Add the proper HLint rules and remove redundant keywords from compiler

6 files changed, 37 insertions, 38 deletions

diff --git a/compiler/GHC/Rename/Bind.hs b/compiler/GHC/Rename/Bind.hs
index 9215ef26fc..953d3c2c9b 100644
--- a/compiler/GHC/Rename/Bind.hs
+++ b/compiler/GHC/Rename/Bind.hs
@@ -885,7 +885,7 @@ rnMethodBindLHS :: Bool -> Name
                 -> LHsBindsLR GhcRn GhcPs
                 -> RnM (LHsBindsLR GhcRn GhcPs)
 rnMethodBindLHS _ cls (L loc bind@(FunBind { fun_id = name })) rest
-  = setSrcSpan loc $ do
+  = setSrcSpan loc $
     do { sel_name <- wrapLocM (lookupInstDeclBndr cls (text "method")) name
                      -- We use the selector name as the binder
        ; let bind' = bind { fun_id = sel_name, fun_ext = noExtField }
@@ -1034,7 +1034,7 @@ renameSig _ctxt sig@(CompleteMatchSig _ s (L l bf) mty)
        new_mty  <- traverse lookupLocatedOccRn mty
 
        this_mod <- fmap tcg_mod getGblEnv
-       unless (any (nameIsLocalOrFrom this_mod . unLoc) new_bf) $ do
+       unless (any (nameIsLocalOrFrom this_mod . unLoc) new_bf) $
          -- Why 'any'? See Note [Orphan COMPLETE pragmas]
          addErrCtxt (text "In" <+> ppr sig) $ failWithTc orphanError
 
@@ -1173,20 +1173,20 @@ rnMatch :: Outputable (body GhcPs) => HsMatchContext GhcRn
         -> RnM (LMatch GhcRn (Located (body GhcRn)), FreeVars)
 rnMatch ctxt rnBody = wrapLocFstM (rnMatch' ctxt rnBody)
 
+-- Note that there are no local fixity decls for matches
 rnMatch' :: Outputable (body GhcPs) => HsMatchContext GhcRn
          -> (Located (body GhcPs) -> RnM (Located (body GhcRn), FreeVars))
          -> Match GhcPs (Located (body GhcPs))
          -> RnM (Match GhcRn (Located (body GhcRn)), FreeVars)
-rnMatch' ctxt rnBody (Match { m_ctxt = mf, m_pats = pats, m_grhss = grhss })
-  = do  { -- Note that there are no local fixity decls for matches
-        ; rnPats ctxt pats      $ \ pats' -> do
+rnMatch' ctxt rnBody (Match { m_ctxt = mf, m_pats = pats, m_grhss = grhss }) =
+  rnPats ctxt pats $ \ pats' -> do
         { (grhss', grhss_fvs) <- rnGRHSs ctxt rnBody grhss
         ; let mf' = case (ctxt, mf) of
-                      (FunRhs { mc_fun = L _ funid }, FunRhs { mc_fun = L lf _ })
-                                            -> mf { mc_fun = L lf funid }
-                      _                     -> ctxt
+                      (FunRhs { mc_fun = L _ funid }, FunRhs { mc_fun = L lf _ }) ->
+                           mf { mc_fun = L lf funid }
+                      _ -> ctxt
         ; return (Match { m_ext = noExtField, m_ctxt = mf', m_pats = pats'
-                        , m_grhss = grhss'}, grhss_fvs ) }}
+                        , m_grhss = grhss'}, grhss_fvs ) }
 
 emptyCaseErr :: HsMatchContext GhcRn -> SDoc
 emptyCaseErr ctxt = hang (text "Empty list of alternatives in" <+> pp_ctxt)
diff --git a/compiler/GHC/Rename/Expr.hs b/compiler/GHC/Rename/Expr.hs
index 14218b01f6..b38b4679b1 100644
--- a/compiler/GHC/Rename/Expr.hs
+++ b/compiler/GHC/Rename/Expr.hs
@@ -108,16 +108,16 @@ finishHsVar (L l name)
       ; return (HsVar noExtField (L l name), unitFV name) }
 
 rnUnboundVar :: RdrName -> RnM (HsExpr GhcRn, FreeVars)
-rnUnboundVar v
- = do { if isUnqual v
-        then -- Treat this as a "hole"
-             -- Do not fail right now; instead, return HsUnboundVar
-             -- and let the type checker report the error
-             return (HsUnboundVar noExtField (rdrNameOcc v), emptyFVs)
+rnUnboundVar v =
+  if isUnqual v
+  then -- Treat this as a "hole"
+       -- Do not fail right now; instead, return HsUnboundVar
+       -- and let the type checker report the error
+       return (HsUnboundVar noExtField (rdrNameOcc v), emptyFVs)
 
-        else -- Fail immediately (qualified name)
-             do { n <- reportUnboundName v
-                ; return (HsVar noExtField (noLoc n), emptyFVs) } }
+  else -- Fail immediately (qualified name)
+       do { n <- reportUnboundName v
+          ; return (HsVar noExtField (noLoc n), emptyFVs) }
 
 rnExpr (HsVar _ (L l v))
   = do { opt_DuplicateRecordFields <- xoptM LangExt.DuplicateRecordFields
@@ -847,10 +847,10 @@ rnStmt ctxt rnBody (L loc (BindStmt _ pat body)) thing_inside
         -- but it does not matter because the names are unique
 
 rnStmt _ _ (L loc (LetStmt _ (L l binds))) thing_inside
-  = do  { rnLocalBindsAndThen binds $ \binds' bind_fvs -> do
+  =     rnLocalBindsAndThen binds $ \binds' bind_fvs -> do
         { (thing, fvs) <- thing_inside (collectLocalBinders binds')
         ; return ( ([(L loc (LetStmt noExtField (L l binds')), bind_fvs)], thing)
-                 , fvs) }  }
+                 , fvs) }
 
 rnStmt ctxt rnBody (L loc (RecStmt { recS_stmts = rec_stmts })) thing_inside
   = do  { (return_op, fvs1)  <- lookupQualifiedDoStmtName ctxt returnMName
diff --git a/compiler/GHC/Rename/Module.hs b/compiler/GHC/Rename/Module.hs
index f815cd5c4a..d535f008ae 100644
--- a/compiler/GHC/Rename/Module.hs
+++ b/compiler/GHC/Rename/Module.hs
@@ -449,8 +449,8 @@ checkCanonicalInstances cls poly_ty mbinds = do
     --  * Warn if '(*>)' is defined backwards (i.e. @(*>) = (>>)@).
     --
     checkCanonicalMonadInstances refURL
-      | cls == applicativeClassName  = do
-          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $ do
+      | cls == applicativeClassName =
+          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $
               case mbind of
                   FunBind { fun_id = L _ name
                           , fun_matches = mg }
@@ -464,8 +464,8 @@ checkCanonicalInstances cls poly_ty mbinds = do
 
                   _ -> return ()
 
-      | cls == monadClassName  = do
-          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $ do
+      | cls == monadClassName =
+          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $
               case mbind of
                   FunBind { fun_id = L _ name
                           , fun_matches = mg }
@@ -495,8 +495,8 @@ checkCanonicalInstances cls poly_ty mbinds = do
     --  * Warn if '(<>)' is defined backwards (i.e. @(<>) = mappend@).
     --
     checkCanonicalMonoidInstances refURL
-      | cls == semigroupClassName  = do
-          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $ do
+      | cls == semigroupClassName =
+          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $
               case mbind of
                   FunBind { fun_id      = L _ name
                           , fun_matches = mg }
@@ -506,8 +506,8 @@ checkCanonicalInstances cls poly_ty mbinds = do
 
                   _ -> return ()
 
-      | cls == monoidClassName  = do
-          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $ do
+      | cls == monoidClassName =
+          forM_ (bagToList mbinds) $ \(L loc mbind) -> setSrcSpan loc $
               case mbind of
                   FunBind { fun_id = L _ name
                           , fun_matches = mg }
@@ -531,7 +531,7 @@ checkCanonicalInstances cls poly_ty mbinds = do
     isAliasMG _ = Nothing
 
     -- got "lhs = rhs" but expected something different
-    addWarnNonCanonicalMethod1 refURL flag lhs rhs = do
+    addWarnNonCanonicalMethod1 refURL flag lhs rhs =
         addWarn (Reason flag) $ vcat
                        [ text "Noncanonical" <+>
                          quotes (text (lhs ++ " = " ++ rhs)) <+>
@@ -545,7 +545,7 @@ checkCanonicalInstances cls poly_ty mbinds = do
                        ]
 
     -- expected "lhs = rhs" but got something else
-    addWarnNonCanonicalMethod2 refURL flag lhs rhs = do
+    addWarnNonCanonicalMethod2 refURL flag lhs rhs =
         addWarn (Reason flag) $ vcat
                        [ text "Noncanonical" <+>
                          quotes (text lhs) <+>
diff --git a/compiler/GHC/Rename/Names.hs b/compiler/GHC/Rename/Names.hs
index ac8117e4a1..cde4fe6d4a 100644
--- a/compiler/GHC/Rename/Names.hs
+++ b/compiler/GHC/Rename/Names.hs
@@ -1025,7 +1025,7 @@ filterImports iface decl_spec (Just (want_hiding, L l import_items))
         -- different parents).  See Note [Dealing with imports]
     lookup_ie :: IE GhcPs
               -> IELookupM ([(IE GhcRn, AvailInfo)], [IELookupWarning])
-    lookup_ie ie = handle_bad_import $ do
+    lookup_ie ie = handle_bad_import $
       case ie of
         IEVar _ (L l n) -> do
             (name, avail, _) <- lookup_name ie $ ieWrappedName n
diff --git a/compiler/GHC/Rename/Splice.hs b/compiler/GHC/Rename/Splice.hs
index c18074097d..48378ba670 100644
--- a/compiler/GHC/Rename/Splice.hs
+++ b/compiler/GHC/Rename/Splice.hs
@@ -37,17 +37,16 @@ import Control.Monad    ( unless, when )
 
 import {-# SOURCE #-} GHC.Rename.Expr ( rnLExpr )
 
-import GHC.Tc.Utils.Env     ( checkWellStaged )
-import GHC.Builtin.Names.TH ( liftName )
+import GHC.Tc.Utils.Env     ( checkWellStaged, tcMetaTy )
 
 import GHC.Driver.Session
 import GHC.Data.FastString
 import GHC.Utils.Error  ( dumpIfSet_dyn_printer, DumpFormat (..) )
 import GHC.Utils.Panic
-import GHC.Tc.Utils.Env ( tcMetaTy )
 import GHC.Driver.Hooks
-import GHC.Builtin.Names.TH ( quoteExpName, quotePatName, quoteDecName, quoteTypeName
-                            , decsQTyConName, expQTyConName, patQTyConName, typeQTyConName, )
+import GHC.Builtin.Names.TH ( decsQTyConName, expQTyConName, liftName
+                            , patQTyConName, quoteDecName, quoteExpName
+                            , quotePatName, quoteTypeName, typeQTyConName)
 
 import {-# SOURCE #-} GHC.Tc.Gen.Expr   ( tcCheckPolyExpr )
 import {-# SOURCE #-} GHC.Tc.Gen.Splice
diff --git a/compiler/GHC/Rename/Utils.hs b/compiler/GHC/Rename/Utils.hs
index a29a8b6602..68d453a68f 100644
--- a/compiler/GHC/Rename/Utils.hs
+++ b/compiler/GHC/Rename/Utils.hs
@@ -366,8 +366,8 @@ checkUnusedRecordWildcard :: SrcSpan
                           -> FreeVars
                           -> Maybe [Name]
                           -> RnM ()
-checkUnusedRecordWildcard _ _ Nothing    = return ()
-checkUnusedRecordWildcard loc _ (Just [])  = do
+checkUnusedRecordWildcard _ _ Nothing     = return ()
+checkUnusedRecordWildcard loc _ (Just []) =
   -- Add a new warning if the .. pattern binds no variables
   setSrcSpan loc $ warnRedundantRecordWildcard
 checkUnusedRecordWildcard loc fvs (Just dotdot_names) =