diff --git a/CaseBi.hs b/CaseBi.hs --- a/CaseBi.hs +++ b/CaseBi.hs @@ -2,6 +2,7 @@ -- Module : CaseBi -- Copyright : (c) OleksandrZhabenko 2019 -- License : MIT +-- Stability : Experimental -- Maintainer : olexandr543@yahoo.com -- -- A library that can be used as a @case ... of@ constuction analogue for the multiple @Ord a => a -> b@ transformations and data representation. diff --git a/CaseBi/Unboxed.hs b/CaseBi/Unboxed.hs new file mode 100644 --- /dev/null +++ b/CaseBi/Unboxed.hs @@ -0,0 +1,87 @@ +-- | +-- Module : CaseBi.Unboxed +-- Copyright : (c) OleksandrZhabenko 2019-2020 +-- License : MIT +-- Stability : Experimental +-- Maintainer : olexandr543@yahoo.com +-- + +module CaseBi.Unboxed ( +-- * Function that can be used instead of @case ... of@ construction +-- +-- > case var of +-- > a1 -> b1 +-- > a2 -> b2 +-- > a3 -> b3 +-- > ... +-- > an -> bn +-- > _ -> def +-- +-- for efficiency or other data representation + getBFst', getBFst, getBFstV, +-- * Additional functions that are used to sort a list of pairs (which can be obtained e. g. by 'Prelude.zip') + sortFst, sortFstV, +-- ** Function that can be used for changing the @Vector (a, b)@ during its creation + filterP +) where + +import qualified Data.Vector.Unboxed as V (Vector,unsafeIndex,unsafeSlice,length,fromList,map) +import qualified Data.List as L (groupBy,nubBy) +import Data.Vector.Unboxed.Base + +-- | A variant of the 'CaseBi.getBFst'' function that operates on the unboxed 'V.Vector'. +-- +getBFst' + :: (Ord a, Unbox a, Unbox b) + => (b, V.Vector (a, b)) -- ^ @b@ is a default value that can be substituted if there is no correspendence in the set of @(a, b)@ tuples (the 'otherwise' or irrefutable pattern analogue). Vector of the @(a, b)@ tuples that must be sorted in ascending order for the first argument. If there are several pairs @(a, b)@ with the same @a@, the function gives a resulting @b@ as if there is only the first one + -> a -- ^ an element for which the corresponding resulting b must be found + -> b -- ^ the result +getBFst' (def, vec) l | if compare l (fst (V.unsafeIndex vec 0)) == LT then True else compare l (fst (V.unsafeIndex vec (V.length vec - 1))) == GT = def + | compare (V.length vec) 2 /= LT = if compare l (fst (V.unsafeIndex vec ((V.length vec `quot` 2) - 1))) /= GT + then getBFst' (def, (V.unsafeSlice 0 (V.length vec `quot` 2) vec)) l + else getBFst' (def, (V.unsafeSlice (V.length vec `quot` 2) (V.length vec - (V.length vec `quot` 2)) vec)) l + | otherwise = snd (V.unsafeIndex vec 0) +{-# INLINE getBFst' #-} + +-- | A variant of the 'CaseBi.getBFstV' that operates on the unboxed 'V.Vector'. +-- +getBFstV :: (Ord a, Unbox a, Unbox b) => V.Vector (a, b) -- ^ Vector of the @(a, b)@ tuples that are sorted in ascending order for the first argument + -> b -- ^ a default value that can be substituted if there is no correspendence in the set of @(a, b)@ tuples (the 'otherwise' or irrefutable pattern analogue) + -> V.Vector a -- ^ a Vector needed to be transformed accordingly to the correct @(a, b)@ tuple pairs + -> V.Vector b -- ^ the resulting Vector +getBFstV c y = V.map (getBFst' (y, c)) +{-# INLINE getBFstV #-} + +-- | A variant of the 'CaseBi.getBFst' that operates on the unboxed 'V.Vector'. +-- +getBFst :: (Ord a, Unbox a, Unbox b) => V.Vector (a, b) -- ^ Vector of the @(a, b)@ tuples that must be sorted in ascending order for the first argument + -> b -- ^ a default value that can be substituted if there is no correspendence in the set of @(a, b)@ tuples (the 'otherwise' or irrefutable pattern analogue) + -> [a] -- ^ a list of values needed to be transformed accordingly to the correct @(a, b)@ tuple pairs + -> [b] -- ^ the resulting list +getBFst c y = map (getBFst' (y, c)) +{-# INLINE getBFst #-} + +-- | A variant of the 'CaseBi.sortFst' that operates on the unboxed 'V.Vector'. It is inspired by the work: https://wiki.haskell.org/Introduction +sortFst :: (Ord a, Unbox a, Unbox b) => [(a, b)] -> [(a, b)] +sortFst xs = if null xs then [] else sortFst (filter (\(x, _) -> compare x (fst (head xs)) == LT) xs) ++ filter (\(x, _) -> x == (fst (head xs))) xs ++ + sortFst (filter (\(x, _) -> compare x (fst (head xs)) == GT) xs) +{-# INLINE sortFst #-} + +-- | A variant of the 'CaseBi.sortFstV' that operates on the unboxed 'V.Vector'. +-- +sortFstV + :: (Ord a, Unbox a, Unbox b) => [(a, b)] -- ^ The list of conditions that is then converted to the corresponding Vector + -> V.Vector (a, b) -- ^ the resulting sorted Vector that can be used further in getBFst' and its successors. +sortFstV = V.fromList . L.nubBy (\(x, _) (y, _) -> x == y) . sortFst +{-# INLINE sortFstV #-} + +-- | A variant of the 'CaseBi.filterP' that operates on the unboxed 'V.Vector'. +filterP + :: (Ord a, Unbox a, Unbox b) => ((a, b) -> Bool) -- ^ The predicate @p@ used to select the only one value of @b@ in the pairs @(a, b)@ with the same @a@. + -- ^ If there are several pairs @(a, b)@ for the same @a@ that satisfies a predicate then the first one is used. For large @[(a, b)]@ + -- ^ it can be rather complex. + -> [(a, b)] -- ^ The list of @(a, b)@ sorted in the ascending order by the first element a (e. g. by the 'sortFst' function) + -> V.Vector (a, b) -- ^ The resulting filtered @Vector (a, b)@ that can be used for getFstB' and its successor functions. +-- +filterP p xs = V.fromList . concatMap (\x -> take 1 . dropWhile (not . p) $ x) . L.groupBy (\(x1,_) (x2,_) -> x1 == x2) $ xs +{-# INLINE filterP #-} diff --git a/ChangeLog.md b/ChangeLog.md --- a/ChangeLog.md +++ b/ChangeLog.md @@ -6,7 +6,7 @@ ## 0.1.3.0 -- 2019-09-27 -* First release revised B. Some performance changes and changing the imported functions. +* First release revised B. Some performance changes and changing the imported functions. Moreover, fixed constraints in cabal file. Make more exact the vector usage. ## 0.1.4.0 -- 2019-09-28 @@ -35,4 +35,8 @@ ## 0.1.8.0 -- 2020-05-14 * First version revised H. Changed the dependency bounds so that it now can be compiled with GHC 8.10* series. Some documentation improvements. + +## 0.2.0.0 -- 2020-10-15 + +* Second version. Added a new module CaseBi.Unboxed with functions that operate on the unboxed vectors. diff --git a/README.md b/README.md --- a/README.md +++ b/README.md @@ -2,3 +2,4 @@ mmsyn2 is the library that can be used for multiple (Ord a) => a -> b transformations. +Since the 0.2.0.0 version there are two modules with the similar functionality: for boxed and unboxed vectors. The last one is probably more efficient in some cases. diff --git a/mmsyn2.cabal b/mmsyn2.cabal --- a/mmsyn2.cabal +++ b/mmsyn2.cabal @@ -2,7 +2,7 @@ -- see http://haskell.org/cabal/users-guide/ name: mmsyn2 -version: 0.1.8.0 +version: 0.2.0.0 synopsis: The library that can be used for multiple (Ord a) => a -> b transformations description: The library that can be used for optimization or another representation of multiple (Ord a) => a -> b transformations homepage: https://oleksandrzhabenko.github.io/mmsyn2 @@ -10,14 +10,14 @@ license-file: LICENSE author: OleksandrZhabenko maintainer: olexandr543@yahoo.com --- copyright: +copyright: Oleksandr Zhabenko category: Development build-type: Simple extra-source-files: ChangeLog.md README.md cabal-version: >=1.10 library - exposed-modules: CaseBi + exposed-modules: CaseBi, CaseBi.Unboxed -- other-modules: -- other-extensions: build-depends: base >=4.3 && <4.15, vector >=0.11 && <0.14