-- round)
-- (1) Do class and family instance declarations
- ; let { idxty_decls = filter (isFamInstDecl . unLoc) tycl_decls }
+ ; idx_tycons <- mapAndRecoverM (tcFamInstDecl TopLevel) $
+ filter (isFamInstDecl . unLoc) tycl_decls
; local_info_tycons <- mapAndRecoverM tcLocalInstDecl1 inst_decls
- ; idx_tycons <- mapAndRecoverM tcIdxTyInstDeclTL idxty_decls
; let { (local_info,
at_tycons_s) = unzip local_info_tycons
; at_idx_tycons = concat at_tycons_s ++ idx_tycons
; clas_decls = filter (isClassDecl.unLoc) tycl_decls
; implicit_things = concatMap implicitTyThings at_idx_tycons
- ; aux_binds = mkAuxBinds at_idx_tycons
+ ; aux_binds = mkRecSelBinds at_idx_tycons
}
-- (2) Add the tycons of indexed types and their implicit
-- Next, construct the instance environment so far, consisting
-- of
- -- a) local instance decls
- -- b) generic instances
- -- c) local family instance decls
+ -- (a) local instance decls
+ -- (b) generic instances
+ -- (c) local family instance decls
; addInsts local_info $
addInsts generic_inst_info $
addFamInsts at_idx_tycons $ do {
generic_inst_info ++ deriv_inst_info ++ local_info,
aux_binds `plusHsValBinds` deriv_binds)
}}}
- where
- -- Make sure that toplevel type instance are not for associated types.
- -- !!!TODO: Need to perform this check for the TyThing of type functions,
- -- too.
- tcIdxTyInstDeclTL ldecl@(L loc decl) =
- do { tything <- tcFamInstDecl ldecl
- ; setSrcSpan loc $
- when (isAssocFamily tything) $
- addErr $ assocInClassErr (tcdName decl)
- ; return tything
- }
- isAssocFamily (ATyCon tycon) =
- case tyConFamInst_maybe tycon of
- Nothing -> panic "isAssocFamily: no family?!?"
- Just (fam, _) -> isTyConAssoc fam
- isAssocFamily _ = panic "isAssocFamily: no tycon?!?"
-
-assocInClassErr :: Name -> SDoc
-assocInClassErr name =
- ptext (sLit "Associated type") <+> quotes (ppr name) <+>
- ptext (sLit "must be inside a class instance")
addInsts :: [InstInfo Name] -> TcM a -> TcM a
addInsts infos thing_inside
-- Next, process any associated types.
; idx_tycons <- recoverM (return []) $
- do { idx_tycons <- checkNoErrs $ mapAndRecoverM tcFamInstDecl ats
+ do { idx_tycons <- checkNoErrs $
+ mapAndRecoverM (tcFamInstDecl NotTopLevel) ats
; checkValidAndMissingATs clas (tyvars, inst_tys)
(zip ats idx_tycons)
; return idx_tycons }
\begin{code}
tcInstDecls2 :: [LTyClDecl Name] -> [InstInfo Name]
- -> TcM (LHsBinds Id, TcLclEnv)
+ -> TcM (LHsBinds Id)
-- (a) From each class declaration,
-- generate any default-method bindings
-- (b) From each instance decl
tcInstDecls2 tycl_decls inst_decls
= do { -- (a) Default methods from class decls
let class_decls = filter (isClassDecl . unLoc) tycl_decls
- ; (dm_ids_s, dm_binds_s) <- mapAndUnzipM tcClassDecl2 class_decls
+ ; dm_binds_s <- mapM tcClassDecl2 class_decls
+ ; let dm_binds = unionManyBags dm_binds_s
- ; tcExtendIdEnv (concat dm_ids_s) $ do
-
-- (b) instance declarations
- { inst_binds_s <- mapM tcInstDecl2 inst_decls
+ ; let dm_ids = collectHsBindsBinders dm_binds
+ -- Add the default method Ids (again)
+ -- See Note [Default methods and instances]
+ ; inst_binds_s <- tcExtendIdEnv dm_ids $
+ mapM tcInstDecl2 inst_decls
-- Done
- ; let binds = unionManyBags dm_binds_s `unionBags`
- unionManyBags inst_binds_s
- ; tcl_env <- getLclEnv -- Default method Ids in here
- ; return (binds, tcl_env) } }
+ ; return (dm_binds `unionBags` unionManyBags inst_binds_s) }
tcInstDecl2 :: InstInfo Name -> TcM (LHsBinds Id)
tcInstDecl2 (InstInfo { iSpec = ispec, iBinds = ibinds })
loc = getSrcSpan dfun_id
\end{code}
+See Note [Default methods and instances]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The default method Ids are already in the type environment (see Note
+[Default method Ids and Template Haskell] in TcTyClsDcls), BUT they
+don't have their InlinePragmas yet. Usually that would not matter,
+because the simplifier propagates information from binding site to
+use. But, unusually, when compiling instance decls we *copy* the
+INLINE pragma from the default method to the method for that
+particular operation (see Note [INLINE and default methods] below).
+
+So right here in tcInstDecl2 we must re-extend the type envt with
+the default method Ids replete with their INLINE pragmas. Urk.
\begin{code}
tc_inst_decl2 :: Id -> InstBindings Name -> TcM (LHsBinds Id)
= add_meth_ctxt rn_bind $
do { (meth_id1, spec_prags) <- tcPrags NonRecursive False True
meth_id (prag_fn sel_name)
- ; tcInstanceMethodBody (instLoc this_dict)
+ ; bind <- tcInstanceMethodBody (instLoc this_dict)
tyvars dfun_dicts
([this_dict], this_dict_bind)
meth_id1 local_meth_id
meth_sig_fn
(SpecPrags (spec_inst_prags ++ spec_prags))
- rn_bind }
+ rn_bind
+ ; return (meth_id1, bind) }
--------------
tc_default :: DefMeth -> TcM (Id, LHsBind Id)
projects / ghc-hetmet.git / blobdiff