Refactor uses of `partitionEithers . map`

This patch changes occurences of the idiom
`partitionEithers (map f xs)` by the simpler form
`partitionWith f xs` where `partitionWith` is the utility function
defined in `GHC.Utils.Misc`.

Resolves: #23953

compiler/GHC/Cmm/DebugBlock.hs

@@ -47,7 +47,7 @@ import GHC.Utils.Outputable
 import GHC.Utils.Panic
 import GHC.Types.SrcLoc
 import GHC.Types.Tickish
-import GHC.Utils.Misc      ( seqList )
+import GHC.Utils.Misc      ( partitionWith, seqList )
 
 import GHC.Cmm.Dataflow.Block
 import GHC.Cmm.Dataflow.Collections
@@ -58,7 +58,6 @@ import Data.Maybe
 import Data.List     ( minimumBy, nubBy )
 import Data.Ord      ( comparing )
 import qualified Data.Map as Map
-import Data.Either   ( partitionEithers )
 
 -- | Debug information about a block of code. Ticks scope over nested
 -- blocks.
@@ -110,7 +109,7 @@ cmmDebugGen modLoc decls = map (blocksForScope Nothing) topScopes
       -- Analyse tick scope structure: Each one is either a top-level
       -- tick scope, or the child of another.
       (topScopes, childScopes)
-        = partitionEithers $ map (\a -> findP a a) $ Map.keys blockCtxs
+        = partitionWith (\a -> findP a a) $ Map.keys blockCtxs
       findP tsc GlobalScope = Left tsc -- top scope
       findP tsc scp | scp' `Map.member` blockCtxs = Right (scp', tsc)
                     | otherwise                   = findP tsc scp'

compiler/GHC/HsToCore/Pmc/Solver.hs

@@ -91,7 +91,6 @@ import Control.Monad (foldM, forM, guard, mzero, when, filterM)
 import Control.Monad.Trans.Class (lift)
 import Control.Monad.Trans.State.Strict
 import Data.Coerce
-import Data.Either   (partitionEithers)
 import Data.Foldable (foldlM, minimumBy, toList)
 import Data.Monoid   (Any(..))
 import Data.List     (sortBy, find)
@@ -608,7 +607,7 @@ addPhiCts nabla cts = runMaybeT $ do
   inhabitationTest initFuel (nabla_ty_st nabla) nabla''
 
 partitionPhiCts :: PhiCts -> ([PredType], [PhiCt])
-partitionPhiCts = partitionEithers . map to_either . toList
+partitionPhiCts = partitionWith to_either . toList
   where
     to_either (PhiTyCt pred_ty) = Left pred_ty
     to_either ct                = Right ct

compiler/GHC/Linker/Deps.hs

@@ -55,7 +55,6 @@ import Control.Applicative
 import qualified Data.Set as Set
 import qualified Data.Map as M
 import Data.List (isSuffixOf)
-import Data.Either
 
 import System.FilePath
 import System.Directory
@@ -131,7 +130,7 @@ get_link_deps opts pls maybe_normal_osuf span mods = do
       let
         -- 2.  Exclude ones already linked
         --      Main reason: avoid findModule calls in get_linkable
-            (mods_needed, links_got) = partitionEithers (map split_mods mods_s)
+            (mods_needed, links_got) = partitionWith split_mods mods_s
             pkgs_needed = eltsUDFM $ getUniqDSet pkgs_s `minusUDFM` pkgs_loaded pls
 
             split_mods mod =

compiler/GHC/Runtime/Eval.hs

@@ -130,7 +130,6 @@ import Control.Monad
 import Control.Monad.Catch as MC
 import Data.Array
 import Data.Dynamic
-import Data.Either
 import Data.IntMap (IntMap)
 import qualified Data.IntMap as IntMap
 import Data.List (find,intercalate)
@@ -808,7 +807,7 @@ findGlobalRdrEnv :: HscEnv -> [InteractiveImport]
 findGlobalRdrEnv hsc_env imports
   = do { idecls_env <- hscRnImportDecls hsc_env idecls
                     -- This call also loads any orphan modules
-       ; return $ case partitionEithers (map mkEnv imods) of
+       ; return $ case partitionWith mkEnv imods of
          (err : _, _)     -> Left err
          ([], imods_env0) ->
             -- Need to rehydrate the 'GlobalRdrEnv' to recover the 'GREInfo's.

compiler/GHC/StgToJS/Expr.hs

@@ -496,9 +496,10 @@ optimizeFree offset ids = do
       l    = length ids'
   slots <- drop offset . take l . (++repeat SlotUnknown) <$> getSlots
   let slm                = M.fromList (zip slots [0..])
-      (remaining, fixed) = partitionEithers $
-         map (\inp@(i,n) -> maybe (Left inp) (\j -> Right (i,n,j,True))
-            (M.lookup (SlotId i n) slm)) ids'
+      (remaining, fixed) = partitionWith (\inp@(i,n) -> maybe (Left inp)
+                                                              (\j -> Right (i,n,j,True))
+                                                              (M.lookup (SlotId i n) slm))
+                                         ids'
       takenSlots         = S.fromList (fmap (\(_,_,x,_) -> x) fixed)
       freeSlots          = filter (`S.notMember` takenSlots) [0..l-1]
       remaining'         = zipWith (\(i,n) j -> (i,n,j,False)) remaining freeSlots

compiler/GHC/StgToJS/Sinker.hs

@@ -15,10 +15,10 @@ import GHC.Unit.Module
 import GHC.Types.Literal
 import GHC.Data.Graph.Directed
 
+import GHC.Utils.Misc (partitionWith)
 import GHC.StgToJS.Utils
 
 import Data.Char
-import Data.Either
 import Data.List (partition)
 import Data.Maybe
 
@@ -38,7 +38,7 @@ sinkPgm m pgm = (sunk, map StgTopLifted pgm'' ++ stringLits)
   where
     selectLifted (StgTopLifted b) = Left b
     selectLifted x                = Right x
-    (pgm', stringLits) = partitionEithers (map selectLifted pgm)
+    (pgm', stringLits) = partitionWith selectLifted pgm
     (sunk, pgm'')      = sinkPgm' m pgm'
 
 sinkPgm'

compiler/GHC/Unit/Module/Graph.hs

@@ -58,6 +58,7 @@ import GHC.Types.SourceFile ( hscSourceString )
 import GHC.Unit.Module.ModSummary
 import GHC.Unit.Types
 import GHC.Utils.Outputable
+import GHC.Utils.Misc ( partitionWith )
 
 import System.FilePath
 import qualified Data.Map as Map
@@ -68,7 +69,6 @@ import GHC.Unit.Module
 import GHC.Linker.Static.Utils
 
 import Data.Bifunctor
-import Data.Either
 import Data.Function
 import Data.List (sort)
 import GHC.Data.List.SetOps
@@ -336,7 +336,7 @@ moduleGraphNodes drop_hs_boot_nodes summaries =
   (graphFromEdgedVerticesUniq nodes, lookup_node)
   where
     -- Map from module to extra boot summary dependencies which need to be merged in
-    (boot_summaries, nodes) = bimap Map.fromList id $ partitionEithers (map go numbered_summaries)
+    (boot_summaries, nodes) = bimap Map.fromList id $ partitionWith go numbered_summaries
 
       where
         go (s, key) =