Merge pull request #11189 from cabalism/hlint/first-second

HLint: use first and use second

Author: mergify[bot]

.hlint.yaml

@@ -28,20 +28,19 @@
 - ignore: {name: "Use ++"} # 4 hints
 - ignore: {name: "Use :"} # 28 hints
 - ignore: {name: "Use <$"} # 2 hints
-- ignore: {name: "Use <$>"} # 88 hints
+- ignore: {name: "Use <$>"} # 89 hints
 - ignore: {name: "Use <&>"} # 16 hints
 - ignore: {name: "Use <=<"} # 4 hints
 - ignore: {name: "Use =<<"} # 7 hints
-- ignore: {name: "Use =="} # 3 hints
+- ignore: {name: "Use =="} # 2 hints
 - ignore: {name: "Use >=>"} # 3 hints
 - ignore: {name: "Use Down"} # 3 hints
 - ignore: {name: "Use bimap"} # 7 hints
 - ignore: {name: "Use camelCase"} # 96 hints
 - ignore: {name: "Use catMaybes"} # 4 hints
 - ignore: {name: "Use concatMap"} # 2 hints
 - ignore: {name: "Use const"} # 37 hints
-- ignore: {name: "Use first"} # 5 hints
-- ignore: {name: "Use fmap"} # 24 hints
+- ignore: {name: "Use fmap"} # 23 hints
 - ignore: {name: "Use fold"} # 1 hint
 - ignore: {name: "Use fromMaybe"} # 5 hints
 - ignore: {name: "Use fst"} # 2 hints
@@ -57,7 +56,6 @@
 - ignore: {name: "Use record patterns"} # 16 hints
 - ignore: {name: "Use replicateM_"} # 2 hints
 - ignore: {name: "Use rights"} # 2 hints
-- ignore: {name: "Use second"} # 7 hints
 - ignore: {name: "Use section"} # 18 hints
 - ignore: {name: "Use tuple-section"} # 28 hints
 - ignore: {name: "Use typeRep"} # 2 hints

Cabal-syntax/src/Distribution/Compat/Graph.hs

@@ -128,7 +128,7 @@ instance Show a => Show (Graph a) where
   show = show . toList
 
 instance (IsNode a, Read a, Show (Key a)) => Read (Graph a) where
-  readsPrec d s = map (\(a, r) -> (fromDistinctList a, r)) (readsPrec d s)
+  readsPrec d s = map (first fromDistinctList) (readsPrec d s)
 
 instance (IsNode a, Binary a, Show (Key a)) => Binary (Graph a) where
   put x = put (toList x)

Cabal/src/Distribution/Simple/BuildTarget.hs

@@ -40,6 +40,7 @@ module Distribution.Simple.BuildTarget
   , reportBuildTargetProblems
   ) where
 
+import Data.Bifunctor (second)
 import Distribution.Compat.Prelude
 import Prelude ()
 
@@ -407,7 +408,7 @@ reportBuildTargetProblems verbosity problems = do
     targets ->
       dieWithException verbosity $
         UnknownBuildTarget $
-          map (\(target, nosuch) -> (showUserBuildTarget target, nosuch)) targets
+          map (first showUserBuildTarget) targets
 
   case [(t, ts) | BuildTargetAmbiguous t ts <- problems] of
     [] -> return ()
@@ -652,7 +653,7 @@ matchComponentKindAndName cs ckind str =
   orNoSuchThing (showComponentKind ckind ++ " component") str $
     increaseConfidenceFor $
       matchInexactly
-        (\(ck, cn) -> (ck, caseFold cn))
+        (second caseFold)
         [((cinfoKind c, cinfoStrName c), c) | c <- cs]
         (ckind, str)
 

Cabal/src/Distribution/Utils/MapAccum.hs

@@ -1,13 +1,14 @@
 module Distribution.Utils.MapAccum (mapAccumM) where
 
+import Data.Bifunctor (second)
 import Distribution.Compat.Prelude
 import Prelude ()
 
 -- Like StateT but with return tuple swapped
 newtype StateM s m a = StateM {runStateM :: s -> m (s, a)}
 
 instance Functor m => Functor (StateM s m) where
-  fmap f (StateM x) = StateM $ \s -> fmap (\(s', a) -> (s', f a)) (x s)
+  fmap f (StateM x) = StateM $ \s -> fmap (second f) (x s)
 
 instance Monad m => Applicative (StateM s m) where
   pure x = StateM $ \s -> return (s, x)

cabal-install/src/Distribution/Client/IndexUtils/ActiveRepos.hs

@@ -11,6 +11,7 @@ module Distribution.Client.IndexUtils.ActiveRepos
   , organizeByRepos
   ) where
 
+import Data.Bifunctor (second)
 import Distribution.Client.Compat.Prelude
 import Distribution.Client.Types.RepoName (RepoName (..))
 import Prelude ()
@@ -177,12 +178,10 @@ organizeByRepos (ActiveRepos xs0) sel ys0 =
     go :: [a] -> [ActiveRepoEntry] -> [a] -> Either String ([a], [(a, CombineStrategy)])
     go _rest [] ys = Right (ys, [])
     go rest (ActiveRepoRest s : xs) ys =
-      go rest xs ys <&> \(rest', result) ->
-        (rest', map (\x -> (x, s)) rest ++ result)
+      go rest xs ys <&> second (map (\x -> (x, s)) rest ++)
     go rest (ActiveRepo r s : xs) ys = do
       (z, zs) <- extract r ys
-      go rest xs zs <&> \(rest', result) ->
-        (rest', (z, s) : result)
+      go rest xs zs <&> second ((z, s) :)
 
     extract :: RepoName -> [a] -> Either String (a, [a])
     extract r = loop id

cabal-install/src/Distribution/Client/ProjectConfig.hs

@@ -76,6 +76,7 @@ module Distribution.Client.ProjectConfig
   , maxNumFetchJobs
   ) where
 
+import Data.Bifunctor (second)
 import Distribution.Client.Compat.Prelude hiding (empty)
 import Distribution.Parsec.Source
 import Distribution.Simple.Utils
@@ -1681,7 +1682,7 @@ syncAndReadSourcePackagesRemoteRepos
               repoPaths
 
           mapGroup :: Ord k => [(k, v)] -> [(k, NonEmpty v)]
-          mapGroup = Map.toList . Map.fromListWith (<>) . map (\(k, v) -> (k, pure v))
+          mapGroup = Map.toList . Map.fromListWith (<>) . map (second pure)
 
           -- The repos in a group are given distinct names by simple enumeration
           -- foo, foo-2, foo-3 etc

cabal-install/src/Distribution/Client/ProjectOrchestration.hs

@@ -853,7 +853,7 @@ availableTargetIndexes installPlan = AvailableTargetIndexes{..}
     availableTargetsByPackageNameAndComponentName =
       Map.mapKeysWith
         (++)
-        (\(pkgid, cname) -> (packageName pkgid, cname))
+        (first packageName)
         availableTargetsByPackageIdAndComponentName
 
     availableTargetsByPackageNameAndUnqualComponentName
@@ -952,7 +952,7 @@ availableTargetIndexesFromSourcePackages pkgSpecifiers = AvailableTargetIndexes{
     availableTargetsByPackageNameAndComponentName =
       Map.mapKeysWith
         (++)
-        (\(pkgid, cname) -> (packageName pkgid, cname))
+        (first packageName)
         availableTargetsByPackageIdAndComponentName
 
     availableTargetsByPackageNameAndUnqualComponentName

cabal-install/src/Distribution/Client/TargetSelector.hs

@@ -100,6 +100,7 @@ import Control.Arrow ((&&&))
 import Control.Monad hiding
   ( mfilter
   )
+import Data.Bifunctor (second)
 #if MIN_VERSION_base(4,20,0)
 import Data.Functor as UZ (unzip)
 #else
@@ -827,7 +828,7 @@ reportTargetSelectorProblems verbosity problems = do
     targets ->
       dieWithException verbosity $
         NoSuchTargetSelectorErr $
-          map (\(target, nosuch) -> (showTargetString target, nosuch)) targets
+          map (first showTargetString) targets
 
   case [(t, ts) | TargetSelectorAmbiguous t ts <- problems] of
     [] -> return ()
@@ -2186,7 +2187,7 @@ matchComponentKindAndName cs ckind str =
     (map render cs)
     $ increaseConfidenceFor
     $ matchInexactly
-      (\(ck, cn) -> (ck, caseFold cn))
+      (second caseFold)
       (\c -> (cinfoKind c, cinfoStrName c))
       cs
       (ckind, str)

cabal-install/tests/UnitTests/Distribution/Solver/Modular/Builder.hs

@@ -4,6 +4,7 @@ module UnitTests.Distribution.Solver.Modular.Builder
 
 import Distribution.Solver.Modular.Builder
 
+import Data.Bifunctor (second)
 import Test.Tasty
 import Test.Tasty.QuickCheck
 
@@ -15,7 +16,7 @@ tests =
 -- | Simpler splits implementation
 splits' :: [a] -> [(a, [a])]
 splits' [] = []
-splits' (x : xs) = (x, xs) : map (\(y, ys) -> (y, x : ys)) (splits' xs)
+splits' (x : xs) = (x, xs) : map (second (x :)) (splits' xs)
 
 splitsTest :: [Int] -> Property
 splitsTest xs = splits' xs === splits xs