\begin{code}
module TcGenDeriv (
- DerivAuxBind(..), DerivAuxBinds, isDupAux,
+ DerivAuxBinds, isDupAux,
gen_Bounded_binds,
gen_Enum_binds,
gen_Show_binds,
gen_Data_binds,
gen_Typeable_binds,
- genAuxBind,
-
- con2tag_RDR, tag2con_RDR, maxtag_RDR
+ genAuxBind
) where
#include "HsVersions.h"
type DerivAuxBinds = [DerivAuxBind]
data DerivAuxBind -- Please add these auxiliary top-level bindings
- = DerivAuxBind (LHsBind RdrName)
- | GenCon2Tag TyCon -- The con2Tag for given TyCon
+ = GenCon2Tag TyCon -- The con2Tag for given TyCon
| GenTag2Con TyCon -- ...ditto tag2Con
| GenMaxTag TyCon -- ...and maxTag
+ -- Scrap your boilerplate
+ | MkDataCon DataCon -- For constructor C we get $cC :: Constr
+ | MkTyCon TyCon -- For tycon T we get $tT :: DataType
+
+
isDupAux :: DerivAuxBind -> DerivAuxBind -> Bool
isDupAux (GenCon2Tag tc1) (GenCon2Tag tc2) = tc1 == tc2
isDupAux (GenTag2Con tc1) (GenTag2Con tc2) = tc1 == tc2
isDupAux (GenMaxTag tc1) (GenMaxTag tc2) = tc1 == tc2
+isDupAux (MkDataCon dc1) (MkDataCon dc2) = dc1 == dc2
+isDupAux (MkTyCon tc1) (MkTyCon tc2) = tc1 == tc2
isDupAux _ _ = False
\end{code}
\begin{code}
-gen_Eq_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Eq_binds tycon
+gen_Eq_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Eq_binds loc tycon
= (method_binds, aux_binds)
where
- tycon_loc = getSrcSpan tycon
-
(nullary_cons, nonnullary_cons)
| isNewTyCon tycon = ([], tyConDataCons tycon)
| otherwise = partition isNullarySrcDataCon (tyConDataCons tycon)
no_nullary_cons = null nullary_cons
rest | no_nullary_cons
- = case maybeTyConSingleCon tycon of
+ = case tyConSingleDataCon_maybe tycon of
Just _ -> []
Nothing -> -- if cons don't match, then False
[([nlWildPat, nlWildPat], false_Expr)]
| otherwise = [GenCon2Tag tycon]
method_binds = listToBag [
- mk_FunBind tycon_loc eq_RDR ((map pats_etc nonnullary_cons) ++ rest),
- mk_easy_FunBind tycon_loc ne_RDR [a_Pat, b_Pat] (
+ mk_FunBind loc eq_RDR ((map pats_etc nonnullary_cons) ++ rest),
+ mk_easy_FunBind loc ne_RDR [a_Pat, b_Pat] (
nlHsApp (nlHsVar not_RDR) (nlHsPar (nlHsVarApps eq_RDR [a_RDR, b_RDR])))]
------------------------------------------------------------------
JJQC-30-Nov-1997
\begin{code}
-gen_Ord_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Ord_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Ord_binds tycon
+gen_Ord_binds loc tycon
| Just (con, prim_tc) <- primWrapperType_maybe tycon
= gen_PrimOrd_binds con prim_tc
-- `AndMonoBinds` compare
-- The default declaration in PrelBase handles this
where
- tycon_loc = getSrcSpan tycon
- --------------------------------------------------------------------
aux_binds | single_con_type = []
| otherwise = [GenCon2Tag tycon]
- compare = L tycon_loc (mkFunBind (L tycon_loc compare_RDR) compare_matches)
+ compare = L loc (mkFunBind (L loc compare_RDR) compare_matches)
compare_matches = [mkMatch [a_Pat, b_Pat] compare_rhs cmp_eq_binds]
cmp_eq_binds = HsValBinds (ValBindsIn (unitBag cmp_eq) [])
| isNewTyCon tycon = ([], tyConDataCons tycon)
| otherwise = partition isNullarySrcDataCon tycon_data_cons
- cmp_eq = mk_FunBind tycon_loc cmp_eq_RDR cmp_eq_match
+ cmp_eq = mk_FunBind loc cmp_eq_RDR cmp_eq_match
cmp_eq_match
| isEnumerationTyCon tycon
-- We know the tags are equal, so if it's an enumeration TyCon,
For @enumFromTo@ and @enumFromThenTo@, we use the default methods.
\begin{code}
-gen_Enum_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Enum_binds tycon
+gen_Enum_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Enum_binds loc tycon
= (method_binds, aux_binds)
where
method_binds = listToBag [
]
aux_binds = [GenCon2Tag tycon, GenTag2Con tycon, GenMaxTag tycon]
- tycon_loc = getSrcSpan tycon
- occ_nm = getOccString tycon
+ occ_nm = getOccString tycon
succ_enum
- = mk_easy_FunBind tycon_loc succ_RDR [a_Pat] $
+ = mk_easy_FunBind loc succ_RDR [a_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
nlHsIf (nlHsApps eq_RDR [nlHsVar (maxtag_RDR tycon),
nlHsVarApps intDataCon_RDR [ah_RDR]])
nlHsIntLit 1]))
pred_enum
- = mk_easy_FunBind tycon_loc pred_RDR [a_Pat] $
+ = mk_easy_FunBind loc pred_RDR [a_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
nlHsIf (nlHsApps eq_RDR [nlHsIntLit 0,
nlHsVarApps intDataCon_RDR [ah_RDR]])
nlHsLit (HsInt (-1))]))
to_enum
- = mk_easy_FunBind tycon_loc toEnum_RDR [a_Pat] $
+ = mk_easy_FunBind loc toEnum_RDR [a_Pat] $
nlHsIf (nlHsApps and_RDR
[nlHsApps ge_RDR [nlHsVar a_RDR, nlHsIntLit 0],
nlHsApps le_RDR [nlHsVar a_RDR, nlHsVar (maxtag_RDR tycon)]])
(illegal_toEnum_tag occ_nm (maxtag_RDR tycon))
enum_from
- = mk_easy_FunBind tycon_loc enumFrom_RDR [a_Pat] $
+ = mk_easy_FunBind loc enumFrom_RDR [a_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
nlHsApps map_RDR
[nlHsVar (tag2con_RDR tycon),
(nlHsVar (maxtag_RDR tycon)))]
enum_from_then
- = mk_easy_FunBind tycon_loc enumFromThen_RDR [a_Pat, b_Pat] $
+ = mk_easy_FunBind loc enumFromThen_RDR [a_Pat, b_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR), (b_RDR, bh_RDR)] $
nlHsApp (nlHsVarApps map_RDR [tag2con_RDR tycon]) $
nlHsPar (enum_from_then_to_Expr
))
from_enum
- = mk_easy_FunBind tycon_loc fromEnum_RDR [a_Pat] $
+ = mk_easy_FunBind loc fromEnum_RDR [a_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
(nlHsVarApps intDataCon_RDR [ah_RDR])
\end{code}
%************************************************************************
\begin{code}
-gen_Bounded_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Bounded_binds tycon
+gen_Bounded_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Bounded_binds loc tycon
| isEnumerationTyCon tycon
= (listToBag [ min_bound_enum, max_bound_enum ], [])
| otherwise
(listToBag [ min_bound_1con, max_bound_1con ], [])
where
data_cons = tyConDataCons tycon
- tycon_loc = getSrcSpan tycon
----- enum-flavored: ---------------------------
- min_bound_enum = mkVarBind tycon_loc minBound_RDR (nlHsVar data_con_1_RDR)
- max_bound_enum = mkVarBind tycon_loc maxBound_RDR (nlHsVar data_con_N_RDR)
+ min_bound_enum = mkVarBind loc minBound_RDR (nlHsVar data_con_1_RDR)
+ max_bound_enum = mkVarBind loc maxBound_RDR (nlHsVar data_con_N_RDR)
data_con_1 = head data_cons
data_con_N = last data_cons
----- single-constructor-flavored: -------------
arity = dataConSourceArity data_con_1
- min_bound_1con = mkVarBind tycon_loc minBound_RDR $
+ min_bound_1con = mkVarBind loc minBound_RDR $
nlHsVarApps data_con_1_RDR (nOfThem arity minBound_RDR)
- max_bound_1con = mkVarBind tycon_loc maxBound_RDR $
+ max_bound_1con = mkVarBind loc maxBound_RDR $
nlHsVarApps data_con_1_RDR (nOfThem arity maxBound_RDR)
\end{code}
(p.~147).
\begin{code}
-gen_Ix_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Ix_binds :: SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Ix_binds tycon
+gen_Ix_binds loc tycon
| isEnumerationTyCon tycon
= (enum_ixes, [GenCon2Tag tycon, GenTag2Con tycon, GenMaxTag tycon])
| otherwise
= (single_con_ixes, [GenCon2Tag tycon])
where
- tycon_loc = getSrcSpan tycon
-
--------------------------------------------------------------
enum_ixes = listToBag [ enum_range, enum_index, enum_inRange ]
enum_range
- = mk_easy_FunBind tycon_loc range_RDR [nlTuplePat [a_Pat, b_Pat] Boxed] $
+ = mk_easy_FunBind loc range_RDR [nlTuplePat [a_Pat, b_Pat] Boxed] $
untag_Expr tycon [(a_RDR, ah_RDR)] $
untag_Expr tycon [(b_RDR, bh_RDR)] $
nlHsApp (nlHsVarApps map_RDR [tag2con_RDR tycon]) $
(nlHsVarApps intDataCon_RDR [bh_RDR]))
enum_index
- = mk_easy_FunBind tycon_loc unsafeIndex_RDR
+ = mk_easy_FunBind loc unsafeIndex_RDR
[noLoc (AsPat (noLoc c_RDR)
(nlTuplePat [a_Pat, nlWildPat] Boxed)),
d_Pat] (
)
enum_inRange
- = mk_easy_FunBind tycon_loc inRange_RDR [nlTuplePat [a_Pat, b_Pat] Boxed, c_Pat] $
+ = mk_easy_FunBind loc inRange_RDR [nlTuplePat [a_Pat, b_Pat] Boxed, c_Pat] $
untag_Expr tycon [(a_RDR, ah_RDR)] (
untag_Expr tycon [(b_RDR, bh_RDR)] (
untag_Expr tycon [(c_RDR, ch_RDR)] (
= listToBag [single_con_range, single_con_index, single_con_inRange]
data_con
- = case maybeTyConSingleCon tycon of -- just checking...
+ = case tyConSingleDataCon_maybe tycon of -- just checking...
Nothing -> panic "get_Ix_binds"
Just dc | any isUnLiftedType (dataConOrigArgTys dc)
-> pprPanic "Can't derive Ix for a single-constructor type with primitive argument types:" (ppr tycon)
--------------------------------------------------------------
single_con_range
- = mk_easy_FunBind tycon_loc range_RDR
+ = mk_easy_FunBind loc range_RDR
[nlTuplePat [con_pat as_needed, con_pat bs_needed] Boxed] $
nlHsDo ListComp stmts con_expr
where
----------------
single_con_index
- = mk_easy_FunBind tycon_loc unsafeIndex_RDR
+ = mk_easy_FunBind loc unsafeIndex_RDR
[nlTuplePat [con_pat as_needed, con_pat bs_needed] Boxed,
con_pat cs_needed]
-- We need to reverse the order we consider the components in
------------------
single_con_inRange
- = mk_easy_FunBind tycon_loc inRange_RDR
+ = mk_easy_FunBind loc inRange_RDR
[nlTuplePat [con_pat as_needed, con_pat bs_needed] Boxed,
con_pat cs_needed] $
foldl1 and_Expr (zipWith3Equal "single_con_inRange" in_range as_needed bs_needed cs_needed)
\begin{code}
-gen_Read_binds :: FixityEnv -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Read_binds :: FixityEnv -> SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Read_binds get_fixity tycon
+gen_Read_binds get_fixity loc tycon
= (listToBag [read_prec, default_readlist, default_readlistprec], [])
where
-----------------------------------------------------------------------
= mkVarBind loc readListPrec_RDR (nlHsVar readListPrecDefault_RDR)
-----------------------------------------------------------------------
- loc = getSrcSpan tycon
data_cons = tyConDataCons tycon
(nullary_cons, non_nullary_cons) = partition isNullarySrcDataCon data_cons
con_str = data_con_str data_con
prefix_parser = mk_parser prefix_prec prefix_stmts body
- prefix_stmts -- T a b c
- = (if not (isSym con_str) then
- [bindLex (ident_pat con_str)]
- else [read_punc "(", bindLex (symbol_pat con_str), read_punc ")"])
- ++ read_args
+
+ read_prefix_con
+ | isSym con_str = [read_punc "(", bindLex (symbol_pat con_str), read_punc ")"]
+ | otherwise = [bindLex (ident_pat con_str)]
+ read_infix_con
+ | isSym con_str = [bindLex (symbol_pat con_str)]
+ | otherwise = [read_punc "`", bindLex (ident_pat con_str), read_punc "`"]
+
+ prefix_stmts -- T a b c
+ = read_prefix_con ++ read_args
+
infix_stmts -- a %% b, or a `T` b
= [read_a1]
- ++ (if isSym con_str
- then [bindLex (symbol_pat con_str)]
- else [read_punc "`", bindLex (ident_pat con_str), read_punc "`"])
+ ++ read_infix_con
++ [read_a2]
record_stmts -- T { f1 = a, f2 = b }
- = [bindLex (ident_pat (wrapOpParens con_str)),
- read_punc "{"]
+ = read_prefix_con
+ ++ [read_punc "{"]
++ concat (intersperse [read_punc ","] field_stmts)
++ [read_punc "}"]
-- the most tightly-binding operator
\begin{code}
-gen_Show_binds :: FixityEnv -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
+gen_Show_binds :: FixityEnv -> SrcSpan -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
-gen_Show_binds get_fixity tycon
+gen_Show_binds get_fixity loc tycon
= (listToBag [shows_prec, show_list], [])
where
- tycon_loc = getSrcSpan tycon
-----------------------------------------------------------------------
- show_list = mkVarBind tycon_loc showList_RDR
+ show_list = mkVarBind loc showList_RDR
(nlHsApp (nlHsVar showList___RDR) (nlHsPar (nlHsApp (nlHsVar showsPrec_RDR) (nlHsIntLit 0))))
-----------------------------------------------------------------------
- shows_prec = mk_FunBind tycon_loc showsPrec_RDR (map pats_etc (tyConDataCons tycon))
+ shows_prec = mk_FunBind loc showsPrec_RDR (map pats_etc (tyConDataCons tycon))
where
pats_etc data_con
| nullary_con = -- skip the showParen junk...
We are passed the Typeable2 class as well as T
\begin{code}
-gen_Typeable_binds :: TyCon -> LHsBinds RdrName
-gen_Typeable_binds tycon
+gen_Typeable_binds :: SrcSpan -> TyCon -> LHsBinds RdrName
+gen_Typeable_binds loc tycon
= unitBag $
- mk_easy_FunBind tycon_loc
+ mk_easy_FunBind loc
(mk_typeOf_RDR tycon) -- Name of appropriate type0f function
[nlWildPat]
(nlHsApps mkTypeRep_RDR [tycon_rep, nlList []])
where
- tycon_loc = getSrcSpan tycon
tycon_rep = nlHsVar mkTyConRep_RDR `nlHsApp` nlHsLit (mkHsString (showSDoc (ppr tycon)))
mk_typeOf_RDR :: TyCon -> RdrName
dataTypeOf _ = $dT
\begin{code}
-gen_Data_binds :: FixityEnv
+gen_Data_binds :: SrcSpan
-> TyCon
-> (LHsBinds RdrName, -- The method bindings
DerivAuxBinds) -- Auxiliary bindings
-gen_Data_binds _ tycon
+gen_Data_binds loc tycon
= (listToBag [gfoldl_bind, gunfold_bind, toCon_bind, dataTypeOf_bind],
-- Auxiliary definitions: the data type and constructors
- DerivAuxBind datatype_bind : map mk_con_bind data_cons)
+ MkTyCon tycon : map MkDataCon data_cons)
where
- tycon_loc = getSrcSpan tycon
- tycon_name = tyConName tycon
data_cons = tyConDataCons tycon
n_cons = length data_cons
one_constr = n_cons == 1
------------ gfoldl
- gfoldl_bind = mk_FunBind tycon_loc gfoldl_RDR (map gfoldl_eqn data_cons)
+ gfoldl_bind = mk_FunBind loc gfoldl_RDR (map gfoldl_eqn data_cons)
gfoldl_eqn con = ([nlVarPat k_RDR, nlVarPat z_RDR, nlConVarPat con_name as_needed],
foldl mk_k_app (nlHsVar z_RDR `nlHsApp` nlHsVar con_name) as_needed)
where
mk_k_app e v = nlHsPar (nlHsOpApp e k_RDR (nlHsVar v))
------------ gunfold
- gunfold_bind = mk_FunBind tycon_loc
+ gunfold_bind = mk_FunBind loc
gunfold_RDR
[([k_Pat, z_Pat, if one_constr then nlWildPat else c_Pat],
gunfold_rhs)]
tag = dataConTag dc
------------ toConstr
- toCon_bind = mk_FunBind tycon_loc toConstr_RDR (map to_con_eqn data_cons)
+ toCon_bind = mk_FunBind loc toConstr_RDR (map to_con_eqn data_cons)
to_con_eqn dc = ([nlWildConPat dc], nlHsVar (mk_constr_name dc))
------------ dataTypeOf
dataTypeOf_bind = mk_easy_FunBind
- tycon_loc
+ loc
dataTypeOf_RDR
[nlWildPat]
- (nlHsVar data_type_name)
-
- ------------ $dT
-
- data_type_name = mkDerivedRdrName tycon_name mkDataTOcc
- datatype_bind = mkVarBind
- tycon_loc
- data_type_name
- ( nlHsVar mkDataType_RDR
- `nlHsApp` nlHsLit (mkHsString (showSDoc (ppr tycon)))
- `nlHsApp` nlList constrs
- )
- constrs = [nlHsVar (mk_constr_name con) | con <- data_cons]
-
-
- ------------ $cT1 etc
- mk_constr_name con = mkDerivedRdrName (dataConName con) mkDataCOcc
- mk_con_bind dc = DerivAuxBind $
- mkVarBind
- tycon_loc
- (mk_constr_name dc)
- (nlHsApps mkConstr_RDR (constr_args dc))
- constr_args dc =
- [ -- nlHsIntLit (toInteger (dataConTag dc)), -- Tag
- nlHsVar data_type_name, -- DataType
- nlHsLit (mkHsString (occNameString dc_occ)), -- String name
- nlList labels, -- Field labels
- nlHsVar fixity] -- Fixity
- where
- labels = map (nlHsLit . mkHsString . getOccString)
- (dataConFieldLabels dc)
- dc_occ = getOccName dc
- is_infix = isDataSymOcc dc_occ
- fixity | is_infix = infix_RDR
- | otherwise = prefix_RDR
+ (nlHsVar (mk_data_type_name tycon))
+
gfoldl_RDR, gunfold_RDR, toConstr_RDR, dataTypeOf_RDR, mkConstr_RDR,
mkDataType_RDR, conIndex_RDR, prefix_RDR, infix_RDR :: RdrName
fiddling around.
\begin{code}
-genAuxBind :: DerivAuxBind -> LHsBind RdrName
-
-genAuxBind (DerivAuxBind bind)
- = bind
-
-genAuxBind (GenCon2Tag tycon)
+genAuxBind :: SrcSpan -> DerivAuxBind -> LHsBind RdrName
+genAuxBind loc (GenCon2Tag tycon)
| lots_of_constructors
- = mk_FunBind tycon_loc rdr_name [([], get_tag_rhs)]
+ = mk_FunBind loc rdr_name [([], get_tag_rhs)]
| otherwise
- = mk_FunBind tycon_loc rdr_name (map mk_stuff (tyConDataCons tycon))
+ = mk_FunBind loc rdr_name (map mk_stuff (tyConDataCons tycon))
where
rdr_name = con2tag_RDR tycon
- tycon_loc = getSrcSpan tycon
tvs = map (mkRdrUnqual . getOccName) (tyConTyVars tycon)
-- We can't use gerRdrName because that makes an Exact RdrName
-- Give a signature to the bound variable, so
-- that the case expression generated by getTag is
-- monomorphic. In the push-enter model we get better code.
- get_tag_rhs = noLoc $ ExprWithTySig
+ get_tag_rhs = L loc $ ExprWithTySig
(nlHsLam (mkSimpleHsAlt (nlVarPat a_RDR)
(nlHsApp (nlHsVar getTag_RDR) a_Expr)))
(noLoc (mkExplicitHsForAllTy (map (noLoc.UserTyVar) tvs) (noLoc []) con2tag_ty))
mk_stuff con = ([nlWildConPat con],
nlHsLit (HsIntPrim (toInteger ((dataConTag con) - fIRST_TAG))))
-genAuxBind (GenTag2Con tycon)
- = mk_FunBind (getSrcSpan tycon) rdr_name
+genAuxBind loc (GenTag2Con tycon)
+ = mk_FunBind loc rdr_name
[([nlConVarPat intDataCon_RDR [a_RDR]],
noLoc (ExprWithTySig (nlHsApp (nlHsVar tagToEnum_RDR) a_Expr)
(nlHsTyVar (getRdrName tycon))))]
where
rdr_name = tag2con_RDR tycon
-genAuxBind (GenMaxTag tycon)
- = mkVarBind (getSrcSpan tycon) rdr_name
+genAuxBind loc (GenMaxTag tycon)
+ = mkVarBind loc rdr_name
(nlHsApp (nlHsVar intDataCon_RDR) (nlHsLit (HsIntPrim max_tag)))
where
rdr_name = maxtag_RDR tycon
max_tag = case (tyConDataCons tycon) of
data_cons -> toInteger ((length data_cons) - fIRST_TAG)
+
+genAuxBind loc (MkTyCon tycon) -- $dT
+ = mkVarBind loc (mk_data_type_name tycon)
+ ( nlHsVar mkDataType_RDR
+ `nlHsApp` nlHsLit (mkHsString (showSDoc (ppr tycon)))
+ `nlHsApp` nlList constrs )
+ where
+ constrs = [nlHsVar (mk_constr_name con) | con <- tyConDataCons tycon]
+
+genAuxBind loc (MkDataCon dc) -- $cT1 etc
+ = mkVarBind loc (mk_constr_name dc)
+ (nlHsApps mkConstr_RDR constr_args)
+ where
+ constr_args
+ = [ -- nlHsIntLit (toInteger (dataConTag dc)), -- Tag
+ nlHsVar (mk_data_type_name (dataConTyCon dc)), -- DataType
+ nlHsLit (mkHsString (occNameString dc_occ)), -- String name
+ nlList labels, -- Field labels
+ nlHsVar fixity] -- Fixity
+
+ labels = map (nlHsLit . mkHsString . getOccString)
+ (dataConFieldLabels dc)
+ dc_occ = getOccName dc
+ is_infix = isDataSymOcc dc_occ
+ fixity | is_infix = infix_RDR
+ | otherwise = prefix_RDR
+
+mk_data_type_name :: TyCon -> RdrName -- "$tT"
+mk_data_type_name tycon = mkAuxBinderName (tyConName tycon) mkDataTOcc
+
+mk_constr_name :: DataCon -> RdrName -- "$cC"
+mk_constr_name con = mkAuxBinderName (dataConName con) mkDataCOcc
\end{code}
%************************************************************************
maxtag_RDR tycon = mk_tc_deriv_name tycon mkMaxTagOcc
mk_tc_deriv_name :: TyCon -> (OccName -> OccName) -> RdrName
-mk_tc_deriv_name tycon fun = mkDerivedRdrName (tyConName tycon) fun
+mk_tc_deriv_name tycon occ_fun = mkAuxBinderName (tyConName tycon) occ_fun
+
+mkAuxBinderName :: Name -> (OccName -> OccName) -> RdrName
+mkAuxBinderName parent occ_fun = mkRdrUnqual (occ_fun (nameOccName parent))
+-- Was: mkDerivedRdrName name occ_fun, which made an original name
+-- But: (a) that does not work well for standalone-deriving
+-- (b) an unqualified name is just fine, provided it can't clash with user code
\end{code}
s RdrName for PrimOps. Can't be done in PrelNames, because PrimOp imports