%
+% (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}
+{-# 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 HsTypes (
HsType(..), LHsType,
HsTyVarBndr(..), LHsTyVarBndr,
LBangType, BangType, HsBang(..),
getBangType, getBangStrictness,
- mkExplicitHsForAllTy, mkImplicitHsForAllTy,
+ mkExplicitHsForAllTy, mkImplicitHsForAllTy, hsExplicitTvs,
hsTyVarName, hsTyVarNames, replaceTyVarName,
hsLTyVarName, hsLTyVarNames, hsLTyVarLocName, hsLTyVarLocNames,
splitHsInstDeclTy, splitHsFunType,
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
\end{code}
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
-----------------------
Implicit `plus` Implicit = Implicit
exp1 `plus` exp2 = Explicit
+hsExplicitTvs :: LHsType name -> [name]
+-- The explicitly-given forall'd type variables of a HsType
+hsExplicitTvs (L _ (HsForAllTy Explicit tvs _ _)) = hsLTyVarNames tvs
+hsExplicitTvs other = []
+
+---------------------
type LHsTyVarBndr name = Located (HsTyVarBndr name)
data HsTyVarBndr name
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 _ _ other = pprPanic "splitHsInstDeclTy" (ppr inst_ty)
-- Splits HsType into the (init, last) parts
-- Breaks up any parens in the result type:
%* *
%************************************************************************
-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
= 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 ctxt_prec (HsFunTy ty1 ty2) = ppr_fun_ty ctxt_prec ty1 ty2
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 (HsPredTy pred) = ppr pred
ppr_mono_ty ctxt_prec (HsNumTy n) = integer n -- generics only
ppr_mono_ty ctxt_prec (HsSpliceTy s) = pprSplice s
-- 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 ctxt_prec (HsDocTy ty doc)
+ = ppr ty <+> ppr (unLoc doc)
+
--------------------------
ppr_fun_ty ctxt_prec ty1 ty2
= let p1 = ppr_mono_lty pREC_FUN ty1