[commit: ghc] wip/T16212-fixed, wip/sgraf-no-exnstr: Use `NameEnv Id` instead of `Map Name Id` (6fa3866)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branches: wip/T16212-fixed,wip/sgraf-no-exnstr
Link       : http://ghc.haskell.org/trac/ghc/changeset/6fa38663d1abb22e988159ce3f80c824de3b243d/ghc

>---------------------------------------------------------------

commit 6fa38663d1abb22e988159ce3f80c824de3b243d
Author: Alec Theriault <alec.theriault at gmail.com>
Date:   Thu Jan 24 13:59:18 2019 -0800

    Use `NameEnv Id` instead of `Map Name Id`
    
    This is more consistent with the rest of the GHC codebase.


>---------------------------------------------------------------

6fa38663d1abb22e988159ce3f80c824de3b243d
 compiler/hieFile/HieAst.hs | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/compiler/hieFile/HieAst.hs b/compiler/hieFile/HieAst.hs
index 401b861..35440f0 100644
--- a/compiler/hieFile/HieAst.hs
+++ b/compiler/hieFile/HieAst.hs
@@ -28,6 +28,7 @@ import HscTypes
 import Module                     ( ModuleName, ml_hs_file )
 import MonadUtils                 ( concatMapM, liftIO )
 import Name                       ( Name, nameSrcSpan, setNameLoc )
+import NameEnv                    ( NameEnv, emptyNameEnv, extendNameEnv, lookupNameEnv )
 import SrcLoc
 import TcHsSyn                    ( hsPatType )
 import Type                       ( Type )
@@ -60,11 +61,11 @@ We don't care about the distinction between mono and poly bindings,
 so we replace all occurrences of the mono name with the poly name.
 -}
 newtype HieState = HieState
-  { name_remapping :: M.Map Name Id
+  { name_remapping :: NameEnv Id
   }
 
 initState :: HieState
-initState = HieState M.empty
+initState = HieState emptyNameEnv
 
 class ModifyState a where -- See Note [Name Remapping]
   addSubstitution :: a -> a -> HieState -> HieState
@@ -74,7 +75,7 @@ instance ModifyState Name where
 
 instance ModifyState Id where
   addSubstitution mono poly hs =
-    hs{name_remapping = M.insert (varName mono) poly (name_remapping hs)}
+    hs{name_remapping = extendNameEnv (name_remapping hs) (varName mono) poly}
 
 modifyState :: ModifyState (IdP p) => [ABExport p] -> HieState -> HieState
 modifyState = foldr go id
@@ -377,7 +378,9 @@ instance ToHie (Context (Located Var)) where
       C context (L (RealSrcSpan span) name')
         -> do
         m <- asks name_remapping
-        let name = M.findWithDefault name' (varName name') m
+        let name = case lookupNameEnv m (varName name') of
+              Just var -> var
+              Nothing-> name'
         pure
           [Node
             (NodeInfo S.empty [] $
@@ -392,7 +395,7 @@ instance ToHie (Context (Located Name)) where
   toHie c = case c of
       C context (L (RealSrcSpan span) name') -> do
         m <- asks name_remapping
-        let name = case M.lookup name' m of
+        let name = case lookupNameEnv m name' of
               Just var -> varName var
               Nothing -> name'
         pure