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| author | Vladislav Zavialov <vlad.z.4096@gmail.com> | 2020-08-03 19:13:23 +0300 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-08-06 13:34:06 -0400 |
| commit | 826d07db0e0f31fe2b2d2e0661be7f0cb3cde3c7 (patch) | |
| tree | d9283575ffe865b911d4cbaa6fb53b03fecc2eba /compiler/GHC/Core | |
| parent | 6770e199645b0753d2edfddc68c199861a1be980 (diff) | |
| download | haskell-826d07db0e0f31fe2b2d2e0661be7f0cb3cde3c7.tar.gz | |
Fix debug_ppr_ty ForAllTy (#18522)
Before this change, GHC would
pretty-print forall k. forall a -> ()
as forall @k a. ()
which isn't even valid Haskell.
Diffstat (limited to 'compiler/GHC/Core')
| -rw-r--r-- | compiler/GHC/Core/TyCo/Ppr.hs | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/compiler/GHC/Core/TyCo/Ppr.hs b/compiler/GHC/Core/TyCo/Ppr.hs index ea9417e360..d48cf84c4e 100644 --- a/compiler/GHC/Core/TyCo/Ppr.hs +++ b/compiler/GHC/Core/TyCo/Ppr.hs @@ -36,7 +36,8 @@ import {-# SOURCE #-} GHC.CoreToIface import {-# SOURCE #-} GHC.Core.DataCon ( dataConFullSig , dataConUserTyVarBinders, DataCon ) -import GHC.Core.Type ( pickyIsLiftedTypeKind, pattern One, pattern Many ) +import GHC.Core.Type ( pickyIsLiftedTypeKind, pattern One, pattern Many, + splitForAllTysReq, splitForAllTysInvis ) import GHC.Core.TyCon import GHC.Core.TyCo.Rep @@ -268,19 +269,34 @@ debug_ppr_ty prec (CastTy ty co) debug_ppr_ty _ (CoercionTy co) = parens (text "CO" <+> ppr co) -debug_ppr_ty prec ty@(ForAllTy {}) - | (tvs, body) <- split ty +-- Invisible forall: forall {k} (a :: k). t +debug_ppr_ty prec t + | (bndrs, body) <- splitForAllTysInvis t + , not (null bndrs) = maybeParen prec funPrec $ - hang (text "forall" <+> fsep (map ppr tvs) <> dot) - -- The (map ppr tvs) will print kind-annotated - -- tvs, because we are (usually) in debug-style - 2 (ppr body) + sep [ text "forall" <+> fsep (map ppr_bndr bndrs) <> dot, + ppr body ] where - split ty | ForAllTy tv ty' <- ty - , (tvs, body) <- split ty' - = (tv:tvs, body) - | otherwise - = ([], ty) + -- (ppr tv) will print the binder kind-annotated + -- when in debug-style + ppr_bndr (Bndr tv InferredSpec) = braces (ppr tv) + ppr_bndr (Bndr tv SpecifiedSpec) = ppr tv + +-- Visible forall: forall x y -> t +debug_ppr_ty prec t + | (bndrs, body) <- splitForAllTysReq t + , not (null bndrs) + = maybeParen prec funPrec $ + sep [ text "forall" <+> fsep (map ppr_bndr bndrs) <+> arrow, + ppr body ] + where + -- (ppr tv) will print the binder kind-annotated + -- when in debug-style + ppr_bndr (Bndr tv ()) = ppr tv + +-- Impossible case: neither visible nor invisible forall. +debug_ppr_ty _ ForAllTy{} + = panic "debug_ppr_ty: neither splitForAllTysInvis nor splitForAllTysReq returned any binders" {- Note [Infix type variables] |