Commit 84e10e6c authored by simonpj@microsoft.com's avatar simonpj@microsoft.com

Refactor pretty printing of TyThings to fix Trac #4015

parent 79324024
......@@ -9,7 +9,7 @@
module PprTyThing (
PrintExplicitForalls,
pprTyThing,
pprTyThingInContext,
pprTyThingInContext, pprTyThingParent_maybe,
pprTyThingLoc,
pprTyThingInContextLoc,
pprTyThingHdr,
......@@ -19,6 +19,9 @@ module PprTyThing (
import qualified GHC
import GHC ( TyThing(..) )
import DataCon
import Id
import IdInfo
import TyCon
import TcType
import Var
......@@ -34,6 +37,12 @@ import FastString
type PrintExplicitForalls = Bool
type ShowMe = Name -> Bool
-- The ShowMe function says which sub-components to print
-- True <=> print
-- False <=> elide to "..."
----------------------------
-- | Pretty-prints a 'TyThing' with its defining location.
pprTyThingLoc :: PrintExplicitForalls -> TyThing -> SDoc
pprTyThingLoc pefas tyThing
......@@ -42,26 +51,41 @@ pprTyThingLoc pefas tyThing
-- | Pretty-prints a 'TyThing'.
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
pprTyThing pefas thing = ppr_ty_thing pefas (const True) thing
-- | Like 'pprTyThingInContext', but adds the defining location.
pprTyThingInContextLoc :: PrintExplicitForalls -> TyThing -> SDoc
pprTyThingInContextLoc pefas tyThing
= showWithLoc loc (pprTyThingInContext pefas tyThing)
where loc = pprNameLoc (GHC.getName tyThing)
ppr_ty_thing :: PrintExplicitForalls -> ShowMe -> TyThing -> SDoc
ppr_ty_thing pefas _ (AnId id) = pprId pefas id
ppr_ty_thing pefas _ (ADataCon dataCon) = pprDataConSig pefas dataCon
ppr_ty_thing pefas show_me (ATyCon tyCon) = pprTyCon pefas show_me tyCon
ppr_ty_thing pefas show_me (AClass cls) = pprClass pefas show_me cls
-- | 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 :: 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
pprTyThingInContext pefas thing
| Just parent <- pprTyThingParent_maybe thing
= ppr_ty_thing pefas (== GHC.getName thing) parent
| otherwise
= pprTyThing pefas thing
-- | Like 'pprTyThingInContext', but adds the defining location.
pprTyThingInContextLoc :: PrintExplicitForalls -> TyThing -> SDoc
pprTyThingInContextLoc pefas tyThing
= showWithLoc (pprNameLoc (GHC.getName tyThing))
(pprTyThingInContext pefas tyThing)
pprTyThingParent_maybe :: TyThing -> Maybe TyThing
-- (pprTyThingParent_maybe x) returns (Just p)
-- when pprTyThingInContext sould print a declaration for p
-- (albeit with some "..." in it) when asked to show x
pprTyThingParent_maybe (ADataCon dc) = Just (ATyCon (dataConTyCon dc))
pprTyThingParent_maybe (AnId id) = case idDetails id of
RecSelId { sel_tycon = tc } -> Just (ATyCon tc)
ClassOpId cls -> Just (AClass cls)
_other -> Nothing
pprTyThingParent_maybe _other = Nothing
-- | Pretty-prints the 'TyThing' header. For functions and data constructors
-- the function is equivalent to 'pprTyThing' but for type constructors
......@@ -96,32 +120,19 @@ pprTyConHdr _ tyCon
| otherwise = empty -- Returns 'empty' if null theta
pprDataConSig :: PrintExplicitForalls -> GHC.DataCon -> SDoc
pprDataConSig pefas dataCon =
ppr_bndr dataCon <+> dcolon <+> pprTypeForUser pefas (GHC.dataConType dataCon)
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") <+>
GHC.pprThetaArrow (GHC.classSCTheta cls) <+>
ppr_bndr cls <+>
hsep (map ppr tyVars) <+>
GHC.pprFundeps funDeps
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 :: PrintExplicitForalls -> Id -> SDoc
pprRecordSelector pefas id
= pprAlgTyCon pefas tyCon show_con show_label
pprClassHdr _ cls
= ptext (sLit "class") <+>
GHC.pprThetaArrow (GHC.classSCTheta cls) <+>
ppr_bndr cls <+>
hsep (map ppr tyVars) <+>
GHC.pprFundeps funDeps
where
(tyCon,label) = GHC.recordSelectorFieldLabel id
show_con dataCon = label `elem` GHC.dataConFieldLabels dataCon
show_label label' = label == label'
(tyVars, funDeps) = GHC.classTvsFds cls
pprId :: PrintExplicitForalls -> Var -> SDoc
pprId pefas ident
= hang (ppr_bndr ident <+> dcolon)
......@@ -143,8 +154,8 @@ pprTypeForUser print_foralls ty
tidy_ty = tidyTopType ty
(ctxt, ty') = tcMultiSplitSigmaTy tidy_ty
pprTyCon :: PrintExplicitForalls -> TyCon -> SDoc
pprTyCon pefas tyCon
pprTyCon :: PrintExplicitForalls -> ShowMe -> TyCon -> SDoc
pprTyCon pefas show_me tyCon
| GHC.isSynTyCon tyCon
= if GHC.isOpenTyCon tyCon
then pprTyConHdr pefas tyCon <+> dcolon <+>
......@@ -153,11 +164,10 @@ pprTyCon pefas tyCon
let rhs_type = GHC.synTyConType tyCon
in hang (pprTyConHdr pefas tyCon <+> equals) 2 (pprTypeForUser pefas rhs_type)
| otherwise
= pprAlgTyCon pefas tyCon (const True) (const True)
= pprAlgTyCon pefas show_me tyCon
pprAlgTyCon :: PrintExplicitForalls -> TyCon -> (GHC.DataCon -> Bool)
-> (FieldLabel -> Bool) -> SDoc
pprAlgTyCon pefas tyCon ok_con ok_label
pprAlgTyCon :: PrintExplicitForalls -> ShowMe -> TyCon -> SDoc
pprAlgTyCon pefas show_me tyCon
| gadt = pprTyConHdr pefas tyCon <+> ptext (sLit "where") $$
nest 2 (vcat (ppr_trim show_con datacons))
| otherwise = hang (pprTyConHdr pefas tyCon)
......@@ -166,20 +176,16 @@ pprAlgTyCon pefas tyCon ok_con ok_label
datacons = GHC.tyConDataCons tyCon
gadt = any (not . GHC.isVanillaDataCon) datacons
show_con dataCon
| ok_con dataCon = Just (pprDataConDecl pefas gadt ok_label dataCon)
| otherwise = Nothing
ok_con dc = show_me (dataConName dc) || any show_me (dataConFieldLabels dc)
show_con dc
| ok_con dc = Just (pprDataConDecl pefas show_me gadt dc)
| otherwise = Nothing
pprDataCon :: PrintExplicitForalls -> GHC.DataCon -> SDoc
pprDataCon pefas dataCon = pprAlgTyCon pefas tyCon (== dataCon) (const True)
where tyCon = GHC.dataConTyCon dataCon
pprDataConDecl :: PrintExplicitForalls -> Bool -> (FieldLabel -> Bool)
-> GHC.DataCon -> SDoc
pprDataConDecl _ gadt_style show_label dataCon
pprDataConDecl :: PrintExplicitForalls -> ShowMe -> Bool -> GHC.DataCon -> SDoc
pprDataConDecl pefas show_me gadt_style dataCon
| not gadt_style = ppr_fields tys_w_strs
| otherwise = ppr_bndr dataCon <+> dcolon <+>
sep [ GHC.pprForAll forall_tvs, GHC.pprThetaArrow theta, pp_tau ]
sep [ pp_foralls, GHC.pprThetaArrow theta, pp_tau ]
-- Printing out the dataCon as a type signature, in GADT style
where
(forall_tvs, theta, tau) = tcSplitSigmaTy (GHC.dataConUserType dataCon)
......@@ -187,6 +193,8 @@ pprDataConDecl _ gadt_style show_label dataCon
labels = GHC.dataConFieldLabels dataCon
stricts = GHC.dataConStrictMarks dataCon
tys_w_strs = zip stricts arg_tys
pp_foralls | pefas = GHC.pprForAll forall_tvs
| otherwise = empty
pp_tau = foldr add (ppr res_ty) tys_w_strs
add str_ty pp_ty = pprParendBangTy str_ty <+> arrow <+> pp_ty
......@@ -196,8 +204,8 @@ pprDataConDecl _ gadt_style show_label dataCon
pprBangTy bang ty = ppr bang <> ppr ty
maybe_show_label (lbl,(strict,tp))
| show_label lbl = Just (ppr lbl <+> dcolon <+> pprBangTy strict tp)
| otherwise = Nothing
| show_me lbl = Just (ppr lbl <+> dcolon <+> pprBangTy strict tp)
| otherwise = Nothing
ppr_fields [ty1, ty2]
| GHC.dataConIsInfix dataCon && null labels
......@@ -210,24 +218,17 @@ pprDataConDecl _ gadt_style show_label dataCon
braces (sep (punctuate comma (ppr_trim maybe_show_label
(zip labels fields))))
pprClass :: PrintExplicitForalls -> GHC.Class -> SDoc
pprClass pefas cls
| null methods =
pprClassHdr pefas cls
| otherwise =
hang (pprClassHdr pefas cls <+> ptext (sLit "where"))
2 (vcat (map (pprClassMethod pefas) methods))
where
methods = GHC.classMethods cls
pprClassOneMethod :: PrintExplicitForalls -> GHC.Class -> Id -> SDoc
pprClassOneMethod pefas cls this_one
pprClass :: PrintExplicitForalls -> ShowMe -> GHC.Class -> SDoc
pprClass pefas show_me cls
| null methods
= pprClassHdr pefas cls
| otherwise
= hang (pprClassHdr pefas cls <+> ptext (sLit "where"))
2 (vcat (ppr_trim show_meth methods))
2 (vcat (ppr_trim show_meth methods))
where
methods = GHC.classMethods cls
show_meth id | id == this_one = Just (pprClassMethod pefas id)
| otherwise = Nothing
methods = GHC.classMethods cls
show_meth id | show_me (idName id) = Just (pprClassMethod pefas id)
| otherwise = Nothing
pprClassMethod :: PrintExplicitForalls -> Id -> SDoc
pprClassMethod pefas id
......
......@@ -32,7 +32,7 @@ import Packages
-- import PackageConfig
import UniqFM
import HscTypes ( implicitTyThings, handleFlagWarnings )
import HscTypes ( handleFlagWarnings )
import qualified RdrName ( getGRE_NameQualifier_maybes ) -- should this come via GHC?
import Outputable hiding (printForUser, printForUserPartWay)
import Module -- for ModuleEnv
......@@ -824,9 +824,12 @@ info s = handleSourceError GHC.printExceptionAndWarnings $ do
-- constructor in the same type
filterOutChildren :: (a -> TyThing) -> [a] -> [a]
filterOutChildren get_thing xs
= [x | x <- xs, not (getName (get_thing x) `elemNameSet` implicits)]
= filterOut has_parent xs
where
implicits = mkNameSet [getName t | x <- xs, t <- implicitTyThings (get_thing x)]
all_names = mkNameSet (map (getName . get_thing) xs)
has_parent x = case pprTyThingParent_maybe (get_thing x) of
Just p -> getName p `elemNameSet` all_names
Nothing -> False
pprInfo :: PrintExplicitForalls -> (TyThing, Fixity, [GHC.Instance]) -> SDoc
pprInfo pefas (thing, fixity, insts)
......
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