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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2012-10-01 10:38:22 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2012-10-01 10:38:22 +0100 |
| commit | 7fdcf2c755fde160d9fe5211cedc65d65fef68f1 (patch) | |
| tree | b40be13ad96ae5e7e374f07ca813d506eee54334 /compiler/typecheck/TcCanonical.lhs | |
| parent | adb6bcb7b85410dd42828a4824962ce9c6e9d667 (diff) | |
| download | haskell-7fdcf2c755fde160d9fe5211cedc65d65fef68f1.tar.gz | |
Simplify the reOrient function (no change in behaviour)
Diffstat (limited to 'compiler/typecheck/TcCanonical.lhs')
| -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 |