Fix HLint warnings

src/Ormolu.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE BangPatterns #-}
-{-# LANGUAGE RecordWildCards #-}
 
 -- | A formatter for Haskell source code.
 module Ormolu
@@ -29,7 +28,6 @@ import Ormolu.Parser.Result
 import Ormolu.Printer
 import Ormolu.Utils (showOutputable)
 import qualified SrcLoc as GHC
-import System.IO (hGetContents, stdin)
 
 -- | Format a 'String', return formatted version as 'Text'.
 --
@@ -115,7 +113,7 @@ ormoluStdin ::
   -- | Resulting rendition
   m Text
 ormoluStdin cfg =
-  liftIO (hGetContents stdin) >>= ormolu cfg "<stdin>"
+  liftIO getContents >>= ormolu cfg "<stdin>"
 
 ----------------------------------------------------------------------------
 -- Helpers

src/Ormolu/Config.hs

@@ -1,7 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
-
 -- | Configuration options used by the tool.
 module Ormolu.Config
   ( Config (..),

src/Ormolu/Diff.hs

@@ -1,6 +1,4 @@
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE RecordWildCards #-}
 
 -- | Diffing GHC ASTs modulo span positions.
 module Ormolu.Diff
@@ -107,7 +105,7 @@ matchIgnoringSrcSpans = genericQuery
     appendSpan :: SrcSpan -> Diff -> Diff
     appendSpan s (Different ss) | fresh && helpful = Different (s : ss)
       where
-        fresh = not $ any (flip isSubspanOf s) ss
+        fresh = not $ any (`isSubspanOf` s) ss
         helpful = isGoodSrcSpan s
     appendSpan _ d = d
 

src/Ormolu/Exception.hs

@@ -49,10 +49,12 @@ instance Exception OrmoluException where
       unlines $
         [ "AST of input and AST of formatted code differ."
         ]
-          ++ ( fmap withIndent $ case fmap (\s -> "at " ++ showOutputable s) ss of
-                 [] -> ["in " ++ path]
-                 xs -> xs
-             )
+          ++ fmap
+            withIndent
+            ( case fmap (\s -> "at " ++ showOutputable s) ss of
+                [] -> ["in " ++ path]
+                xs -> xs
+            )
           ++ ["Please, consider reporting the bug."]
     OrmoluNonIdempotentOutput loc left right ->
       showParsingErr
@@ -80,12 +82,12 @@ withPrettyOrmoluExceptions m = m `catch` h
       exitWith . ExitFailure $
         case e of
           -- Error code 1 is for `error` or `notImplemented`
-          OrmoluCppEnabled _ -> 2
-          OrmoluParsingFailed _ _ -> 3
-          OrmoluOutputParsingFailed _ _ -> 4
-          OrmoluASTDiffers _ _ -> 5
-          OrmoluNonIdempotentOutput _ _ _ -> 6
-          OrmoluUnrecognizedOpts _ -> 7
+          OrmoluCppEnabled {} -> 2
+          OrmoluParsingFailed {} -> 3
+          OrmoluOutputParsingFailed {} -> 4
+          OrmoluASTDiffers {} -> 5
+          OrmoluNonIdempotentOutput {} -> 6
+          OrmoluUnrecognizedOpts {} -> 7
 
 ----------------------------------------------------------------------------
 -- Helpers

src/Ormolu/Parser.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
 -- | Parser for Haskell source code.

src/Ormolu/Parser/CommentStream.hs

@@ -1,8 +1,6 @@
-{-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE TupleSections #-}
 
 -- | Functions for working with comment stream.
 module Ormolu.Parser.CommentStream

src/Ormolu/Parser/Pragma.hs

@@ -54,7 +54,7 @@ parseExtensions :: String -> Maybe [String]
 parseExtensions str = tokenize str >>= go
   where
     go = \case
-      (L.ITconid ext : []) -> return [unpackFS ext]
+      [L.ITconid ext] -> return [unpackFS ext]
       (L.ITconid ext : L.ITcomma : xs) -> (unpackFS ext :) <$> go xs
       _ -> Nothing
 

src/Ormolu/Printer.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 
 -- | Pretty-printer for Haskell AST.

src/Ormolu/Printer/Combinators.hs

@@ -2,7 +2,6 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 
 -- | Printing combinators. The definitions here are presented in such an
 -- order so you can just go through the Haddocks and by the end of the file

src/Ormolu/Printer/Comments.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 -- | Helpers for formatting of comments. This is low-level code, use
@@ -244,11 +243,10 @@ commentFollowsElt ref mnSpn meSpn mlastSpn (L l comment) =
         Nothing -> True
         Just espn ->
           let startColumn = srcLocCol . realSrcSpanStart
-           in if startColumn espn > startColumn ref
-                then True
-                else
-                  abs (startColumn espn - startColumn l)
-                    >= abs (startColumn ref - startColumn l)
+           in startColumn espn > startColumn ref
+                || ( abs (startColumn espn - startColumn l)
+                       >= abs (startColumn ref - startColumn l)
+                   )
     continuation =
       case mlastSpn of
         Nothing -> False

src/Ormolu/Printer/Internal.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
 

src/Ormolu/Printer/Meat/Declaration.hs

@@ -257,6 +257,6 @@ patBindNames (SigPat _ p _) = patBindNames p
 patBindNames (NPat NoExt _ _ _) = []
 patBindNames (NPlusKPat NoExt (L _ n) _ _ _ _) = [n]
 patBindNames (ConPatIn _ d) = concatMap (patBindNames . unLoc) (hsConPatArgs d)
-patBindNames (ConPatOut _ _ _ _ _ _ _) = notImplemented "ConPatOut" -- created by renamer
+patBindNames ConPatOut {} = notImplemented "ConPatOut" -- created by renamer
 patBindNames (CoPat NoExt _ p _) = patBindNames p
 patBindNames (XPat p) = patBindNames (unLoc p)

src/Ormolu/Printer/Meat/Declaration/Data.hs

@@ -9,8 +9,7 @@ module Ormolu.Printer.Meat.Declaration.Data
 where
 
 import Control.Monad
-import Data.Maybe (isJust)
-import Data.Maybe (maybeToList)
+import Data.Maybe (isJust, maybeToList)
 import GHC
 import Ormolu.Printer.Combinators
 import Ormolu.Printer.Meat.Common
@@ -73,7 +72,7 @@ p_dataDecl style name tpats fixity HsDataDefn {..} = do
                   (newline >> txt "|" >> space)
           sep s (sitcc . located' p_conDecl) dd_cons
   unless (null $ unLoc dd_derivs) breakpoint
-  inci . located dd_derivs $ \xs -> do
+  inci . located dd_derivs $ \xs ->
     sep newline (located' p_hsDerivingClause) xs
 p_dataDecl _ _ _ _ (XHsDataDefn NoExt) = notImplemented "XHsDataDefn"
 

src/Ormolu/Printer/Meat/Declaration/RoleAnnotation.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE TypeFamilies #-}
 
 -- | Rendering of Role annotation declarations.

src/Ormolu/Printer/Meat/Declaration/Rule.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 
 module Ormolu.Printer.Meat.Declaration.Rule
   ( p_ruleDecls,

src/Ormolu/Printer/Meat/Declaration/TypeFamily.hs

@@ -37,8 +37,7 @@ p_famDecl style FamilyDecl {fdTyVars = HsQTvs {..}, ..} = do
         (p_rdrName fdLName)
         (located' p_hsTyVarBndr <$> hsq_explicit)
     let rsig = p_familyResultSigL fdResultSig
-    unless (isNothing rsig && isNothing fdInjectivityAnn) $
-      space
+    unless (isNothing rsig && isNothing fdInjectivityAnn) space
     inci $ do
       sequence_ rsig
       when (isJust rsig && isJust fdInjectivityAnn) breakpoint

src/Ormolu/Printer/Meat/Declaration/Value.hs

@@ -32,8 +32,7 @@ import Ormolu.Printer.Meat.Declaration.Signature
 import Ormolu.Printer.Meat.Type
 import Ormolu.Printer.Operators
 import Ormolu.Utils
-import RdrName (RdrName (..))
-import RdrName (rdrNameOcc)
+import RdrName (RdrName (..), rdrNameOcc)
 import SrcLoc (combineSrcSpans, isOneLineSpan)
 
 -- | Style of a group of equations.
@@ -456,7 +455,7 @@ p_hsLocalBinds = \case
         -- Assigns 'False' to the last element, 'True' to the rest.
         markInit :: [a] -> [(Bool, a)]
         markInit [] = []
-        markInit (x : []) = [(False, x)]
+        markInit [x] = [(False, x)]
         markInit (x : xs) = (True, x) : markInit xs
     -- NOTE When in a single-line layout, there is a chance that the inner
     -- elements will also contain semicolons and they will confuse the
@@ -838,7 +837,7 @@ p_case ::
   -- | Expression
   LHsExpr GhcPs ->
   -- | Match group
-  (MatchGroup GhcPs (Located body)) ->
+  MatchGroup GhcPs (Located body) ->
   R ()
 p_case placer render e mgroup = do
   txt "case"
@@ -1164,7 +1163,7 @@ blockPlacement ::
   (body -> Placement) ->
   [LGRHS GhcPs (Located body)] ->
   Placement
-blockPlacement placer [(L _ (GRHS NoExt _ (L _ x)))] = placer x
+blockPlacement placer [L _ (GRHS NoExt _ (L _ x))] = placer x
 blockPlacement _ _ = Normal
 
 -- | Check if given command has a hanging form.
@@ -1257,7 +1256,7 @@ p_exprOpTree isDollarSpecial s (OpBranch x op y) = do
           Hanging -> useBraces
           Normal -> dontUseBraces
       gotDollar = case getOpName (unLoc op) of
-        Just rname -> mkVarOcc "$" == (rdrNameOcc rname)
+        Just rname -> mkVarOcc "$" == rdrNameOcc rname
         _ -> False
       lhs =
         switchLayout [opTreeLoc x] $

src/Ormolu/Printer/Meat/Declaration/Warning.hs

@@ -28,14 +28,16 @@ p_warnDecl XWarnDecl {} = notImplemented "XWarnDecl"
 p_moduleWarning :: WarningTxt -> R ()
 p_moduleWarning wtxt = do
   let (pragmaText, lits) = warningText wtxt
-  switchLayout (getLoc <$> lits) $ do
-    inci $ pragma pragmaText (inci $ p_lits lits)
+  switchLayout (getLoc <$> lits)
+    $ inci
+    $ pragma pragmaText (inci $ p_lits lits)
 
 p_topLevelWarning :: [Located RdrName] -> WarningTxt -> R ()
 p_topLevelWarning fnames wtxt = do
   let (pragmaText, lits) = warningText wtxt
-  switchLayout (fmap getLoc fnames ++ fmap getLoc lits) $ do
-    pragma pragmaText . inci $ do
+  switchLayout (fmap getLoc fnames ++ fmap getLoc lits)
+    $ pragma pragmaText . inci
+    $ do
       sitcc $ sep (comma >> breakpoint) p_rdrName fnames
       breakpoint
       p_lits lits

src/Ormolu/Printer/Meat/ImportExport.hs

@@ -56,7 +56,7 @@ p_hsmodImport ImportDecl {..} = do
         when hiding (txt "hiding")
     case ideclHiding of
       Nothing -> return ()
-      Just (_, (L _ xs)) -> do
+      Just (_, L _ xs) -> do
         breakpoint
         parens N . sitcc $ do
           layout <- getLayout

src/Ormolu/Printer/Meat/Module.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 

src/Ormolu/Printer/Meat/Type.hs

@@ -84,9 +84,10 @@ p_hsType' multilineArgs = \case
   HsSumTy NoExt xs ->
     parensHash N . sitcc $
       sep (txt "|" >> breakpoint) (sitcc . located' p_hsType) xs
-  HsOpTy NoExt x op y -> sitcc $ do
-    let opTree = OpBranch (tyOpTree x) op (tyOpTree y)
-     in p_tyOpTree (reassociateOpTree Just opTree)
+  HsOpTy NoExt x op y ->
+    sitcc $
+      let opTree = OpBranch (tyOpTree x) op (tyOpTree y)
+       in p_tyOpTree (reassociateOpTree Just opTree)
   HsParTy NoExt t ->
     parens N (located t p_hsType)
   HsIParamTy NoExt n t -> sitcc $ do
@@ -126,14 +127,14 @@ p_hsType' multilineArgs = \case
       -- If both this list itself and the first element is promoted,
       -- we need to put a space in between or it fails to parse.
       case (p, xs) of
-        (IsPromoted, ((L _ t) : _)) | isPromoted t -> space
+        (IsPromoted, L _ t : _) | isPromoted t -> space
         _ -> return ()
       sitcc $ sep (comma >> breakpoint) (sitcc . located' p_hsType) xs
   HsExplicitTupleTy NoExt xs -> do
     txt "'"
     parens N $ do
       case xs of
-        ((L _ t) : _) | isPromoted t -> space
+        L _ t : _ | isPromoted t -> space
         _ -> return ()
       sep (comma >> breakpoint) (located' p_hsType) xs
   HsTyLit NoExt t ->
@@ -145,8 +146,8 @@ p_hsType' multilineArgs = \case
   where
     isPromoted = \case
       HsTyVar _ IsPromoted _ -> True
-      HsExplicitListTy _ _ _ -> True
-      HsExplicitTupleTy _ _ -> True
+      HsExplicitListTy {} -> True
+      HsExplicitTupleTy {} -> True
       _ -> False
     interArgBreak =
       if multilineArgs
@@ -158,7 +159,7 @@ p_hsType' multilineArgs = \case
 -- attached to it.
 hasDocStrings :: HsType GhcPs -> Bool
 hasDocStrings = \case
-  HsDocTy _ _ _ -> True
+  HsDocTy {} -> True
   HsFunTy _ (L _ x) (L _ y) -> hasDocStrings x || hasDocStrings y
   _ -> False
 
@@ -220,7 +221,7 @@ tyOpTree n = OpNode n
 p_tyOpTree :: OpTree (LHsType GhcPs) (Located RdrName) -> R ()
 p_tyOpTree (OpNode n) = located n p_hsType
 p_tyOpTree (OpBranch l op r) = do
-  switchLayout [opTreeLoc l] $ do
+  switchLayout [opTreeLoc l] $
     p_tyOpTree l
   breakpoint
   inci . switchLayout [opTreeLoc r] $ do

src/Ormolu/Printer/Operators.hs

@@ -129,17 +129,17 @@ buildFixityMap getOpName opTree =
       rb <- srcSpanStartLine <$> unSrcSpan (opTreeLoc r) -- right begin
       oc <- srcSpanStartCol <$> unSrcSpan (getLoc o) -- operator column
       opName <- getOpName (unLoc o)
-      let s =
-            if le < ob
-              then-- if the operator is in the beginning of a line, assign
+      let s
+            | le < ob =
+              -- if the operator is in the beginning of a line, assign
               -- a score relative to its column within range [0, 1).
-                fromIntegral oc / fromIntegral (maxCol + 1)
-              else-- if the operator is in the end of the line, assign the
+              fromIntegral oc / fromIntegral (maxCol + 1)
+            | oe < rb =
+              -- if the operator is in the end of the line, assign the
               -- score 1.
-
-                if oe < rb
-                  then 1
-                  else 2 -- otherwise, assign a high score.
+              1
+            | otherwise =
+              2 -- otherwise, assign a high score.
       return $ (opName, s) : score r
     avgScores :: [(RdrName, Double)] -> [(RdrName, Double)]
     avgScores =

tests/Ormolu/Parser/PragmaSpec.hs

@@ -4,7 +4,7 @@ import Ormolu.Parser.Pragma
 import Test.Hspec
 
 spec :: Spec
-spec = do
+spec =
   describe "parsePragma" $ do
     stdTest "{-# LANGUAGE Foo #-}" (Just (PragmaLanguage ["Foo"]))
     stdTest "{-# language Foo #-}" (Just (PragmaLanguage ["Foo"]))