--
-----------------------------------------------------------------------------
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module PprTyThing (
PrintExplicitForalls,
pprTyThing,
pprTypeForUser
) where
-#include "HsVersions.h"
-
import qualified GHC
-import GHC ( TyThing(..) )
-import TyCon ( tyConFamInst_maybe )
-import Type ( TyThing(..), tidyTopType, pprTypeApp )
-import TcType ( tcMultiSplitSigmaTy, mkPhiTy )
-import SrcLoc ( SrcSpan )
+import GHC ( TyThing(..) )
+import TyCon
+import Type ( TyThing(..), tidyTopType, pprTypeApp )
+import TcType
import Var
import Name
import Outputable
+import FastString
-- -----------------------------------------------------------------------------
-- Pretty-printing entities that we get from the GHC API
pprTyThingHdr pefas (ADataCon dataCon) = pprDataConSig pefas dataCon
pprTyThingHdr pefas (ATyCon tyCon) = pprTyConHdr pefas tyCon
pprTyThingHdr pefas (AClass cls) = pprClassHdr pefas cls
-
-pprTyConHdr pefas tyCon
- | Just (fam_tc, tys) <- tyConFamInst_maybe tyCon
- = ptext keyword <+> ptext SLIT("instance") <+> pprTypeApp tyCon (ppr_bndr tyCon) tys
+
+pprTyConHdr :: PrintExplicitForalls -> TyCon -> SDoc
+pprTyConHdr _ tyCon
+ | Just (_fam_tc, tys) <- tyConFamInst_maybe tyCon
+ = ptext keyword <+> ptext (sLit "instance") <+> pprTypeApp tyCon (ppr_bndr 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
+ opt_stupid -- The "stupid theta" part of the declaration
+ | isAlgTyCon tyCon = GHC.pprThetaArrow (tyConStupidTheta 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)
-pprClassHdr pefas cls =
+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 :: 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
where
tidy_ty = tidyTopType ty
(ctxt, ty') = tcMultiSplitSigmaTy tidy_ty
+pprTyCon :: PrintExplicitForalls -> TyCon -> SDoc
pprTyCon pefas tyCon
| GHC.isSynTyCon tyCon
= if GHC.isOpenTyCon tyCon
| otherwise
= pprAlgTyCon pefas tyCon (const True) (const True)
+pprAlgTyCon :: PrintExplicitForalls -> TyCon -> (GHC.DataCon -> Bool)
+ -> (FieldLabel -> Bool) -> SDoc
pprAlgTyCon pefas tyCon ok_con ok_label
- | gadt = pprTyConHdr pefas tyCon <+> ptext SLIT("where") $$
+ | gadt = pprTyConHdr pefas tyCon <+> ptext (sLit "where") $$
nest 2 (vcat (ppr_trim show_con datacons))
| otherwise = hang (pprTyConHdr pefas tyCon)
2 (add_bars (ppr_trim show_con datacons))
| ok_con dataCon = Just (pprDataConDecl pefas gadt ok_label dataCon)
| otherwise = Nothing
+pprDataCon :: PrintExplicitForalls -> GHC.DataCon -> SDoc
pprDataCon pefas dataCon = pprAlgTyCon pefas tyCon (== dataCon) (const True)
where tyCon = GHC.dataConTyCon dataCon
-pprDataConDecl pefas 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 ]
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
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"))
+ 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
- = hang (pprClassHdr pefas cls <+> ptext SLIT("where"))
+ = 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 pefas id)
| otherwise = Nothing
+pprClassMethod :: PrintExplicitForalls -> Id -> SDoc
pprClassMethod pefas id
= hang (ppr_bndr id <+> dcolon) 2 (pprTypeForUser pefas op_ty)
where
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)
= hang doc 2 (char '\t' <> comment <+> loc)
-- The tab tries to make them line up a bit
where
- comment = ptext SLIT("--")
+ comment = ptext (sLit "--")