diff options
Diffstat (limited to 'compiler/GHC/Tc/Instance/Class.hs')
| -rw-r--r-- | compiler/GHC/Tc/Instance/Class.hs | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/compiler/GHC/Tc/Instance/Class.hs b/compiler/GHC/Tc/Instance/Class.hs index 00811459c4..349ea1e34c 100644 --- a/compiler/GHC/Tc/Instance/Class.hs +++ b/compiler/GHC/Tc/Instance/Class.hs @@ -121,17 +121,18 @@ matchGlobalInst :: DynFlags -- See Note [Shortcut solving: overlap] -> Class -> [Type] -> TcM ClsInstResult matchGlobalInst dflags short_cut clas tys - | cls_name == knownNatClassName = matchKnownNat dflags short_cut clas tys - | cls_name == knownSymbolClassName = matchKnownSymbol dflags short_cut clas tys - | cls_name == knownCharClassName = matchKnownChar dflags short_cut clas tys - | isCTupleClass clas = matchCTuple clas tys - | cls_name == typeableClassName = matchTypeable clas tys - | cls_name == withDictClassName = matchWithDict tys - | clas `hasKey` heqTyConKey = matchHeteroEquality tys - | clas `hasKey` eqTyConKey = matchHomoEquality tys - | clas `hasKey` coercibleTyConKey = matchCoercible tys - | cls_name == hasFieldClassName = matchHasField dflags short_cut clas tys - | otherwise = matchInstEnv dflags short_cut clas tys + | cls_name == knownNatClassName = matchKnownNat dflags short_cut clas tys + | cls_name == knownSymbolClassName = matchKnownSymbol dflags short_cut clas tys + | cls_name == knownCharClassName = matchKnownChar dflags short_cut clas tys + | isCTupleClass clas = matchCTuple clas tys + | cls_name == typeableClassName = matchTypeable clas tys + | cls_name == withDictClassName = matchWithDict tys + | clas `hasKey` heqTyConKey = matchHeteroEquality tys + | clas `hasKey` eqTyConKey = matchHomoEquality tys + | clas `hasKey` coercibleTyConKey = matchCoercible tys + | cls_name == hasFieldClassName = matchHasField dflags short_cut clas tys + | cls_name == unsatisfiableClassName = return NoInstance -- See (B) in Note [Implementation of Unsatisfiable constraints] in GHC.Tc.Errors + | otherwise = matchInstEnv dflags short_cut clas tys where cls_name = className clas |