foldl 1.4.6 → 1.4.7

raw patch · 3 files changed

+56/−2 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• CHANGELOG.md +4/−0
• foldl.cabal +5/−2
• src/Control/Foldl.hs +47/−0

@@ -1,3 +1,7 @@+1.4.7++* Add `foldByKey{,Hash}Map` functions+ 1.4.6  * Add `nest`/`predropWhile`/`drop`/`dropM`

@@ -1,6 +1,6 @@ Name: foldl-Version: 1.4.6-Cabal-Version: >=1.8.0.2+Version: 1.4.7+Cabal-Version: >=1.10 Build-Type: Simple License: BSD3 License-File: LICENSE@@ -49,6 +49,7 @@         Control.Foldl.Optics         Control.Foldl.Internal     GHC-Options: -O2 -Wall+    Default-Language: Haskell2010  Benchmark benchmarks     Type: exitcode-stdio-1.0@@ -59,6 +60,7 @@         criterion,         foldl     GHC-Options: -O2 -Wall -rtsopts -rtsopts -with-rtsopts=-T+    Default-Language: Haskell2010  Test-Suite doctest     Type: exitcode-stdio-1.0@@ -68,3 +70,4 @@         base,         doctest >= 0.16     GHC-Options: -threaded+    Default-Language: Haskell2010

@@ -39,6 +39,7 @@ {-# LANGUAGE ExistentialQuantification #-} {-# LANGUAGE FlexibleContexts          #-} {-# LANGUAGE RankNTypes                #-}+{-# LANGUAGE ScopedTypeVariables       #-} {-# LANGUAGE Trustworthy               #-}  module Control.Foldl (@@ -99,7 +100,9 @@     , set     , hashSet     , map+    , foldByKeyMap     , hashMap+    , foldByKeyHashMap     , vector     , vectorM @@ -151,6 +154,7 @@ import Data.Foldable (Foldable) import Data.Functor.Identity (Identity, runIdentity) import Data.Functor.Contravariant (Contravariant(..))+import Data.HashMap.Strict (HashMap) import Data.Map.Strict (Map, alter) import Data.Maybe (fromMaybe) import Data.Monoid hiding ((<>))@@ -940,6 +944,28 @@     done = id {-# INLINABLE map #-} ++{- | Given a 'Fold', produces a 'Map' which applies that fold to each @a@ separated by key @k@.++>>> fold (foldByKeyMap Control.Foldl.sum) [("a",1), ("b",2), ("b",20), ("a",10)]+fromList [("a",11),("b",22)]+-}+foldByKeyMap :: forall k a b. Ord k => Fold a b -> Fold (k, a) (Map k b)+foldByKeyMap f = case f of+  Fold (step0 :: x -> a -> x) (ini0 :: x) (end0 :: x -> b) ->+    let+      step :: Map k x -> (k,a) -> Map k x+      step mp (k,a) = Map.alter addToMap k mp where+        addToMap Nothing         = Just $ step0 ini0 a+        addToMap (Just existing) = Just $ step0 existing a++      ini :: Map k x+      ini = Map.empty++      end :: Map k x -> Map k b+      end = fmap end0+    in Fold step ini end where+ {-| Fold pairs into a hash-map. -}@@ -950,6 +976,27 @@     step m (k, v) = HashMap.insert k v m     done = id {-# INLINABLE hashMap #-}++{- | Given a 'Fold', produces a 'HashMap' which applies that fold to each @a@ separated by key @k@.++>>> fold (foldByKeyHashMap Control.Foldl.sum) [("a",1), ("b",2), ("b",20), ("a",10)]+fromList [("a",11),("b",22)]+-}+foldByKeyHashMap :: forall k a b. (Hashable k, Eq k) => Fold a b -> Fold (k, a) (HashMap k b)+foldByKeyHashMap f = case f of+  Fold (step0 :: x -> a -> x) (ini0 :: x) (end0 :: x -> b) ->+    let+      step :: HashMap k x -> (k,a) -> HashMap k x+      step mp (k,a) = HashMap.alter addToHashMap k mp where+        addToHashMap Nothing         = Just $ step0 ini0 a+        addToHashMap (Just existing) = Just $ step0 existing a++      ini :: HashMap k x+      ini = HashMap.empty++      end :: HashMap k x -> HashMap k b+      end = fmap end0+    in Fold step ini end where  -- | Fold all values into a vector vector :: Vector v a => Fold a (v a)