[commit: ghc] wip/T15809: Comments and alpha-renaming (5104ded)

[git at git.haskell.org]

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

On branch  : wip/T15809
Link       : http://ghc.haskell.org/trac/ghc/changeset/5104ded3055d2fe1eab1c38d11055e125df88227/ghc

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

commit 5104ded3055d2fe1eab1c38d11055e125df88227
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Nov 7 23:26:05 2018 +0000

    Comments and alpha-renaming


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

5104ded3055d2fe1eab1c38d11055e125df88227
 compiler/typecheck/TcHsType.hs   |  2 --
 compiler/typecheck/TcInstDcls.hs | 10 +++++-----
 compiler/typecheck/TcMType.hs    |  2 +-
 compiler/typecheck/TcSimplify.hs |  7 ++++---
 4 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/compiler/typecheck/TcHsType.hs b/compiler/typecheck/TcHsType.hs
index 06cf0db..99bc57e 100644
--- a/compiler/typecheck/TcHsType.hs
+++ b/compiler/typecheck/TcHsType.hs
@@ -1745,7 +1745,6 @@ kcImplicitTKBndrs     = kcImplicitTKBndrsX newFlexiKindedTyVarTyVar
 -- | Bring implicitly quantified type/kind variables into scope during
 -- kind checking. The returned TcTyVars are in 1-1 correspondence
 --- with the names passed in.
--- Note [Use TyVarTvs in kind-checking pass] in TcTyClsDecls.
 kcImplicitTKBndrsX :: (Name -> TcM TcTyVar) -- new_tv function
                    -> [Name]              -- of the vars
                    -> TcM a
@@ -2066,7 +2065,6 @@ kcLookupTcTyCon nm
 -- Never emits constraints, though the thing_inside might.
 kcTyClTyVars :: Name -> TcM a -> TcM a
 kcTyClTyVars tycon_name thing_inside
-  -- See Note [Use TyVarTvs in kind-checking pass] in TcTyClsDecls
   = do { tycon <- kcLookupTcTyCon tycon_name
        ; tcExtendNameTyVarEnv (tcTyConScopedTyVars tycon) $ thing_inside }
 
diff --git a/compiler/typecheck/TcInstDcls.hs b/compiler/typecheck/TcInstDcls.hs
index 84f43e9..63c565d 100644
--- a/compiler/typecheck/TcInstDcls.hs
+++ b/compiler/typecheck/TcInstDcls.hs
@@ -465,14 +465,14 @@ tcLocalInstDecl (L _ (XInstDecl _)) = panic "tcLocalInstDecl"
 tcClsInstDecl :: LClsInstDecl GhcRn
               -> TcM ([InstInfo GhcRn], [FamInst], [DerivInfo])
 -- The returned DerivInfos are for any associated data families
-tcClsInstDecl (L loc (ClsInstDecl { cid_poly_ty = poly_ty, cid_binds = binds
+tcClsInstDecl (L loc (ClsInstDecl { cid_poly_ty = hs_ty, cid_binds = binds
                                   , cid_sigs = uprags, cid_tyfam_insts = ats
                                   , cid_overlap_mode = overlap_mode
                                   , cid_datafam_insts = adts }))
   = setSrcSpan loc                      $
-    addErrCtxt (instDeclCtxt1 poly_ty)  $
+    addErrCtxt (instDeclCtxt1 hs_ty)  $
     do  { (tyvars, theta, clas, inst_tys)
-             <- tcHsClsInstType (InstDeclCtxt False) poly_ty
+             <- tcHsClsInstType (InstDeclCtxt False) hs_ty
              -- NB: tcHsClsInstType does checkValidInstance
 
         ; tcExtendTyVarEnv tyvars $
@@ -481,7 +481,7 @@ tcClsInstDecl (L loc (ClsInstDecl { cid_poly_ty = poly_ty, cid_binds = binds
               mb_info    = Just (clas, tyvars, mini_env)
 
         -- Next, process any associated types.
-        ; traceTc "tcLocalInstDecl" (ppr poly_ty)
+        ; traceTc "tcLocalInstDecl" (ppr hs_ty)
         ; tyfam_insts0  <- mapAndRecoverM (tcTyFamInstDecl mb_info)   ats
         ; datafam_stuff <- mapAndRecoverM (tcDataFamInstDecl mb_info) adts
         ; let (datafam_insts, m_deriv_infos) = unzip datafam_stuff
@@ -500,7 +500,7 @@ tcClsInstDecl (L loc (ClsInstDecl { cid_poly_ty = poly_ty, cid_binds = binds
 
         -- Finally, construct the Core representation of the instance.
         -- (This no longer includes the associated types.)
-        ; dfun_name <- newDFunName clas inst_tys (getLoc (hsSigType poly_ty))
+        ; dfun_name <- newDFunName clas inst_tys (getLoc (hsSigType hs_ty))
                 -- Dfun location is that of instance *header*
 
         ; ispec <- newClsInst (fmap unLoc overlap_mode) dfun_name tyvars theta
diff --git a/compiler/typecheck/TcMType.hs b/compiler/typecheck/TcMType.hs
index 8192f75..9edad0f 100644
--- a/compiler/typecheck/TcMType.hs
+++ b/compiler/typecheck/TcMType.hs
@@ -1499,7 +1499,7 @@ defaultTyVar default_kind tv
     -- Do not default TyVarTvs. Doing so would violate the invariants
     -- on TyVarTvs; see Note [Signature skolems] in TcType.
     -- Trac #13343 is an example; #14555 is another
-    -- See Note [Kind generalisation and TyVarTvs]
+    -- See Note [Inferring kinds for type declarations] in TcTyClsDecls
   = return False
 
 
diff --git a/compiler/typecheck/TcSimplify.hs b/compiler/typecheck/TcSimplify.hs
index 750b621..e1a3532 100644
--- a/compiler/typecheck/TcSimplify.hs
+++ b/compiler/typecheck/TcSimplify.hs
@@ -2008,9 +2008,10 @@ promoteTyVarTcS tv
 defaultTyVarTcS :: TcTyVar -> TcS Bool
 defaultTyVarTcS the_tv
   | isRuntimeRepVar the_tv
-  , not (isTyVarTyVar the_tv)  -- TyVarTvs should only be unified with a tyvar
-                             -- never with a type; c.f. TcMType.defaultTyVar
-                             -- See Note [Kind generalisation and TyVarTvs]
+  , not (isTyVarTyVar the_tv)
+    -- TyVarTvs should only be unified with a tyvar
+    -- never with a type; c.f. TcMType.defaultTyVar
+    -- and Note [Inferring kinds for type declarations] in TcTyClsDecls
   = do { traceTcS "defaultTyVarTcS RuntimeRep" (ppr the_tv)
        ; unifyTyVar the_tv liftedRepTy
        ; return True }