\begin{code}
module HsDecls (
HsDecl(..), LHsDecl, TyClDecl(..), LTyClDecl,
- InstDecl(..), LInstDecl, NewOrData(..),
+ InstDecl(..), LInstDecl, DerivDecl(..), LDerivDecl, NewOrData(..),
RuleDecl(..), LRuleDecl, RuleBndr(..),
DefaultDecl(..), LDefaultDecl, SpliceDecl(..),
ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..),
data HsDecl id
= TyClD (TyClDecl id)
| InstD (InstDecl id)
+ | DerivD (DerivDecl id)
| ValD (HsBind id)
| SigD (Sig id)
| DefD (DefaultDecl id)
hs_valds :: HsValBinds id,
hs_tyclds :: [LTyClDecl id],
hs_instds :: [LInstDecl id],
+ hs_derivds :: [LDerivDecl id],
hs_fixds :: [LFixitySig id],
-- Snaffled out of both top-level fixity signatures,
emptyRdrGroup = emptyGroup { hs_valds = emptyValBindsIn }
emptyRnGroup = emptyGroup { hs_valds = emptyValBindsOut }
-emptyGroup = HsGroup { hs_tyclds = [], hs_instds = [],
+emptyGroup = HsGroup { hs_tyclds = [], hs_instds = [], hs_derivds = [],
hs_fixds = [], hs_defds = [], hs_fords = [],
hs_depds = [], hs_ruleds = [],
hs_valds = error "emptyGroup hs_valds: Can't happen" }
hs_valds = val_groups1,
hs_tyclds = tyclds1,
hs_instds = instds1,
+ hs_derivds = derivds1,
hs_fixds = fixds1,
hs_defds = defds1,
hs_fords = fords1,
hs_valds = val_groups2,
hs_tyclds = tyclds2,
hs_instds = instds2,
+ hs_derivds = derivds2,
hs_fixds = fixds2,
hs_defds = defds2,
hs_fords = fords2,
hs_valds = val_groups1 `plusHsValBinds` val_groups2,
hs_tyclds = tyclds1 ++ tyclds2,
hs_instds = instds1 ++ instds2,
+ hs_derivds = derivds1 ++ derivds2,
hs_fixds = fixds1 ++ fixds2,
hs_defds = defds1 ++ defds2,
hs_fords = fords1 ++ fords2,
ppr (ValD binds) = ppr binds
ppr (DefD def) = ppr def
ppr (InstD inst) = ppr inst
+ ppr (DerivD deriv) = ppr deriv
ppr (ForD fd) = ppr fd
ppr (SigD sd) = ppr sd
ppr (RuleD rd) = ppr rd
ppr (HsGroup { hs_valds = val_decls,
hs_tyclds = tycl_decls,
hs_instds = inst_decls,
+ hs_derivds = deriv_decls,
hs_fixds = fix_decls,
hs_depds = deprec_decls,
hs_fords = foreign_decls,
ppr_ds deprec_decls, ppr_ds rule_decls,
ppr val_decls,
ppr_ds tycl_decls, ppr_ds inst_decls,
+ ppr_ds deriv_decls,
ppr_ds foreign_decls]
where
ppr_ds [] = empty
-- definition of an instance of an indexed type
isIdxTyDecl tydecl
- | isSynDecl tydecl || isDataDecl tydecl = isJust (tcdTyPats tydecl)
- | otherwise = False
+ | isTEqnDecl tydecl = True
+ | isDataDecl tydecl = isJust (tcdTyPats tydecl)
+ | otherwise = False
\end{code}
Dealing with names
dcolon <+> pprKind kind
where
typeMaybeIso = if iso
- then ptext SLIT("type iso")
- else ptext SLIT("type")
+ then ptext SLIT("type family iso")
+ else ptext SLIT("type family")
ppr (TySynonym {tcdLName = ltycon, tcdTyVars = tyvars, tcdTyPats = typats,
tcdSynRhs = mono_ty})
- = hang (ptext SLIT("type") <+> pp_decl_head [] ltycon tyvars typats <+>
+ = hang (ptext SLIT("type") <+>
+ (if isJust typats then ptext SLIT("instance") else empty) <+>
+ pp_decl_head [] ltycon tyvars typats <+>
equals)
4 (ppr mono_ty)
ppr (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = ltycon,
tcdTyVars = tyvars, tcdTyPats = typats, tcdKindSig = mb_sig,
tcdCons = condecls, tcdDerivs = derivings})
- = pp_tydecl (ppr new_or_data <+>
+ = pp_tydecl (null condecls && isJust mb_sig)
+ (ppr new_or_data <+>
+ (if isJust typats then ptext SLIT("instance") else empty) <+>
pp_decl_head (unLoc context) ltycon tyvars typats <+>
ppr_sig mb_sig)
(pp_condecls condecls)
pp_condecls cs -- In H98 syntax
= equals <+> sep (punctuate (ptext SLIT(" |")) (map ppr cs))
-pp_tydecl pp_head pp_decl_rhs derivings
+pp_tydecl True pp_head pp_decl_rhs derivings
+ = pp_head
+pp_tydecl False pp_head pp_decl_rhs derivings
= hang pp_head 4 (sep [
- pp_decl_rhs,
- case derivings of
- Nothing -> empty
- Just ds -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)]
+ pp_decl_rhs,
+ case derivings of
+ Nothing -> empty
+ Just ds -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)]
])
instance Outputable NewOrData where
%************************************************************************
%* *
+\subsection[DerivDecl]{A stand-alone instance deriving declaration
+%* *
+%************************************************************************
+
+\begin{code}
+type LDerivDecl name = Located (DerivDecl name)
+
+data DerivDecl name
+ = DerivDecl (LHsType name) (Located name)
+
+instance (OutputableBndr name) => Outputable (DerivDecl name) where
+ ppr (DerivDecl ty n)
+ = hsep [ptext SLIT("deriving"), ppr ty, ptext SLIT("for"), ppr n]
+\end{code}
+
+%************************************************************************
+%* *
\subsection[DefaultDecl]{A @default@ declaration}
%* *
%************************************************************************