Fix various warnings for dhall package (#2363)

Author: Gabriella439

.hlint.yaml

@@ -31,6 +31,12 @@
 - ignore: {name: "Use ."}
 - ignore: {name: "Use list comprehension"}
 - ignore: {name: "Use fromMaybe"}
+- ignore: {name: "Avoid lambda using `infix`"}
+- ignore: {name: "Use tuple-section"}
+- ignore: {name: "Use <$>"}
+- ignore: {name: "Redundant <$>"}
+- ignore: {name: "Replace case with maybe"}
+- ignore: {name: "Replace case with fromMaybe"}
 
 
 # Specify additional command line arguments

dhall/src/Dhall.hs

@@ -1,23 +1,15 @@
 {-# LANGUAGE ApplicativeDo              #-}
 {-# LANGUAGE ConstraintKinds            #-}
-{-# LANGUAGE DefaultSignatures          #-}
-{-# LANGUAGE DeriveFunctor              #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
-{-# LANGUAGE MultiWayIf                 #-}
 {-# LANGUAGE OverloadedStrings          #-}
 {-# LANGUAGE PolyKinds                  #-}
 {-# LANGUAGE RankNTypes                 #-}
 {-# LANGUAGE RecordWildCards            #-}
 {-# LANGUAGE ScopedTypeVariables        #-}
-{-# LANGUAGE TupleSections              #-}
-{-# LANGUAGE TypeApplications           #-}
 {-# LANGUAGE TypeFamilies               #-}
-{-# LANGUAGE TypeOperators              #-}
 {-# LANGUAGE UndecidableInstances       #-}
-{-# LANGUAGE ViewPatterns               #-}
 
 {-| Please read the "Dhall.Tutorial" module, which contains a tutorial explaining
     how to use the language, the compiler, and this library

dhall/src/Dhall/Deriving.hs

@@ -1,7 +1,6 @@
 {-# LANGUAGE AllowAmbiguousTypes  #-}
 {-# LANGUAGE DataKinds            #-}
 {-# LANGUAGE FlexibleContexts     #-}
-{-# LANGUAGE KindSignatures       #-}
 {-# LANGUAGE PolyKinds            #-}
 {-# LANGUAGE ScopedTypeVariables  #-}
 {-# LANGUAGE TypeApplications     #-}

dhall/src/Dhall/Eval.hs

@@ -10,8 +10,6 @@
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE ViewPatterns         #-}
 
-{-# OPTIONS_GHC -O #-}
-
 {-| Eval-apply environment machine with conversion checking and quoting to
     normal forms. Fairly similar to GHCI's STG machine algorithmically, but much
     simpler, with no known call optimization or environment trimming.

dhall/src/Dhall/Format.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE LambdaCase        #-}
-{-# LANGUAGE NamedFieldPuns    #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
 

dhall/src/Dhall/Freeze.hs

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

dhall/src/Dhall/Import.hs

@@ -9,7 +9,6 @@
 {-# LANGUAGE RecordWildCards     #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications    #-}
-{-# LANGUAGE ViewPatterns        #-}
 
 {-# OPTIONS_GHC -Wall #-}
 

dhall/src/Dhall/Import/Types.hs

@@ -50,7 +50,7 @@ instance Pretty Chained where
     pretty (Chained import_) = pretty import_
 
 -- | An import that has been fully interpeted
-data ImportSemantics = ImportSemantics
+newtype ImportSemantics = ImportSemantics
     { importSemantics :: Expr Void Void
     -- ^ The fully resolved import, typechecked and beta-normal.
     }

dhall/src/Dhall/Main.hs

@@ -361,7 +361,7 @@ parseMode =
       where
         -- Parse explicit stdin in the input filepaths
         parseStdin inputs
-            | any (== InputFile "-") inputs = StandardInput : filter (/= InputFile "-") inputs
+            | InputFile "-" `elem` inputs = StandardInput : filter (/= InputFile "-") inputs
             | otherwise = inputs
 
         f = fromMaybe (pure StandardInput) . nonEmpty . parseStdin . fmap InputFile

dhall/src/Dhall/Marshal/Decode.hs

@@ -7,14 +7,12 @@
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
-{-# LANGUAGE MultiWayIf                 #-}
 {-# LANGUAGE OverloadedStrings          #-}
 {-# LANGUAGE PolyKinds                  #-}
 {-# LANGUAGE RankNTypes                 #-}
 {-# LANGUAGE RecordWildCards            #-}
 {-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE StandaloneDeriving         #-}
-{-# LANGUAGE TupleSections              #-}
 {-# LANGUAGE TypeApplications           #-}
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE TypeOperators              #-}

dhall/src/Dhall/Schemas.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE DeriveAnyClass    #-}
-{-# LANGUAGE OverloadedLists   #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
 

dhall/src/Dhall/Syntax.hs

@@ -4,7 +4,6 @@
 {-# LANGUAGE DeriveLift                 #-}
 {-# LANGUAGE DeriveTraversable          #-}
 {-# LANGUAGE DerivingStrategies         #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE LambdaCase                 #-}
 {-# LANGUAGE OverloadedLists            #-}
 {-# LANGUAGE OverloadedStrings          #-}

dhall/src/Dhall/Util.hs

@@ -1,7 +1,6 @@
 {-# LANGUAGE NamedFieldPuns    #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards   #-}
-{-# LANGUAGE TypeApplications  #-}
 
 -- | Shared utility functions