Remove dependency on either package

Following the deprecation and removal of the EitherT transformer

brittany.cabal

@@ -112,7 +112,6 @@ library {
     , unsafe >=0.0 && <0.1
     , safe >=0.3.9 && <0.4
     , deepseq >=1.4.2.0 && <1.5
-    , either >=4.4.1.1 && <4.5
     , semigroups >=0.18.2 && <0.19
     , cmdargs >=0.10.14 && <0.11
     , czipwith >=1.0.0.0 && <1.1
@@ -175,7 +174,6 @@ executable brittany
     , unsafe
     , safe
     , deepseq
-    , either
     , semigroups
     , cmdargs
     , czipwith
@@ -252,7 +250,6 @@ test-suite unittests
     , unsafe
     , safe
     , deepseq
-    , either
     , semigroups
     , cmdargs
     , czipwith
@@ -324,7 +321,6 @@ test-suite littests
     , unsafe
     , safe
     , deepseq
-    , either
     , semigroups
     , cmdargs
     , czipwith

src-brittany/Main.hs

@@ -193,8 +193,8 @@ coreIO
   -> Maybe FilePath.FilePath -- ^ input filepath; stdin if Nothing.
   -> Maybe FilePath.FilePath -- ^ output filepath; stdout if Nothing.
   -> IO (Either Int ())      -- ^ Either an errorNo, or success.
-coreIO putErrorLnIO config suppressOutput inputPathM outputPathM = EitherT.runEitherT $ do
+coreIO putErrorLnIO config suppressOutput inputPathM outputPathM = ExceptT.runExceptT $ do
-  let putErrorLn         = liftIO . putErrorLnIO :: String -> EitherT.EitherT e IO ()
+  let putErrorLn         = liftIO . putErrorLnIO :: String -> ExceptT.ExceptT e IO ()
   let ghcOptions         = config & _conf_forward & _options_ghc & runIdentity
   -- there is a good of code duplication between the following code and the
   -- `pureModuleTransform` function. Unfortunately, there are also a good
@@ -234,7 +234,7 @@ coreIO putErrorLnIO config suppressOutput inputPathM outputPathM = EitherT.runEi
     Left left -> do
       putErrorLn "parse error:"
       putErrorLn $ show left
-      EitherT.left 60
+      ExceptT.throwE 60
     Right (anns, parsedSource, hasCPP) -> do
       when (config & _conf_debug .> _dconf_dump_ast_full .> confUnpack) $ do
         let val = printTreeWithCustom 100 (customLayouterF anns) parsedSource
@@ -300,7 +300,7 @@ coreIO putErrorLnIO config suppressOutput inputPathM outputPathM = EitherT.runEi
         Nothing -> liftIO $ TextL.IO.putStr $ outLText
         Just p  -> liftIO $ TextL.IO.writeFile p $ outLText
 
-      when hasErrors $ EitherT.left 70
+      when hasErrors $ ExceptT.throwE 70
  where
   addTraceSep conf =
     if or

src/Language/Haskell/Brittany/Internal.hs

@@ -20,7 +20,7 @@ import qualified Language.Haskell.GHC.ExactPrint.Types as ExactPrint.Types
 import qualified Language.Haskell.GHC.ExactPrint.Parsers as ExactPrint.Parsers
 
 import           Data.Data
-import           Control.Monad.Trans.Either
+import           Control.Monad.Trans.Except
 import           Data.HList.HList
 import           Data.CZipWith
 
@@ -62,7 +62,7 @@ import qualified GHC.LanguageExtensions.Type as GHC
 -- Note that this function ignores/resets all config values regarding
 -- debugging, i.e. it will never use `trace`/write to stderr.
 parsePrintModule :: Config -> Text -> IO (Either [BrittanyError] Text)
-parsePrintModule configRaw inputText = runEitherT $ do
+parsePrintModule configRaw inputText = runExceptT $ do
   let config = configRaw { _conf_debug = _conf_debug staticDefaultConfig }
   let ghcOptions         = config & _conf_forward & _options_ghc & runIdentity
   let config_pp          = config & _conf_preprocessor
@@ -87,7 +87,7 @@ parsePrintModule configRaw inputText = runEitherT $ do
       cppCheckFunc
       (hackTransform $ Text.unpack inputText)
     case parseResult of
-      Left  err -> left $ [ErrorInput err]
+      Left  err -> throwE $ [ErrorInput err]
       Right x   -> pure $ x
   (errsWarns, outputTextL) <- do
     let omitCheck =
@@ -117,7 +117,7 @@ parsePrintModule configRaw inputText = runEitherT $ do
         case config & _conf_errorHandling & _econf_Werror & confUnpack of
           False -> 0 < maximum (-1 : fmap customErrOrder errsWarns)
           True  -> not $ null errsWarns
-  if hasErrors then left $ errsWarns else pure $ TextL.toStrict outputTextL
+  if hasErrors then throwE $ errsWarns else pure $ TextL.toStrict outputTextL
 
 
 

src/Language/Haskell/Brittany/Internal/ExactPrintUtils.hs

@@ -58,26 +58,24 @@ parseModuleWithCpp
   -> (GHC.DynFlags -> IO (Either String a))
   -> IO (Either String (ExactPrint.Anns, GHC.ParsedSource, a))
 parseModuleWithCpp cpp opts args fp dynCheck =
-  ExactPrint.ghcWrapper $ EitherT.runEitherT $ do
+  ExactPrint.ghcWrapper $ ExceptT.runExceptT $ do
     dflags0                       <- lift $ GHC.getSessionDynFlags
-    (dflags1, leftover, warnings) <- lift $ GHC.parseDynamicFlagsCmdLine
+    (dflags1, leftover, warnings) <- lift
-      dflags0
+      $ GHC.parseDynamicFlagsCmdLine dflags0 (GHC.noLoc <$> args)
-      (GHC.noLoc <$> args)
     void $ lift $ GHC.setSessionDynFlags dflags1
     dflags2 <- lift $ ExactPrint.initDynFlags fp
     when (not $ null leftover)
-      $  EitherT.left
+      $  ExceptT.throwE
       $  "when parsing ghc flags: leftover flags: "
       ++ show (leftover <&> \(L _ s) -> s)
     when (not $ null warnings)
-      $  EitherT.left
+      $  ExceptT.throwE
       $  "when parsing ghc flags: encountered warnings: "
       ++ show (warnings <&> \(L _ s) -> s)
-    x <- EitherT.EitherT $ liftIO $ dynCheck dflags2
+    x   <- ExceptT.ExceptT $ liftIO $ dynCheck dflags2
     res <- lift $ ExactPrint.parseModuleApiAnnsWithCppInternal cpp dflags2 fp
-    EitherT.hoistEither
+    either (\(span, err) -> ExceptT.throwE $ show span ++ ": " ++ err)
-      $ either (\(span, err) -> Left $ show span ++ ": " ++ err)
+           (\(a, m) -> pure (a, m, x))
-               (\(a, m) -> Right (a, m, x))
       $ ExactPrint.postParseTransform res opts
 
 parseModuleFromString
@@ -87,22 +85,21 @@ parseModuleFromString
   -> String
   -> IO (Either String (ExactPrint.Anns, GHC.ParsedSource, a))
 parseModuleFromString args fp dynCheck str =
-  ExactPrint.ghcWrapper $ EitherT.runEitherT $ do
+  ExactPrint.ghcWrapper $ ExceptT.runExceptT $ do
     dflags0                       <- lift $ ExactPrint.initDynFlagsPure fp str
-    (dflags1, leftover, warnings) <-
+    (dflags1, leftover, warnings) <- lift
-      lift $ GHC.parseDynamicFlagsCmdLine dflags0 (GHC.noLoc <$> args)
+      $ GHC.parseDynamicFlagsCmdLine dflags0 (GHC.noLoc <$> args)
     when (not $ null leftover)
-      $  EitherT.left
+      $  ExceptT.throwE
       $  "when parsing ghc flags: leftover flags: "
       ++ show (leftover <&> \(L _ s) -> s)
     when (not $ null warnings)
-      $  EitherT.left
+      $  ExceptT.throwE
       $  "when parsing ghc flags: encountered warnings: "
       ++ show (warnings <&> \(L _ s) -> s)
-    x <- EitherT.EitherT $ liftIO $ dynCheck dflags1
+    x <- ExceptT.ExceptT $ liftIO $ dynCheck dflags1
-    EitherT.hoistEither
+    either (\(span, err) -> ExceptT.throwE $ show span ++ ": " ++ err)
-      $ either (\(span, err) -> Left $ show span ++ ": " ++ err)
+           (\(a, m) -> pure (a, m, x))
-               (\(a, m) -> Right (a, m, x))
       $ ExactPrint.parseWith dflags1 fp GHC.parseModule str
 
 -----------

srcinc/prelude.inc

@@ -136,7 +136,7 @@ import qualified Data.Text.Lazy.IO as TextL.IO
 import qualified Control.Monad.Trans.State as State
 import qualified Control.Monad.Trans.State.Lazy as StateL
 import qualified Control.Monad.Trans.State.Strict as StateS
-import qualified Control.Monad.Trans.Either as EitherT
+import qualified Control.Monad.Trans.Except as ExceptT
 
 import qualified Data.Strict.Maybe as Strict