Follow hlint suggestion: redundant lambda

- Satisfy fourmolu
- Use partial type sig to avoid -XFlexibleContexts
- Fixes the "Non type-variable argument" error
- Import GenEntry from Codec.Archive.Tar
- Styling change only, use less vertical space
- Remove comment and -XScopedTypeVariables
- Add unpack and unpackT
- More reuse of unpackNormalFile
- Renaming, unpackCheck and unpackCheckM
- Move helper functions next to other helpers
- Satisfy fourmolu after rebasing

Author: philderbeast

.hlint.yaml

@@ -7,7 +7,6 @@
 - ignore: {name: "Redundant $!"} # 3 hints
 - ignore: {name: "Redundant guard"} # 1 hint
 - ignore: {name: "Redundant if"} # 6 hints
-- ignore: {name: "Redundant lambda"} # 16 hints
 - ignore: {name: "Redundant multi-way if"} # 1 hint
 - ignore: {name: "Redundant return"} # 7 hints
 - ignore: {name: "Use ++"} # 4 hints

Cabal/src/Distribution/Compat/Async.hs

@@ -72,7 +72,7 @@ withAsyncNF m = inline withAsyncUsing forkIO (m >>= evaluateNF)
 withAsyncUsing :: (IO () -> IO ThreadId) -> IO a -> (AsyncM a -> IO b) -> IO b
 -- The bracket version works, but is slow.  We can do better by
 -- hand-coding it:
-withAsyncUsing doFork = \action inner -> do
+withAsyncUsing doFork action inner = do
   var <- newEmptyMVar
   mask $ \restore -> do
     t <- doFork $ try (restore action) >>= putMVar var

Cabal/src/Distribution/Simple/BuildTarget.hs

@@ -611,13 +611,13 @@ showComponentKindShort BenchKind = "bench"
 --
 
 matchComponent1 :: [ComponentInfo] -> String -> Match BuildTarget
-matchComponent1 cs = \str1 -> do
+matchComponent1 cs str1 = do
   guardComponentName str1
   c <- matchComponentName cs str1
   return (BuildTargetComponent (cinfoName c))
 
 matchComponent2 :: [ComponentInfo] -> String -> String -> Match BuildTarget
-matchComponent2 cs = \str1 str2 -> do
+matchComponent2 cs str1 str2 = do
   ckind <- matchComponentKind str1
   guardComponentName str2
   c <- matchComponentKindAndName cs ckind str2
@@ -666,7 +666,7 @@ matchComponentKindAndName cs ckind str =
 --
 
 matchModule1 :: [ComponentInfo] -> String -> Match BuildTarget
-matchModule1 cs = \str1 -> do
+matchModule1 cs str1 = do
   guardModuleName str1
   nubMatchErrors $ do
     c <- tryEach cs
@@ -675,7 +675,7 @@ matchModule1 cs = \str1 -> do
     return (BuildTargetModule (cinfoName c) m)
 
 matchModule2 :: [ComponentInfo] -> String -> String -> Match BuildTarget
-matchModule2 cs = \str1 str2 -> do
+matchModule2 cs str1 str2 = do
   guardComponentName str1
   guardModuleName str2
   c <- matchComponentName cs str1

Cabal/src/Distribution/Simple/GHC/Build/ExtraSources.hs

@@ -171,108 +171,108 @@ buildExtraSources
   ghcProg
   buildTargetDir
   (neededLibWays, neededFLibWay, neededExeWay)
-  verbHandles =
-    \PreBuildComponentInputs{buildingWhat, localBuildInfo = lbi, targetInfo} -> do
-      let
-        bi = componentBuildInfo (targetComponent targetInfo)
-        verbosity = mkVerbosity verbHandles $ buildingWhatVerbosity buildingWhat
-        clbi = targetCLBI targetInfo
-        isIndef = componentIsIndefinite clbi
-        mbWorkDir = mbWorkDirLBI lbi
-        i = interpretSymbolicPath mbWorkDir
-        sources = viewSources (targetComponent targetInfo)
-        comp = compiler lbi
-        platform = hostPlatform lbi
-        tempFileOptions = commonSetupTempFileOptions $ buildingWhatCommonFlags buildingWhat
-        runGhcProg =
-          runGHCWithResponseFile
-            "ghc.rsp"
-            Nothing
-            tempFileOptions
-            verbosity
-            ghcProg
-            comp
-            platform
-            mbWorkDir
+  verbHandles
+  PreBuildComponentInputs{buildingWhat, localBuildInfo = lbi, targetInfo} = do
+    let
+      bi = componentBuildInfo (targetComponent targetInfo)
+      verbosity = mkVerbosity verbHandles $ buildingWhatVerbosity buildingWhat
+      clbi = targetCLBI targetInfo
+      isIndef = componentIsIndefinite clbi
+      mbWorkDir = mbWorkDirLBI lbi
+      i = interpretSymbolicPath mbWorkDir
+      sources = viewSources (targetComponent targetInfo)
+      comp = compiler lbi
+      platform = hostPlatform lbi
+      tempFileOptions = commonSetupTempFileOptions $ buildingWhatCommonFlags buildingWhat
+      runGhcProg =
+        runGHCWithResponseFile
+          "ghc.rsp"
+          Nothing
+          tempFileOptions
+          verbosity
+          ghcProg
+          comp
+          platform
+          mbWorkDir
 
-        buildAction :: SymbolicPath Pkg File -> IO ()
-        buildAction sourceFile = do
-          let baseSrcOpts =
-                componentSourceGhcOptions
-                  (verbosityLevel verbosity)
-                  lbi
-                  bi
-                  clbi
-                  buildTargetDir
-                  sourceFile
-              vanillaSrcOpts =
-                -- -fPIC is used in case you are using the repl
-                -- of a dynamically linked GHC
-                baseSrcOpts{ghcOptFPic = toFlag True}
-              profSrcOpts =
-                vanillaSrcOpts
-                  <> mempty
-                    { ghcOptProfilingMode = toFlag True
-                    }
-              sharedSrcOpts =
-                vanillaSrcOpts
-                  <> mempty
-                    { ghcOptFPic = toFlag True
-                    , ghcOptDynLinkMode = toFlag GhcDynamicOnly
-                    }
-              profSharedSrcOpts =
-                vanillaSrcOpts
-                  <> mempty
-                    { ghcOptProfilingMode = toFlag True
-                    , ghcOptFPic = toFlag True
-                    , ghcOptDynLinkMode = toFlag GhcDynamicOnly
-                    }
-              -- TODO: Placing all Haskell, C, & C++ objects in a single directory
-              --       Has the potential for file collisions. In general we would
-              --       consider this a user error. However, we should strive to
-              --       add a warning if this occurs.
-              odir = fromFlag (ghcOptObjDir vanillaSrcOpts)
+      buildAction :: SymbolicPath Pkg File -> IO ()
+      buildAction sourceFile = do
+        let baseSrcOpts =
+              componentSourceGhcOptions
+                (verbosityLevel verbosity)
+                lbi
+                bi
+                clbi
+                buildTargetDir
+                sourceFile
+            vanillaSrcOpts =
+              -- -fPIC is used in case you are using the repl
+              -- of a dynamically linked GHC
+              baseSrcOpts{ghcOptFPic = toFlag True}
+            profSrcOpts =
+              vanillaSrcOpts
+                <> mempty
+                  { ghcOptProfilingMode = toFlag True
+                  }
+            sharedSrcOpts =
+              vanillaSrcOpts
+                <> mempty
+                  { ghcOptFPic = toFlag True
+                  , ghcOptDynLinkMode = toFlag GhcDynamicOnly
+                  }
+            profSharedSrcOpts =
+              vanillaSrcOpts
+                <> mempty
+                  { ghcOptProfilingMode = toFlag True
+                  , ghcOptFPic = toFlag True
+                  , ghcOptDynLinkMode = toFlag GhcDynamicOnly
+                  }
+            -- TODO: Placing all Haskell, C, & C++ objects in a single directory
+            --       Has the potential for file collisions. In general we would
+            --       consider this a user error. However, we should strive to
+            --       add a warning if this occurs.
+            odir = fromFlag (ghcOptObjDir vanillaSrcOpts)
 
-              compileIfNeeded :: GhcOptions -> IO ()
-              compileIfNeeded opts = do
-                needsRecomp <- checkNeedsRecompilation mbWorkDir sourceFile opts
-                when needsRecomp $ runGhcProg opts
+            compileIfNeeded :: GhcOptions -> IO ()
+            compileIfNeeded opts = do
+              needsRecomp <- checkNeedsRecompilation mbWorkDir sourceFile opts
+              when needsRecomp $ runGhcProg opts
 
-          createDirectoryIfMissingVerbose verbosity True (i odir)
-          case targetComponent targetInfo of
-            -- For libraries, we compile extra objects in the four ways: vanilla, shared, profiled and profiled shared.
-            -- We suffix shared objects with `.dyn_o`, profiled ones with `.p_o` and profiled shared ones with `.p_dyn_o`.
-            CLib _lib
-              -- Unless for repl, in which case we only need the vanilla way
-              | BuildRepl _ <- buildingWhat ->
-                  compileIfNeeded vanillaSrcOpts
-              | otherwise ->
-                  do
-                    forM_ (neededLibWays isIndef) $ \case
-                      StaticWay -> compileIfNeeded vanillaSrcOpts
-                      DynWay -> compileIfNeeded sharedSrcOpts{ghcOptObjSuffix = toFlag "dyn_o"}
-                      ProfWay -> compileIfNeeded profSrcOpts{ghcOptObjSuffix = toFlag "p_o"}
-                      ProfDynWay -> compileIfNeeded profSharedSrcOpts{ghcOptObjSuffix = toFlag "p_dyn_o"}
-            CFLib flib ->
-              case neededFLibWay (withDynFLib flib) of
-                StaticWay -> compileIfNeeded vanillaSrcOpts
-                DynWay -> compileIfNeeded sharedSrcOpts
-                ProfWay -> compileIfNeeded profSrcOpts
-                ProfDynWay -> compileIfNeeded profSharedSrcOpts
-            -- For the remaining component types (Exec, Test, Bench), we also
-            -- determine with which options to build the objects (vanilla vs shared vs
-            -- profiled), but predicate is the same for the three kinds.
-            _exeLike ->
-              case neededExeWay of
-                StaticWay -> compileIfNeeded vanillaSrcOpts
-                DynWay -> compileIfNeeded sharedSrcOpts
-                ProfWay -> compileIfNeeded profSrcOpts
-                ProfDynWay -> compileIfNeeded profSharedSrcOpts
+        createDirectoryIfMissingVerbose verbosity True (i odir)
+        case targetComponent targetInfo of
+          -- For libraries, we compile extra objects in the four ways: vanilla, shared, profiled and profiled shared.
+          -- We suffix shared objects with `.dyn_o`, profiled ones with `.p_o` and profiled shared ones with `.p_dyn_o`.
+          CLib _lib
+            -- Unless for repl, in which case we only need the vanilla way
+            | BuildRepl _ <- buildingWhat ->
+                compileIfNeeded vanillaSrcOpts
+            | otherwise ->
+                do
+                  forM_ (neededLibWays isIndef) $ \case
+                    StaticWay -> compileIfNeeded vanillaSrcOpts
+                    DynWay -> compileIfNeeded sharedSrcOpts{ghcOptObjSuffix = toFlag "dyn_o"}
+                    ProfWay -> compileIfNeeded profSrcOpts{ghcOptObjSuffix = toFlag "p_o"}
+                    ProfDynWay -> compileIfNeeded profSharedSrcOpts{ghcOptObjSuffix = toFlag "p_dyn_o"}
+          CFLib flib ->
+            case neededFLibWay (withDynFLib flib) of
+              StaticWay -> compileIfNeeded vanillaSrcOpts
+              DynWay -> compileIfNeeded sharedSrcOpts
+              ProfWay -> compileIfNeeded profSrcOpts
+              ProfDynWay -> compileIfNeeded profSharedSrcOpts
+          -- For the remaining component types (Exec, Test, Bench), we also
+          -- determine with which options to build the objects (vanilla vs shared vs
+          -- profiled), but predicate is the same for the three kinds.
+          _exeLike ->
+            case neededExeWay of
+              StaticWay -> compileIfNeeded vanillaSrcOpts
+              DynWay -> compileIfNeeded sharedSrcOpts
+              ProfWay -> compileIfNeeded profSrcOpts
+              ProfDynWay -> compileIfNeeded profSharedSrcOpts
 
-      -- build any sources
-      if null sources || componentIsIndefinite clbi
-        then return mempty
-        else do
-          info verbosity ("Building " ++ description ++ "...")
-          traverse_ buildAction sources
-          return (toNubListR sources)
+    -- build any sources
+    if null sources || componentIsIndefinite clbi
+      then return mempty
+      else do
+        info verbosity ("Building " ++ description ++ "...")
+        traverse_ buildAction sources
+        return (toNubListR sources)

Cabal/src/Distribution/Simple/SrcDist.hs

@@ -429,7 +429,7 @@ filterAutogenModules pkg_descr0 =
         }
     pathsModule = autogenPathsModuleName pkg_descr0
     packageInfoModule = autogenPackageInfoModuleName pkg_descr0
-    filterFunction bi = \mn ->
+    filterFunction bi mn =
       mn /= pathsModule
         && mn /= packageInfoModule
         && notElem mn (autogenModules bi)

cabal-install-solver/src/Distribution/Solver/Modular/Preference.hs

@@ -254,21 +254,21 @@ enforcePackageConstraints pcs = go
     go (PChoiceF qpn@(Q _ pn) rdm gr                    ts) =
       let c = varToConflictSet (P qpn)
           -- compose the transformation functions for each of the relevant constraint
-          g = \ (POption i _) -> foldl (\ h pc -> h . processPackageConstraintP qpn c i pc)
+          g (POption i _) = foldl (\ h pc -> h . processPackageConstraintP qpn c i pc)
                                        id
                                        (M.findWithDefault [] pn pcs)
       in PChoiceF qpn rdm gr        (W.mapWithKey g ts)
     go (FChoiceF qfn@(FN qpn@(Q _ pn) f) rdm gr tr m d ts) =
       let c = varToConflictSet (F qfn)
           -- compose the transformation functions for each of the relevant constraint
-          g = \ b -> foldl (\ h pc -> h . processPackageConstraintF qpn f c b pc)
+          g b = foldl (\ h pc -> h . processPackageConstraintF qpn f c b pc)
                            id
                            (M.findWithDefault [] pn pcs)
       in FChoiceF qfn rdm gr tr m d (W.mapWithKey g ts)
     go (SChoiceF qsn@(SN qpn@(Q _ pn) f) rdm gr tr   ts) =
       let c = varToConflictSet (S qsn)
           -- compose the transformation functions for each of the relevant constraint
-          g = \ b -> foldl (\ h pc -> h . processPackageConstraintS qpn f c b pc)
+          g b = foldl (\ h pc -> h . processPackageConstraintS qpn f c b pc)
                            id
                            (M.findWithDefault [] pn pcs)
       in SChoiceF qsn rdm gr tr     (W.mapWithKey g ts)

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

@@ -2082,7 +2082,7 @@ guardPackageFile _ (FileStatusExistsFile file)
 guardPackageFile str _ = matchErrorExpected "package .cabal file" str
 
 matchPackage :: [KnownPackage] -> String -> FileStatus -> Match KnownPackage
-matchPackage pinfo = \str fstatus ->
+matchPackage pinfo str fstatus =
   orNoThingIn "project" "" $
     matchPackageName pinfo str
       </> ( matchPackageNameUnknown str
@@ -2091,7 +2091,7 @@ matchPackage pinfo = \str fstatus ->
           )
 
 matchPackageName :: [KnownPackage] -> String -> Match KnownPackage
-matchPackageName ps = \str -> do
+matchPackageName ps str = do
   guard (validPackageName str)
   orNoSuchThing
     "package"

cabal-install/tests/UnitTests/Distribution/Client/FetchUtils.hs

@@ -78,7 +78,7 @@ testHttp = withFakeRepoCtxt get200 $ \repoCtxt repo -> do
       pkgId' @?= pkgId
     _ -> assertFailure $ "expected RepoTarballPackage, got " ++ show res
   where
-    get200 = \_uri -> return 200
+    get200 _uri = return 200
 
 testGetInterrupt :: Assertion
 testGetInterrupt = testGetAny UserInterrupt