diff options
| -rw-r--r-- | compiler/typecheck/TcCanonical.lhs | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/compiler/typecheck/TcCanonical.lhs b/compiler/typecheck/TcCanonical.lhs index 826375bd02..18bfe2b416 100644 --- a/compiler/typecheck/TcCanonical.lhs +++ b/compiler/typecheck/TcCanonical.lhs @@ -1071,19 +1071,15 @@ reOrient :: CtEvidence -> TypeClassifier -> TypeClassifier -> Bool -- We try to say False if possible, to minimise evidence generation -- -- Postcondition: After re-orienting, first arg is not OTherCls -reOrient _ev (OtherCls {}) (FunCls {}) = True -reOrient _ev (OtherCls {}) (VarCls {}) = True -reOrient _ev (OtherCls {}) (OtherCls {}) = panic "reOrient" -- One must be Var/Fun +reOrient _ev (OtherCls {}) cls2 = ASSERT( case cls2 of { OtherCls {} -> False; _ -> True } ) + True -- One must be Var/Fun -reOrient _ev (FunCls {}) (VarCls _tv) = False +reOrient _ev (FunCls {}) _ = False -- Fun/Other on rhs -- But consider the following variation: isGiven ev && isMetaTyVar tv - -- See Note [No touchables as FunEq RHS] in TcSMonad -reOrient _ev (FunCls {}) _ = False -- Fun/Other on rhs - -reOrient _ev (VarCls {}) (FunCls {}) = True -reOrient _ev (VarCls {}) (OtherCls {}) = False +reOrient _ev (VarCls {}) (FunCls {}) = True +reOrient _ev (VarCls {}) (OtherCls {}) = False reOrient _ev (VarCls tv1) (VarCls tv2) | isMetaTyVar tv2 && not (isMetaTyVar tv1) = True | otherwise = False |