[commit: ghc] master: Comments, plus adjust debug print of TcTyThing(ATyVar) (dd89a13)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/dd89a1387aef5280152c03cf7e2a98b8e73216f0/ghc

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

commit dd89a1387aef5280152c03cf7e2a98b8e73216f0
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Aug 2 15:52:49 2017 +0100

    Comments, plus adjust debug print of TcTyThing(ATyVar)


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

dd89a1387aef5280152c03cf7e2a98b8e73216f0
 compiler/hsSyn/HsDecls.hs       | 2 +-
 compiler/hsSyn/HsTypes.hs       | 7 ++-----
 compiler/typecheck/TcRnTypes.hs | 1 +
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/compiler/hsSyn/HsDecls.hs b/compiler/hsSyn/HsDecls.hs
index 2163300..3053f3e 100644
--- a/compiler/hsSyn/HsDecls.hs
+++ b/compiler/hsSyn/HsDecls.hs
@@ -1330,7 +1330,7 @@ type patterns, i.e. fv(pat_tys).  Note in particular
   '_' gets its own unique.  In this context wildcards behave just like
   an ordinary type variable, only anonymous.
 
-* The hsib_vars *including* type variables that are already in scope
+* The hsib_vars *includes* type variables that are already in scope
 
    Eg   class C s t where
           type F t p :: *
diff --git a/compiler/hsSyn/HsTypes.hs b/compiler/hsSyn/HsTypes.hs
index 77b1439..98fad24 100644
--- a/compiler/hsSyn/HsTypes.hs
+++ b/compiler/hsSyn/HsTypes.hs
@@ -280,12 +280,9 @@ isEmptyLHsQTvs _                = False
 
 ------------------------------------------------
 --            HsImplicitBndrs
--- Used to quantify the binders of a type in cases
--- when a HsForAll isn't appropriate:
+-- Used to quantify the implicit binders of a type
+--    * Implicit binders of a type signature (LHsSigType/LHsSigWcType)
 --    * Patterns in a type/data family instance (HsTyPats)
---    * Type of a rule binder (RuleBndr)
---    * Pattern type signatures (SigPatIn)
--- In the last of these, wildcards can happen, so we must accommodate them
 
 -- | Haskell Implicit Binders
 data HsImplicitBndrs pass thing   -- See Note [HsType binders]
diff --git a/compiler/typecheck/TcRnTypes.hs b/compiler/typecheck/TcRnTypes.hs
index f735a93..c633d97 100644
--- a/compiler/typecheck/TcRnTypes.hs
+++ b/compiler/typecheck/TcRnTypes.hs
@@ -1094,6 +1094,7 @@ instance Outputable TcTyThing where     -- Debugging only
                                  <> ppr (varType (tct_id elt)) <> comma
                                  <+> ppr (tct_info elt))
    ppr (ATyVar n tv)    = text "Type variable" <+> quotes (ppr n) <+> equals <+> ppr tv
+                            <+> dcolon <+> ppr (varType tv)
    ppr (ATcTyCon tc)    = text "ATcTyCon" <+> ppr tc <+> dcolon <+> ppr (tyConKind tc)
    ppr (APromotionErr err) = text "APromotionErr" <+> ppr err