Make fourmolu happy

Cabal codebase has now a formatter/style standard (see haskell#8950).

“Ravioli ravioli, give me the formuoli”

Author: ffaf1

Cabal-syntax/src/Distribution/Types/UnqualComponentName.hs

@@ -110,18 +110,29 @@ unqualComponentNameToPackageName = mkPackageNameST . unUnqualComponentNameST
 -- | Combine names in targets if one name is empty or both names are equal
 -- (partial function).
 -- Useful in 'Semigroup' and similar instances.
-combineNames :: a -> a -> (a -> UnqualComponentName) -> String ->
-               UnqualComponentName
+combineNames
+  :: a
+  -> a
+  -> (a -> UnqualComponentName)
+  -> String
+  -> UnqualComponentName
 combineNames a b tacc tt
-            -- One empty or the same.
-        | P.null unb ||
-          una == unb    = na
-        | P.null una = nb
-            -- Both non-empty, different.
-        | otherwise = error $ "Ambiguous values for " ++ tt ++ " field: '"
-                        ++ una ++ "' and '" ++ unb ++ "'"
-    where
-          (na, nb) = (tacc a, tacc b)
-          una = unUnqualComponentName na
-          unb = unUnqualComponentName nb
-
+  -- One empty or the same.
+  | P.null unb
+      || una == unb =
+      na
+  | P.null una = nb
+  -- Both non-empty, different.
+  | otherwise =
+      error $
+        "Ambiguous values for "
+          ++ tt
+          ++ " field: '"
+          ++ una
+          ++ "' and '"
+          ++ unb
+          ++ "'"
+  where
+    (na, nb) = (tacc a, tacc b)
+    una = unUnqualComponentName na
+    unb = unUnqualComponentName nb