X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fmain%2FPprTyThing.hs;h=dfa713fdc0b13276cc52d5ee9ba06ed3cf7e602d;hp=4b309b615d724f72d12b922862af422099c1a4a4;hb=215ce9f15215399ce30ae55c9521087847d78646;hpb=b15724ad3cae2a14c265683e8bb6f7d639dac251 diff --git a/compiler/main/PprTyThing.hs b/compiler/main/PprTyThing.hs index 4b309b6..dfa713f 100644 --- a/compiler/main/PprTyThing.hs +++ b/compiler/main/PprTyThing.hs @@ -7,21 +7,24 @@ ----------------------------------------------------------------------------- module PprTyThing ( + PrintExplicitForalls, pprTyThing, pprTyThingInContext, pprTyThingLoc, pprTyThingInContextLoc, - pprTyThingHdr + pprTyThingHdr, + pprTypeForUser ) where -#include "HsVersions.h" - import qualified GHC -import TyCon ( tyConFamInst_maybe ) -import Type ( pprTypeApp ) -import GHC ( TyThing(..), SrcSpan ) +import GHC ( TyThing(..) ) +import TyCon +import TcType +import Var +import Name import Outputable +import FastString -- ----------------------------------------------------------------------------- -- Pretty-printing entities that we get from the GHC API @@ -29,120 +32,151 @@ import Outputable -- This should be a good source of sample code for using the GHC API to -- inspect source code entities. +type PrintExplicitForalls = Bool + -- | Pretty-prints a 'TyThing' with its defining location. -pprTyThingLoc :: Bool -> TyThing -> SDoc -pprTyThingLoc exts tyThing - = showWithLoc loc (pprTyThing exts tyThing) - where loc = GHC.nameSrcSpan (GHC.getName tyThing) +pprTyThingLoc :: PrintExplicitForalls -> TyThing -> SDoc +pprTyThingLoc pefas tyThing + = showWithLoc loc (pprTyThing pefas tyThing) + where loc = pprNameLoc (GHC.getName tyThing) -- | Pretty-prints a 'TyThing'. -pprTyThing :: Bool -> TyThing -> SDoc -pprTyThing exts (AnId id) = pprId exts id -pprTyThing exts (ADataCon dataCon) = pprDataConSig exts dataCon -pprTyThing exts (ATyCon tyCon) = pprTyCon exts tyCon -pprTyThing exts (AClass cls) = pprClass exts cls - +pprTyThing :: PrintExplicitForalls -> TyThing -> SDoc +pprTyThing pefas (AnId id) = pprId pefas id +pprTyThing pefas (ADataCon dataCon) = pprDataConSig pefas dataCon +pprTyThing pefas (ATyCon tyCon) = pprTyCon pefas tyCon +pprTyThing pefas (AClass cls) = pprClass pefas cls + -- | Like 'pprTyThingInContext', but adds the defining location. -pprTyThingInContextLoc :: Bool -> TyThing -> SDoc -pprTyThingInContextLoc exts tyThing - = showWithLoc loc (pprTyThingInContext exts tyThing) - where loc = GHC.nameSrcSpan (GHC.getName tyThing) +pprTyThingInContextLoc :: PrintExplicitForalls -> TyThing -> SDoc +pprTyThingInContextLoc pefas tyThing + = showWithLoc loc (pprTyThingInContext pefas tyThing) + where loc = pprNameLoc (GHC.getName tyThing) -- | Pretty-prints a 'TyThing' in context: that is, if the entity -- is a data constructor, record selector, or class method, then -- the entity's parent declaration is pretty-printed with irrelevant -- parts omitted. -pprTyThingInContext :: Bool -> TyThing -> SDoc -pprTyThingInContext exts (AnId id) = pprIdInContext exts id -pprTyThingInContext exts (ADataCon dataCon) = pprDataCon exts dataCon -pprTyThingInContext exts (ATyCon tyCon) = pprTyCon exts tyCon -pprTyThingInContext exts (AClass cls) = pprClass exts cls +pprTyThingInContext :: PrintExplicitForalls -> TyThing -> SDoc +pprTyThingInContext pefas (AnId id) = pprIdInContext pefas id +pprTyThingInContext pefas (ADataCon dataCon) = pprDataCon pefas dataCon +pprTyThingInContext pefas (ATyCon tyCon) = pprTyCon pefas tyCon +pprTyThingInContext pefas (AClass cls) = pprClass pefas cls -- | Pretty-prints the 'TyThing' header. For functions and data constructors -- the function is equivalent to 'pprTyThing' but for type constructors -- and classes it prints only the header part of the declaration. -pprTyThingHdr :: Bool -> TyThing -> SDoc -pprTyThingHdr exts (AnId id) = pprId exts id -pprTyThingHdr exts (ADataCon dataCon) = pprDataConSig exts dataCon -pprTyThingHdr exts (ATyCon tyCon) = pprTyConHdr exts tyCon -pprTyThingHdr exts (AClass cls) = pprClassHdr exts cls - -pprTyConHdr exts tyCon - | Just (fam_tc, tys) <- tyConFamInst_maybe tyCon - = ptext keyword <+> ptext SLIT("instance") <+> pprTypeApp tyCon (ppr_bndr tyCon) tys +pprTyThingHdr :: PrintExplicitForalls -> TyThing -> SDoc +pprTyThingHdr pefas (AnId id) = pprId pefas id +pprTyThingHdr pefas (ADataCon dataCon) = pprDataConSig pefas dataCon +pprTyThingHdr pefas (ATyCon tyCon) = pprTyConHdr pefas tyCon +pprTyThingHdr pefas (AClass cls) = pprClassHdr pefas cls + +pprTyConHdr :: PrintExplicitForalls -> TyCon -> SDoc +pprTyConHdr _ tyCon + | Just (_fam_tc, tys) <- tyConFamInst_maybe tyCon + = ptext keyword <+> ptext (sLit "instance") <+> pprTypeApp tyCon tys | otherwise - = ptext keyword <+> opt_family <+> ppr_bndr tyCon <+> hsep (map ppr vars) + = ptext keyword <+> opt_family <+> opt_stupid <+> ppr_bndr tyCon <+> hsep (map ppr vars) where vars | GHC.isPrimTyCon tyCon || GHC.isFunTyCon tyCon = take (GHC.tyConArity tyCon) GHC.alphaTyVars | otherwise = GHC.tyConTyVars tyCon - keyword | GHC.isSynTyCon tyCon = SLIT("type") - | GHC.isNewTyCon tyCon = SLIT("newtype") - | otherwise = SLIT("data") + keyword | GHC.isSynTyCon tyCon = sLit "type" + | GHC.isNewTyCon tyCon = sLit "newtype" + | otherwise = sLit "data" opt_family - | GHC.isOpenTyCon tyCon = ptext SLIT("family") + | GHC.isOpenTyCon tyCon = ptext (sLit "family") | otherwise = empty -pprDataConSig exts dataCon = - ppr_bndr dataCon <+> dcolon <+> pprType exts (GHC.dataConType dataCon) + opt_stupid -- The "stupid theta" part of the declaration + | isAlgTyCon tyCon = GHC.pprThetaArrow (tyConStupidTheta tyCon) + | otherwise = empty -- Returns 'empty' if null theta -pprClassHdr exts cls = +pprDataConSig :: PrintExplicitForalls -> GHC.DataCon -> SDoc +pprDataConSig pefas dataCon = + ppr_bndr dataCon <+> dcolon <+> pprTypeForUser pefas (GHC.dataConType dataCon) + +pprClassHdr :: PrintExplicitForalls -> GHC.Class -> SDoc +pprClassHdr _ cls = let (tyVars, funDeps) = GHC.classTvsFds cls - in ptext SLIT("class") <+> + in ptext (sLit "class") <+> GHC.pprThetaArrow (GHC.classSCTheta cls) <+> ppr_bndr cls <+> hsep (map ppr tyVars) <+> GHC.pprFundeps funDeps -pprIdInContext exts id - | GHC.isRecordSelector id = pprRecordSelector exts id - | Just cls <- GHC.isClassOpId_maybe id = pprClassOneMethod exts cls id - | otherwise = pprId exts id +pprIdInContext :: PrintExplicitForalls -> Var -> SDoc +pprIdInContext pefas id + | GHC.isRecordSelector id = pprRecordSelector pefas id + | Just cls <- GHC.isClassOpId_maybe id = pprClassOneMethod pefas cls id + | otherwise = pprId pefas id -pprRecordSelector exts id - = pprAlgTyCon exts tyCon show_con show_label +pprRecordSelector :: PrintExplicitForalls -> Id -> SDoc +pprRecordSelector pefas id + = pprAlgTyCon pefas tyCon show_con show_label where (tyCon,label) = GHC.recordSelectorFieldLabel id show_con dataCon = label `elem` GHC.dataConFieldLabels dataCon show_label label' = label == label' -pprId exts id - = hang (ppr_bndr id <+> dcolon) 2 - (pprType exts (GHC.idType id)) - -pprType True ty = ppr ty -pprType False ty = ppr (GHC.dropForAlls ty) +pprId :: PrintExplicitForalls -> Var -> SDoc +pprId pefas ident + = hang (ppr_bndr ident <+> dcolon) + 2 (pprTypeForUser pefas (GHC.idType ident)) + +pprTypeForUser :: PrintExplicitForalls -> GHC.Type -> SDoc +-- We do two things here. +-- a) We tidy the type, regardless +-- b) If PrintExplicitForAlls is True, we discard the foralls +-- but we do so `deeply' +-- Prime example: a class op might have type +-- forall a. C a => forall b. Ord b => stuff +-- Then we want to display +-- (C a, Ord b) => stuff +pprTypeForUser print_foralls ty + | print_foralls = ppr tidy_ty + | otherwise = ppr (mkPhiTy [p | (_tvs, ps) <- ctxt, p <- ps] ty') + where + tidy_ty = tidyTopType ty + (ctxt, ty') = tcMultiSplitSigmaTy tidy_ty -pprTyCon exts tyCon +pprTyCon :: PrintExplicitForalls -> TyCon -> SDoc +pprTyCon pefas tyCon | GHC.isSynTyCon tyCon = if GHC.isOpenTyCon tyCon - then pprTyConHdr exts tyCon <+> dcolon <+> - pprType exts (GHC.synTyConResKind tyCon) + then pprTyConHdr pefas tyCon <+> dcolon <+> + pprTypeForUser pefas (GHC.synTyConResKind tyCon) else let rhs_type = GHC.synTyConType tyCon - in hang (pprTyConHdr exts tyCon <+> equals) 2 (pprType exts rhs_type) + in hang (pprTyConHdr pefas tyCon <+> equals) 2 (pprTypeForUser pefas rhs_type) | otherwise - = pprAlgTyCon exts tyCon (const True) (const True) + = pprAlgTyCon pefas tyCon (const True) (const True) -pprAlgTyCon exts tyCon ok_con ok_label - | gadt = pprTyConHdr exts tyCon <+> ptext SLIT("where") $$ +pprAlgTyCon :: PrintExplicitForalls -> TyCon -> (GHC.DataCon -> Bool) + -> (FieldLabel -> Bool) -> SDoc +pprAlgTyCon pefas tyCon ok_con ok_label + | gadt = pprTyConHdr pefas tyCon <+> ptext (sLit "where") $$ nest 2 (vcat (ppr_trim show_con datacons)) - | otherwise = hang (pprTyConHdr exts tyCon) + | otherwise = hang (pprTyConHdr pefas tyCon) 2 (add_bars (ppr_trim show_con datacons)) where datacons = GHC.tyConDataCons tyCon gadt = any (not . GHC.isVanillaDataCon) datacons show_con dataCon - | ok_con dataCon = Just (pprDataConDecl exts gadt ok_label dataCon) + | ok_con dataCon = Just (pprDataConDecl pefas gadt ok_label dataCon) | otherwise = Nothing -pprDataCon exts dataCon = pprAlgTyCon exts tyCon (== dataCon) (const True) +pprDataCon :: PrintExplicitForalls -> GHC.DataCon -> SDoc +pprDataCon pefas dataCon = pprAlgTyCon pefas tyCon (== dataCon) (const True) where tyCon = GHC.dataConTyCon dataCon -pprDataConDecl exts gadt_style show_label dataCon +pprDataConDecl :: PrintExplicitForalls -> Bool -> (FieldLabel -> Bool) + -> GHC.DataCon -> SDoc +pprDataConDecl _ gadt_style show_label dataCon | not gadt_style = ppr_fields tys_w_strs | otherwise = ppr_bndr dataCon <+> dcolon <+> sep [ ppr_tvs, GHC.pprThetaArrow theta, pp_tau ] @@ -156,20 +190,16 @@ pprDataConDecl exts gadt_style show_label dataCon ppr_tvs | null qualVars = empty - | otherwise = ptext SLIT("forall") <+> + | otherwise = ptext (sLit "forall") <+> hsep (map ppr qualVars) <> dot -- printing out the dataCon as a type signature, in GADT style pp_tau = foldr add (ppr res_ty) tys_w_strs - add (str,ty) pp_ty = pprBangTy str ty <+> arrow <+> pp_ty + add str_ty pp_ty = pprParendBangTy str_ty <+> arrow <+> pp_ty - pprParendBangTy (strict,ty) - | GHC.isMarkedStrict strict = char '!' <> GHC.pprParendType ty - | otherwise = GHC.pprParendType ty + pprParendBangTy (bang,ty) = ppr bang <> GHC.pprParendType ty - pprBangTy strict ty - | GHC.isMarkedStrict strict = char '!' <> ppr ty - | otherwise = ppr ty + pprBangTy bang ty = ppr bang <> ppr ty maybe_show_label (lbl,(strict,tp)) | show_label lbl = Just (ppr lbl <+> dcolon <+> pprBangTy strict tp) @@ -177,7 +207,7 @@ pprDataConDecl exts gadt_style show_label dataCon ppr_fields [ty1, ty2] | GHC.dataConIsInfix dataCon && null labels - = sep [pprParendBangTy ty1, ppr dataCon, pprParendBangTy ty2] + = sep [pprParendBangTy ty1, pprInfixName dataCon, pprParendBangTy ty2] ppr_fields fields | null labels = ppr_bndr dataCon <+> sep (map pprParendBangTy fields) @@ -186,30 +216,43 @@ pprDataConDecl exts gadt_style show_label dataCon braces (sep (punctuate comma (ppr_trim maybe_show_label (zip labels fields)))) -pprClass exts cls +pprClass :: PrintExplicitForalls -> GHC.Class -> SDoc +pprClass pefas cls | null methods = - pprClassHdr exts cls + pprClassHdr pefas cls | otherwise = - hang (pprClassHdr exts cls <+> ptext SLIT("where")) - 2 (vcat (map (pprClassMethod exts) methods)) + hang (pprClassHdr pefas cls <+> ptext (sLit "where")) + 2 (vcat (map (pprClassMethod pefas) methods)) where methods = GHC.classMethods cls -pprClassOneMethod exts cls this_one = - hang (pprClassHdr exts cls <+> ptext SLIT("where")) - 2 (vcat (ppr_trim show_meth methods)) +pprClassOneMethod :: PrintExplicitForalls -> GHC.Class -> Id -> SDoc +pprClassOneMethod pefas cls this_one + = hang (pprClassHdr pefas cls <+> ptext (sLit "where")) + 2 (vcat (ppr_trim show_meth methods)) where methods = GHC.classMethods cls - show_meth id | id == this_one = Just (pprClassMethod exts id) + show_meth id | id == this_one = Just (pprClassMethod pefas id) | otherwise = Nothing -pprClassMethod exts id = - hang (ppr_bndr id <+> dcolon) 2 (pprType exts (classOpType id)) +pprClassMethod :: PrintExplicitForalls -> Id -> SDoc +pprClassMethod pefas id + = hang (ppr_bndr id <+> dcolon) 2 (pprTypeForUser pefas op_ty) where -- Here's the magic incantation to strip off the dictionary -- from the class op type. Stolen from IfaceSyn.tyThingToIfaceDecl. - classOpType id = GHC.funResultTy rho_ty - where (_sel_tyvars, rho_ty) = GHC.splitForAllTys (GHC.idType id) + -- + -- It's important to tidy it *before* splitting it up, so that if + -- we have class C a b where + -- op :: forall a. a -> b + -- then the inner forall on op gets renamed to a1, and we print + -- (when dropping foralls) + -- class C a b where + -- op :: a1 -> b + + tidy_sel_ty = tidyTopType (GHC.idType id) + (_sel_tyvars, rho_ty) = GHC.splitForAllTys tidy_sel_ty + op_ty = GHC.funResultTy rho_ty ppr_trim :: (a -> Maybe SDoc) -> [a] -> [SDoc] ppr_trim show xs @@ -218,8 +261,9 @@ ppr_trim show xs go x (eliding, so_far) | Just doc <- show x = (False, doc : so_far) | otherwise = if eliding then (True, so_far) - else (True, ptext SLIT("...") : so_far) + else (True, ptext (sLit "...") : so_far) +add_bars :: [SDoc] -> SDoc add_bars [] = empty add_bars [c] = equals <+> c add_bars (c:cs) = sep ((equals <+> c) : map (char '|' <+>) cs) @@ -228,10 +272,10 @@ add_bars (c:cs) = sep ((equals <+> c) : map (char '|' <+>) cs) ppr_bndr :: GHC.NamedThing a => a -> SDoc ppr_bndr a = GHC.pprParenSymName a -showWithLoc :: SrcSpan -> SDoc -> SDoc +showWithLoc :: SDoc -> SDoc -> SDoc showWithLoc loc doc - = hang doc 2 (char '\t' <> comment <+> GHC.pprDefnLoc loc) + = hang doc 2 (char '\t' <> comment <+> loc) -- The tab tries to make them line up a bit where - comment = ptext SLIT("--") + comment = ptext (sLit "--")