diff options
Diffstat (limited to 'compiler/GHC/Rename')
| -rw-r--r-- | compiler/GHC/Rename/HsType.hs | 44 | ||||
| -rw-r--r-- | compiler/GHC/Rename/Module.hs | 9 |
2 files changed, 7 insertions, 46 deletions
diff --git a/compiler/GHC/Rename/HsType.hs b/compiler/GHC/Rename/HsType.hs index aaaa249ba2..df53523597 100644 --- a/compiler/GHC/Rename/HsType.hs +++ b/compiler/GHC/Rename/HsType.hs @@ -13,7 +13,7 @@ module GHC.Rename.HsType ( -- Type related stuff rnHsType, rnLHsType, rnLHsTypes, rnContext, rnMaybeContext, - rnHsKind, rnLHsKind, rnLHsTypeArgs, + rnLHsKind, rnLHsTypeArgs, rnHsSigType, rnHsWcType, rnHsPatSigTypeBindingVars, HsPatSigTypeScoping(..), rnHsSigWcType, rnHsPatSigType, newTyVarNameRn, @@ -468,35 +468,6 @@ rnImplicitTvBndrs ctx mb_assoc implicit_vs_with_dups thing_inside {- rnHsType is here because we call it from loadInstDecl, and I didn't want a gratuitous knot. - -Note [HsQualTy in kinds] -~~~~~~~~~~~~~~~~~~~~~~ -I was wondering whether HsQualTy could occur only at TypeLevel. But no, -we can have a qualified type in a kind too. Here is an example: - - type family F a where - F Bool = Nat - F Nat = Type - - type family G a where - G Type = Type -> Type - G () = Nat - - data X :: forall k1 k2. (F k1 ~ G k2) => k1 -> k2 -> Type where - MkX :: X 'True '() - -See that k1 becomes Bool and k2 becomes (), so the equality is -satisfied. If I write MkX :: X 'True 'False, compilation fails with a -suitable message: - - MkX :: X 'True '() - • Couldn't match kind ‘G Bool’ with ‘Nat’ - Expected kind: G Bool - Actual kind: F Bool - -However: in a kind, the constraints in the HsQualTy must all be -equalities; or at least, any kinds with a class constraint are -uninhabited. See Note [Constraints in kinds] in GHC.Core.TyCo.Rep. -} data RnTyKiEnv @@ -552,9 +523,6 @@ rnHsType ctxt ty = rnHsTyKi (mkTyKiEnv ctxt TypeLevel RnTypeBody) ty rnLHsKind :: HsDocContext -> LHsKind GhcPs -> RnM (LHsKind GhcRn, FreeVars) rnLHsKind ctxt kind = rnLHsTyKi (mkTyKiEnv ctxt KindLevel RnTypeBody) kind -rnHsKind :: HsDocContext -> HsKind GhcPs -> RnM (HsKind GhcRn, FreeVars) -rnHsKind ctxt kind = rnHsTyKi (mkTyKiEnv ctxt KindLevel RnTypeBody) kind - -- renaming a type only, not a kind rnLHsTypeArg :: HsDocContext -> LHsTypeArg GhcPs -> RnM (LHsTypeArg GhcRn, FreeVars) @@ -610,11 +578,11 @@ rnHsTyKi env ty@(HsForAllTy { hst_tele = tele, hst_body = tau }) , hst_tele = tele' , hst_body = tau' } , fvs) } } -rnHsTyKi env ty@(HsQualTy { hst_ctxt = lctxt, hst_body = tau }) - = do { data_kinds <- xoptM LangExt.DataKinds -- See Note [HsQualTy in kinds] - ; when (not data_kinds && isRnKindLevel env) - (addErr (dataKindsErr env ty)) - ; (ctxt', fvs1) <- rnTyKiContext env lctxt +rnHsTyKi env (HsQualTy { hst_ctxt = lctxt, hst_body = tau }) + = do { -- no need to check type vs kind level here; this is + -- checked in the type checker. See + -- Note [No constraints in kinds] in GHC.Tc.Validity + (ctxt', fvs1) <- rnTyKiContext env lctxt ; (tau', fvs2) <- rnLHsTyKi env tau ; return (HsQualTy { hst_xqual = noExtField, hst_ctxt = ctxt' , hst_body = tau' } diff --git a/compiler/GHC/Rename/Module.hs b/compiler/GHC/Rename/Module.hs index 97726a279c..fc6846e566 100644 --- a/compiler/GHC/Rename/Module.hs +++ b/compiler/GHC/Rename/Module.hs @@ -2064,14 +2064,7 @@ preceded by `type`, with the following restrictions: (R3) There are no strictness flags, because they don't make sense at the type level. -(R4) The types of the constructors contain no constraints other than - equality constraints. (This is the same restriction imposed - on constructors to be promoted with the DataKinds extension in - dc_theta_illegal_constraint called from GHC.Tc.Gen.HsType.tcTyVar, - but in that case the restriction is imposed if and when a data - constructor is used in a type, whereas here it is imposed at - the point of definition. See also Note [Constraints in kinds] - in GHC.Core.TyCo.Rep.) +(R4) The types of the constructors contain no constraints. (R5) There are no deriving clauses. |