HsTypes: Abstract syntax: user-defined types
\begin{code}
-{-# OPTIONS_GHC -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/WorkingConventions#Warnings
--- for details
-
module HsTypes (
HsType(..), LHsType,
HsTyVarBndr(..), LHsTyVarBndr,
--
-- 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 other = []
+hsExplicitTvs _ = []
---------------------
type LHsTyVarBndr name = Located (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 _ _ other = pprPanic "splitHsInstDeclTy" (ppr inst_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
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)
pprHsContext [] = empty
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]
-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) = 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 ctxt_prec (HsDocTy ty doc)
+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
sep [p1, ptext SLIT("->") <+> p2]
--------------------------
+pabrackets :: SDoc -> SDoc
pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]")
\end{code}