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2+{-# LANGUAGE ConstraintKinds #-}
3+{-# LANGUAGE FlexibleContexts #-}
4+{-# LANGUAGE FlexibleInstances #-}
6+{-# LANGUAGE InstanceSigs #-}
7+{-# LANGUAGE LambdaCase #-}
8+{-# LANGUAGE MultiParamTypeClasses #-}
9+{-# LANGUAGE PatternGuards #-}
10+{-# LANGUAGE PolyKinds #-}
11+{-# LANGUAGE Rank2Types #-}
12+{-# LANGUAGE ScopedTypeVariables #-}
13+{-# LANGUAGE StandaloneDeriving #-}
14+{-# LANGUAGE TypeFamilies #-}
15+{-# LANGUAGE UndecidableInstances #-}
16+{-# LANGUAGE UndecidableSuperClasses #-}
18+-- |Module containing @'PatchDMapWithPatchingMove' k v@ and associated functions, which represents a 'Patch' to a @'DMap' k v@ which can insert, update, delete, and
19+-- move values between keys.
20+module Data.Patch.DMapWithPatchingMove where
22+import qualified Control.Category as Cat
23+--import qualified Control.Category.DecidablyEmpty as Cat
25+import Data.Constraint.Extras (Has')
26+import Data.Dependent.Map (DMap)
27+import Data.Dependent.Sum (DSum (..))
28+import qualified Data.Dependent.Map as DMap
29+import Data.Functor.Constant (Constant (..))
30+import Data.Functor.Misc
31+ ( Const2 (..), Proxy3 (..)
35+import Data.Functor.Product (Product (..))
36+import Data.GADT.Compare (GEq (..), GCompare (..))
37+import Data.GADT.Show (GRead, GShow, gshow)
38+import qualified Data.Map as Map
40+import Data.Monoid.DecidablyEmpty
41+import Data.Semigroupoid as Cat
42+#if !MIN_VERSION_base(4,11,0)
43+import Data.Semigroup (Semigroup (..), (<>))
45+import Data.Some (Some (Some), mkSome)
46+import Data.Proxy (Proxy (..))
47+import Data.These (These (..))
48+import Data.Type.Equality ((:~:)(..))
50+import Data.Patch.Class
51+ ( Patch (..), PatchHet (..)
52+ , PatchHet2 (..), PatchSource1, PatchTarget1
55+import Data.Patch.MapWithPatchingMove (PatchMapWithPatchingMove (..))
56+import qualified Data.Patch.MapWithPatchingMove as MapWithPatchingMove
58+-- | Like 'PatchMapWithPatchingMove', but for 'DMap'. Each key carries a 'NodeInfo'
59+-- which describes how it will be changed by the patch and connects move sources
64+-- * A key should not move to itself.
66+-- * A move should always be represented with both the destination key (as a
67+-- 'From_Move') and the source key (as a @'ComposeMaybe' ('Just'
69+newtype PatchDMapWithPatchingMove k v = PatchDMapWithPatchingMove (DMap k (NodeInfo k v))
71+--deriving instance ( GShow k
73+-- , Has' Show k (PatchTarget1 p)
74+-- ) => Show (PatchDMapWithPatchingMove k p)
75+--deriving instance ( GRead k
77+-- , Has' Read k (PatchTarget1 p)
78+-- ) => Read (PatchDMapWithPatchingMove k p)
79+--deriving instance ( GEq k
81+-- , Has' Eq k (PatchTarget1 p)
82+-- ) => Eq (PatchDMapWithPatchingMove k p)
83+--deriving instance ( GCompare k
85+-- , Has' Ord k (PatchTarget1 p)
86+-- ) => Ord (PatchDMapWithPatchingMove k p)
88+-- It won't let me derive for some reason
92+ , PatchSource1 v ~ PatchTarget1 v
93+ ) => DecidablyEmpty (PatchDMapWithPatchingMove k v) where
94+ isEmpty (PatchDMapWithPatchingMove m) = DMap.null m
96+-- | Structure which represents what changes apply to a particular key.
97+-- @_nodeInfo_from@ specifies what happens to this key, and in particular what
98+-- other key the current key is moving from, while @_nodeInfo_to@ specifies what
99+-- key the current key is moving to if involved in a move.
100+data NodeInfo k p a = NodeInfo
101+ { _nodeInfo_from :: !(From k p a)
102+ -- ^ Change applying to the current key, be it an insert, move, or delete.
103+ , _nodeInfo_to :: !(To k p a)
104+ -- ^ Where this key is moving to, if involved in a move. Should only be
105+ -- @ComposeMaybe (Just k)@ when there is a corresponding 'From_Move'.
108+--deriving instance ( Show (k a)
110+-- , Show (PatchTarget1 p a)
111+-- ) => Show (NodeInfo k p a)
112+--deriving instance ( Read (k a)
114+-- , Read (PatchTarget1 p a)
115+-- ) => Read (NodeInfo k p a)
116+--deriving instance ( Eq (k a)
118+-- , Eq (PatchTarget1 p a)
119+-- ) => Eq (NodeInfo k p a)
120+--deriving instance ( Ord (k a)
122+-- , Ord (PatchTarget1 p a)
123+-- ) => Ord (NodeInfo k p a)
125+-- | Structure describing a particular change to a key, be it inserting a new
126+-- key (@From_Insert@), updating an existing key (@From_Insert@ again), deleting
127+-- a key (@From_Delete@), or moving a key (@From_Move@).
129+-- This type isn't used directly as the from field patch, but is instead wrapped
130+-- in an existential. However, it is nice to be able to reason about this in
131+-- isolation as it is itself a @Semigroupoid@ when the underlying patch is.
132+data From (k :: a -> *) (p :: a -> a -> *) :: a -> * where
133+ -- | Insert a new or update an existing key with the given value @PatchTarget1
135+ From_Insert :: PatchTarget1 p to -> From k p to
136+ -- | Delete the existing key
137+ From_Delete :: From k p to
138+ -- | Move the value from the given key @k a@ to this key. The source key
139+ -- should also have an entry in the patch giving the current key as
140+ -- @_nodeInfo_to@, usually but not necessarily with @From_Delete@.
141+ From_Move :: !(DSum k (Flip p to)) -> From k p to
143+deriving instance ( Show (k a), GShow k
144+ , Has' Show k (Flip p a)
145+ , Show (PatchTarget1 p a)
146+ ) => Show (From k p a)
147+deriving instance ( Read (k a), GRead k
148+ , Has' Read k (Flip p a)
149+ , Read (PatchTarget1 p a)
150+ ) => Read (From k p a)
151+deriving instance ( GEq k
152+ , Has' Eq k (Flip p a)
153+ , Eq (PatchTarget1 p a)
154+ ) => Eq (From k p a)
155+deriving instance ( GCompare k
156+ , Has' Eq k (Flip p a) -- superclass bug
157+ , Has' Ord k (Flip p a)
158+ , Ord (PatchTarget1 p a)
159+ ) => Ord (From k p a)
161+newtype Flip p to from = Flip (p from to)
163+instance Cat.Category p => Cat.Category (Flip (p :: k -> k -> *)) where
165+ Flip y . Flip x = Flip $ x Cat.. y
167+-- | The "to" part of a 'NodeInfo'. Rather than be built out of @From@ like @From@
168+-- is, we store just the information necessary to compose a @To@ and @From@ like
169+-- @oLocal@ composes two @From@s.
170+data To (k :: a -> *) (p :: a -> a -> *) :: a -> * where
171+ -- | Delete or leave in place
172+ To_NonMove :: To k p from
173+ -- | Move the value from the given key @k a@ to this key. The target key
174+ -- should also have an entry in the patch giving the current key in
175+ -- @_nodeInfo_from@, usually but not necessarily with @To_Delete@.
176+ To_Move :: !(Some k) -> To k p from
178+deriving instance ( Show (k a), GShow k
180+ , Show (PatchTarget1 p a)
181+ ) => Show (To k p a)
182+deriving instance ( Read (k a), GRead k
184+ , Read (PatchTarget1 p a)
185+ ) => Read (To k p a)
186+deriving instance ( GEq k
188+ , Eq (PatchTarget1 p a)
190+deriving instance ( GCompare k
191+ , Has' Eq k (p a) -- superclass bug
193+ , Ord (PatchTarget1 p a)
196+-- |Test whether a 'PatchDMapWithPatchingMove' satisfies its invariants.
197+validPatchDMapWithPatchingMove
199+ . (GCompare k, GShow k)
200+ => DMap k (NodeInfo k v)
202+validPatchDMapWithPatchingMove = not . null . validationErrorsForPatchDMapWithPatchingMove
204+-- |Enumerate what reasons a 'PatchDMapWithPatchingMove' doesn't satisfy its invariants, returning @[]@ if it's valid.
205+validationErrorsForPatchDMapWithPatchingMove
207+ . (GCompare k, GShow k)
208+ => DMap k (NodeInfo k v)
210+validationErrorsForPatchDMapWithPatchingMove m =
211+ noSelfMoves <> movesBalanced
213+ noSelfMoves = mapMaybe selfMove . DMap.toAscList $ m
214+ selfMove (dst :=> NodeInfo (From_Move (src :=> _)) _)
215+ | Just _ <- dst `geq` src = Just $ "self move of key " <> gshow src <> " at destination side"
216+ selfMove (src :=> NodeInfo _ (To_Move (Some dst)))
217+ | Just _ <- src `geq` dst = Just $ "self move of key " <> gshow dst <> " at source side"
218+ selfMove _ = Nothing
219+ movesBalanced = mapMaybe unbalancedMove . DMap.toAscList $ m
220+ unbalancedMove (dst :=> NodeInfo (From_Move (src :=> _)) _) =
221+ case DMap.lookup src m of
222+ Nothing -> Just $ "unbalanced move at destination key " <> gshow dst <> " supposedly from " <> gshow src <> " but source key is not in the patch"
223+ Just (NodeInfo _ (To_Move (Some dst'))) ->
224+ if isNothing (dst' `geq` dst)
225+ then Just $ "unbalanced move at destination key " <> gshow dst <> " from " <> gshow src <> " is going to " <> gshow dst' <> " instead"
228+ Just $ "unbalanced move at destination key " <> gshow dst <> " supposedly from " <> gshow src <> " but source key has no move to key"
229+ unbalancedMove (src :=> NodeInfo _ (To_Move (Some dst))) =
230+ case DMap.lookup dst m of
231+ Nothing -> Just $ " unbalanced move at source key " <> gshow src <> " supposedly going to " <> gshow dst <> " but destination key is not in the patch"
232+ Just (NodeInfo (From_Move (src' :=> _)) _) ->
233+ if isNothing (src' `geq` src)
234+ then Just $ "unbalanced move at source key " <> gshow src <> " to " <> gshow dst <> " is coming from " <> gshow src' <> " instead"
238+ Just $ "unbalanced move at source key " <> gshow src <> " supposedly going to " <> gshow dst <> " but destination key is not moving"
239+ unbalancedMove _ = Nothing
241+-- |Higher kinded 2-tuple, identical to @Data.Functor.Product@ from base ≥ 4.9
242+data Pair1 f g a = Pair1 (f a) (g a)
244+-- |Helper data structure used for composing patches using the monoid instance.
247+ | Fixup_Update (These (DSum k (From k p)) (To k p a))
249+-- | Compose patches having the same effect as applying the patches in turn:
250+-- @'applyAlways' (p <> q) == 'applyAlways' p . 'applyAlways' q@
253+ , Cat.Semigroupoid p
254+ -- , Cat.DecidablyEmpty p
256+ , PatchSource1 p ~ PatchTarget1 p
258+ => Semigroup (PatchDMapWithPatchingMove k p) where
259+ PatchDMapWithPatchingMove ma <> PatchDMapWithPatchingMove mb = PatchDMapWithPatchingMove m
261+ connections :: [DSum k (Pair1 (To k p) (From k p))]
262+ connections = DMap.toList $ DMap.intersectionWithKey
263+ (\_ a b -> Pair1 (_nodeInfo_to a) (_nodeInfo_from b))
266+ h :: DSum k (Pair1 (To k p) (From k p)) -> [DSum k (Fixup k p)]
267+ h ((between :: k between) :=> Pair1 editAfter editBefore) = case (editAfter, editBefore) of
268+ (To_Move (Some (toAfter :: k after)), From_Move ((fromBefore :: k before) :=> Flip p) :: From k p between) ->
269+ --case toAfter `geq` fromBefore of
270+ -- Just Refl | Just Refl <- Cat.isId p0 ->
271+ -- [ toAfter :=> Fixup_Delete ]
273+ [ toAfter :=> Fixup_Update (This $ between :=> From_Move (fromBefore :=> Flip p))
274+ , fromBefore :=> Fixup_Update (That $ To_Move $ Some toAfter)
276+ (To_NonMove, From_Move (fromBefore :=> _)) ->
277+ -- The item is destroyed in the second patch, so indicate that it is
278+ -- destroyed in the source map
279+ [fromBefore :=> Fixup_Update (That To_NonMove)]
280+ --(To_Move (Some toAfter), From_Insert val) ->
281+ -- [toAfter :=> Fixup_Update (This $ From_Insert $ applyAlwaysHet2 p val)]
282+ --(To_Move (Some toAfter), From_Delete) ->
283+ -- [toAfter :=> Fixup_Update (This From_Delete)]
284+ (To_Move (Some toAfter), _) ->
285+ [toAfter :=> Fixup_Update (This $ between :=> editBefore)]
288+ mergeFixups _ Fixup_Delete Fixup_Delete = Fixup_Delete
289+ mergeFixups _ (Fixup_Update a) (Fixup_Update b)
290+ | This x <- a, That y <- b
291+ = Fixup_Update $ These x y
292+ | That y <- a, This x <- b
293+ = Fixup_Update $ These x y
294+ mergeFixups _ _ _ = error "PatchDMapWithPatchingMove: incompatible fixups"
295+ fixups = DMap.fromListWithKey mergeFixups $ concatMap h connections
296+ combineNodeInfos _ nia nib = NodeInfo
297+ { _nodeInfo_from = _nodeInfo_from nia
298+ , _nodeInfo_to = _nodeInfo_to nib
300+ applyFixup :: k a -> NodeInfo k p a -> Fixup k p a -> Maybe (NodeInfo k p a)
301+ applyFixup _ ni = \case
302+ Fixup_Delete -> Nothing
303+ Fixup_Update u -> Just $ NodeInfo
304+ { _nodeInfo_from = case _nodeInfo_from ni of
305+ f@(From_Move ((between0 :: k between0) :=> Flip (p' :: p between0 a))) -> case getHere u of -- The `from` fixup comes from the "old" patch
306+ Nothing -> f -- If there's no `from` fixup, just use the "new" `from`
307+ Just ((between1 :: k between1) :=> frm) -> case geq between0 between1 of
308+ Nothing -> error "fixup joined-on key did not match"
309+ Just Refl -> case frm of
310+ From_Insert v -> From_Insert $ applyAlwaysHet2 p' v
311+ From_Delete -> From_Delete
312+ From_Move (oldKey :=> Flip (p :: p oldKey between1)) -> From_Move $ oldKey :=> Flip (p' `o` p :: p oldKey a)
313+ _ -> error "PatchMapWithPatchingMove: fixup for non-move From"
314+ , _nodeInfo_to = fromMaybe (_nodeInfo_to ni) $ getThere u
316+ m = DMap.differenceWithKey applyFixup (DMap.unionWithKey combineNodeInfos ma mb) fixups
317+ getHere :: These a b -> Maybe a
322+ getThere :: These a b -> Maybe b
328+-- | Compose patches having the same effect as applying the patches in turn:
329+-- @'applyAlways' (p <> q) == 'applyAlways' p . 'applyAlways' q@
330+instance ( GCompare k
331+ , Cat.Semigroupoid p
332+ -- , DecidablyEmpty p
334+ , PatchSource1 p ~ PatchTarget1 p
335+ ) => Monoid (PatchDMapWithPatchingMove k p) where
336+ mempty = PatchDMapWithPatchingMove mempty
340+mappendPatchDMapWithPatchingMoveSlow :: forall k v. (ShowTag k v, GCompare k) => PatchDMapWithPatchingMove k v -> PatchDMapWithPatchingMove k v -> PatchDMapWithPatchingMove k v
341+PatchDMapWithPatchingMove dstAfter srcAfter `mappendPatchDMapWithPatchingMoveSlow` PatchDMapWithPatchingMove dstBefore srcBefore = PatchDMapWithPatchingMove dst src
343+ getDstAction k m = fromMaybe (From_Move k) $ DMap.lookup k m -- Any key that isn't present is treated as that key moving to itself
344+ removeRedundantDst toKey (From_Move fromKey) | isJust (toKey `geq` fromKey) = Nothing
345+ removeRedundantDst _ a = Just a
346+ f :: forall a. k a -> From k v a -> Maybe (From k v a)
347+ f toKey _ = removeRedundantDst toKey $ case getDstAction toKey dstAfter of
348+ From_Move fromKey -> getDstAction fromKey dstBefore
350+ dst = DMap.mapMaybeWithKey f $ DMap.union dstAfter dstBefore
351+ getSrcAction k m = fromMaybe (ComposeMaybe $ Just k) $ DMap.lookup k m
352+ removeRedundantSrc fromKey (ComposeMaybe (Just toKey)) | isJust (fromKey `geq` toKey) = Nothing
353+ removeRedundantSrc _ a = Just a
354+ g :: forall a. k a -> ComposeMaybe k a -> Maybe (ComposeMaybe k a)
355+ g fromKey _ = removeRedundantSrc fromKey $ case getSrcAction fromKey srcBefore of
356+ ComposeMaybe Nothing -> ComposeMaybe Nothing
357+ ComposeMaybe (Just toKeyBefore) -> getSrcAction toKeyBefore srcAfter
358+ src = DMap.mapMaybeWithKey g $ DMap.union srcAfter srcBefore
361+-- | Make a @'PatchDMapWithPatchingMove' k v@ which has the effect of inserting or
362+-- updating a value @PatchTarget1 p a@ to the given key @k a@, like
364+insertDMapKey :: k a -> PatchTarget1 p a -> PatchDMapWithPatchingMove k p
366+ PatchDMapWithPatchingMove . DMap.singleton k $ NodeInfo (From_Insert v) To_NonMove
368+-- | Make a @'PatchDMapWithPatchingMove' k v@ which has the effect of moving the value
369+-- from the first key @k a@ to the second key @k a@, equivalent to:
372+-- 'DMap.delete' src (maybe dmap ('DMap.insert' dst) (DMap.lookup src dmap))
376+ => k a -> k a -> PatchDMapWithPatchingMove k (Proxy3 v)
377+moveDMapKey src dst = case src `geq` dst of
378+ Nothing -> PatchDMapWithPatchingMove $ DMap.fromList
379+ [ dst :=> NodeInfo (From_Move (src :=> Flip Proxy3)) To_NonMove
380+ , src :=> NodeInfo From_Delete (To_Move $ Some dst)
382+ Just _ -> PatchDMapWithPatchingMove DMap.empty
384+-- | Make a @'PatchDMapWithPatchingMove' k v@ which has the effect of swapping two keys
385+-- in the mapping, equivalent to:
388+-- let aMay = DMap.lookup a dmap
389+-- bMay = DMap.lookup b dmap
390+-- in maybe id (DMap.insert a) (bMay <> aMay)
391+-- . maybe id (DMap.insert b) (aMay <> bMay)
392+-- . DMap.delete a . DMap.delete b $ dmap
394+swapDMapKey :: GCompare k => k a -> k a -> PatchDMapWithPatchingMove k (Proxy3 v)
395+swapDMapKey src dst = case src `geq` dst of
396+ Nothing -> PatchDMapWithPatchingMove $ DMap.fromList
397+ [ dst :=> NodeInfo (From_Move (src :=> Flip Proxy3)) (To_Move $ Some src)
398+ , src :=> NodeInfo (From_Move (dst :=> Flip Proxy3)) (To_Move $ Some dst)
400+ Just _ -> PatchDMapWithPatchingMove DMap.empty
402+-- | Make a @'PatchDMapWithPatchingMove' k v@ which has the effect of deleting a key in
403+-- the mapping, equivalent to 'DMap.delete'.
404+deleteDMapKey :: k a -> PatchDMapWithPatchingMove k v
405+deleteDMapKey k = PatchDMapWithPatchingMove $ DMap.singleton k $ NodeInfo From_Delete To_NonMove
408+k1, k2 :: Const2 Int () ()
411+p1, p2 :: PatchDMapWithPatchingMove (Const2 Int ()) Identity
412+p1 = moveDMapKey k1 k2
413+p2 = moveDMapKey k2 k1
416+p12Slow = p1 `mappendPatchDMapWithPatchingMoveSlow` p2
417+p21Slow = p2 `mappendPatchDMapWithPatchingMoveSlow` p1
419+testPatchDMapWithPatchingMove = do
422+ print $ p12 == deleteDMapKey k1
423+ print $ p21 == deleteDMapKey k2
424+ print $ p12Slow == deleteDMapKey k1
425+ print $ p21Slow == deleteDMapKey k2
427+dst (PatchDMapWithPatchingMove x _) = x
428+src (PatchDMapWithPatchingMove _ x) = x
431+-- | Extract the 'DMap' representing the patch changes from the
432+-- 'PatchDMapWithPatchingMove'.
433+unPatchDMapWithPatchingMove :: PatchDMapWithPatchingMove k v -> DMap k (NodeInfo k v)
434+unPatchDMapWithPatchingMove (PatchDMapWithPatchingMove p) = p
436+-- | Wrap a 'DMap' representing patch changes into a 'PatchDMapWithPatchingMove',
437+-- without checking any invariants.
439+-- __Warning:__ when using this function, you must ensure that the invariants of 'PatchDMapWithPatchingMove' are preserved; they will not be checked.
440+unsafePatchDMapWithPatchingMove :: DMap k (NodeInfo k v) -> PatchDMapWithPatchingMove k v
441+unsafePatchDMapWithPatchingMove = PatchDMapWithPatchingMove
443+-- | Wrap a 'DMap' representing patch changes into a 'PatchDMapWithPatchingMove' while
444+-- checking invariants. If the invariants are satisfied, @Right p@ is returned
445+-- otherwise @Left errors@.
446+patchDMapWithPatchingMove :: (GCompare k, GShow k) => DMap k (NodeInfo k v) -> Either [String] (PatchDMapWithPatchingMove k v)
447+patchDMapWithPatchingMove dm =
448+ case validationErrorsForPatchDMapWithPatchingMove dm of
449+ [] -> Right $ unsafePatchDMapWithPatchingMove dm
452+-- | Map a natural transform @v -> v'@ over the given patch, transforming
453+-- @'PatchDMapWithPatchingMove' k v@ into @'PatchDMapWithPatchingMove' k v'@.
454+mapPatchDMapWithPatchingMove
456+ . (forall a. PatchTarget1 p a -> PatchTarget1 p' a)
457+ -> (forall from to. p from to -> p' from to)
458+ -> PatchDMapWithPatchingMove k p
459+ -> PatchDMapWithPatchingMove k p'
460+mapPatchDMapWithPatchingMove f g (PatchDMapWithPatchingMove m) =
461+ PatchDMapWithPatchingMove $ DMap.map (\ni -> NodeInfo
462+ { _nodeInfo_from = h $ _nodeInfo_from ni
463+ , _nodeInfo_to = j $ _nodeInfo_to ni
465+ where h :: forall a. From k p a -> From k p' a
467+ From_Insert v -> From_Insert $ f v
468+ From_Delete -> From_Delete
469+ From_Move (k :=> Flip p) -> From_Move $ k :=> Flip (g p)
470+ j :: forall a. To k p a -> To k p' a
472+ To_NonMove -> To_NonMove
473+ To_Move (Some k) -> To_Move $ Some k
475+-- | Traverse an effectful function @forall a. PatchTarget1 p a -> m (v ' a)@
476+-- over the given patch, transforming @'PatchDMapWithPatchingMove' k v@ into @m
477+-- ('PatchDMapWithPatchingMove' k v')@.
478+traversePatchDMapWithPatchingMove
481+ => (forall a. PatchTarget1 p a -> m (PatchTarget1 p' a))
482+ -> (forall from to. p from to -> m (p' from to))
483+ -> PatchDMapWithPatchingMove k p
484+ -> m (PatchDMapWithPatchingMove k p')
485+traversePatchDMapWithPatchingMove f g = traversePatchDMapWithPatchingMoveWithKey
489+-- | Map an effectful function @forall a. k a -> PatchTarget1 p a -> m (v ' a)@
490+-- over the given patch, transforming @'PatchDMapWithPatchingMove' k v@ into @m
491+-- ('PatchDMapWithPatchingMove' k v')@.
492+traversePatchDMapWithPatchingMoveWithKey
495+ => (forall a. k a -> PatchTarget1 p a -> m (PatchTarget1 p' a))
496+ -> (forall from to. k from -> k to -> p from to -> m (p' from to))
497+ -> PatchDMapWithPatchingMove k p
498+ -> m (PatchDMapWithPatchingMove k p')
499+traversePatchDMapWithPatchingMoveWithKey f g (PatchDMapWithPatchingMove m) =
500+ PatchDMapWithPatchingMove <$> DMap.traverseWithKey (\k ni -> NodeInfo
501+ <$> h k (_nodeInfo_from ni)
502+ <*> j k (_nodeInfo_to ni)) m
503+ where h :: forall a. k a -> From k p a -> m (From k p' a)
505+ From_Insert v -> From_Insert <$> f k v
506+ From_Delete -> pure From_Delete
507+ From_Move (fromKey :=> Flip p) -> From_Move . (fromKey :=>) . Flip <$> g fromKey k p
508+ j :: forall a. k a -> To k p a -> m (To k p' a)
510+ To_NonMove -> pure To_NonMove
511+ To_Move (Some toKey) -> pure $ To_Move $ Some toKey
513+-- | Map a function which transforms @'From k PatchTarget1 p a@ into a @'From k
514+-- PatchTarget1 p' a@ over a @'NodeInfo' k PatchTarget1 p a@.
516+ :: (From k p a -> From k p' a)
517+ -> (To k p a -> To k p' a)
520+nodeInfoMapFrom f g ni = NodeInfo
521+ { _nodeInfo_from = f $ _nodeInfo_from ni
522+ , _nodeInfo_to = g $ _nodeInfo_to ni
525+-- | Map an effectful function which transforms @'From k PatchTarget1 p a@ into
526+-- a @f ('From k PatchTarget1 p' a)@ over a @'NodeInfo' k PatchTarget1 p a@.
529+ => (From k p a -> f (From k p' a))
530+ -> (To k p a -> f (To k p' a))
532+ -> f (NodeInfo k p' a)
533+nodeInfoMapFromM f g ni = NodeInfo
534+ <$> f (_nodeInfo_from ni)
535+ <*> g (_nodeInfo_to ni)
537+-- | Weaken a 'PatchDMapWithPatchingMove' to a 'PatchMapWithPatchingMove' by weakening the keys
538+-- from @k a@ to @'Some' k@ and applying a given weakening function
539+-- @PatchTarget1 p a -> v'@ to values.
540+weakenPatchDMapWithPatchingMoveWith
542+ . (forall a. PatchTarget1 p a -> PatchTarget p')
543+ -> (forall from to. p from to -> p')
544+ -> PatchDMapWithPatchingMove k p
545+ -> PatchMapWithPatchingMove (Some k) p'
546+weakenPatchDMapWithPatchingMoveWith f g (PatchDMapWithPatchingMove m) =
547+ PatchMapWithPatchingMove $ weakenDMapWith h m
548+ where h :: forall a. NodeInfo k p a -> MapWithPatchingMove.NodeInfo (Some k) p'
549+ h ni = MapWithPatchingMove.NodeInfo
550+ { MapWithPatchingMove._nodeInfo_from = case _nodeInfo_from ni of
551+ From_Insert v -> MapWithPatchingMove.From_Insert $ f v
552+ From_Delete -> MapWithPatchingMove.From_Delete
553+ From_Move (k :=> Flip p) -> MapWithPatchingMove.From_Move (mkSome k) $ g p
554+ , MapWithPatchingMove._nodeInfo_to = case _nodeInfo_to ni of
555+ To_NonMove -> Nothing
556+ To_Move (Some k) -> Just (mkSome k)
559+-- | "Weaken" a @'PatchDMapWithPatchingMove' (Const2 k a) v@ to a @'PatchMapWithPatchingMove' k
560+-- v'@. Weaken is in scare quotes because the 'Const2' has already disabled any
561+-- dependency in the typing and all points are already @a@, hence the function
562+-- to map each value to @v'@ is not higher rank.
563+patchDMapWithPatchingMoveToPatchMapWithPatchingMoveWith
565+ . (PatchTarget1 p a -> PatchTarget p')
567+ -> PatchDMapWithPatchingMove (Const2 k a) p
568+ -> PatchMapWithPatchingMove k p'
569+patchDMapWithPatchingMoveToPatchMapWithPatchingMoveWith f g (PatchDMapWithPatchingMove m) =
570+ PatchMapWithPatchingMove $ dmapToMapWith h m
571+ where h :: NodeInfo (Const2 k a) p a -> MapWithPatchingMove.NodeInfo k p'
572+ h ni = MapWithPatchingMove.NodeInfo
573+ { MapWithPatchingMove._nodeInfo_from = case _nodeInfo_from ni of
574+ From_Insert v -> MapWithPatchingMove.From_Insert $ f v
575+ From_Delete -> MapWithPatchingMove.From_Delete
576+ From_Move (Const2 k :=> Flip p) -> MapWithPatchingMove.From_Move k $ g p
577+ , MapWithPatchingMove._nodeInfo_to = case _nodeInfo_to ni of
578+ To_NonMove -> Nothing
579+ To_Move (Some (Const2 k)) -> Just k
582+-- | "Strengthen" a @'PatchMapWithPatchingMove' k v@ into a @'PatchDMapWithPatchingMove
583+-- ('Const2' k a)@; that is, turn a non-dependently-typed patch into a
584+-- dependently typed one but which always has a constant key type represented by
585+-- 'Const2'. Apply the given function to each @v@ to produce a @PatchTarget1 p'
586+-- a@. Completemented by 'patchDMapWithPatchingMoveToPatchMapWithPatchingMoveWith'
587+const2PatchDMapWithPatchingMoveWith
590+ -> PatchMapWithPatchingMove k (Proxy v)
591+ -> PatchDMapWithPatchingMove (Const2 k a) (Proxy3 v')
592+const2PatchDMapWithPatchingMoveWith f (PatchMapWithPatchingMove p) =
593+ PatchDMapWithPatchingMove $ DMap.fromDistinctAscList $ g <$> Map.toAscList p
594+ where g :: (k, MapWithPatchingMove.NodeInfo k (Proxy v))
595+ -> DSum (Const2 k a) (NodeInfo (Const2 k a) (Proxy3 v'))
596+ g (k, ni) = Const2 k :=> NodeInfo
597+ { _nodeInfo_from = case MapWithPatchingMove._nodeInfo_from ni of
598+ MapWithPatchingMove.From_Insert v -> From_Insert $ f v
599+ MapWithPatchingMove.From_Delete -> From_Delete
600+ MapWithPatchingMove.From_Move fromKey Proxy -> From_Move $ Const2 fromKey :=> Flip Proxy3
601+ , _nodeInfo_to = case MapWithPatchingMove._nodeInfo_to ni of
602+ Nothing -> To_NonMove
603+ Just toKey -> To_Move $ Some (Const2 toKey)
606+-- | Apply the insertions, deletions, and moves to a given 'DMap'.
607+instance ( GCompare k
609+ , PatchSource1 p ~ PatchTarget1 p
610+ ) => PatchHet (PatchDMapWithPatchingMove k p) where
611+ type PatchSource (PatchDMapWithPatchingMove k p) = DMap k (PatchSource1 p)
612+ type PatchTarget (PatchDMapWithPatchingMove k p) = DMap k (PatchTarget1 p)
614+instance ( GCompare k
616+ , PatchSource1 p ~ PatchTarget1 p
617+ ) => Patch (PatchDMapWithPatchingMove k p) where
618+ apply (PatchDMapWithPatchingMove m) old = Just $! insertions `DMap.union` (old `DMap.difference` deletions)
619+ -- TODO: return Nothing sometimes --Note: the strict application here is
620+ -- critical to ensuring that incremental merges don't hold onto all their
621+ -- prerequisite events forever; can we make this more robust?
622+ where insertions = DMap.mapMaybeWithKey insertFunc m
623+ insertFunc :: forall a. k a -> NodeInfo k p a -> Maybe (PatchTarget1 p a)
624+ insertFunc _ ni = case _nodeInfo_from ni of
625+ From_Insert v -> Just v
626+ From_Move (k :=> Flip p) -> applyAlwaysHet2 p <$> DMap.lookup k old
627+ From_Delete -> Nothing
628+ deletions = DMap.mapMaybeWithKey deleteFunc m
629+ deleteFunc :: forall a. k a -> NodeInfo k p a -> Maybe (Constant () a)
630+ deleteFunc _ ni = case _nodeInfo_from ni of
631+ From_Delete -> Just $ Constant ()
634+-- | Get the values that will be replaced, deleted, or moved if the given patch
635+-- is applied to the given 'DMap'.
638+ , PatchSource1 p ~ PatchTarget1 p
640+ => PatchDMapWithPatchingMove k p
641+ -> DMap k (PatchSource1 p)
642+ -> DMap k (Product (PatchTarget1 p) (To k p))
643+getDeletionsAndMoves (PatchDMapWithPatchingMove p) m = DMap.intersectionWithKey f m p
644+ where f _ v ni = Pair v $ _nodeInfo_to ni