Add support for GHC 8.6.3

13 files changed, 833 insertions, 123 deletions

diff --git a/README.md b/README.md
index a6b0ce8..8e5b8f7 100644
--- a/README.md
+++ b/README.md
@@ -43,14 +43,20 @@ cd haskell-code-explorer
 
 To build Haskell Code Explorer Stack ([https://docs.haskellstack.org/en/stable/README/](https://docs.haskellstack.org/en/stable/README/)) is needed.
 
-At the moment Haskell Code Explorer supports GHC 8.4.4, GHC 8.4.3, GHC 8.2.2, and 8.0.2.
+At the moment Haskell Code Explorer supports GHC 8.6.3, GHC 8.4.4, GHC 8.4.3, GHC 8.2.2, and 8.0.2.
 
-For GHC 8.4.4:
+For GHC 8.6.3:
 
 ```bash
 stack install
 ```
 
+For GHC 8.4.4:
+
+```bash
+stack --stack-yaml=stack-8.4.4.yaml install
+```
+
 For GHC 8.4.3:
 
 ```bash
diff --git a/app/Indexer.hs b/app/Indexer.hs
index c91cb70..ee6a330 100644
--- a/app/Indexer.hs
+++ b/app/Indexer.hs
@@ -73,7 +73,10 @@ data Compression
   | NoCompression
   deriving (Show, Eq)
 
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,4,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,3,0)
+ghcVersion :: Version
+ghcVersion = Version {versionBranch = [8, 6, 3, 0], versionTags = []}    
+#elif MIN_VERSION_GLASGOW_HASKELL(8,4,4,0) 
 ghcVersion :: Version
 ghcVersion = Version {versionBranch = [8, 4, 4, 0], versionTags = []}
 #elif MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
diff --git a/src/HaskellCodeExplorer/AST/RenamedSource.hs b/src/HaskellCodeExplorer/AST/RenamedSource.hs
index 52e92e6..90f9ceb 100644
--- a/src/HaskellCodeExplorer/AST/RenamedSource.hs
+++ b/src/HaskellCodeExplorer/AST/RenamedSource.hs
@@ -132,8 +132,13 @@ namesFromRenamedSource =
 fieldOccName :: Bool -> FieldOcc GhcRn -> NameOccurrence
 #else
 fieldOccName :: Bool -> FieldOcc Name -> NameOccurrence
-#endif    
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+fieldOccName _ (XFieldOcc _) = undefined
+fieldOccName isBinder (FieldOcc name (L span _)) =
+#else
 fieldOccName isBinder (FieldOcc (L span _) name) =
+#endif
   NameOccurrence
     { locatedName = L span (Just name)
     , description = "FieldOcc"
@@ -147,6 +152,9 @@ conDeclFieldNames :: ConDeclField Name -> [NameOccurrence]
 #endif    
 conDeclFieldNames ConDeclField {..} =
   map (fieldOccName True . unLoc) cd_fld_names
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+conDeclFieldNames _ = []    
+#endif    
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 hsRecFieldExprNames :: HsRecField' (FieldOcc GhcRn) (LHsExpr GhcRn) -> [NameOccurrence]
@@ -164,14 +172,19 @@ hsRecAmbFieldExprNames HsRecField {..} =
   let (L span recField) = hsRecFieldLbl
       mbName =
         case recField of
-          Ambiguous _ _ -> Nothing
+          Ambiguous _ _ -> Nothing          
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,3,0)
+          Unambiguous name _ -> Just name
+          _ -> Nothing
+#else
           Unambiguous _ name -> Just name
+#endif          
    in [ NameOccurrence
           { locatedName = L span mbName
           , description = "AmbiguousFieldOcc"
           , isBinder = False
           }
-      ]
+      ]      
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 hsRecFieldPatNames :: HsRecField' (FieldOcc GhcRn) (LPat GhcRn) -> [NameOccurrence]
@@ -184,8 +197,12 @@ hsRecFieldPatNames HsRecField {..} = [fieldOccName False $ unLoc hsRecFieldLbl]
 hsExprNames :: LHsExpr GhcRn -> [NameOccurrence]
 #else
 hsExprNames :: LHsExpr Name -> [NameOccurrence]
-#endif    
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsExprNames (L _span (HsVar _ name)) =
+#else
 hsExprNames (L _span (HsVar name)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "HsVar"
@@ -201,28 +218,44 @@ hsExprNames (L span (ExplicitList _ _ exprs))
       }
     ]
   | otherwise = []
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsExprNames (L _span (RecordCon _ name _)) =
+#else
 hsExprNames (L _span (RecordCon name _conLike _instFun _binds)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "RecordCon"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsExprNames (L _span (HsRecFld _ (Unambiguous name (L span _)))) =
+#else
 hsExprNames (L _span (HsRecFld (Unambiguous (L span _) name))) =
+#endif
   [ NameOccurrence
     { locatedName = L span (Just name)
     , description = "HsRecFld"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsExprNames (L _span (HsRecFld _ (Ambiguous _name (L span _)))) =
+#else
 hsExprNames (L _span (HsRecFld (Ambiguous (L span _) _name))) =
+#endif
   [ NameOccurrence
     { locatedName = L span Nothing
     , description = "HsRecFld"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+hsExprNames (L span (HsRnBracketOut _ (VarBr _ quote name) _)) =
+#else
 hsExprNames (L span (HsRnBracketOut (VarBr quote name) _)) =
+#endif
   case span of
     RealSrcSpan realSpan ->
       let start = realSrcSpanStart realSpan
@@ -278,7 +311,11 @@ bindNames :: LHsBindLR GhcRn GhcRn -> [NameOccurrence]
 #else
 bindNames :: LHsBindLR Name Name -> [NameOccurrence]
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+bindNames (L _span (PatSynBind _ PSB {..})) =
+#else
 bindNames (L _span (PatSynBind PSB {..})) =
+#endif
   [ NameOccurrence
       { locatedName = Just <$> psb_id
       , description = "PatSynBind"
@@ -318,8 +355,12 @@ importNames =
 patNames :: LPat GhcRn -> [NameOccurrence]
 #else
 patNames :: LPat Name -> [NameOccurrence]
-#endif    
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+patNames (L _span (VarPat _ name)) =
+#else
 patNames (L _span (VarPat name)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "VarPat"
@@ -333,14 +374,22 @@ patNames (L _span (ConPatIn name _)) =
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+patNames (L _span (AsPat _ name _)) =
+#else
 patNames (L _span (AsPat name _)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "AsPat"
     , isBinder = True
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+patNames (L _span (NPlusKPat _ name _ _ _ _)) =
+#else
 patNames (L _span (NPlusKPat name _ _ _ _ _)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "NPlusKPat"
@@ -354,8 +403,13 @@ patNames _ = []
 sigNames :: LSig GhcRn -> [NameOccurrence]
 #else
 sigNames :: LSig Name -> [NameOccurrence]
-#endif    
+#endif
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (TypeSig _ names _)) =
+#else
 sigNames (L _span (TypeSig names _)) =
+#endif
   map
     (\n ->
         NameOccurrence
@@ -364,9 +418,11 @@ sigNames (L _span (TypeSig names _)) =
         , isBinder = False
         })
     names
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)    
-sigNames (L _span (PatSynSig names _)) =
-  map (\name -> NameOccurrence (Just <$> name) "PatSynSig" False) names
+    
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (PatSynSig _ names _)) = map (\name -> NameOccurrence (Just <$> name) "PatSynSig" False) names    
+#elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+sigNames (L _span (PatSynSig names _)) = map (\name -> NameOccurrence (Just <$> name) "PatSynSig" False) names
 #else
 sigNames (L _span (PatSynSig name _)) =
   [ NameOccurrence
@@ -376,7 +432,11 @@ sigNames (L _span (PatSynSig name _)) =
     }
   ]
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (ClassOpSig _ _ names _)) =
+#else
 sigNames (L _span (ClassOpSig _ names _)) =
+#endif
   map
     (\n ->
         NameOccurrence
@@ -385,7 +445,11 @@ sigNames (L _span (ClassOpSig _ names _)) =
         , isBinder = True
         })
     names
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (FixSig _ (FixitySig _ names _))) =
+#else
 sigNames (L _span (FixSig (FixitySig names _))) =
+#endif
   map
     (\n ->
         NameOccurrence
@@ -394,21 +458,33 @@ sigNames (L _span (FixSig (FixitySig names _))) =
         , isBinder = False
         })
     names
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (InlineSig _ name _)) =
+#else
 sigNames (L _span (InlineSig name _)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "InlineSig"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNames (L _span (SpecSig _ name _ _)) =
+#else
 sigNames (L _span (SpecSig name _ _)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "SpecSig"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+sigNames (L _span (MinimalSig _ _ (L _ boolFormula))) =
+#else
 sigNames (L _span (MinimalSig _ (L _ boolFormula))) =
+#endif
   map
     (\n ->
         NameOccurrence
@@ -431,7 +507,9 @@ hsTypeNames :: LHsType GhcRn -> [NameOccurrence]
 #else
 hsTypeNames :: LHsType Name -> [NameOccurrence]
 #endif 
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsTypeNames (L _span (HsTyVar _ _promoted name)) =    
+#elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
 hsTypeNames (L _span (HsTyVar _promoted name)) =
 #else
 hsTypeNames (L _span (HsTyVar name)) =
@@ -442,7 +520,11 @@ hsTypeNames (L _span (HsTyVar name)) =
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+hsTypeNames (L span (HsTyLit _ lit)) =
+#else
 hsTypeNames (L span (HsTyLit lit)) =
+#endif
   let kind =
         case lit of
           HsNumTy _ _ -> typeNatKind
@@ -453,14 +535,22 @@ hsTypeNames (L span (HsTyLit lit)) =
        , kind = kind
        }
      ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)     
+hsTypeNames (L _span (HsOpTy _ _ name _)) =
+#else
 hsTypeNames (L _span (HsOpTy _ name _)) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> name
     , description = "HsOpTy"
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+hsTypeNames (L span (HsTupleTy _ tupleSort types))
+#else
 hsTypeNames (L span (HsTupleTy tupleSort types))
+#endif
   | null types =
     let sort =
           case tupleSort of
@@ -486,20 +576,32 @@ hsTyVarBndrNames :: HsTyVarBndr GhcRn -> [NameOccurrence]
 #else
 hsTyVarBndrNames :: HsTyVarBndr Name -> [NameOccurrence]
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+hsTyVarBndrNames (UserTyVar _ n) =
+#else
 hsTyVarBndrNames (UserTyVar n) =
+#endif  
   [ NameOccurrence
     { locatedName = Just <$> n
     , description = "UserTyVar"
     , isBinder = True
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+hsTyVarBndrNames (KindedTyVar _ n _) =
+#else
 hsTyVarBndrNames (KindedTyVar n _) =
+#endif
   [ NameOccurrence
     { locatedName = Just <$> n
     , description = "KindedTyVar"
     , isBinder = True
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+hsTyVarBndrNames _ = []
+#endif    
+  
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 tyClDeclNames :: LTyClDecl GhcRn -> [NameOccurrence]
@@ -543,7 +645,7 @@ tyClDeclNames _ = []
 familyDeclNames :: FamilyDecl GhcRn -> [NameOccurrence]
 #else
 familyDeclNames :: FamilyDecl Name -> [NameOccurrence]
-#endif    
+#endif
 familyDeclNames FamilyDecl {..} =
   [ NameOccurrence
     { locatedName = Just <$> fdLName
@@ -551,7 +653,9 @@ familyDeclNames FamilyDecl {..} =
     , isBinder = True
     }
   ]
-
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+familyDeclNames _ = []
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 familyEqNames :: FamEqn GhcRn (HsTyPats GhcRn) (LHsType GhcRn) -> [NameOccurrence]
@@ -562,6 +666,9 @@ familyEqNames FamEqn {feqn_tycon = tyCon} =
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+familyEqNames _ = []
+#endif
 
 dataEqNames :: FamEqn GhcRn (HsTyPats GhcRn) (HsDataDefn GhcRn) -> [NameOccurrence]
 dataEqNames FamEqn {feqn_tycon = tyCon} =
@@ -571,6 +678,10 @@ dataEqNames FamEqn {feqn_tycon = tyCon} =
     , isBinder = False
     }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+dataEqNames _ = []
+#endif
+
 #else    
 tyFamilyEqNames :: TyFamEqn Name (HsTyPats Name) -> [NameOccurrence]
 tyFamilyEqNames TyFamEqn {tfe_tycon = tyCon} =
@@ -598,7 +709,7 @@ dataFamInstDeclNames DataFamInstDecl {dfid_tycon = tyCon} =
     , isBinder = False
     }
   ]
-#endif 
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 conDeclNames :: ConDecl GhcRn -> [NameOccurrence]
@@ -623,6 +734,9 @@ conDeclNames con =
         , isBinder = True
         }
       ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+    _ -> []
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foreignDeclNames :: ForeignDecl GhcRn -> [NameOccurrence]
@@ -642,13 +756,20 @@ roleAnnotationNames :: RoleAnnotDecl GhcRn -> [NameOccurrence]
 #else
 roleAnnotationNames :: RoleAnnotDecl Name -> [NameOccurrence]
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+roleAnnotationNames (RoleAnnotDecl _ n _) =
+#else
 roleAnnotationNames (RoleAnnotDecl n _) =
+#endif
   [ NameOccurrence
       { locatedName = Just <$> n
       , description = "RoleAnnotDecl"
       , isBinder = False
       }
   ]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+roleAnnotationNames _ = []
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 injectivityAnnotationNames :: InjectivityAnn GhcRn -> [NameOccurrence]
@@ -665,3 +786,4 @@ injectivityAnnotationNames (InjectivityAnn lhsName rhsNames) =
         , description = "InjectivityAnn"
         , isBinder = False
         }
+        
diff --git a/src/HaskellCodeExplorer/AST/TypecheckedSource.hs b/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
index 6f9a4cf..02f406b 100644
--- a/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
+++ b/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -78,6 +77,14 @@ import HsSyn
   , PatSynBind(..)
   , StmtLR(..)
   , selectorAmbiguousFieldOcc
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  , RecordConTc (..)
+  , RecordUpdTc (..)
+  , ListPatTc (..)
+  , OverLitTc (..)
+  , MatchGroupTc (..)
+  , NHsValBindsLR (..)  
+#endif
   )
 import HscTypes (TypeEnv, lookupTypeEnv)
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
@@ -175,11 +182,16 @@ data ExprSort
   deriving (Show, Eq)
 
 exprSort :: HsExpr a -> ExprSort
-exprSort (HsVar _) = Simple
-exprSort (HsIPVar _) = Simple
-exprSort (HsOverLit _) = Simple
-exprSort (HsLit _) = Simple
+exprSort HsVar {} = Simple
+exprSort HsIPVar {} = Simple
+exprSort HsOverLit {} = Simple
+exprSort HsLit {} = Simple
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+exprSort (ExplicitTuple _ args _)
+#else
 exprSort (ExplicitTuple args _)
+#endif
   | null args = Simple
   | otherwise = Composite   
 exprSort (ExplicitList _ _ args) 
@@ -187,14 +199,23 @@ exprSort (ExplicitList _ _ args)
   | otherwise = Composite     
 exprSort _ = Composite
 
+
 patSort :: Pat a -> ExprSort
-patSort (WildPat _typ) = Simple
-patSort (LitPat _lit) = Simple
+patSort WildPat {} = Simple
+patSort LitPat {} = Simple
 patSort NPat {} = Simple
-patSort (ListPat pats _ _) 
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+patSort (ListPat _ pats)
+#else
+patSort (ListPat pats _ _)
+#endif
   | null pats = Simple
-  | otherwise = Composite       
+  | otherwise = Composite
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+patSort (TuplePat  _ pats _)
+#else
 patSort (TuplePat pats _ _)
+#endif
   | null pats = Simple
   | otherwise = Composite
 patSort _ = Composite
@@ -557,29 +578,42 @@ foldLHsExpr :: LHsExpr GhcTc -> State ASTState (Maybe Type)
 #else
 foldLHsExpr :: LHsExpr Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L _span (XExpr _)) = return Nothing
+foldLHsExpr (L _ (HsOverLit _ (XOverLit _))) = return Nothing
+foldLHsExpr (L _ (HsLam _ (XMatchGroup _))) = return Nothing
+foldLHsExpr (L _ (HsLamCase _ (XMatchGroup _))) = return Nothing
+foldLHsExpr (L _ (HsCase _ _ (XMatchGroup _))) = return Nothing
+foldLHsExpr (L span (HsVar _ (L _ identifier))) =
+#else
 foldLHsExpr (L span (HsVar (L _ identifier))) =
+#endif
   restoreTidyEnv $ do
     (identifier', mbTypes) <- tidyIdentifier identifier
     addIdentifierToIdSrcSpanMap span identifier' mbTypes
     return . Just . varType $ identifier'
-foldLHsExpr (L _ (HsUnboundVar _)) = return Nothing
+foldLHsExpr (L _ HsUnboundVar {}) = return Nothing
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L _ (HsConLikeOut _ conLike)) =
+#else
 foldLHsExpr (L _ (HsConLikeOut conLike)) =
-  restoreTidyEnv $ do    
-    let mbType = varType <$> conLikeWrapId_maybe conLike    
-    mbType' <- maybe (return Nothing) (fmap Just . tidyType) mbType    
-    return mbType'
 #endif
-foldLHsExpr (L _ (HsRecFld _)) = return Nothing
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
-foldLHsExpr (L _ (HsOverLabel _ _)) = return Nothing
-#else
-foldLHsExpr (L _ (HsOverLabel _)) = return Nothing
+  restoreTidyEnv $ do
+    let mbType = varType <$> conLikeWrapId_maybe conLike
+    mbType' <- maybe (return Nothing) (fmap Just . tidyType) mbType
+    return mbType'
 #endif
-foldLHsExpr (L span expr@(HsIPVar _)) = do
+foldLHsExpr (L _ HsRecFld {}) = return Nothing
+foldLHsExpr (L _ HsOverLabel {}) = return Nothing
+foldLHsExpr (L span expr@HsIPVar {}) = do
   addExprInfo span Nothing "HsIPVar" (exprSort expr)
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span (HsOverLit _ (OverLit (OverLitTc _ ol_type) _ _))) =
+#else
 foldLHsExpr (L span (HsOverLit OverLit {ol_type})) =
+#endif
   restoreTidyEnv $ do
     typ <- tidyType ol_type
     addExprInfo
@@ -590,7 +624,11 @@ foldLHsExpr (L span (HsOverLit OverLit {ol_type})) =
          then Simple
          else Composite)
     return $ Just typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsExpr (L span (HsLit _ lit)) =
+#else
 foldLHsExpr (L span (HsLit lit)) =
+#endif
   restoreTidyEnv $ do
     typ <- tidyType $ hsLitType lit
     addExprInfo
@@ -601,14 +639,22 @@ foldLHsExpr (L span (HsLit lit)) =
          then Simple
          else Composite)
     return $ Just typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span expr@(HsLam _ (MG (MatchGroupTc {..}) mg_alts _))) =
+#else
 foldLHsExpr (L span expr@(HsLam MG {..})) =
+#endif
   restoreTidyEnv $ do
     typ <- tidyType $ mkFunTys mg_arg_tys mg_res_ty
     addExprInfo span (Just typ) "HsLam" (exprSort expr)
     mapM_ foldLMatch $ unLoc mg_alts
     return $ Just typ
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)    
+#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span expr@(HsLamCase _ (MG (MatchGroupTc {..}) mg_alts _))) =
+#else
 foldLHsExpr (L span expr@(HsLamCase MG {..})) =
+#endif
 #else
 foldLHsExpr (L span expr@(HsLamCase _typ MG {..})) =
 #endif
@@ -617,52 +663,82 @@ foldLHsExpr (L span expr@(HsLamCase _typ MG {..})) =
     addExprInfo span (Just typ) "HsLamCase" (exprSort expr)
     mapM_ foldLMatch $ unLoc mg_alts
     return $ Just typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsExpr (L span expr@(HsApp _ fun arg)) = do
+#else
 foldLHsExpr (L span expr@(HsApp fun arg)) = do
+#endif
   funTy <- foldLHsExpr fun
   _argTy <- foldLHsExpr arg
-  typ <- fromMaybe (return Nothing) (funResultTySafe span "HsApp" <$> funTy)
+  typ <- maybe (return Nothing) (funResultTySafe span "HsApp") funTy    
   addExprInfo span typ "HsApp" (exprSort expr)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span ex@(HsAppType _ expr)) = do
+#else
 foldLHsExpr (L _ (HsAppType _ _)) = return Nothing
 foldLHsExpr (L span ex@(HsAppTypeOut expr _)) = do
+#endif
   typ <- foldLHsExpr expr
-  addExprInfo span typ "HsAppTypeOut" (exprSort ex)
-  return typ  
+  addExprInfo span typ "HsAppType" (exprSort ex)
+  return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLHsExpr (L span expr@(OpApp _ left op right)) = do
+#else
 foldLHsExpr (L span expr@(OpApp left op _fixity right)) = do
+#endif
   opTyp <- foldLHsExpr op
-  typ <- fromMaybe (return Nothing) (funResultTy2Safe span "HsApp" <$> opTyp)
+  typ <- maybe (return Nothing) (funResultTy2Safe span "HsApp") opTyp  
   _ <- foldLHsExpr left
   _ <- foldLHsExpr right
   addExprInfo span typ "OpApp" (exprSort expr)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsExpr (L span e@(NegApp _ expr _syntaxExp)) = do
+#else
 foldLHsExpr (L span e@(NegApp expr _syntaxExp)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "NegApp" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)        
+foldLHsExpr (L _span (HsPar _ expr)) = foldLHsExpr expr
+#else
 foldLHsExpr (L _span (HsPar expr)) = foldLHsExpr expr
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span expr@(SectionL _ operand operator)) = do
+#else
 foldLHsExpr (L span expr@(SectionL operand operator)) = do
+#endif
   opType <- foldLHsExpr operator
   _ <- foldLHsExpr operand
-  mbTypes <-
-    fromMaybe (return Nothing) (splitFunTy2Safe span "SectionL" <$> opType)
+  mbTypes <- maybe (return Nothing) (splitFunTy2Safe span "SectionL") opType    
   let typ =
         case mbTypes of
           Just (_arg1, arg2, res) -> Just $ mkFunTy arg2 res
           Nothing -> Nothing
   addExprInfo span typ "SectionL" (exprSort expr)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(SectionR _ operator operand)) = do
+#else
 foldLHsExpr (L span e@(SectionR operator operand)) = do
+#endif
   opType <- foldLHsExpr operator
   _ <- foldLHsExpr operand
-  mbTypes <-
-    fromMaybe (return Nothing) (splitFunTy2Safe span "SectionR" <$> opType)
+  mbTypes <- maybe (return Nothing) (splitFunTy2Safe span "SectionR") opType    
   let typ =
         case mbTypes of
           Just (arg1, _arg2, res) -> Just $ mkFunTy arg1 res
           Nothing -> Nothing
   addExprInfo span typ "SectionR" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(ExplicitTuple _ tupArgs boxity)) = do
+#else
 foldLHsExpr (L span e@(ExplicitTuple tupArgs boxity)) = do
+#endif
   tupleArgs <- mapM foldLHsTupArg tupArgs
   let tupleSectionArgTys =
         mapM fst . filter ((== TupArgMissing) . snd) $ tupleArgs
@@ -672,24 +748,36 @@ foldLHsExpr (L span e@(ExplicitTuple tupArgs boxity)) = do
   tidyEnv <- astStateTidyEnv <$> get
   addExprInfo
     span
-    ((snd . tidyOpenType tidyEnv) <$> resultType)
+    (snd . tidyOpenType tidyEnv <$> resultType)
     "ExplicitTuple"
     (exprSort e)
   return resultType
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L _span (ExplicitSum _ _ _ expr)) = do
+#else
 foldLHsExpr (L _span (ExplicitSum _ _ expr _types)) = do
+#endif
   -- TODO
   _ <- foldLHsExpr expr
   return Nothing    
-#endif    
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(HsCase _ expr (MG (MatchGroupTc {..}) mg_alts _))) =
+#else
 foldLHsExpr (L span e@(HsCase expr MG {..})) =
+#endif
   restoreTidyEnv $ do
     typ <- tidyType mg_res_ty
     _ <- foldLHsExpr expr
     mapM_ foldLMatch (unLoc mg_alts)
     addExprInfo span (Just typ) "HsCase" (exprSort e)
     return $ Just typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(HsIf _ _mbSynExpr condExpr thenExpr elseExpr)) = do
+#else
 foldLHsExpr (L span e@(HsIf _mbSynExpr condExpr thenExpr elseExpr)) = do
+#endif
   _ <- foldLHsExpr condExpr
   typ <- foldLHsExpr thenExpr
   _ <- foldLHsExpr elseExpr
@@ -701,12 +789,20 @@ foldLHsExpr (L span e@(HsMultiIf typ grhss)) =
     addExprInfo span (Just typ') "HsMultiIf" (exprSort e)
     mapM_ foldLGRHS grhss
     return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsExpr (L span e@(HsLet _ (L _ binds) expr)) = do
+#else
 foldLHsExpr (L span e@(HsLet (L _ binds) expr)) = do
+#endif
   _ <- foldHsLocalBindsLR binds
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsLet" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsExpr (L span expr@(HsDo typ _context (L _ stmts))) =
+#else
 foldLHsExpr (L span expr@(HsDo _context (L _ stmts) typ)) =
+#endif
   restoreTidyEnv $ do
     typ' <- tidyType typ
     addExprInfo span (Just typ') "HsDo" (exprSort expr)
@@ -718,20 +814,31 @@ foldLHsExpr (L span (ExplicitList typ _syntaxExpr exprs)) =
     unless (null exprs) $ addExprInfo span (Just typ') "ExplicitList" Composite
     mapM_ foldLHsExpr exprs
     return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+#else
 foldLHsExpr (L span e@(ExplicitPArr typ exprs)) =
   restoreTidyEnv $ do
     typ' <- tidyType typ
     addExprInfo span (Just typ') "ExplicitPArr" (exprSort e)
     mapM_ foldLHsExpr exprs
     return $ Just typ'
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(RecordCon (RecordConTc _ conExpr) _ binds)) = do
+#else
 foldLHsExpr (L span e@(RecordCon (L _ _) _conLike conExpr binds)) = do
+#endif
     mbConType <-
       fmap (snd . splitFunTys) <$>
       foldLHsExpr (L (UnhelpfulSpan $ mkFastString "RecordCon") conExpr)
     addExprInfo span mbConType "RecordCon" (exprSort e)
     _ <- foldHsRecFields binds
     return mbConType
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsExpr (L span e@(RecordUpd (RecordUpdTc cons _inputTys outTys _wrapper) expr binds)) =
+#else
 foldLHsExpr (L span e@(RecordUpd expr binds cons _inputTys outTys _wrapper)) =
+#endif
   restoreTidyEnv $ do   
     -- cons is a non-empty list of DataCons that have  all the upd'd fields
     let typ = conLikeResTy (head cons) outTys
@@ -740,10 +847,14 @@ foldLHsExpr (L span e@(RecordUpd expr binds cons _inputTys outTys _wrapper)) =
     _ <- foldLHsExpr expr
     mapM_ foldLHsRecUpdField binds
     return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(ExprWithTySig _ expr)) = do
+#else
 foldLHsExpr (L _span (ExprWithTySig _expr _type)) = return Nothing
 foldLHsExpr (L span e@(ExprWithTySigOut expr _type)) = do
+#endif
   typ <- foldLHsExpr expr
-  addExprInfo span typ "ExprWithTySigOut" (exprSort e)
+  addExprInfo span typ "ExprWithTySig" (exprSort e)
   return typ
 foldLHsExpr (L span e@(ArithSeq postTcExpr _mbSyntaxExpr seqInfo)) = do
   typ <-
@@ -758,23 +869,38 @@ foldLHsExpr (L span e@(ArithSeq postTcExpr _mbSyntaxExpr seqInfo)) = do
         foldLHsExpr expr1 >> foldLHsExpr expr2 >> foldLHsExpr expr3
   addExprInfo span typ "ArithSeq" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+#else    
 foldLHsExpr (L span e@(PArrSeq postTcExpr _seqInfo)) = do
   typ <- foldLHsExpr (L (UnhelpfulSpan $ mkFastString "PArrSeq") postTcExpr)
   addExprInfo span typ "ArithSeq" (exprSort e)
   return typ
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(HsSCC _ _sourceText _fastString expr)) = do
+#else
 foldLHsExpr (L span e@(HsSCC _sourceText _fastString expr)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsSCC" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(HsCoreAnn _ _sourceText _fastString expr)) = do
+#else
 foldLHsExpr (L span e@(HsCoreAnn _sourceText _fastString expr)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsCoreAnn" (exprSort e)
   return typ
-foldLHsExpr (L _span (HsBracket _bracket)) = return Nothing
-foldLHsExpr (L _span (HsRnBracketOut _ _)) = return Nothing
-foldLHsExpr (L _span (HsTcBracketOut _bracket _splice)) = return Nothing
-foldLHsExpr (L _span (HsSpliceE _)) = return Nothing
+foldLHsExpr (L _span HsBracket {}) = return Nothing
+foldLHsExpr (L _span HsRnBracketOut {}) = return Nothing
+foldLHsExpr (L _span HsTcBracketOut {}) = return Nothing
+foldLHsExpr (L _span HsSpliceE {}) = return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span expr@(HsProc _ pat cmd)) = do
+#else
 foldLHsExpr (L span expr@(HsProc pat cmd)) = do
+#endif
   _ <- foldLPat pat
   _ <- foldLHsCmdTop cmd
   addExprInfo span Nothing "HsProc" (exprSort expr)
@@ -789,29 +915,45 @@ foldLHsExpr (L span e@(HsStatic expr)) = do
   return typ
 foldLHsExpr (L _ HsArrForm {}) = return Nothing
 foldLHsExpr (L _ HsArrApp {}) = return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span e@(HsTick _ _ expr)) = do
+#else
 foldLHsExpr (L span e@(HsTick _ expr)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsTick" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLHsExpr (L span e@(HsBinTick _ _ _ expr)) = do
+#else
 foldLHsExpr (L span e@(HsBinTick _ _ expr)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsBinTick" (exprSort e)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsExpr (L span e@(HsTickPragma _ _ _ _ expr)) = do
+#else
 foldLHsExpr (L span e@(HsTickPragma _ _ _ expr)) = do
+#endif
   typ <- foldLHsExpr expr
   addExprInfo span typ "HsTickPragma" (exprSort e)
   return typ
-foldLHsExpr (L _span EWildPat) = return Nothing
-foldLHsExpr (L _span (EAsPat _ _)) = return Nothing
-foldLHsExpr (L _span (EViewPat _ _)) = return Nothing
-foldLHsExpr (L _span (ELazyPat _)) = return Nothing
+foldLHsExpr (L _span EWildPat {}) = return Nothing
+foldLHsExpr (L _span EAsPat {}) = return Nothing
+foldLHsExpr (L _span EViewPat {}) = return Nothing
+foldLHsExpr (L _span ELazyPat {}) = return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsExpr (L span (HsWrap _ wrapper expr)) =
+#else
 foldLHsExpr (L span (HsWrap wrapper expr)) =
+#endif
   restoreHsWrapper $ do
     case exprSort expr of
       Simple -> modify' (\s -> s {astStateHsWrapper = Just wrapper})
       Composite -> return () -- Not sure if it is possible
     typ <- foldLHsExpr (L span expr)
-    return $ applyWrapper wrapper <$> typ
+    return $ applyWrapper wrapper <$> typ    
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldHsRecFields :: HsRecFields GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
@@ -831,7 +973,12 @@ foldLHsRecField :: LHsRecField GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Ty
 #else
 foldLHsRecField :: LHsRecField Id (LHsExpr Id) -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsRecField (L _span (HsRecField (L _idSpan (XFieldOcc _)) _ _)) = return Nothing
+foldLHsRecField (L span (HsRecField (L idSpan (FieldOcc identifier _)) arg pun)) =
+#else
 foldLHsRecField (L span (HsRecField (L idSpan (FieldOcc _ identifier)) arg pun)) =
+#endif
   restoreTidyEnv $ do
     (identifier', mbTypes) <- tidyIdentifier identifier
     addIdentifierToIdSrcSpanMap idSpan identifier' mbTypes
@@ -872,7 +1019,12 @@ foldLHsTupArg :: LHsTupArg GhcTc -> State ASTState (Maybe Type, TupArg)
 #else
 foldLHsTupArg :: LHsTupArg Id -> State ASTState (Maybe Type, TupArg)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsTupArg (L _span (XTupArg _)) = return (Nothing, TupArgMissing)
+foldLHsTupArg (L _span (Present _ expr)) =
+#else
 foldLHsTupArg (L _span (Present expr)) =
+#endif
   restoreTidyEnv $ do
     typ <- foldLHsExpr expr
     typ' <-
@@ -893,7 +1045,10 @@ foldLMatch :: LMatch Id (LHsExpr Id) -> State ASTState (Maybe Type)
 foldLMatch (L _span Match {..}) = do
   mapM_ foldLPat m_pats
   _ <- foldGRHSs m_grhss
-  return Nothing    
+  return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLMatch (L _span _) = return Nothing    
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)      
 foldLMatchCmd :: LMatch GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
@@ -904,6 +1059,9 @@ foldLMatchCmd (L _span Match {..}) = do
   mapM_ foldLPat m_pats
   _ <- foldGRHSsCmd m_grhss
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLMatchCmd (L _span _) = return Nothing    
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)      
 foldGRHSsCmd :: GRHSs GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
@@ -914,6 +1072,9 @@ foldGRHSsCmd GRHSs {..} = do
   mapM_ foldLGRHSCmd grhssGRHSs
   _ <- foldHsLocalBindsLR (unLoc grhssLocalBinds)
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldGRHSsCmd (_) = return Nothing    
+#endif  
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldGRHSs :: GRHSs GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
@@ -924,28 +1085,52 @@ foldGRHSs GRHSs {..} = do
   mapM_ foldLGRHS grhssGRHSs
   _ <- foldHsLocalBindsLR (unLoc grhssLocalBinds)
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldGRHSs (_) = return Nothing    
+#endif
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldLStmtLR :: LStmtLR GhcTc GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
 #else
 foldLStmtLR :: LStmtLR Id Id (LHsExpr Id) -> State ASTState (Maybe Type)
 #endif
-foldLStmtLR (L span (LastStmt body _ _)) =  
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLR (L _span (XStmtLR _)) = return Nothing
+foldLStmtLR (L span (LastStmt _ body _ _)) =
+#else
+foldLStmtLR (L span (LastStmt body _ _)) =
+#endif
   do typ <- foldLHsExpr body
      addExprInfo span typ "LastStmt" Composite
      return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLR (L _span (BindStmt _ pat body _ _)) = do
+#else
 foldLStmtLR (L _span (BindStmt pat body _ _ _)) = do
+#endif
   _ <- foldLPat pat
   _ <- foldLHsExpr body
   return Nothing
-foldLStmtLR (L span (BodyStmt body _ _ _)) = do
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLStmtLR (L span (BodyStmt _ body _ _)) = do
+#else
+foldLStmtLR (L span (BodyStmt body _  _ _)) = do
+#endif
   mbTyp <- foldLHsExpr body
   addExprInfo span mbTyp "BodyStmt" Composite
   return mbTyp
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLStmtLR (L _ (LetStmt _ (L _ binds))) = do
+#else
 foldLStmtLR (L _ (LetStmt (L _ binds))) = do
+#endif
   _ <- foldHsLocalBindsLR binds
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLStmtLR (L _ (ParStmt _ blocks _ _)) = do
+#else
 foldLStmtLR (L _ (ParStmt blocks _ _ _)) = do
+#endif
   mapM_ foldParStmtBlock blocks
   return Nothing
 foldLStmtLR (L _ TransStmt {..}) = do
@@ -956,30 +1141,45 @@ foldLStmtLR (L _ TransStmt {..}) = do
 foldLStmtLR (L _span RecStmt {..}) = do
   mapM_ foldLStmtLR recS_stmts
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLR (L span (ApplicativeStmt typ args _)) =
+#else
 foldLStmtLR (L span (ApplicativeStmt args _ typ)) =
+#endif
   restoreTidyEnv $ do
     typ' <- tidyType typ
     mapM_ (foldApplicativeArg . snd) args
     addExprInfo span (Just typ') "ApplicativeStmt" Composite
     return Nothing
 
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldApplicativeArg :: ApplicativeArg GhcTc -> State ASTState (Maybe Type)    
+#elif MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldApplicativeArg :: ApplicativeArg GhcTc GhcTc -> State ASTState (Maybe Type)
 #else
 foldApplicativeArg :: ApplicativeArg Id Id -> State ASTState (Maybe Type)
 #endif
 foldApplicativeArg appArg =
   case appArg of
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)    
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+    XApplicativeArg _ -> return Nothing
+    ApplicativeArgOne _ pat expr _bool -> do
+#else
     ApplicativeArgOne pat expr _bool -> do
+#endif
 #else
     ApplicativeArgOne pat expr -> do
 #endif
       _ <- foldLPat pat
       _ <- foldLHsExpr expr
       return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)            
+    ApplicativeArgMany _ exprStmts _ pat -> do
+#else
     ApplicativeArgMany exprStmts _ pat -> do
-      _ <- mapM_ foldLStmtLR exprStmts
+#endif
+      mapM_ foldLStmtLR exprStmts
       _ <- foldLPat pat
       return Nothing  
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
@@ -987,23 +1187,44 @@ foldLStmtLRCmd ::
      LStmtLR GhcTc GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
 #else
 foldLStmtLRCmd :: LStmtLR Id Id (LHsCmd Id) -> State ASTState (Maybe Type)
-#endif                  
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLRCmd (L _ (XStmtLR _)) = return Nothing
+foldLStmtLRCmd (L span (LastStmt _ body _syntaxExpr _)) = do
+#else
 foldLStmtLRCmd (L span (LastStmt body _syntaxExpr _)) = do
+#endif
   typ <- foldLHsCmd body
   addExprInfo span typ "LastStmt Cmd" Composite
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLRCmd (L _ (BindStmt _ pat body _ _)) = do
+#else
 foldLStmtLRCmd (L _ (BindStmt pat body _ _ _)) = do
+#endif
   _ <- foldLPat pat
   _ <- foldLHsCmd body
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLStmtLRCmd (L span (BodyStmt _ body _ _)) = do
+#else
 foldLStmtLRCmd (L span (BodyStmt body _ _ _)) = do
+#endif
   typ <- foldLHsCmd body
   addExprInfo span typ "BodyStmt Cmd" Composite
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLStmtLRCmd (L _ (LetStmt _ (L _ binds))) = do
+#else
 foldLStmtLRCmd (L _ (LetStmt (L _ binds))) = do
+#endif
   _ <- foldHsLocalBindsLR binds
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLStmtLRCmd (L _ (ParStmt _ blocks _ _)) = do
+#else
 foldLStmtLRCmd (L _ (ParStmt blocks _ _ _)) = do
+#endif
   mapM_ foldParStmtBlock blocks
   return Nothing
 foldLStmtLRCmd (L _ TransStmt {..}) = do
@@ -1014,7 +1235,11 @@ foldLStmtLRCmd (L _ TransStmt {..}) = do
 foldLStmtLRCmd (L _ RecStmt {..}) = do
   mapM_ foldLStmtLRCmd recS_stmts
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLStmtLRCmd (L span (ApplicativeStmt typ args _)) =
+#else
 foldLStmtLRCmd (L span (ApplicativeStmt args _ typ)) =
+#endif
   restoreTidyEnv $ do
     typ' <- tidyType typ
     mapM_ (foldApplicativeArg . snd) args
@@ -1026,7 +1251,12 @@ foldLGRHS :: LGRHS GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
 #else
 foldLGRHS :: LGRHS Id (LHsExpr Id) -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLGRHS (L _span (XGRHS _)) = return Nothing
+foldLGRHS (L _span (GRHS _ guards body)) = do
+#else
 foldLGRHS (L _span (GRHS guards body)) = do
+#endif
   typ <- foldLHsExpr body
   mapM_ foldLStmtLR guards
   return typ
@@ -1036,7 +1266,12 @@ foldLGRHSCmd :: LGRHS GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
 #else
 foldLGRHSCmd :: LGRHS Id (LHsCmd Id) -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLGRHSCmd (L _span (XGRHS _)) = return Nothing
+foldLGRHSCmd (L _span (GRHS _ guards body)) = do
+#else
 foldLGRHSCmd (L _span (GRHS guards body)) = do
+#endif
   typ <- foldLHsCmd body
   mapM_ foldLStmtLR guards
   return typ   
@@ -1046,7 +1281,12 @@ foldParStmtBlock :: ParStmtBlock GhcTc GhcTc -> State ASTState (Maybe Type)
 #else
 foldParStmtBlock :: ParStmtBlock Id Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldParStmtBlock (XParStmtBlock _) = return Nothing
+foldParStmtBlock (ParStmtBlock _ exprStmts _ids _syntaxExpr) = do
+#else
 foldParStmtBlock (ParStmtBlock exprStmts _ids _syntaxExpr) = do
+#endif
   mapM_ foldLStmtLR exprStmts
   return Nothing
 
@@ -1055,21 +1295,35 @@ foldHsLocalBindsLR :: HsLocalBindsLR GhcTc GhcTc -> State ASTState (Maybe Type)
 #else
 foldHsLocalBindsLR :: HsLocalBindsLR Id Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldHsLocalBindsLR (XHsLocalBindsLR _) = return Nothing
+foldHsLocalBindsLR (HsValBinds _ binds) = do
+#else
 foldHsLocalBindsLR (HsValBinds binds) = do
+#endif
   _ <- foldHsValBindsLR binds
   return Nothing
-foldHsLocalBindsLR (HsIPBinds _binds) = return Nothing
-foldHsLocalBindsLR EmptyLocalBinds = return Nothing
+foldHsLocalBindsLR HsIPBinds {} = return Nothing
+foldHsLocalBindsLR EmptyLocalBinds {} = return Nothing
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
 foldHsValBindsLR :: HsValBindsLR GhcTc GhcTc -> State ASTState (Maybe Type)
 #else
 foldHsValBindsLR :: HsValBindsLR Id Id -> State ASTState (Maybe Type)
 #endif
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldHsValBindsLR (ValBinds _ _binds _) = do  
+  return Nothing
+foldHsValBindsLR (XValBindsLR (NValBinds binds _)) = do
+  _ <- mapM_ (foldLHsBindsLR . snd) binds
+  return Nothing      
+#else    
 foldHsValBindsLR (ValBindsIn _ _) = return Nothing
 foldHsValBindsLR (ValBindsOut binds _) = do
-  _ <- mapM_ (foldLHsBindsLR . snd) binds
+  mapM_ (foldLHsBindsLR . snd) binds
   return Nothing
+#endif  
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
 foldLHsBindsLR :: LHsBinds GhcTc -> State ASTState ()
@@ -1078,7 +1332,7 @@ foldLHsBindsLR :: LHsBinds Id -> State ASTState ()
 #endif
 foldLHsBindsLR = mapM_ (`foldLHsBindLR` Nothing) . bagToList
 
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldLHsBindLR :: LHsBindLR GhcTc GhcTc
               -> Maybe Id -- ^ Polymorphic id
               -> State ASTState (Maybe Type)
@@ -1087,6 +1341,10 @@ foldLHsBindLR :: LHsBindLR Id Id
               -> Maybe Id -- ^ Polymorphic id
               -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsBindLR (L _span (XHsBindsLR _)) _ = return Nothing
+foldLHsBindLR (L _span (PatSynBind _ (XPatSynBind _))) _ = return Nothing
+#endif
 foldLHsBindLR (L _span FunBind {..}) mbPolyId
   | mg_origin fun_matches == FromSource =
     restoreTidyEnv $ do
@@ -1108,8 +1366,7 @@ foldLHsBindLR (L _ PatBind {..}) _ = do
   return Nothing
 foldLHsBindLR (L _ VarBind {..}) _ = return Nothing
 foldLHsBindLR (L _ AbsBinds {..}) _ = do
-  _ <-
-    mapM_ (\(bind, typ) -> foldLHsBindLR bind (Just typ)) $
+  mapM_ (\(bind, typ) -> foldLHsBindLR bind (Just typ)) $
     zip (bagToList abs_binds) (map abe_poly abs_exports)
   return Nothing
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
@@ -1118,7 +1375,11 @@ foldLHsBindLR (L _ AbsBindsSig {..}) _ = do
   _ <- foldLHsBindLR abs_sig_bind (Just abs_sig_export)
   return Nothing
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsBindLR (L _ (PatSynBind _ PSB {..})) _ =
+#else
 foldLHsBindLR (L _ (PatSynBind PSB {..})) _ =
+#endif
   restoreTidyEnv $ do
     _ <- foldLPat psb_def
     _ <-
@@ -1151,7 +1412,14 @@ foldLPat :: LPat GhcTc -> State ASTState (Maybe Type)
 #else
 foldLPat :: LPat Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L _span (XPat _)) = return Nothing
+foldLPat (L _ (NPat _ (L _ (XOverLit _)) _ _)) = return Nothing
+foldLPat (L _ (NPlusKPat _ (L _ _) (L _ (XOverLit _)) _ _ _)) = return Nothing
+foldLPat (L span (VarPat _ (L _ identifier))) = do
+#else
 foldLPat (L span (VarPat (L _ identifier))) = do
+#endif
   (identifier', _) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap span identifier' Nothing
   return . Just . varType $ identifier'
@@ -1159,43 +1427,74 @@ foldLPat (L span pat@(WildPat typ)) = do
   typ' <- tidyType typ
   addExprInfo span (Just typ') "WildPat" (patSort pat)
   return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L span p@(LazyPat _ pat)) = do
+#else
 foldLPat (L span p@(LazyPat pat)) = do
+#endif
   mbType <- foldLPat pat
   addExprInfo span mbType "LazyPat" (patSort p)
   return mbType
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L span p@(AsPat _ (L idSpan identifier) pat)) = do
+#else
 foldLPat (L span p@(AsPat (L idSpan identifier) pat)) = do
+#endif
   (identifier', _) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap idSpan identifier' Nothing
   addExprInfo span (Just . varType $ identifier') "AsPat" (patSort p)
   _ <- foldLPat pat
   return . Just . varType $ identifier'
-foldLPat (L _span (ParPat pat)) = foldLPat pat  
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L _span (ParPat _ pat)) = foldLPat pat
+#else
+foldLPat (L _span (ParPat pat)) = foldLPat pat
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L span p@(BangPat _ pat)) = do
+#else
 foldLPat (L span p@(BangPat pat)) = do
+#endif
   typ <- foldLPat pat
   addExprInfo span typ "BangPat" (patSort p)
   return typ
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L span p@(ListPat (ListPatTc typ _) pats)) = do
+#else
 foldLPat (L span p@(ListPat pats typ _)) = do
+#endif
   typ' <- tidyType typ
   let listType = mkListTy typ'
   addExprInfo span (Just listType) "ListPat" (patSort p)
-  _ <- mapM_ foldLPat pats
+  mapM_ foldLPat pats
   return $ Just listType
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L span pat@(TuplePat types pats boxity)) = do
+#else
 foldLPat (L span pat@(TuplePat pats boxity types)) = do
+#endif
   typ' <- tidyType $ mkTupleTy boxity types
   addExprInfo span (Just typ') "TuplePat" (patSort pat)
-  _ <- mapM_ foldLPat pats
+  mapM_ foldLPat pats
   return $ Just typ'
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLPat (L _span (SumPat _ pat _ _)) = do
+#else
 foldLPat (L _span (SumPat pat _ _ _types)) = do
+#endif
   -- TODO
   _ <- foldLPat pat
   return Nothing  
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+#else
 foldLPat (L span pat@(PArrPat pats typ)) = do
   typ' <- tidyType typ
   addExprInfo span (Just typ') "PArrPat" (patSort pat)
-  _ <- mapM_ foldLPat pats
+  mapM_ foldLPat pats
   return $ Just typ'
+#endif  
 foldLPat (L _span (ConPatIn _ _)) = return Nothing
 foldLPat (L span pat@ConPatOut {..}) = do
   let (L idSpan conLike) = pat_con 
@@ -1210,14 +1509,22 @@ foldLPat (L span pat@ConPatOut {..}) = do
   addExprInfo span (Just typ') "ConPatOut" (patSort pat)
   _ <- foldHsConPatDetails pat_args
   return . Just . varType $ identifier'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLPat (L span p@(ViewPat typ expr pat)) = do
+#else
 foldLPat (L span p@(ViewPat expr pat typ)) = do
+#endif
   typ' <- tidyType typ
   addExprInfo span (Just typ') "ViewPat" (patSort p)
   _ <- foldLPat pat
   _ <- foldLHsExpr expr
   return $ Just typ'
-foldLPat (L _ (SplicePat _)) = return Nothing
+foldLPat (L _ SplicePat {}) = return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L span (LitPat _ hsLit)) = do
+#else
 foldLPat (L span (LitPat hsLit)) = do
+#endif
   typ' <- tidyType $ hsLitType hsLit
   addExprInfo
     span
@@ -1227,11 +1534,19 @@ foldLPat (L span (LitPat hsLit)) = do
        then Simple
        else Composite)
   return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L span pat@(NPat _ (L _spanLit (OverLit (OverLitTc {..}) _ _)) _ _)) = do
+#else
 foldLPat (L span pat@(NPat (L _spanLit OverLit {ol_type}) _ _ _)) = do
+#endif
   typ' <- tidyType ol_type
   addExprInfo span (Just typ') "NPat" (patSort pat)
   return $ Just ol_type
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L span pat@(NPlusKPat typ (L idSpan identifier) (L litSpan (OverLit (OverLitTc {..}) _ _)) _ _ _)) = do
+#else
 foldLPat (L span pat@(NPlusKPat (L idSpan identifier) (L litSpan OverLit {ol_type}) _ _ _ typ)) = do
+#endif
   (identifier', _) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap idSpan identifier' Nothing
   typ' <- tidyType typ
@@ -1245,12 +1560,23 @@ foldLPat (L span pat@(NPlusKPat (L idSpan identifier) (L litSpan OverLit {ol_typ
        then Simple
        else Composite)
   return $ Just typ'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLPat (L _span (SigPat typ pat)) = do
+  typ' <- tidyType typ
+  _ <- foldLPat pat
+  return $ Just typ'    
+#else
 foldLPat (L _span (SigPatIn _ _)) = return Nothing  
 foldLPat (L _span (SigPatOut pat typ)) = do
   typ' <- tidyType typ
   _ <- foldLPat pat
   return $ Just typ'
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLPat (L span p@(CoPat _ _ pat typ)) = do
+#else
 foldLPat (L span p@(CoPat _ pat typ)) = do
+#endif
   typ' <- tidyType typ
   addExprInfo span (Just typ') "CoPat" (patSort p)
   _ <- foldLPat (L span pat)
@@ -1266,7 +1592,7 @@ foldHsConPatDetails
   -> State ASTState (Maybe Type)
 #endif  
 foldHsConPatDetails (PrefixCon args) = do
-  _ <- mapM_ foldLPat args
+  mapM_ foldLPat args
   return Nothing
 foldHsConPatDetails (RecCon rec) = do
   _ <- foldHsRecFieldsPat rec
@@ -1286,7 +1612,7 @@ foldHsRecFieldsPat HsRecFields {..} = do
         case rec_dotdot of
           Just i -> take i
           Nothing -> id
-  _ <- mapM_ foldLHsRecFieldPat $ onlyUserWritten rec_flds
+  mapM_ foldLHsRecFieldPat $ onlyUserWritten rec_flds
   return Nothing
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
@@ -1294,18 +1620,30 @@ foldLHsRecFieldPat :: LHsRecField GhcTc (LPat GhcTc) -> State ASTState (Maybe Ty
 #else
 foldLHsRecFieldPat :: LHsRecField Id (LPat Id) -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsRecFieldPat (L _ (HsRecField (L idSpan (FieldOcc identifier _)) arg pun)) = do
+#else
 foldLHsRecFieldPat (L _ (HsRecField (L idSpan (FieldOcc _ identifier)) arg pun)) = do
+#endif
   (identifier', mbTypes) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap idSpan identifier' mbTypes
   unless pun $ void $ foldLPat arg
   return . Just . varType $ identifier'
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsRecFieldPat (L _ (HsRecField (L _idSpan (XFieldOcc _)) _arg _pun)) = return Nothing    
+#endif    
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 foldLHsCmdTop :: LHsCmdTop GhcTc -> State ASTState (Maybe Type)
 #else
 foldLHsCmdTop :: LHsCmdTop Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLHsCmdTop (L _span (XCmdTop _)) = return Nothing
+foldLHsCmdTop (L span (HsCmdTop _ cmd)) = do
+#else
 foldLHsCmdTop (L span (HsCmdTop cmd _ _ _)) = do
+#endif
   mbTyp <- foldLHsCmd cmd
   addExprInfo span mbTyp "HsCmdTop" Composite
   return mbTyp
@@ -1315,44 +1653,87 @@ foldLHsCmd :: LHsCmd GhcTc -> State ASTState (Maybe Type)
 #else
 foldLHsCmd :: LHsCmd Id -> State ASTState (Maybe Type)
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsCmd (L _ (XCmd _)) = return Nothing
+foldLHsCmd (L _ (HsCmdLam _ (XMatchGroup _))) = return Nothing
+foldLHsCmd (L _ (HsCmdCase _ _ (XMatchGroup _))) = return Nothing
+foldLHsCmd (L _ (HsCmdArrApp _ expr1 expr2 _ _)) = do
+#else
 foldLHsCmd (L _ (HsCmdArrApp expr1 expr2 _ _ _)) = do
+#endif
   _ <- foldLHsExpr expr1
   _ <- foldLHsExpr expr2
   return Nothing
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)  
+#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsCmd (L _ (HsCmdArrForm _ expr _  _ topCmds)) = do
+#else
 foldLHsCmd (L _ (HsCmdArrForm expr _  _ topCmds)) = do
+#endif
 #else
 foldLHsCmd (L _ (HsCmdArrForm expr _ topCmds)) = do
 #endif
   _ <- foldLHsExpr expr
-  _ <- mapM_ foldLHsCmdTop topCmds
-  return Nothing  
+  mapM_ foldLHsCmdTop topCmds
+  return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsCmd (L _ (HsCmdApp _ cmd expr)) = do
+#else
 foldLHsCmd (L _ (HsCmdApp cmd expr)) = do
+#endif
   _ <- foldLHsCmd cmd
   _ <- foldLHsExpr expr
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsCmd (L _ (HsCmdLam _ MG {..})) = do
+#else
 foldLHsCmd (L _ (HsCmdLam MG {..})) = do
+#endif
   mapM_ foldLMatchCmd $ unLoc mg_alts
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLHsCmd (L _ (HsCmdCase _ expr MG {..})) = do
+#else
 foldLHsCmd (L _ (HsCmdCase expr MG {..})) = do
+#endif
   _ <- foldLHsExpr expr
   mapM_ foldLMatchCmd $ unLoc mg_alts
-  return Nothing   
+  return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+foldLHsCmd (L _ (HsCmdPar _ cmd)) = do
+#else
 foldLHsCmd (L _ (HsCmdPar cmd)) = do
+#endif
   _ <- foldLHsCmd cmd
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+foldLHsCmd (L _ (HsCmdIf _ _ expr cmd1 cmd2)) = do
+#else
 foldLHsCmd (L _ (HsCmdIf _ expr cmd1 cmd2)) = do
+#endif
   _ <- foldLHsCmd cmd1
   _ <- foldLHsCmd cmd2
   _ <- foldLHsExpr expr
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+foldLHsCmd (L _ (HsCmdLet _ (L _ binds) cmd)) = do
+#else
 foldLHsCmd (L _ (HsCmdLet (L _ binds) cmd)) = do
+#endif
   _ <- foldLHsCmd cmd
   _ <- foldHsLocalBindsLR binds
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsCmd (L _ (HsCmdDo _ stmts)) = do
+#else
 foldLHsCmd (L _ (HsCmdDo stmts _)) = do
+#endif
   mapM_ foldLStmtLRCmd $ unLoc stmts
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)      
+foldLHsCmd (L span (HsCmdWrap _ _ cmd)) = do
+#else
 foldLHsCmd (L span (HsCmdWrap _ cmd)) = do
+#endif    
   _ <- foldLHsCmd (L span cmd)
   return Nothing
diff --git a/src/HaskellCodeExplorer/GhcUtils.hs b/src/HaskellCodeExplorer/GhcUtils.hs
index 3a4ec26..3ac1f86 100644
--- a/src/HaskellCodeExplorer/GhcUtils.hs
+++ b/src/HaskellCodeExplorer/GhcUtils.hs
@@ -69,7 +69,6 @@ import qualified Data.Generics.Uniplate.Data()
 import qualified Data.HashMap.Strict as HM
 import qualified Data.List as L
 import Data.Maybe (fromMaybe, isJust, mapMaybe)
-import Data.Ord (comparing)
 import qualified Data.Text as T
 import DataCon (dataConWorkId, flSelector)
 import Documentation.Haddock.Parser (overIdentifier, parseParas)
@@ -103,10 +102,9 @@ import GHC
   , IE(..)  
   , TyThing(..)
   , LHsDecl  
-  , HsDecl(..)  
+  , HsDecl(..)
   , DocDecl(..)  
   , ConDecl(..)
-  , PostRn  
   , HsConDetails(..)  
   , ConDeclField(..)  
   , DataFamInstDecl(..)
@@ -119,8 +117,16 @@ import GHC
   , getLoc
   , hsSigType
   , getConNames
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  , NHsValBindsLR(..)
+  , getConArgs
+  , unpackHDS
+  , NoExt(..)
+  , extFieldOcc  
+#else
   , getConDetails
   , selectorFieldOcc
+#endif
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)    
   , tyClGroupTyClDecls
   , LIEWrappedName
@@ -275,11 +281,32 @@ instanceDeclToText :: DynFlags -> InstDecl Name -> T.Text
 #endif
 instanceDeclToText flags decl =
   case decl of
-    ClsInstD ClsInstDecl {..} -> T.append "instance " (toText flags cid_poly_ty)
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+    XInstDecl _ -> ""
+    ClsInstD _ (XClsInstDecl _) -> ""
+    ClsInstD _ ClsInstDecl {..} ->
+#else
+    ClsInstD ClsInstDecl {..} ->
+#endif
+      T.append "instance " (toText flags cid_poly_ty)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+    DataFamInstD _ di ->
+      let args =
+            T.intercalate " " . map (toText flags) .  feqn_pats  . hsib_body . dfid_eqn $ di
+       in T.concat
+            ["data instance ", toText flags (unLoc $ feqn_tycon . hsib_body . dfid_eqn $ di), " ", args]
+    TyFamInstD _ ti ->
+      let args =
+            T.intercalate " " .
+            map (toText flags) . feqn_pats . hsib_body . tfid_eqn $
+            ti
+       in T.concat
+            ["type instance ", toText flags $ tyFamInstDeclName ti, " ", args]
+#elif MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
     DataFamInstD di ->
       let args =
-            T.intercalate " " . map (toText flags) .  feqn_pats  .hsib_body . dfid_eqn $ di
+            T.intercalate " " . map (toText flags) .  feqn_pats  . hsib_body . dfid_eqn $ di
        in T.concat
             ["data instance ", toText flags (unLoc $ feqn_tycon . hsib_body . dfid_eqn $ di), " ", args]
     TyFamInstD ti ->
@@ -313,7 +340,7 @@ tyClDeclPrefix tyClDecl =
       isNewTy DataDecl {tcdDataDefn = HsDataDefn {dd_ND = NewType}} = True
       isNewTy _ = False
    in case tyClDecl of
-        FamDecl _
+        FamDecl {}
           | isDataFamilyDecl tyClDecl -> "data family "
           | otherwise -> "type family "
         SynDecl {} -> "type "
@@ -321,6 +348,9 @@ tyClDeclPrefix tyClDecl =
           | isNewTy tyClDecl -> "newtype "
           | otherwise -> "data "
         ClassDecl {} -> "class "
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+        XTyClDecl _ -> ""
+#endif    
     
 demangleOccName :: Name -> T.Text
 demangleOccName name
@@ -411,7 +441,11 @@ hsGroupVals :: HsGroup Name -> [GenLocated SrcSpan (HsBindLR Name Name)]
 hsGroupVals hsGroup =
   filter (isGoodSrcSpan . getLoc) $
   case hs_valds hsGroup of
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+    XValBindsLR (NValBinds binds _) -> concatMap (bagToList . snd) binds
+#else
     ValBindsOut binds _ -> concatMap (bagToList . snd) binds
+#endif
     _ -> []
 
 hsPatSynDetails :: HsPatSynDetails a -> [a]
@@ -450,15 +484,36 @@ ieLocNames :: IE pass -> [Located (IdP pass)]
 #else
 ieLocNames :: IE Name -> [Located Name]
 #endif
-ieLocNames (IEVar n) = [unwrapName n]
-ieLocNames (IEThingAbs n) = [unwrapName n]
-ieLocNames (IEThingAll n) = [unwrapName n]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+ieLocNames (XIE _) = []
+ieLocNames (IEVar _ n) =
+#else
+ieLocNames (IEVar n) = 
+#endif
+  [unwrapName n]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+ieLocNames (IEThingAbs _ n) =
+#else
+ieLocNames (IEThingAbs n) =
+#endif
+  [unwrapName n]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+ieLocNames (IEThingAll _ n) =
+#else
+ieLocNames (IEThingAll n) =
+#endif
+  [unwrapName n]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+ieLocNames (IEThingWith _ n _ ns labels) =
+#else
 ieLocNames (IEThingWith n _ ns labels) =
+#endif
   unwrapName n : (map unwrapName ns ++ map (fmap flSelector) labels)
-ieLocNames (IEModuleContents (L _ _)) = []
-ieLocNames (IEGroup _ _) = []
-ieLocNames (IEDoc _) = []
-ieLocNames (IEDocNamed _) = []
+ieLocNames IEModuleContents {} = []
+ieLocNames IEGroup {} = []
+ieLocNames IEDoc {} = []
+ieLocNames IEDocNamed {} = []
 
 --------------------------------------------------------------------------------
 -- Lookups
@@ -959,10 +1014,19 @@ collectDocs = go Nothing []
   where
     go Nothing _ [] = []
     go (Just prev) docs [] = finished prev docs []
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+    go prev docs (L _ (DocD _ (DocCommentNext str)):ds)
+#else
     go prev docs (L _ (DocD (DocCommentNext str)):ds)
+#endif
+
       | Nothing <- prev = go Nothing (str : docs) ds
       | Just decl <- prev = finished decl docs (go Nothing [str] ds)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)        
+    go prev docs (L _ (DocD _ (DocCommentPrev str)):ds) = go prev (str : docs) ds
+#else
     go prev docs (L _ (DocD (DocCommentPrev str)):ds) = go prev (str : docs) ds
+#endif
     go Nothing docs (d:ds) = go (Just d) docs ds
     go (Just prev) docs (d:ds) = finished prev docs (go (Just d) [] ds)
     finished decl docs rest = (decl, reverse docs) : rest
@@ -973,33 +1037,62 @@ ungroup :: HsGroup GhcRn -> [LHsDecl GhcRn]
 ungroup :: HsGroup Name -> [LHsDecl Name]
 #endif
 ungroup group_ =
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  mkDecls (tyClGroupTyClDecls . hs_tyclds) (TyClD NoExt) group_ ++  
+#elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
   mkDecls (tyClGroupTyClDecls . hs_tyclds) TyClD group_ ++  
 #else
   mkDecls (tyClGroupConcat . hs_tyclds) TyClD group_ ++
 #endif
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  mkDecls hs_derivds (DerivD NoExt) group_ ++
+  mkDecls hs_defds (DefD NoExt) group_ ++
+  mkDecls hs_fords (ForD NoExt) group_ ++
+  mkDecls hs_docs (DocD NoExt) group_ ++  
+#else
   mkDecls hs_derivds DerivD group_ ++
   mkDecls hs_defds DefD group_ ++
   mkDecls hs_fords ForD group_ ++
   mkDecls hs_docs DocD group_ ++
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)  
+#endif
+  
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  mkDecls hsGroupInstDecls (InstD NoExt) group_ ++
+#elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)  
   mkDecls hsGroupInstDecls InstD group_ ++
 #else
   mkDecls hs_instds InstD group_ ++
 #endif
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+  mkDecls (typesigs . hs_valds) (SigD NoExt) group_ ++
+  mkDecls (valbinds . hs_valds) (ValD NoExt) group_
+#else
   mkDecls (typesigs . hs_valds) SigD group_ ++
   mkDecls (valbinds . hs_valds) ValD group_
+#endif  
+
+  
   where
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+    typesigs (XValBindsLR (NValBinds _ sigs)) = filter isUserLSig sigs
+#else
     typesigs (ValBindsOut _ sigs) = filter isUserLSig sigs
+#endif
     typesigs _ = []
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)        
+    valbinds (XValBindsLR (NValBinds binds _)) = concatMap bagToList . snd . unzip $ binds
+#else
     valbinds (ValBindsOut binds _) = concatMap bagToList . snd . unzip $ binds
+#endif
     valbinds _ = []
 
 mkDecls :: (a -> [Located b]) -> (b -> c) -> a -> [Located c]
 mkDecls field con struct = [L loc (con decl) | L loc decl <- field struct]
 
 sortByLoc :: [Located a] -> [Located a]
-sortByLoc = L.sortBy (comparing getLoc)
+sortByLoc = L.sortOn getLoc
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 classDeclDocs :: TyClDecl GhcRn -> [(LHsDecl GhcRn, [HsDocString])]
@@ -1009,10 +1102,18 @@ classDeclDocs :: TyClDecl Name -> [(LHsDecl Name, [HsDocString])]
 classDeclDocs class_ = collectDocs . sortByLoc $ decls
   where
     decls = docs ++ defs ++ sigs ++ ats
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+    docs = mkDecls tcdDocs (DocD NoExt) class_
+    defs = mkDecls (bagToList . tcdMeths) (ValD NoExt) class_
+    sigs = mkDecls tcdSigs (SigD NoExt) class_
+    ats = mkDecls tcdATs ((TyClD NoExt) . (FamDecl NoExt)) class_
+#else
     docs = mkDecls tcdDocs DocD class_
     defs = mkDecls (bagToList . tcdMeths) ValD class_
     sigs = mkDecls tcdSigs SigD class_
     ats = mkDecls tcdATs (TyClD . FamDecl) class_
+#endif
+
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 conDeclDocs :: ConDecl GhcRn -> [(Name, [HsDocString], SrcSpan)]
@@ -1025,18 +1126,30 @@ conDeclDocs conDecl =
   conDecl
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
-selectorDocs :: ConDecl pass -> [(PostRn pass (IdP pass), [HsDocString], SrcSpan)]
+selectorDocs :: ConDecl GhcRn -> [(Name, [HsDocString], SrcSpan)]
 #else
-selectorDocs :: ConDecl name -> [(PostRn name name, [HsDocString], SrcSpan)]
+selectorDocs :: ConDecl Name -> [(Name, [HsDocString], SrcSpan)]
 #endif
 selectorDocs con =
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)  
+  case getConArgs con of
+#else
   case getConDetails con of
+#endif
     RecCon (L _ flds) ->
       concatMap
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+        (\(L _ (ConDeclField _ fieldOccs _ mbDoc)) ->
+#else
         (\(L _ (ConDeclField fieldOccs _ mbDoc)) ->
+#endif
            map
              (\(L span f) ->
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+                (extFieldOcc f, maybe [] ((: []) . unLoc) mbDoc, span))
+#else
                 (selectorFieldOcc f, maybe [] ((: []) . unLoc) mbDoc, span))
+#endif
              fieldOccs)
         flds
     _ -> []
@@ -1050,14 +1163,27 @@ subordinateNamesWithDocs =
     concatMap
     (\(L span tyClDecl) ->
        case tyClDecl of
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+         TyClD _ classDecl@ClassDecl {..} ->
+#else
          TyClD classDecl@ClassDecl {..} ->
+#endif
            concatMap
              (\(L _ decl, docs) -> map (, docs, span) $ getMainDeclBinder decl) $
            classDeclDocs classDecl
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+         TyClD _ DataDecl {..} ->
+#else
          TyClD DataDecl {..} ->
+#endif
            concatMap (\(L _ con) -> conDeclDocs con ++ selectorDocs con) $
            dd_cons tcdDataDefn
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+         InstD _ (DataFamInstD _ DataFamInstDecl {..}) ->
+#else
          InstD (DataFamInstD DataFamInstDecl {..}) ->
+#endif
+
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)               
            concatMap (conDeclDocs . unLoc) . dd_cons . feqn_rhs  . hsib_body $ dfid_eqn
 #else
@@ -1076,14 +1202,35 @@ getMainDeclBinder :: HsDecl pass -> [IdP pass]
 #else
 getMainDeclBinder :: HsDecl name -> [name]
 #endif
-getMainDeclBinder (TyClD d) = [tcdName d]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+getMainDeclBinder (TyClD _ d) =
+#else
+getMainDeclBinder (TyClD d) =
+#endif
+  [tcdName d]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+getMainDeclBinder (ValD _ d) =
+#else
 getMainDeclBinder (ValD d) =
+#endif
   case collectHsBindBinders d of
     [] -> []
     (name:_) -> [name]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+getMainDeclBinder (SigD _ d) = sigNameNoLoc d
+#else
 getMainDeclBinder (SigD d) = sigNameNoLoc d
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+getMainDeclBinder (ForD _ (ForeignImport _ name _ _)) = [unLoc name]
+#else
 getMainDeclBinder (ForD (ForeignImport name _ _ _)) = [unLoc name]
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+getMainDeclBinder (ForD _ ForeignExport {}) = []
+#else
 getMainDeclBinder (ForD ForeignExport {}) = []
+#endif
 getMainDeclBinder _ = []
 
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
@@ -1091,20 +1238,45 @@ sigNameNoLoc :: Sig pass -> [IdP pass]
 #else    
 sigNameNoLoc :: Sig name -> [name]
 #endif
-sigNameNoLoc (TypeSig      ns _)       = map unLoc ns
-sigNameNoLoc (ClassOpSig _ ns _)       = map unLoc ns
-#if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
-sigNameNoLoc (PatSynSig    ns _)        = map unLoc ns
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (TypeSig _ ns _) = map unLoc ns
+#else
+sigNameNoLoc (TypeSig ns _) = map unLoc ns
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (ClassOpSig _ _ ns _) = map unLoc ns
+#else
+sigNameNoLoc (ClassOpSig _ ns _) = map unLoc ns
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (PatSynSig _ ns _) = map unLoc ns
+#elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
+sigNameNoLoc (PatSynSig ns _) = map unLoc ns
+#else
+sigNameNoLoc (PatSynSig n _) = [unLoc n]
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (SpecSig _ n _ _) = [unLoc n]
+#else
+sigNameNoLoc (SpecSig n _ _) = [unLoc n]
+#endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (InlineSig _ n _) = [unLoc n]
 #else
-sigNameNoLoc (PatSynSig    n _)        = [unLoc n]
+sigNameNoLoc (InlineSig n _) = [unLoc n]
 #endif
-sigNameNoLoc (SpecSig      n _ _)      = [unLoc n]
-sigNameNoLoc (InlineSig    n _)        = [unLoc n]
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+sigNameNoLoc (FixSig _ (FixitySig _ ns _)) = map unLoc ns
+#else
 sigNameNoLoc (FixSig (FixitySig ns _)) = map unLoc ns
+#endif
 sigNameNoLoc _                         = []
 
 clsInstDeclSrcSpan :: ClsInstDecl a -> SrcSpan
 clsInstDeclSrcSpan ClsInstDecl {cid_poly_ty = ty} = getLoc (hsSigType ty)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+clsInstDeclSrcSpan (XClsInstDecl _) = UnhelpfulSpan "XClsinstdecl"
+#endif
 
 hsDocsToDocH :: DynFlags -> GlobalRdrEnv -> [HsDocString] -> Doc Name
 hsDocsToDocH flags rdrEnv =
@@ -1116,7 +1288,11 @@ hsDocsToDocH flags rdrEnv =
 #else
     . parseParas
 #endif
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)    
+    . concatMap unpackHDS
+#else
     . concatMap (unpackFS . (\(HsDocString s) -> s))
+#endif
 
 parseIdent :: DynFlags -> String -> Maybe RdrName
 parseIdent dflags str0 =
diff --git a/src/HaskellCodeExplorer/ModuleInfo.hs b/src/HaskellCodeExplorer/ModuleInfo.hs
index e908af2..a97d758 100644
--- a/src/HaskellCodeExplorer/ModuleInfo.hs
+++ b/src/HaskellCodeExplorer/ModuleInfo.hs
@@ -25,7 +25,6 @@ import qualified Data.IntMap.Strict as IM
 import qualified Data.IntervalMap.Strict as IVM
 import qualified Data.List as L hiding (span)
 import Data.Maybe (fromMaybe, mapMaybe)
-import Data.Ord (comparing)
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 import HsExtension (GhcRn)
 #endif
@@ -241,7 +240,7 @@ createModuleInfo (fileMap, defSiteMap, moduleNameMap) (flags, typecheckedModule,
                    (HM.fromList .
                     (( HCE.HaskellFilePath $ HCE.getHaskellModulePath modulePath
                      , modulePath) :) .
-                    map (\includedFile -> (includedFile, modulePath)) $
+                    map (, modulePath) $
                     includedFiles)
                    fileMap
                , HM.union (HM.singleton modulePath defSites) defSiteMap
@@ -279,9 +278,11 @@ prepareSourceCode ::
   -> (HCE.SourceCodeTransformation, T.Text)
 prepareSourceCode sourceCodePreprocessing originalSourceCode modSum modulePath =
   let sourceCodeAfterPreprocessing =
-        case TE.decodeUtf8'
-               (fromMaybe (error "ms_hspp_buf is Nothing") $
-                stringBufferToByteString <$> ms_hspp_buf modSum) of
+        case TE.decodeUtf8' $
+             maybe
+               (error "ms_hspp_buf is Nothing")
+               stringBufferToByteString
+               (ms_hspp_buf modSum) of
           Right text -> T.replace "\t" "        " text
           Left err ->
             error $
@@ -322,12 +323,12 @@ createDefinitionSiteMap flags currentPackageId compId defSiteMap fileMap globalR
 #if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
       allDecls :: [GenLocated SrcSpan (HsDecl GhcRn)]
 #endif
-      allDecls = L.sortBy (comparing getLoc) . ungroup $ hsGroup
+      allDecls = L.sortOn getLoc . ungroup $ hsGroup
       (instanceDeclsWithDocs, valueAndTypeDeclsWithDocs) =
         L.partition
           (\(L _ decl, _) ->
              case decl of
-               InstD _ -> True
+               InstD {} -> True
                _ -> False) $
         collectDocs allDecls
       --------------------------------------------------------------------------------
@@ -340,7 +341,11 @@ createDefinitionSiteMap flags currentPackageId compId defSiteMap fileMap globalR
         mapMaybe
           (\(L _n decl, docs) ->
              case decl of
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)               
+               InstD _ (ClsInstD _ inst) -> Just (clsInstDeclSrcSpan inst, docs)
+#else  
                InstD (ClsInstD inst) -> Just (clsInstDeclSrcSpan inst, docs)
+#endif  
                _ -> Nothing) $
         instanceDeclsWithDocs
       nameLocation :: Maybe SrcSpan -> Name -> HCE.LocationInfo
@@ -563,7 +568,7 @@ createDeclarations flags hsGroup typeEnv exportedSet transformation =
               (lineNumber loc)
       fords = map foreignFunToDeclaration $ hs_fords hsGroup
       --------------------------------------------------------------------------------
-   in L.sortBy (comparing HCE.lineNumber) $ vals ++ tyclds ++ insts ++ fords
+   in L.sortOn HCE.lineNumber $ vals ++ tyclds ++ insts ++ fords
 
 foldAST :: Environment -> TypecheckedModule -> SourceInfo
 foldAST environment typecheckedModule =
@@ -616,7 +621,11 @@ foldAST environment typecheckedModule =
               (\(L span ie) ->
 #endif
                  case ie of
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
+                   IEModuleContents _ (L _ modName) ->
+#else
                    IEModuleContents (L _ modName) ->
+#endif
                      Just
                        ( modName
                        , span
@@ -632,7 +641,7 @@ foldAST environment typecheckedModule =
       addImportedAndExportedModulesToIdOccMap ::
            HCE.IdentifierOccurrenceMap -> HCE.IdentifierOccurrenceMap
       addImportedAndExportedModulesToIdOccMap =
-        IM.map (L.sortBy $ comparing fst) .
+        IM.map (L.sortOn fst) .
         addModules
           (envTransformation environment)
           (importedModules ++ exportedModules)
diff --git a/src/HaskellCodeExplorer/PackageInfo.hs b/src/HaskellCodeExplorer/PackageInfo.hs
index 2b1eeac..46b02c4 100644
--- a/src/HaskellCodeExplorer/PackageInfo.hs
+++ b/src/HaskellCodeExplorer/PackageInfo.hs
@@ -443,7 +443,7 @@ indexBuildComponent sourceCodePreprocessing currentPackageId componentId deps@(f
       (flags', _, _) <-
         parseDynamicFlagsCmdLine
           flags
-          (L.map noLoc . L.filter ((/=) "-Werror") $ options) -- -Werror flag makes warnings fatal 
+          (L.map noLoc . L.filter ("-Werror" /=) $ options) -- -Werror flag makes warnings fatal 
       (flags'', _) <- liftIO $ initPackages flags'
       logFn <- askLoggerIO
       let logAction ::
diff --git a/stack-8.4.4.yaml b/stack-8.4.4.yaml
new file mode 100644
index 0000000..66a7c8a
--- /dev/null
+++ b/stack-8.4.4.yaml
@@ -0,0 +1,8 @@
+resolver: lts-12.16
+packages:
+- '.'
+- location: vendor/cabal-helper-0.8.1.2
+  extra-dep: true
+allow-newer: true
+extra-deps:
+  - cabal-plan-0.4.0.0
diff --git a/stack.yaml b/stack.yaml
index 66a7c8a..0930998 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-12.16
+resolver: nightly-2018-12-21
 packages:
 - '.'
 - location: vendor/cabal-helper-0.8.1.2
diff --git a/test/Main.hs b/test/Main.hs
index 542829e..3ed32a4 100644
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -155,8 +155,10 @@ moduleInfoSpec modInfo =
       HCE.idOccMap (modInfo :: HCE.ModuleInfo) `shouldBe` testIdOccMap
 
 stackYamlArg :: [String]
-#if MIN_VERSION_GLASGOW_HASKELL(8,4,4,0)
+#if MIN_VERSION_GLASGOW_HASKELL(8,6,1,0)
 stackYamlArg = []
+#elif MIN_VERSION_GLASGOW_HASKELL(8,4,4,0)
+stackYamlArg = ["--stack-yaml=stack-8.4.4.yaml"]
 #elif MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
 stackYamlArg = ["--stack-yaml=stack-8.4.3.yaml" ]
 #elif MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
diff --git a/test/test-package/stack-8.4.4.yaml b/test/test-package/stack-8.4.4.yaml
new file mode 100644
index 0000000..92d07c7
--- /dev/null
+++ b/test/test-package/stack-8.4.4.yaml
@@ -0,0 +1 @@
+resolver: lts-12.16
diff --git a/test/test-package/stack.yaml b/test/test-package/stack.yaml
index 92d07c7..4e996a7 100644
--- a/test/test-package/stack.yaml
+++ b/test/test-package/stack.yaml
@@ -1 +1 @@
-resolver: lts-12.16
+resolver: nightly-2018-12-21
diff --git a/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs b/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs
index 1d93b84..a0d32fd 100644
--- a/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs
+++ b/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs
@@ -380,8 +380,10 @@ invokeHelper QueryEnv {..} args = do
 
 getPackageId :: MonadQuery m => m (String, Version)
 getPackageId = ask >>= \QueryEnv {..} -> do
-  [ Just (ChResponseVersion pkgName pkgVer) ] <- readHelper [ "package-id" ]
-  return (pkgName, pkgVer)
+  helper  <- readHelper [ "package-id" ]
+  case helper of
+    [ Just (ChResponseVersion pkgName pkgVer) ] -> return (pkgName, pkgVer)
+    _ -> error "getPackageId : readHelper"
 
 getSomeConfigState :: MonadQuery m => m SomeLocalBuildInfo
 getSomeConfigState = ask >>= \QueryEnv {..} -> do