@@ -45,7 +45,7 @@ import Data.Kind (Type)
4545import Data.Type.Equality ((:~:) (..), TestEquality (..))
4646import Data.List (intercalate, nubBy)
4747import Data.Maybe (fromMaybe)
48−import Data.Primitive.Array (Array, MutableArray, indexArray, mapArray', readArray, sizeofArray,
48+import Data.Primitive.Array (Array, MutableArray, indexArray, mapArray', sizeofArray,
4949 thawArray, unsafeFreezeArray, writeArray)
5050import Data.Primitive.PrimArray (writePrimArray, newPrimArray, unsafeFreezePrimArray, primArrayToList, MutablePrimArray, primArrayFromListN, PrimArray, indexPrimArray, sizeofPrimArray)
5151import Data.Semigroup (Semigroup (..), All(..))
@@ -180,27 +180,38 @@ one x = TypeRepMap (primArrayFromListN 1 [fa])
180180{- |
181181
182182Insert a value into a 'TypeRepMap'.
183+TypeRepMap optimizes for fast reads rather than inserts, as a trade-off inserts are @O(n)@.
183184
184185prop> size (insert v tm) >= size tm
185186prop> member @a (insert (x :: f a) tm) == True
186187
187188-}
188189insert :: forall a f . Typeable a => f a -> TypeRepMap f -> TypeRepMap f
189−insert x = fromTriples . addX . toTriples
190+insert x m
191+ | size m == 0 = one x
192+ | otherwise = case cachedBinarySearch (typeFp @a) (fingerprintAs m) (fingerprintBs m) of
193+ Nothing -> union m $ one x
194+ Just i -> m {trAnys = changeAnyArr i (trAnys m)}
190195 where
191− tripleX :: (Fingerprint, Any, Any)
192− tripleX@(fpX, _, _) = (calcFp @a, toAny x, unsafeCoerce $ typeRep @a)
193−
194− addX :: [(Fingerprint, Any, Any)] -> [(Fingerprint, Any, Any)]
195− addX l = tripleX : deleteByFst fpX l
196+ changeAnyArr :: Int -> Array Any -> Array Any
197+ changeAnyArr i trAs = runST $ do
198+ let n = sizeofArray trAs
199+ mutArr <- thawArray trAs 0 n
200+ writeArray mutArr i $ toAny x
201+ unsafeFreezeArray mutArr
196202{-# INLINE insert #-}
197203
198204-- Extract the kind of a type. We use it to work around lack of syntax for
199205-- inferred type variables (which are not subject to type applications).
200206type KindOf (a :: k) = k
201207
208+type ArgKindOf (f :: k -> l) = k
209+
202210{- | Delete a value from a 'TypeRepMap'.
203211
212+TypeRepMap optimizes for fast reads rather than modifications, as a trade-off deletes are
213+@O(n)@, with an @O(log(n))@ optimization for when the element is already missing.
214+
204215prop> size (delete @a tm) <= size tm
205216prop> member @a (delete @a tm) == False
206217
@@ -213,30 +224,60 @@ False
213224True
214225-}
215226delete :: forall a (f :: KindOf a -> Type) . Typeable a => TypeRepMap f -> TypeRepMap f
216−delete = fromTriples . deleteByFst (typeFp @a) . toTriples
227+delete m
228+ -- Lookups are fast, so check if we even have the element first.
229+ | not (member @a m) = m
230+ -- We know we have the element, If the map has exactly one element, we can return the empty map
231+ | size m == 1 = empty
232+ -- Otherwise, filter out the element in linear time.
233+ | otherwise = fromSortedTriples . deleteFirst ((== typeFp @a) . fst3) . toSortedTriples $ m
217234{-# INLINE delete #-}
218235
236+deleteFirst :: (a -> Bool) -> [a] -> [a]
237+deleteFirst _ [] = []
238+deleteFirst p (x : xs) = if p x then xs else x : deleteFirst p xs
239+
219240{- |
220−Update a value at a specific key with the result of the provided function. When
221−the key is not a member of the map, the original map is returned.
241+Update a value at a specific key with the result of the provided function.
242+When the key is not a member of the map, the original map is returned.
222243
223244>>> trmap = fromList @(TypeRepMap Identity) [WrapTypeable $ Identity "a"]
224245>>> lookup @String $ adjust (fmap (++ "ww")) trmap
225246Just (Identity "aww")
226247-}
227248adjust :: forall a f . Typeable a => (f a -> f a) -> TypeRepMap f -> TypeRepMap f
228−adjust fun tr = case cachedBinarySearch (typeFp @a) (fingerprintAs tr) (fingerprintBs tr) of
229− Nothing -> tr
230− Just i -> tr {trAnys = changeAnyArr i (trAnys tr)}
249+adjust fun = alter (fmap fun)
250+{-# INLINE adjust #-}
251+
252+{- |
253+Updates a value at a specific key, whether or not it exists.
254+This can be used to insert, delete, or update a value of a given type in the map.
255+
256+>>> func = (\case Nothing -> Just (Identity "new"); Just (Identity s) -> Just (Identity (reverse s)))
257+>>> lookup @String $ alter func empty
258+Just (Identity "new")
259+>>> trmap = fromList @(TypeRepMap Identity) [WrapTypeable $ Identity "helllo"]
260+>>> lookup @String $ alter func trmap
261+>>> Just (Identity "olleh")
262+-}
263+alter :: forall a f . Typeable a => (Maybe (f a) -> Maybe (f a)) -> TypeRepMap f -> TypeRepMap f
264+alter fun tr = case cachedBinarySearch (typeFp @a) (fingerprintAs tr) (fingerprintBs tr) of
265+ Nothing ->
266+ case (fun Nothing) of
267+ Nothing -> tr
268+ Just v -> insert v tr
269+ Just i ->
270+ case fun (Just . fromAny $ indexArray (trAnys tr) i) of
271+ Nothing -> delete @a tr
272+ Just v -> tr{trAnys = replaceAnyAt i (toAny v) (trAnys tr)}
231273 where
232− changeAnyArr :: Int -> Array Any -> Array Any
233− changeAnyArr i trAs = runST $ do
274+ replaceAnyAt :: Int -> Any -> Array Any -> Array Any
275+ replaceAnyAt i v trAs = runST $ do
234276 let n = sizeofArray trAs
235277 mutArr <- thawArray trAs 0 n
236− a <- toAny . fun . fromAny <$> readArray mutArr i
237− writeArray mutArr i a
278+ writeArray mutArr i v
238279 unsafeFreezeArray mutArr
239−{-# INLINE adjust #-}
280+{-# INLINE alter #-}
240281
241282{- | Map over the elements of a 'TypeRepMap'.
242283
@@ -311,6 +352,48 @@ union :: TypeRepMap f -> TypeRepMap f -> TypeRepMap f
311352union = unionWith const
312353{-# INLINE union #-}
313354
355+-- | The 'intersection' of two 'TypeRepMap's using a combining function
356+--
357+-- @O(n + m)@
358+intersectionWith :: forall f. (forall x. Typeable x => f x -> f x -> f x) -> TypeRepMap f -> TypeRepMap f -> TypeRepMap f
359+intersectionWith f ma mb =
360+ fromSortedTriples $ mergeMaps (toSortedTriples ma) (toSortedTriples mb)
361+ where
362+ f' :: forall x. TypeRep x -> f x -> f x -> f x
363+ f' tr = withTypeable tr f
364+
365+ combine :: (Fingerprint, Any, Any) -> (Fingerprint, Any, Any) -> (Fingerprint, Any, Any)
366+ combine (fp, av, ak) (_, bv, _) = (fp, toAny $ f' (fromAny ak) (fromAny av) (fromAny bv), ak)
367+
368+ -- Merges two typrepmaps into a sorted, dedup'd list of triples.
369+ mergeMaps :: [(Fingerprint, Any, Any)] -> [(Fingerprint, Any, Any)] -> [(Fingerprint, Any, Any)]
370+ -- If either list is empty, the intersection must be finished.
371+ mergeMaps _ [] = []
372+ mergeMaps [] _ = []
373+ -- Merge the two maps considering one element at a time.
374+ mergeMaps (a@(af, _, _) : as) (b@(bf, _, _) : bs) =
375+ case compare af bf of
376+ -- Fingerprints are equal, union the elements using our function
377+ -- If the incoming maps were de-duped, there shouldn't be any other equivalent
378+ -- fingerprints
379+ EQ -> combine a b : mergeMaps as bs
380+ -- First fingerprint must not be in the second map or we would have seen it by now
381+ -- Skip it an move on
382+ LT -> mergeMaps as (b : bs)
383+ -- Second fingerprint must not be in the first map or we would have seen it by now
384+ -- Skip it an move on
385+ GT -> mergeMaps (a:as) bs
386+{-# INLINE intersectionWith #-}
387+
388+-- | The intersection of two 'TypeRepMap's.
389+-- It keeps all values from the first map whose keys are present in the second.
390+--
391+-- @O(n + m)@
392+intersection :: TypeRepMap f -> TypeRepMap f -> TypeRepMap f
393+intersection = intersectionWith const
394+{-# INLINE intersection #-}
395+
396+
314397{- | Check if a value of the given type is present in a 'TypeRepMap'.
315398
316399>>> member @Char $ one (Identity 'a')
@@ -346,9 +429,22 @@ size = sizeofPrimArray . fingerprintAs
346429
347430-- | Return the list of 'SomeTypeRep' from the keys.
348431keys :: TypeRepMap f -> [SomeTypeRep]
349−keys TypeRepMap{..} = SomeTypeRep . anyToTypeRep <$> toList trKeys
432+keys = keysWith SomeTypeRep
350433{-# INLINE keys #-}
351434
435+-- | Return the list of keys by wrapping them with a user-provided function.
436+keysWith :: (forall (a :: ArgKindOf f). TypeRep a -> r) -> TypeRepMap f -> [r]
437+keysWith f TypeRepMap{..} = f . anyToTypeRep <$> toList trKeys
438+{-# INLINE keysWith #-}
439+
440+-- | Return the list of key-value pairs by wrapping them with a user-provided function.
441+toListWith :: forall f r. (forall (a :: ArgKindOf f). Typeable a => f a -> r) -> TypeRepMap f -> [r]
442+toListWith f = map toF . toTriples
443+ where
444+ withTypeRep :: TypeRep a -> f a -> r
445+ withTypeRep tr an = withTypeable tr $ f an
446+ toF (_, an, k) = withTypeRep (unsafeCoerce k) (fromAny an)
447+
352448-- | Binary searched based on this article
353449-- http://bannalia.blogspot.com/2015/06/cache-friendly-binary-search.html
354450-- with modification for our two-vector search case.
@@ -407,9 +503,6 @@ toSortedTriples tm = trip <$> ordering
407503 ordering :: [ Int ]
408504 ordering = generateOrderMapping (size tm)
409505
410−deleteByFst :: Eq a => a -> [(a, b, c)] -> [(a, b, c)]
411−deleteByFst x = filter ((/= x) . fst3)
412−
413506nubByFst :: (Eq a) => [(a, b, c)] -> [(a, b, c)]
414507nubByFst = nubBy ((==) `on` fst3)
415508
@@ -428,9 +521,6 @@ data WrapTypeable f where
428521instance Show (WrapTypeable f) where
429522 show (WrapTypeable (_ :: f a)) = show $ calcFp @a
430523
431−wrapTypeable :: TypeRep a -> f a -> WrapTypeable f
432−wrapTypeable tr = withTypeable tr WrapTypeable
433−
434524{- |
435525
436526prop> fromList . toList == 'id'
@@ -458,10 +548,7 @@ instance IsList (TypeRepMap f) where
458548 k (WrapTypeable (_ :: f a)) = unsafeCoerce $ typeRep @a
459549
460550 toList :: TypeRepMap f -> [WrapTypeable f]
461− toList = map toWrapTypeable . toTriples
462− where
463− toWrapTypeable :: (Fingerprint, Any, Any) -> WrapTypeable f
464− toWrapTypeable (_, an, k) = wrapTypeable (unsafeCoerce k) (fromAny an)
551+ toList = toListWith WrapTypeable
465552
466553calcFp :: forall a . Typeable a => Fingerprint
467554calcFp = typeRepFingerprint $ typeRep @a