Apply some hlint suggestions, silence some others.

Author: peterwicksstringfield

GenChangelogs.hs

@@ -24,7 +24,7 @@ main = do
 
   prs <- github' $ pullRequestsForR "haskell" "haskell-language-server" stateClosed FetchAll
   let prsAfterLastTag = either (error . show)
-                        (foldMap (\pr -> if inRange pr then [pr] else []))
+                        (foldMap (\pr -> [pr | inRange pr]))
                         prs
       inRange pr
         | Just mergedDate <- simplePullRequestMergedAt pr = mergedDate > lastDate

ghcide/.hlint.yaml

@@ -11,7 +11,6 @@
 - ignore: {name: "Redundant do"}
 - ignore: {name: "Avoid lambda"}
 - ignore: {name: "Use newtype instead of data"}
-- ignore: {name: "Use fromMaybe"}
 - ignore: {name: "Use unless"}
 - ignore: {name: "Move brackets to avoid $"}
 - ignore: {name: "Eta reduce"}
@@ -25,6 +24,16 @@
 - ignore: {name: "Use uncurry"}
 - ignore: {name: "Avoid lambda using `infix`"}
 
+# We are using the "redundant" return/pure to assign a name. We do not want to
+# delete it. In particular, this is not an improvement:
+# Found:
+#   do options <- somethingComplicated
+#      pure options
+# Perhaps:
+#   do somethingComplicated
+- ignore: {name: "Redundant return"}
+- ignore: {name: "Redundant pure"}
+
 # Off by default hints we like
 - warn: {name: Use module export list}
 

ghcide/src/Development/IDE/Spans/AtPoint.hs

@@ -56,7 +56,7 @@ documentHighlight hf rf pos = MaybeT $ pure (Just highlights)
     ns = concat $ pointCommand hf pos (rights . M.keys . nodeIdentifiers . nodeInfo)
     highlights = do
       n <- ns
-      ref <- maybe [] id (M.lookup (Right n) rf)
+      ref <- fromMaybe [] (M.lookup (Right n) rf)
       pure $ makeHighlight ref
     makeHighlight (sp,dets) =
       DocumentHighlight (realSrcSpanToRange sp) (Just $ highlightType $ identInfo dets)
@@ -199,5 +199,3 @@ pointCommand hf pos k =
    sp fs = mkRealSrcSpan (sloc fs) (sloc fs)
    line = _line pos
    cha = _character pos
-
-

hls-plugin-api/src/Ide/PluginUtils.hs

@@ -142,7 +142,7 @@ clientSupportsDocumentChanges caps =
         WorkspaceEditClientCapabilities mDc <- _workspaceEdit wCaps
         mDc
   in
-    fromMaybe False supports
+    Just True == supports
 
 -- ---------------------------------------------------------------------
 
@@ -226,7 +226,7 @@ allLspCmdIds' pid mp = mkPlugin (allLspCmdIds pid) (Just . pluginCommands)
 
 
 allLspCmdIds :: T.Text -> [(PluginId, [PluginCommand ideState])] -> [T.Text]
-allLspCmdIds pid commands = concat $ map go commands
+allLspCmdIds pid commands = concatMap go commands
   where
     go (plid, cmds) = map (mkLspCmdId pid plid . commandId) cmds
 

install/src/Cabal.hs

@@ -96,7 +96,7 @@ getProjectFile ver = do
             else "cabal.project"
 
 checkCabal_ :: [String] -> Action ()
-checkCabal_ args = checkCabal args >> return ()
+checkCabal_ args = void $ checkCabal args
 
 -- | check `cabal` has the required version
 checkCabal :: [String] -> Action String

install/src/Env.hs

@@ -54,7 +54,7 @@ findInstalledGhcs = do
     -- sort by version to make it coherent with getHlsVersions
     $ sortBy (comparing fst)
     -- nub by version. knownGhcs takes precedence.
-    $ nubBy ((==) `on` fst)
+    $ nubOrdBy (compare `on` fst)
     -- filter out stack provided GHCs (assuming that stack programs path is the default one in linux)
     $ filter (not . isInfixOf ".stack" . snd) (knownGhcs ++ availableGhcs)
 

install/src/Print.hs

@@ -25,7 +25,7 @@ printInStars = liftIO . putStrLn . embedInStars
 
 -- | Trim whitespace of both ends of a string
 trim :: String -> String
-trim = dropWhileEnd isSpace . dropWhile isSpace
+trim = trimEnd . trimStart
 
 -- | Trim the whitespace of the stdout of a command
 trimmedStdout :: Stdout String -> String

plugins/default/src/Ide/Plugin/Fourmolu.hs

@@ -100,7 +100,7 @@ provider lf ideState typ contents fp fo = withIndefiniteProgress lf title Cancel
 
 convertDynFlags :: DynFlags -> IO [DynOption]
 convertDynFlags df =
-    let pp = if null p then [] else ["-pgmF=" <> p]
+    let pp = ["-pgmF=" <> p | not (null p)]
         p = D.sPgm_F $ D.settings df
         pm = map (("-fplugin=" <>) . moduleNameString) $ D.pluginModNames df
         ex = map showExtension $ S.toList $ D.extensionFlags df

plugins/default/src/Ide/Plugin/Ormolu.hs

@@ -45,7 +45,7 @@ provider lf ideState typ contents fp _ = withIndefiniteProgress lf title Cancell
       let
         pp =
           let p = D.sPgm_F $ D.settings df
-          in  if null p then [] else ["-pgmF=" <> p]
+          in  ["-pgmF=" <> p | not (null p)]
         pm = map (("-fplugin=" <>) . moduleNameString) $ D.pluginModNames df
         ex = map showExtension $ S.toList $ D.extensionFlags df
       in

plugins/default/src/Ide/Plugin/Pragmas.hs

@@ -14,6 +14,7 @@ module Ide.Plugin.Pragmas
 import           Control.Lens                    hiding (List)
 import           Data.Aeson
 import qualified Data.HashMap.Strict             as H
+import           Data.Maybe                      (catMaybes)
 import qualified Data.Text                       as T
 import           Development.IDE                 as D
 import qualified GHC.Generics                    as Generics
@@ -85,7 +86,7 @@ codeActionProvider _ state _plId docId _ (J.CodeActionContext (J.List diags) _mo
             disabled
               | Just dynFlags <- mDynflags
                 -- GHC does not export 'OnOff', so we have to view it as string
-              = [ e | Just e <- T.stripPrefix "Off " . T.pack . prettyPrint <$> extensions dynFlags]
+              = catMaybes $ T.stripPrefix "Off " . T.pack . prettyPrint <$> extensions dynFlags
               | otherwise
                 -- When the module failed to parse, we don't have access to its
                 -- dynFlags. In that case, simply don't disable any pragmas.