Refactor excepts

lib/GHCup/Errors.hs

@@ -141,6 +141,7 @@ instance Pretty AlreadyInstalled where
 
 -- | The Directory is supposed to be empty, but wasn't.
 data DirNotEmpty = DirNotEmpty {path :: FilePath}
+  deriving Show
 
 instance Pretty DirNotEmpty where
   pPrint (DirNotEmpty path) = do
@@ -344,6 +345,17 @@ instance Pretty DownloadFailed where
 
 deriving instance Show DownloadFailed
 
+data InstallSetError = forall xs1 xs2 . (Show (V xs1), Pretty (V xs1), Show (V xs2), Pretty (V xs2)) => InstallSetError (V xs1) (V xs2)
+
+instance Pretty InstallSetError where
+  pPrint (InstallSetError reason1 reason2) =
+     text "Both installation and setting the tool failed. Install error was:"
+      <+> pPrint reason1
+      <+> text "\nSet error was:"
+      <+> pPrint reason2
+
+deriving instance Show InstallSetError
+
 
 -- | A build failed.
 data BuildFailed = forall es . (ToVariantMaybe BuildFailed es, PopVariant BuildFailed es, Pretty (V es), Show (V es)) => BuildFailed FilePath (V es)

lib/GHCup/Prelude.hs

@@ -4,6 +4,7 @@
 {-# LANGUAGE FlexibleInstances   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
 
 {-|
 Module      : GHCup.Prelude
@@ -27,6 +28,7 @@ module GHCup.Prelude
   )
 where
 
+import           GHCup.Errors
 import           GHCup.Prelude.Internal
 import           GHCup.Types.Optics   (HasLog)
 import           GHCup.Prelude.Logger (logWarn)
@@ -52,3 +54,29 @@ catchWarn :: forall es m env . ( Pretty (V es)
                              , Monad m) => Excepts es m () -> Excepts '[] m ()
 catchWarn = catchAllE @_ @es (\v -> lift $ logWarn (T.pack . prettyShow $ v))
 
+
+runBothE' :: forall e m a b .
+             ( Monad m
+             , Show (V e)
+             , Pretty (V e)
+             , PopVariant InstallSetError e
+             , LiftVariant' e (InstallSetError ': e)
+             , e :<< (InstallSetError ': e)
+             )
+          => Excepts e m a
+          -> Excepts e m b
+          -> Excepts (InstallSetError ': e) m ()
+runBothE' a1 a2 = do
+   r1 <- lift $ runE @e a1
+   r2 <- lift $ runE @e a2
+   case (r1, r2) of
+      (VLeft e1, VLeft e2) -> throwE (InstallSetError e1 e2)
+      (VLeft e , _       ) -> throwSomeE e
+      (_       , VLeft e ) -> throwSomeE e
+      (VRight _, VRight _) -> pure ()
+
+
+-- | Throw some exception
+throwSomeE :: forall es' es a m. (Monad m, LiftVariant es' es) => V es' -> Excepts es m a
+{-# INLINABLE throwSomeE #-}
+throwSomeE = Excepts . pure . VLeft . liftVariant