIn
846− aType <- local mergeEnv (typeForGraphRefAtomExpr (tupleAttributes tupIn) cons)
847− argAtoms <- local mergeEnv $
848− mapM (evalGraphRefAtomExpr tupIn) dConsArgs
759+ rstate <- ask
760+ runExceptT $ do
761+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
762+ relAtom <- either throwE pure (runReader (evalRelationalExpr relExpr) newState)
763+ pure (RelationAtom relAtom)
764+evalAtomExpr tupIn cons@(ConstructedAtomExpr dConsName dConsArgs ()) = runExceptT $ do
765+ rstate <- lift ask
766+ let newState = mergeTuplesIntoRelationalExprState tupIn rstate
767+ aType <- either throwE pure (runReader (typeFromAtomExpr (tupleAttributes tupIn) cons) newState)
768+ argAtoms <- mapM (\arg -> either throwE pure (runReader (evalAtomExpr tupIn arg) newState)) dConsArgs
849769 pure (ConstructedAtom dConsName aType argAtoms)
850770
851−typeForGraphRefAtomExpr :: Attributes -> GraphRefAtomExpr -> GraphRefRelationalExprM AtomType
852−typeForGraphRefAtomExpr attrs (AttributeAtomExpr attrName) = do
853− renv <- askEnv
771+typeFromAtomExpr :: Attributes -> AtomExpr -> RelationalExprState (Either RelationalError AtomType)
772+typeFromAtomExpr attrs (AttributeAtomExpr attrName) = do
773+ rstate <- ask
854774 case A.atomTypeForAttributeName attrName attrs of
855− Right aType -> pure aType
856− Left err@(NoSuchAttributeNamesError _) ->
857− let envTup = envTuple renv
858− envAttrs = envAttributes renv in
859− case A.attributeForName attrName envAttrs of
860− Right attr -> pure (A.atomType attr)
861− Left _ -> case atomForAttributeName attrName envTup of
862− Right atom -> pure (atomTypeForAtom atom)
863− Left _ -> --throwError (traceStack (show ("typeForGRAtomExpr", attrs, envTup)) err)
864− throwError err
865− Left err -> throwError err
866−
867−typeForGraphRefAtomExpr _ (NakedAtomExpr atom) = pure (atomTypeForAtom atom)
868−typeForGraphRefAtomExpr attrs (FunctionAtomExpr funcName atomArgs transId) = do
869− funcs <- atomFunctions <$> gfDatabaseContextForMarker transId
775+ Right aType -> pure (Right aType)
776+ Left err@(NoSuchAttributeNamesError _) -> case rstate of
777+ RelationalExprStateAttrsElems _ attrs' -> case A.attributeForName attrName attrs' of
778+ Left err' -> pure (Left err')
779+ Right attr -> pure (Right (A.atomType attr))
780+ RelationalExprStateElems _ -> pure (Left err)
781+ RelationalExprStateTupleElems _ tup -> case atomForAttributeName attrName tup of
782+ Left err' -> pure (Left err')
783+ Right atom -> pure (Right (atomTypeForAtom atom))
784+ Left err -> pure (Left err)
785+typeFromAtomExpr _ (NakedAtomExpr atom) = pure (Right (atomTypeForAtom atom))
786+typeFromAtomExpr attrs (FunctionAtomExpr funcName atomArgs _) = do
787+ context <- fmap stateElemsContext ask
788+ let funcs = atomFunctions context
870789 case atomFunctionForName funcName funcs of
871− Left err -> throwError err
790+ Left err -> pure (Left err)
872791 Right func -> do
873792 let funcRetType = last (atomFuncType func)
874793 funcArgTypes = init (atomFuncType func)
875− argTypes <- mapM (typeForGraphRefAtomExpr attrs) atomArgs
876− let eTvMap = resolveTypeVariables funcArgTypes argTypes
877− case eTvMap of
878− Left err -> throwError err
879− Right tvMap -> lift $ except $ resolveFunctionReturnValue funcName tvMap funcRetType
880−typeForGraphRefAtomExpr attrs (RelationAtomExpr relExpr) = do
881− relType <- R.local (mergeAttributesIntoGraphRefRelationalExprEnv attrs) (typeForGraphRefRelationalExpr relExpr)
794+ eArgTypes <- mapM (typeFromAtomExpr attrs) atomArgs
795+ case lefts eArgTypes of
796+ errs@(_:_) -> pure (Left (someErrors errs))
797+ [] -> do
798+ let eTvMap = resolveTypeVariables funcArgTypes argTypes
799+ argTypes = rights eArgTypes
800+ case eTvMap of
801+ Left err -> pure (Left err)
802+ Right tvMap -> pure (resolveFunctionReturnValue funcName tvMap funcRetType)
803+typeFromAtomExpr attrs (RelationAtomExpr relExpr) = runExceptT $ do
804+ rstate <- lift ask
805+ relType <- either throwE pure (runReader (typeForRelationalExpr relExpr) (mergeAttributesIntoRelationalExprState attrs rstate))
882806 pure (RelationAtomType (attributes relType))
883807-- grab the type of the data constructor, then validate that the args match the expected types
884−typeForGraphRefAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs tid) =
885− do
886− argsTypes <- mapM (typeForGraphRefAtomExpr attrs) dConsArgs
887− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker tid
888− lift $ except $ atomTypeForDataConstructor tConsMap dConsName argsTypes
808+typeFromAtomExpr attrs (ConstructedAtomExpr dConsName dConsArgs _) =
809+ runExceptT $ do
810+ argsTypes <- mapM (liftE . typeFromAtomExpr attrs) dConsArgs
811+ context <- fmap stateElemsContext (lift ask)
812+ aType <- either throwE pure (atomTypeForDataConstructor (typeConstructorMapping context) dConsName argsTypes)
813+ pure aType
889814
890815-- | Validate that the type of the AtomExpr matches the expected type.
891−verifyGraphRefAtomExprTypes :: Relation -> GraphRefAtomExpr -> AtomType -> GraphRefRelationalExprM AtomType
892−verifyGraphRefAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = do
893− env <- askEnv
816+verifyAtomExprTypes :: Relation -> AtomExpr -> AtomType -> RelationalExprState (Either RelationalError AtomType)
817+verifyAtomExprTypes relIn (AttributeAtomExpr attrName) expectedType = runExceptT $ do
818+ rstate <- lift ask
894819 case A.atomTypeForAttributeName attrName (attributes relIn) of
895− Right aType -> lift $ except $ atomTypeVerify expectedType aType
896− (Left err@(NoSuchAttributeNamesError _)) ->
897− let attrs' = envAttributes env in
898− if attrs' == emptyAttributes then
899− throwError err
900− else
901− case A.attributeForName attrName attrs' of
902− Left err' -> throwError err'
903− Right attrType -> lift $ except $ atomTypeVerify expectedType (A.atomType attrType)
904− Left err -> throwError err
905−
906−verifyGraphRefAtomExprTypes _ (NakedAtomExpr atom) expectedType =
907− lift $ except $ atomTypeVerify expectedType (atomTypeForAtom atom)
908−verifyGraphRefAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs tid) expectedType = do
909− context <- gfDatabaseContextForMarker tid
820+ Right aType -> either throwE pure (atomTypeVerify expectedType aType)
821+ (Left err@(NoSuchAttributeNamesError _)) -> case rstate of
822+ RelationalExprStateTupleElems _ _ -> throwE err
823+ RelationalExprStateElems _ -> throwE err
824+ RelationalExprStateAttrsElems _ attrs -> case A.attributeForName attrName attrs of
825+ Left err' -> throwE err'
826+ Right attrType -> either throwE pure (atomTypeVerify expectedType (A.atomType attrType))
827+ Left err -> throwE err
828+verifyAtomExprTypes _ (NakedAtomExpr atom) expectedType = pure (atomTypeVerify expectedType (atomTypeForAtom atom))
829+verifyAtomExprTypes relIn (FunctionAtomExpr funcName funcArgExprs _) expectedType = do
830+ rstate <- ask
910831 let functions = atomFunctions context
911− func <- lift $ except $ atomFunctionForName funcName functions
912− let expectedArgTypes = atomFuncType func
913− funcArgVerifier (atomExpr, expectedType2, argCount) = do
914− let handler :: RelationalError -> GraphRefRelationalExprM AtomType
915− handler (AtomTypeMismatchError expSubType actSubType) = throwError (AtomFunctionTypeError funcName argCount expSubType actSubType)
916− handler err = throwError err
917− verifyGraphRefAtomExprTypes relIn atomExpr expectedType2 `catchError` handler
918− funcArgTypes <- mapM funcArgVerifier $ zip3 funcArgExprs expectedArgTypes [1..]
919− if length funcArgTypes /= length expectedArgTypes - 1 then
920− throwError (AtomTypeCountError funcArgTypes expectedArgTypes)
832+ context = stateElemsContext rstate
833+ runExceptT $ do
834+ func <- either throwE pure (atomFunctionForName funcName functions)
835+ let expectedArgTypes = atomFuncType func
836+ funcArgTypes <- mapM (\(atomExpr,expectedType2,argCount) -> case runReader (verifyAtomExprTypes relIn atomExpr expectedType2) rstate of
837+ Left (AtomTypeMismatchError expSubType actSubType) -> throwE (AtomFunctionTypeError funcName argCount expSubType actSubType)
838+ Left err -> throwE err
839+ Right x -> pure x
840+ ) $ zip3 funcArgExprs expectedArgTypes [1..]
841+ if length funcArgTypes /= length expectedArgTypes - 1 then
842+ throwE (AtomTypeCountError funcArgTypes expectedArgTypes)
921843 else
922− lift $ except $ atomTypeVerify expectedType (last expectedArgTypes)
923−verifyGraphRefAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType =
924− do
925− let mergedAttrsEnv e = mergeAttributesIntoGraphRefRelationalExprEnv (attributes relIn) e
926− relType <- R.local mergedAttrsEnv (typeForGraphRefRelationalExpr relationExpr)
927− lift $ except $ atomTypeVerify expectedType (RelationAtomType (attributes relType))
928−verifyGraphRefAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = do
929− cType <- typeForGraphRefAtomExpr (attributes rel) cons
930− lift $ except $ atomTypeVerify expectedType cType
844+ either throwE pure (atomTypeVerify expectedType (last expectedArgTypes))
845+verifyAtomExprTypes relIn (RelationAtomExpr relationExpr) expectedType = runExceptT $ do
846+ rstate <- lift ask
847+ relType <- either throwE pure (runReader (typeForRelationalExpr relationExpr) (mergeAttributesIntoRelationalExprState (attributes relIn) rstate))
848+ either throwE pure (atomTypeVerify expectedType (RelationAtomType (attributes relType)))
849+verifyAtomExprTypes rel cons@ConstructedAtomExpr{} expectedType = runExceptT $ do
850+ cType <- liftE (typeFromAtomExpr (attributes rel) cons)
851+ either throwE pure (atomTypeVerify expectedType cType)
931852
932853-- | Look up the type's name and create a new attribute.
933−evalGraphRefAttrExpr :: GraphRefAttributeExpr -> GraphRefRelationalExprM Attribute
934−evalGraphRefAttrExpr (AttributeAndTypeNameExpr attrName tCons transId) = do
935− tConsMap <- typeConstructorMapping <$> gfDatabaseContextForMarker transId
936− aType <- lift $ except $ atomTypeForTypeConstructorValidate True tCons tConsMap M.empty
937− lift $ except $ validateAtomType aType tConsMap
938− pure $ Attribute attrName aType
854+evalAttrExpr :: TypeConstructorMapping -> AttributeExpr -> Either RelationalError Attribute
855+evalAttrExpr aTypes (AttributeAndTypeNameExpr attrName tCons ()) = do
856+ aType <- atomTypeForTypeConstructor tCons aTypes M.empty
857+ Right (Attribute attrName aType)
939858
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
859+evalAttrExpr _ (NakedAttributeExpr attr) = Right attr
860+
861+evalTupleExpr :: Maybe Attributes -> TupleExpr -> RelationalExprState (Either RelationalError RelationTuple)
862+evalTupleExpr attrs (TupleExpr tupMap) = do
863+ context <- fmap stateElemsContext ask
864+ runExceptT $ do
992865 -- 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
993866 -- I could adjust this logic so that when the attributes are not specified (Nothing), then I can attempt to extract the attributes from the tuple- the type resolution will blow up if an ambiguous data constructor is used (Left 4) and this should allow simple cases to "relation{tuple{a 4}}" to be processed
994− let attrs = fromMaybe A.emptyAttributes mAttrs
995− resolveOneAtom (attrName, aExpr) =
996− do
997− --provided when the relation header is available
998− let eExpectedAtomType = A.atomTypeForAttributeName attrName attrs
999− unresolvedType <- typeForGraphRefAtomExpr attrs aExpr
1000− resolvedType <- case eExpectedAtomType of
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
867+ attrAtoms <- mapM (\(attrName, aExpr) -> do
868+ newAtomType <- liftE (typeFromAtomExpr A.emptyAttributes aExpr)
869+ newAtom <- liftE (evalAtomExpr emptyTuple aExpr)
870+ pure (attrName, newAtom, newAtomType)
871+ ) (M.toList tupMap)
872+ let tupAttrs = A.attributesFromList $ map (\(attrName, _, aType) -> Attribute attrName aType) attrAtoms
873+ atoms = V.fromList $ map (\(_, atom, _) -> atom) attrAtoms
874+ tup = mkRelationTuple tupAttrs atoms
875+ tConss = typeConstructorMapping context
876+ finalAttrs = fromMaybe tupAttrs attrs
1011877 --verify that the attributes match
1012− when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwError (TupleAttributeTypeMismatchError tupAttrs)
1013− --we can't resolve types here- they have to be resolved at the atom level where the graph ref is held
1014− --tup' <- lift $ except (resolveTypesInTuple finalAttrs tConss (reorderTuple finalAttrs tup))
1015− let tup' = reorderTuple finalAttrs tup
1016− --TODO: restore type resolution
1017−-- _ <- lift $ except (validateTuple tup' tConss)
1018− pure tup'
1019−
1020−--temporary implementation until we have a proper planner+executor
1021−evalGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1022−evalGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1023− mAttrs <- case mAttrExprs of
1024− Just _ ->
1025− Just . A.attributesFromList <$> mapM evalGraphRefAttrExpr (fromMaybe [] mAttrExprs)
1026− Nothing -> pure Nothing
1027− tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1028− let attrs = fromMaybe firstTupleAttrs mAttrs
1029− firstTupleAttrs = if null tuples then A.emptyAttributes else tupleAttributes (head tuples)
1030− lift $ except $ mkRelation attrs (RelationTupleSet tuples)
1031−evalGraphRefRelationalExpr (MakeStaticRelation attributeSet tupleSet) =
1032− lift $ except $ mkRelation attributeSet tupleSet
1033−evalGraphRefRelationalExpr (ExistingRelation rel) = pure rel
1034−evalGraphRefRelationalExpr (RelationVariable name tid) = do
1035− ctx <- gfDatabaseContextForMarker tid
1036− case M.lookup name (relationVariables ctx) of
1037− Nothing -> throwError (RelVarNotDefinedError name)
1038− Just rv -> evalGraphRefRelationalExpr rv
1039−evalGraphRefRelationalExpr (Project attrNames expr) = do
1040− attrNameSet <- evalGraphRefAttributeNames attrNames expr
1041− rel <- evalGraphRefRelationalExpr expr
1042− lift $ except $ project attrNameSet rel
1043−evalGraphRefRelationalExpr (Union exprA exprB) = do
1044− relA <- evalGraphRefRelationalExpr exprA
1045− relB <- evalGraphRefRelationalExpr exprB
1046− lift $ except $ union relA relB
1047−evalGraphRefRelationalExpr (Join exprA exprB) = do
1048− relA <- evalGraphRefRelationalExpr exprA
1049− relB <- evalGraphRefRelationalExpr exprB
1050− lift $ except $ join relA relB
1051−evalGraphRefRelationalExpr (Rename oldName newName expr) = do
1052− rel <- evalGraphRefRelationalExpr expr
1053− lift $ except $ rename oldName newName rel
1054−evalGraphRefRelationalExpr (Difference exprA exprB) = do
1055− relA <- evalGraphRefRelationalExpr exprA
1056− relB <- evalGraphRefRelationalExpr exprB
1057− lift $ except $ difference relA relB
1058−evalGraphRefRelationalExpr (Group groupAttrNames newAttrName expr) = do
1059− groupNames <- evalGraphRefAttributeNames groupAttrNames expr
1060− rel <- evalGraphRefRelationalExpr expr
1061− lift $ except $ group groupNames newAttrName rel
1062−evalGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1063− rel <- evalGraphRefRelationalExpr expr
1064− lift $ except $ ungroup groupAttrName rel
1065−evalGraphRefRelationalExpr (Restrict predExpr expr) = do
1066− rel <- evalGraphRefRelationalExpr expr
1067− filt <- predicateRestrictionFilter (attributes rel) predExpr
1068− lift $ except $ restrict filt rel
1069−evalGraphRefRelationalExpr (Equals exprA exprB) = do
1070− relA <- evalGraphRefRelationalExpr exprA
1071− relB <- evalGraphRefRelationalExpr exprB
1072− pure $ if relA == relB then relationTrue else relationFalse
1073−evalGraphRefRelationalExpr (NotEquals exprA exprB) = do
1074− relA <- evalGraphRefRelationalExpr exprA
1075− relB <- evalGraphRefRelationalExpr exprB
1076− pure $ if relA == relB then relationFalse else relationTrue
1077−evalGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1078− rel <- evalGraphRefRelationalExpr expr
1079− (newAttrs, tupProc) <- extendGraphRefTupleExpressionProcessor rel extendTupleExpr
1080− lift $ except $ relMogrify tupProc newAttrs rel
1081−evalGraphRefRelationalExpr expr@With{} =
1082− --strategy A: add relation variables to the contexts in the graph
1083− --strategy B: drop in macros in place (easier programmatically)
1084− --strategy B implementation
1085− evalGraphRefRelationalExpr (substituteWithNameMacros [] expr)
1086−
1087−dbContextForTransId :: TransactionId -> TransactionGraph -> Either RelationalError DatabaseContext
1088−dbContextForTransId tid graph = do
1089− trans <- transactionForId tid graph
1090− pure (concreteDatabaseContext trans)
1091−
1092−transactionForId :: TransactionId -> TransactionGraph -> Either RelationalError Transaction
1093−transactionForId tid graph
1094− | tid == U.nil =
1095− Left RootTransactionTraversalError
1096− | S.null matchingTrans =
1097− Left $ NoSuchTransactionError tid
1098− | otherwise =
1099− Right $ head (S.toList matchingTrans)
1100− where
1101− matchingTrans = S.filter (\(Transaction idMatch _ _) -> idMatch == tid) (transactionsForGraph graph)
1102−
1103−typeForGraphRefRelationalExpr :: GraphRefRelationalExpr -> GraphRefRelationalExprM Relation
1104−typeForGraphRefRelationalExpr (MakeStaticRelation attrs _) = lift $ except $ mkRelation attrs emptyTupleSet
1105−typeForGraphRefRelationalExpr (ExistingRelation rel) = pure (emptyRelationWithAttrs (attributes rel))
1106−typeForGraphRefRelationalExpr (MakeRelationFromExprs mAttrExprs tupleExprs) = do
1107− mAttrs <- case mAttrExprs of
1108− Just attrExprs -> do
1109− attrs <- mapM evalGraphRefAttributeExpr attrExprs
1110− pure (Just (attributesFromList attrs))
1111− Nothing -> pure Nothing
1112− tuples <- evalGraphRefTupleExprs mAttrs tupleExprs
1113− let retAttrs = case tuples of
1114− (tup:_) -> tupleAttributes tup
1115− [] -> fromMaybe A.emptyAttributes mAttrs
1116− pure $ emptyRelationWithAttrs retAttrs
1117−
1118−typeForGraphRefRelationalExpr (RelationVariable rvName tid) = do
1119− relVars <- relationVariables <$> gfDatabaseContextForMarker tid
1120− case M.lookup rvName relVars of
1121− Nothing -> throwError (RelVarNotDefinedError rvName)
1122− Just rvExpr ->
1123− typeForGraphRefRelationalExpr rvExpr
1124−typeForGraphRefRelationalExpr (Project attrNames expr) = do
1125− exprType' <- typeForGraphRefRelationalExpr expr
1126− projectionAttrs <- evalGraphRefAttributeNames attrNames expr
1127− lift $ except $ project projectionAttrs exprType'
1128−typeForGraphRefRelationalExpr (Union exprA exprB) = do
1129− exprA' <- typeForGraphRefRelationalExpr exprA
1130− exprB' <- typeForGraphRefRelationalExpr exprB
1131− lift $ except $ union exprA' exprB'
1132−typeForGraphRefRelationalExpr (Join exprA exprB) = do
1133− exprA' <- typeForGraphRefRelationalExpr exprA
1134− exprB' <- typeForGraphRefRelationalExpr exprB
1135− lift $ except $ join exprA' exprB'
1136−typeForGraphRefRelationalExpr (Rename oldAttr newAttr expr) = do
1137− expr' <- typeForGraphRefRelationalExpr expr
1138− lift $ except $ rename oldAttr newAttr expr'
1139−typeForGraphRefRelationalExpr (Difference exprA exprB) = do
1140− exprA' <- typeForGraphRefRelationalExpr exprA
1141− exprB' <- typeForGraphRefRelationalExpr exprB
1142− lift $ except $ difference exprA' exprB'
1143−typeForGraphRefRelationalExpr (Group groupNames attrName expr) = do
1144− expr' <- typeForGraphRefRelationalExpr expr
1145− groupNames' <- evalGraphRefAttributeNames groupNames expr
1146− lift $ except $ group groupNames' attrName expr'
1147−typeForGraphRefRelationalExpr (Ungroup groupAttrName expr) = do
1148− expr' <- typeForGraphRefRelationalExpr expr
1149− lift $ except $ ungroup groupAttrName expr'
1150−typeForGraphRefRelationalExpr (Restrict pred' expr) = do
1151− expr' <- typeForGraphRefRelationalExpr expr
1152− filt <- predicateRestrictionFilter (attributes expr') pred'
1153− lift $ except $ restrict filt expr'
1154−typeForGraphRefRelationalExpr Equals{} =
1155− pure relationFalse
1156−typeForGraphRefRelationalExpr NotEquals{} =
1157− pure relationFalse
1158−typeForGraphRefRelationalExpr (Extend extendTupleExpr expr) = do
1159− rel <- typeForGraphRefRelationalExpr expr
1160− evalGraphRefRelationalExpr (Extend extendTupleExpr (ExistingRelation rel))
1161−typeForGraphRefRelationalExpr expr@(With withs _) = do
1162− let expr' = substituteWithNameMacros [] expr
1163− checkMacroName (WithNameExpr macroName tid) = do
1164− rvs <- relationVariables <$> gfDatabaseContextForMarker tid
1165− case M.lookup macroName rvs of
1166− Just _ -> lift $ except $ Left (RelVarAlreadyDefinedError macroName) --this error does not include the transaction marker, but should be good enough to identify the cause
1167− Nothing -> pure ()
1168− mapM_ (checkMacroName . fst) withs
1169− typeForGraphRefRelationalExpr expr'
1170−
1171−evalGraphRefAttributeNames :: GraphRefAttributeNames -> GraphRefRelationalExpr -> GraphRefRelationalExprM (S.Set AttributeName)
1172−evalGraphRefAttributeNames attrNames expr = do
1173− exprType' <- typeForGraphRefRelationalExpr expr
1174− let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprType')))
1175− case attrNames of
1176− AttributeNames names ->
1177− case A.projectionAttributesForNames names (attributes exprType') of
1178− Left err -> throwError err
1179− Right attrs -> pure (S.fromList (V.toList (A.attributeNames attrs)))
878+ when (A.attributeNameSet finalAttrs /= A.attributeNameSet tupAttrs) $ throwE (TupleAttributeTypeMismatchError tupAttrs)
879+ tup' <- either throwE pure (resolveTypesInTuple finalAttrs (reorderTuple finalAttrs tup))
880+ _ <- either throwE pure (validateTuple tup' tConss)
881+ pure tup'
882+
883+evalAttributeNames :: AttributeNames -> RelationalExpr -> RelationalExprState (Either RelationalError (S.Set AttributeName))
884+evalAttributeNames attrNames expr = do
885+ eExprType <- typeForRelationalExpr expr
886+ case eExprType of
887+ Left err -> pure (Left err)
888+ Right exprTyp -> do
889+ let typeNameSet = S.fromList (V.toList (A.attributeNames (attributes exprTyp)))
890+ case attrNames of
891+ AttributeNames names ->
892+ case A.projectionAttributesForNames names (attributes exprTyp) of
893+ Left err -> pure (Left err)
894+ Right attrs -> pure (Right (S.fromList (V.toList (A.attributeNames attrs))))
1180895
1181− InvertedAttributeNames names -> do
896+ InvertedAttributeNames names -> do
1182897 let nonExistentAttributeNames = A.attributeNamesNotContained names typeNameSet
1183898 if not (S.null nonExistentAttributeNames) then
1184− throwError $ AttributeNamesMismatchError nonExistentAttributeNames
899+ pure (Left (AttributeNamesMismatchError nonExistentAttributeNames))
1185900 else
1186− pure (A.nonMatchingAttributeNameSet names typeNameSet)
901+ pure (Right (A.nonMatchingAttributeNameSet names typeNameSet))
1187902
1188− UnionAttributeNames namesA namesB -> do
1189− nameSetA <- evalGraphRefAttributeNames namesA expr
1190− nameSetB <- evalGraphRefAttributeNames namesB expr
1191− pure (S.union nameSetA nameSetB)
903+ UnionAttributeNames namesA namesB -> do
904+ eNameSetA <- evalAttributeNames namesA expr
905+ case eNameSetA of
906+ Left err -> pure (Left err)
907+ Right nameSetA -> do
908+ eNameSetB <- evalAttributeNames namesB expr
909+ case eNameSetB of
910+ Left err -> pure (Left err)
911+ Right nameSetB ->
912+ pure (Right (S.union nameSetA nameSetB))
1192913
1193− IntersectAttributeNames namesA namesB -> do
1194− nameSetA <- evalGraphRefAttributeNames namesA expr
1195− nameSetB <- evalGraphRefAttributeNames namesB expr
1196− pure (S.intersection nameSetA nameSetB)
914+ IntersectAttributeNames namesA namesB -> do
915+ eNameSetA <- evalAttributeNames namesA expr
916+ case eNameSetA of
917+ Left err -> pure (Left err)
918+ Right nameSetA -> do
919+ eNameSetB <- evalAttributeNames namesB expr
920+ case eNameSetB of
921+ Left err -> pure (Left err)
922+ Right nameSetB ->
923+ pure (Right (S.intersection nameSetA nameSetB))
1197924
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
925+ RelationalExprAttributeNames attrExpr -> do
926+ eAttrExprType <- typeForRelationalExpr attrExpr
927+ case eAttrExprType of
928+ Left err -> pure (Left err)
929+ Right attrExprType -> pure (Right (A.attributeNameSet (attributes attrExprType)))
930+
1391931
1392−