%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[HsTypes]{Abstract syntax: user-defined types}
+
+HsTypes: Abstract syntax: user-defined types
\begin{code}
module HsTypes (
LBangType, BangType, HsBang(..),
getBangType, getBangStrictness,
- mkExplicitHsForAllTy, mkImplicitHsForAllTy,
+ mkExplicitHsForAllTy, mkImplicitHsForAllTy, hsExplicitTvs,
hsTyVarName, hsTyVarNames, replaceTyVarName,
hsLTyVarName, hsLTyVarNames, hsLTyVarLocName, hsLTyVarLocNames,
splitHsInstDeclTy, splitHsFunType,
pprParendHsType, pprHsForAll, pprHsContext, ppr_hs_context, pprHsTyVarBndr
) where
-#include "HsVersions.h"
-
import {-# SOURCE #-} HsExpr ( HsSplice, pprSplice )
-import Type ( Type )
-import Kind ( {- instance Outputable Kind -} Kind,
- pprParendKind, pprKind, isLiftedTypeKind )
-import BasicTypes ( IPName, Boxity, tupleParens )
-import SrcLoc ( Located(..), unLoc, noSrcSpan )
-import StaticFlags ( opt_PprStyle_Debug )
+import Type
+import HsDoc
+import BasicTypes
+import SrcLoc
+import StaticFlags
import Outputable
+import FastString
\end{code}
instance Outputable HsBang where
ppr (HsNoBang) = empty
ppr (HsStrict) = char '!'
- ppr (HsUnbox) = ptext SLIT("!!")
+ ppr (HsUnbox) = ptext (sLit "!!")
getBangType :: LHsType a -> LHsType a
getBangType (L _ (HsBangTy _ ty)) = ty
type LHsPred name = Located (HsPred name)
-data HsPred name = HsClassP name [LHsType name]
+data HsPred name = HsClassP name [LHsType name] -- class constraint
+ | HsEqualP (LHsType name) (LHsType name)-- equality constraint
| HsIParam (IPName name) (LHsType name)
type LHsType name = Located (HsType name)
| HsSpliceTy (HsSplice name)
+ | HsDocTy (LHsType name) (LHsDoc name) -- A documented type
+
data HsExplicitForAll = Explicit | Implicit
-----------------------
--
-- A valid type must have one for-all at the top of the type, or of the fn arg types
+mkImplicitHsForAllTy :: LHsContext name -> LHsType name -> HsType name
+mkExplicitHsForAllTy :: [LHsTyVarBndr name] -> LHsContext name -> LHsType name -> HsType name
mkImplicitHsForAllTy ctxt ty = mkHsForAllTy Implicit [] ctxt ty
mkExplicitHsForAllTy tvs ctxt ty = mkHsForAllTy Explicit tvs ctxt ty
mkHsForAllTy exp tvs ctxt ty = HsForAllTy exp tvs ctxt ty
-- mk_forall_ty makes a pure for-all type (no context)
+mk_forall_ty :: HsExplicitForAll -> [LHsTyVarBndr name] -> LHsType name -> HsType name
mk_forall_ty exp tvs (L _ (HsParTy ty)) = mk_forall_ty exp tvs ty
mk_forall_ty exp1 tvs1 (L _ (HsForAllTy exp2 tvs2 ctxt ty)) = mkHsForAllTy (exp1 `plus` exp2) (tvs1 ++ tvs2) ctxt ty
mk_forall_ty exp tvs ty = HsForAllTy exp tvs (L noSrcSpan []) ty
-- (see the sigtype production in Parser.y.pp)
-- so that (forall. ty) isn't implicitly quantified
+plus :: HsExplicitForAll -> HsExplicitForAll -> HsExplicitForAll
Implicit `plus` Implicit = Implicit
-exp1 `plus` exp2 = Explicit
+_ `plus` _ = Explicit
+
+hsExplicitTvs :: LHsType name -> [name]
+-- The explicitly-given forall'd type variables of a HsType
+hsExplicitTvs (L _ (HsForAllTy Explicit tvs _ _)) = hsLTyVarNames tvs
+hsExplicitTvs _ = []
+---------------------
type LHsTyVarBndr name = Located (HsTyVarBndr name)
data HsTyVarBndr name
hsLTyVarLocNames = map hsLTyVarLocName
replaceTyVarName :: HsTyVarBndr name1 -> name2 -> HsTyVarBndr name2
-replaceTyVarName (UserTyVar n) n' = UserTyVar n'
-replaceTyVarName (KindedTyVar n k) n' = KindedTyVar n' k
+replaceTyVarName (UserTyVar _) n' = UserTyVar n'
+replaceTyVarName (KindedTyVar _ k) n' = KindedTyVar n' k
\end{code}
where
split_tau tvs cxt (HsPredTy (HsClassP cls tys)) = (tvs, cxt, cls, tys)
split_tau tvs cxt (HsParTy (L _ ty)) = split_tau tvs cxt ty
+ split_tau _ _ _ = pprPanic "splitHsInstDeclTy" (ppr inst_ty)
-- Splits HsType into the (init, last) parts
-- Breaks up any parens in the result type:
-- splitHsFunType (a -> (b -> c)) = ([a,b], c)
splitHsFunType :: LHsType name -> ([LHsType name], LHsType name)
-splitHsFunType (L l (HsFunTy x y)) = (x:args, res)
+splitHsFunType (L _ (HsFunTy x y)) = (x:args, res)
where
(args, res) = splitHsFunType y
splitHsFunType (L _ (HsParTy ty)) = splitHsFunType ty
%* *
%************************************************************************
-NB: these types get printed into interface files, so
- don't change the printing format lightly
-
\begin{code}
instance (OutputableBndr name) => Outputable (HsType name) where
ppr ty = pprHsType ty
ppr (KindedTyVar name kind) = pprHsTyVarBndr name kind
instance OutputableBndr name => Outputable (HsPred name) where
- ppr (HsClassP clas tys) = ppr clas <+> hsep (map (pprParendHsType.unLoc) tys)
- ppr (HsIParam n ty) = hsep [ppr n, dcolon, ppr ty]
+ ppr (HsClassP clas tys) = ppr clas <+> hsep (map pprLHsType tys)
+ ppr (HsEqualP t1 t2) = hsep [pprLHsType t1, ptext (sLit "~"),
+ pprLHsType t2]
+ ppr (HsIParam n ty) = hsep [ppr n, dcolon, ppr ty]
+
+pprLHsType :: OutputableBndr name => LHsType name -> SDoc
+pprLHsType = pprParendHsType . unLoc
pprHsTyVarBndr :: Outputable name => name -> Kind -> SDoc
pprHsTyVarBndr name kind | isLiftedTypeKind kind = ppr name
| otherwise = hsep [ppr name, dcolon, pprParendKind kind]
+pprHsForAll :: OutputableBndr name => HsExplicitForAll -> [LHsTyVarBndr name] -> LHsContext name -> SDoc
pprHsForAll exp tvs cxt
| show_forall = forall_part <+> pprHsContext (unLoc cxt)
| otherwise = pprHsContext (unLoc cxt)
show_forall = opt_PprStyle_Debug
|| (not (null tvs) && is_explicit)
is_explicit = case exp of {Explicit -> True; Implicit -> False}
- forall_part = ptext SLIT("forall") <+> interppSP tvs <> dot
+ forall_part = ptext (sLit "forall") <+> interppSP tvs <> dot
pprHsContext :: (OutputableBndr name) => HsContext name -> SDoc
pprHsContext [] = empty
-pprHsContext cxt = ppr_hs_context cxt <+> ptext SLIT("=>")
+pprHsContext cxt = ppr_hs_context cxt <+> ptext (sLit "=>")
+ppr_hs_context :: (OutputableBndr name) => HsContext name -> SDoc
ppr_hs_context [] = empty
ppr_hs_context cxt = parens (interpp'SP cxt)
\end{code}
\begin{code}
-pREC_TOP = (0 :: Int) -- type in ParseIface.y
-pREC_FUN = (1 :: Int) -- btype in ParseIface.y
- -- Used for LH arg of (->)
-pREC_OP = (2 :: Int) -- Used for arg of any infix operator
- -- (we don't keep their fixities around)
-pREC_CON = (3 :: Int) -- Used for arg of type applicn:
- -- always parenthesise unless atomic
+pREC_TOP, pREC_FUN, pREC_OP, pREC_CON :: Int
+pREC_TOP = 0 -- type in ParseIface.y
+pREC_FUN = 1 -- btype in ParseIface.y
+ -- Used for LH arg of (->)
+pREC_OP = 2 -- Used for arg of any infix operator
+ -- (we don't keep their fixities around)
+pREC_CON = 3 -- Used for arg of type applicn:
+ -- always parenthesise unless atomic
maybeParen :: Int -- Precedence of context
-> Int -- Precedence of top-level operator
-- (a) Remove outermost HsParTy parens
-- (b) Drop top-level for-all type variables in user style
-- since they are implicit in Haskell
+prepare :: PprStyle -> HsType name -> HsType name
prepare sty (HsParTy ty) = prepare sty (unLoc ty)
-prepare sty ty = ty
+prepare _ ty = ty
+ppr_mono_lty :: (OutputableBndr name) => Int -> LHsType name -> SDoc
ppr_mono_lty ctxt_prec ty = ppr_mono_ty ctxt_prec (unLoc ty)
+ppr_mono_ty :: (OutputableBndr name) => Int -> HsType name -> SDoc
ppr_mono_ty ctxt_prec (HsForAllTy exp tvs ctxt ty)
= maybeParen ctxt_prec pREC_FUN $
sep [pprHsForAll exp tvs ctxt, ppr_mono_lty pREC_TOP ty]
--- gaw 2004
-ppr_mono_ty ctxt_prec (HsBangTy b ty) = ppr b <> ppr ty
-ppr_mono_ty ctxt_prec (HsTyVar name) = ppr name
+ppr_mono_ty _ (HsBangTy b ty) = ppr b <> ppr ty
+ppr_mono_ty _ (HsTyVar name) = ppr name
ppr_mono_ty ctxt_prec (HsFunTy ty1 ty2) = ppr_fun_ty ctxt_prec ty1 ty2
-ppr_mono_ty ctxt_prec (HsTupleTy con tys) = tupleParens con (interpp'SP tys)
-ppr_mono_ty ctxt_prec (HsKindSig ty kind) = parens (ppr_mono_lty pREC_TOP ty <+> dcolon <+> pprKind kind)
-ppr_mono_ty ctxt_prec (HsListTy ty) = brackets (ppr_mono_lty pREC_TOP ty)
-ppr_mono_ty ctxt_prec (HsPArrTy ty) = pabrackets (ppr_mono_lty pREC_TOP ty)
-ppr_mono_ty ctxt_prec (HsPredTy pred) = braces (ppr pred)
-ppr_mono_ty ctxt_prec (HsNumTy n) = integer n -- generics only
-ppr_mono_ty ctxt_prec (HsSpliceTy s) = pprSplice s
+ppr_mono_ty _ (HsTupleTy con tys) = tupleParens con (interpp'SP tys)
+ppr_mono_ty _ (HsKindSig ty kind) = parens (ppr_mono_lty pREC_TOP ty <+> dcolon <+> pprKind kind)
+ppr_mono_ty _ (HsListTy ty) = brackets (ppr_mono_lty pREC_TOP ty)
+ppr_mono_ty _ (HsPArrTy ty) = pabrackets (ppr_mono_lty pREC_TOP ty)
+ppr_mono_ty _ (HsPredTy pred) = ppr pred
+ppr_mono_ty _ (HsNumTy n) = integer n -- generics only
+ppr_mono_ty _ (HsSpliceTy s) = pprSplice s
ppr_mono_ty ctxt_prec (HsAppTy fun_ty arg_ty)
= maybeParen ctxt_prec pREC_CON $
= maybeParen ctxt_prec pREC_OP $
ppr_mono_lty pREC_OP ty1 <+> ppr op <+> ppr_mono_lty pREC_OP ty2
-ppr_mono_ty ctxt_prec (HsParTy ty)
+ppr_mono_ty _ (HsParTy ty)
= parens (ppr_mono_lty pREC_TOP ty)
-- Put the parens in where the user did
-- But we still use the precedence stuff to add parens because
-- toHsType doesn't put in any HsParTys, so we may still need them
+ppr_mono_ty _ (HsDocTy ty doc)
+ = ppr ty <+> ppr (unLoc doc)
+
--------------------------
+ppr_fun_ty :: (OutputableBndr name) => Int -> LHsType name -> LHsType name -> SDoc
ppr_fun_ty ctxt_prec ty1 ty2
= let p1 = ppr_mono_lty pREC_FUN ty1
p2 = ppr_mono_lty pREC_TOP ty2
in
maybeParen ctxt_prec pREC_FUN $
- sep [p1, ptext SLIT("->") <+> p2]
+ sep [p1, ptext (sLit "->") <+> p2]
--------------------------
-pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
+pabrackets :: SDoc -> SDoc
+pabrackets p = ptext (sLit "[:") <> p <> ptext (sLit ":]")
\end{code}