[commit: ghc] wip/orf-reboot: Better plusParent (794ce74)

[git at git.haskell.org]

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

On branch  : wip/orf-reboot
Link       : http://ghc.haskell.org/trac/ghc/changeset/794ce74139492cea950c7dc34adda265c9278f5d/ghc

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

commit 794ce74139492cea950c7dc34adda265c9278f5d
Author: Adam Gundry <adam at well-typed.com>
Date:   Tue Oct 6 15:54:49 2015 +0100

    Better plusParent


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

794ce74139492cea950c7dc34adda265c9278f5d
 compiler/basicTypes/RdrName.hs | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/compiler/basicTypes/RdrName.hs b/compiler/basicTypes/RdrName.hs
index 4828766..209544f 100644
--- a/compiler/basicTypes/RdrName.hs
+++ b/compiler/basicTypes/RdrName.hs
@@ -437,26 +437,20 @@ instance Outputable Parent where
 
 plusParent :: Parent -> Parent -> Parent
 -- See Note [Combining parents]
-plusParent (ParentIs n)    p2 = hasParentIs n p2
-plusParent (FldParent n f) p2 = hasFldParent n f p2
-plusParent p1 (ParentIs n)    = hasParentIs n p1
-plusParent p1 (FldParent n f) = hasFldParent n f p1
-plusParent NoParent NoParent  = NoParent
+plusParent p1@(ParentIs _)    p2 = hasParent p1 p2
+plusParent p1@(FldParent _ _) p2 = hasParent p1 p2
+plusParent p1 p2@(ParentIs _)    = hasParent p2 p1
+plusParent p1 p2@(FldParent _ _) = hasParent p2 p1
+plusParent NoParent NoParent     = NoParent
 
-hasParentIs :: Name -> Parent -> Parent
+hasParent :: Parent -> Parent -> Parent
 #ifdef DEBUG
-hasParentIs n (ParentIs n')
-  | n /= n' = pprPanic "hasParentIs" (ppr n <+> ppr n')  -- Parents should agree
+hasParent p NoParent = p
+hasParent p p'
+  | p /= p' = pprPanic "hasParent" (ppr p <+> ppr p')  -- Parents should agree
 #endif
-hasParentIs n _  = ParentIs n
+hasParent p _  = p
 
-hasFldParent :: Name -> Maybe FieldLabelString -> Parent -> Parent
-#ifdef DEBUG
-hasFldParent n f (FldParent n' f')
-  | n /= n' || f /= f'    -- Parents should agree
-    = pprPanic "hasFldParent" (ppr n <+> ppr f <+> ppr n' <+> ppr f')
-#endif
-hasFldParent n f _  = FldParent n f
 
 {- Note [GlobalRdrElt provenance]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~