-- for details
module TcGenDeriv (
+ DerivAuxBind(..), DerivAuxBinds, isDupAux,
+
gen_Bounded_binds,
gen_Enum_binds,
gen_Eq_binds,
gen_Show_binds,
gen_Data_binds,
gen_Typeable_binds,
- gen_tag_n_con_monobind,
-
- con2tag_RDR, tag2con_RDR, maxtag_RDR,
+ genAuxBind,
- TagThingWanted(..)
+ con2tag_RDR, tag2con_RDR, maxtag_RDR
) where
#include "HsVersions.h"
import Data.List ( partition, intersperse )
\end{code}
-%************************************************************************
-%* *
-\subsection{Generating code, by derivable class}
-%* *
-%************************************************************************
+\begin{code}
+type DerivAuxBinds = [DerivAuxBind]
+
+data DerivAuxBind -- Please add these auxiliary top-level bindings
+ = DerivAuxBind (LHsBind RdrName)
+ | GenCon2Tag TyCon -- The con2Tag for given TyCon
+ | GenTag2Con TyCon -- ...ditto tag2Con
+ | GenMaxTag TyCon -- ...and maxTag
+
+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 b1 b2 = False
+\end{code}
+
%************************************************************************
%* *
-\subsubsection{Generating @Eq@ instance declarations}
+ Eq instances
%* *
%************************************************************************
\begin{code}
-gen_Eq_binds :: TyCon -> LHsBinds RdrName
-
+gen_Eq_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Eq_binds tycon
- = let
- tycon_loc = getSrcSpan tycon
-
- (nullary_cons, nonnullary_cons)
- | isNewTyCon tycon = ([], tyConDataCons tycon)
- | otherwise = partition isNullarySrcDataCon (tyConDataCons tycon)
-
- rest
- = if (null nullary_cons) then
- case maybeTyConSingleCon tycon of
- Just _ -> []
- Nothing -> -- if cons don't match, then False
- [([nlWildPat, nlWildPat], false_Expr)]
- else -- calc. and compare the tags
- [([a_Pat, b_Pat],
- untag_Expr tycon [(a_RDR,ah_RDR), (b_RDR,bh_RDR)]
- (genOpApp (nlHsVar ah_RDR) eqInt_RDR (nlHsVar bh_RDR)))]
- in
- listToBag [
- mk_FunBind tycon_loc eq_RDR ((map pats_etc nonnullary_cons) ++ rest),
- mk_easy_FunBind tycon_loc ne_RDR [a_Pat, b_Pat] (
- nlHsApp (nlHsVar not_RDR) (nlHsPar (nlHsVarApps eq_RDR [a_RDR, b_RDR])))
- ]
+ = (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
+ Just _ -> []
+ Nothing -> -- if cons don't match, then False
+ [([nlWildPat, nlWildPat], false_Expr)]
+ | otherwise -- calc. and compare the tags
+ = [([a_Pat, b_Pat],
+ untag_Expr tycon [(a_RDR,ah_RDR), (b_RDR,bh_RDR)]
+ (genOpApp (nlHsVar ah_RDR) eqInt_RDR (nlHsVar bh_RDR)))]
+
+ aux_binds | no_nullary_cons = []
+ | 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] (
+ nlHsApp (nlHsVar not_RDR) (nlHsPar (nlHsVarApps eq_RDR [a_RDR, b_RDR])))]
+
------------------------------------------------------------------
pats_etc data_con
= let
%************************************************************************
%* *
-\subsubsection{Generating @Ord@ instance declarations}
+ Ord instances
%* *
%************************************************************************
JJQC-30-Nov-1997
\begin{code}
-gen_Ord_binds :: TyCon -> LHsBinds RdrName
+gen_Ord_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Ord_binds tycon
- = unitBag compare -- `AndMonoBinds` compare
- -- The default declaration in PrelBase handles this
+ = (unitBag compare, aux_binds)
+ -- `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_matches = [mkMatch [a_Pat, b_Pat] compare_rhs cmp_eq_binds]
else
[([nlWildPat, nlWildPat], default_rhs)])
- where
- pats_etc data_con
- = ([con1_pat, con2_pat],
- nested_compare_expr tys_needed as_needed bs_needed)
- where
- con1_pat = nlConVarPat data_con_RDR as_needed
- con2_pat = nlConVarPat data_con_RDR bs_needed
+ default_rhs | null nullary_cons = impossible_Expr -- Keep desugarer from complaining about
+ -- inexhaustive patterns
+ | otherwise = eqTag_Expr -- Some nullary constructors;
+ -- Tags are equal, no args => return EQ
+ pats_etc data_con
+ = ([con1_pat, con2_pat],
+ nested_compare_expr tys_needed as_needed bs_needed)
+ where
+ con1_pat = nlConVarPat data_con_RDR as_needed
+ con2_pat = nlConVarPat data_con_RDR bs_needed
- data_con_RDR = getRdrName data_con
- con_arity = length tys_needed
- as_needed = take con_arity as_RDRs
- bs_needed = take con_arity bs_RDRs
- tys_needed = dataConOrigArgTys data_con
+ data_con_RDR = getRdrName data_con
+ con_arity = length tys_needed
+ as_needed = take con_arity as_RDRs
+ bs_needed = take con_arity bs_RDRs
+ tys_needed = dataConOrigArgTys data_con
- nested_compare_expr [ty] [a] [b]
- = careful_compare_Case tycon ty eqTag_Expr (nlHsVar a) (nlHsVar b)
+ nested_compare_expr [ty] [a] [b]
+ = careful_compare_Case tycon ty eqTag_Expr (nlHsVar a) (nlHsVar b)
- nested_compare_expr (ty:tys) (a:as) (b:bs)
- = let eq_expr = nested_compare_expr tys as bs
+ nested_compare_expr (ty:tys) (a:as) (b:bs)
+ = let eq_expr = nested_compare_expr tys as bs
in careful_compare_Case tycon ty eq_expr (nlHsVar a) (nlHsVar b)
- nested_compare_expr _ _ _ = panic "nested_compare_expr" -- Args always equal length
+ nested_compare_expr _ _ _ = panic "nested_compare_expr" -- Args always equal length
- default_rhs | null nullary_cons = impossible_Expr -- Keep desugarer from complaining about
- -- inexhaustive patterns
- | otherwise = eqTag_Expr -- Some nullary constructors;
- -- Tags are equal, no args => return EQ
\end{code}
%************************************************************************
%* *
-\subsubsection{Generating @Enum@ instance declarations}
+ Enum instances
%* *
%************************************************************************
For @enumFromTo@ and @enumFromThenTo@, we use the default methods.
\begin{code}
-gen_Enum_binds :: TyCon -> LHsBinds RdrName
-
+gen_Enum_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Enum_binds tycon
- = listToBag [
- succ_enum,
- pred_enum,
- to_enum,
- enum_from,
- enum_from_then,
- from_enum
- ]
+ = (method_binds, aux_binds)
where
+ method_binds = listToBag [
+ succ_enum,
+ pred_enum,
+ to_enum,
+ enum_from,
+ enum_from_then,
+ from_enum
+ ]
+ aux_binds = [GenCon2Tag tycon, GenTag2Con tycon, GenMaxTag tycon]
+
tycon_loc = getSrcSpan tycon
occ_nm = getOccString tycon
%************************************************************************
%* *
-\subsubsection{Generating @Bounded@ instance declarations}
+ Bounded instances
%* *
%************************************************************************
\begin{code}
+gen_Bounded_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Bounded_binds tycon
- = if isEnumerationTyCon tycon then
- listToBag [ min_bound_enum, max_bound_enum ]
- else
- ASSERT(isSingleton data_cons)
- listToBag [ min_bound_1con, max_bound_1con ]
+ | isEnumerationTyCon tycon
+ = (listToBag [ min_bound_enum, max_bound_enum ], [])
+ | otherwise
+ = ASSERT(isSingleton data_cons)
+ (listToBag [ min_bound_1con, max_bound_1con ], [])
where
data_cons = tyConDataCons tycon
tycon_loc = getSrcSpan tycon
%************************************************************************
%* *
-\subsubsection{Generating @Ix@ instance declarations}
+ Ix instances
%* *
%************************************************************************
(p.~147).
\begin{code}
-gen_Ix_binds :: TyCon -> LHsBinds RdrName
+gen_Ix_binds :: TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Ix_binds tycon
- = if isEnumerationTyCon tycon
- then enum_ixes
- else single_con_ixes
+ | isEnumerationTyCon tycon
+ = (enum_ixes, [GenCon2Tag tycon, GenTag2Con tycon, GenMaxTag tycon])
+ | otherwise
+ = (single_con_ixes, [GenCon2Tag tycon])
where
tycon_loc = getSrcSpan tycon
%************************************************************************
%* *
-\subsubsection{Generating @Read@ instance declarations}
+ Read instances
%* *
%************************************************************************
\begin{code}
-gen_Read_binds :: FixityEnv -> TyCon -> LHsBinds RdrName
+gen_Read_binds :: FixityEnv -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Read_binds get_fixity tycon
- = listToBag [read_prec, default_readlist, default_readlistprec]
+ = (listToBag [read_prec, default_readlist, default_readlistprec], [])
where
-----------------------------------------------------------------------
default_readlist
%************************************************************************
%* *
-\subsubsection{Generating @Show@ instance declarations}
+ Show instances
%* *
%************************************************************************
-- the most tightly-binding operator
\begin{code}
-gen_Show_binds :: FixityEnv -> TyCon -> LHsBinds RdrName
+gen_Show_binds :: FixityEnv -> TyCon -> (LHsBinds RdrName, DerivAuxBinds)
gen_Show_binds get_fixity tycon
- = listToBag [shows_prec, show_list]
+ = (listToBag [shows_prec, show_list], [])
where
tycon_loc = getSrcSpan tycon
-----------------------------------------------------------------------
%************************************************************************
%* *
-\subsection{Data}
+ Data instances
%* *
%************************************************************************
gen_Data_binds :: FixityEnv
-> TyCon
-> (LHsBinds RdrName, -- The method bindings
- LHsBinds RdrName) -- Auxiliary bindings
+ DerivAuxBinds) -- Auxiliary bindings
gen_Data_binds fix_env tycon
= (listToBag [gfoldl_bind, gunfold_bind, toCon_bind, dataTypeOf_bind],
-- Auxiliary definitions: the data type and constructors
- datatype_bind `consBag` listToBag (map mk_con_bind data_cons))
+ DerivAuxBind datatype_bind : map mk_con_bind data_cons)
where
tycon_loc = getSrcSpan tycon
tycon_name = tyConName tycon
------------ $cT1 etc
mk_constr_name con = mkDerivedRdrName (dataConName con) mkDataCOcc
- mk_con_bind dc = mkVarBind
+ mk_con_bind dc = DerivAuxBind $
+ mkVarBind
tycon_loc
(mk_constr_name dc)
(nlHsApps mkConstr_RDR (constr_args dc))
fiddling around.
\begin{code}
-data TagThingWanted
- = GenCon2Tag | GenTag2Con | GenMaxTag
+genAuxBind :: DerivAuxBind -> LHsBind RdrName
-gen_tag_n_con_monobind
- :: ( RdrName, -- (proto)Name for the thing in question
- TyCon, -- tycon in question
- TagThingWanted)
- -> LHsBind RdrName
+genAuxBind (DerivAuxBind bind)
+ = bind
-gen_tag_n_con_monobind (rdr_name, tycon, GenCon2Tag)
+genAuxBind (GenCon2Tag tycon)
| lots_of_constructors
= mk_FunBind tycon_loc rdr_name [([], get_tag_rhs)]
= mk_FunBind tycon_loc rdr_name (map mk_stuff (tyConDataCons tycon))
where
+ rdr_name = con2tag_RDR tycon
tycon_loc = getSrcSpan tycon
tvs = map (mkRdrUnqual . getOccName) (tyConTyVars tycon)
mk_stuff con = ([nlWildConPat con],
nlHsLit (HsIntPrim (toInteger ((dataConTag con) - fIRST_TAG))))
-gen_tag_n_con_monobind (rdr_name, tycon, GenTag2Con)
+genAuxBind (GenTag2Con tycon)
= mk_FunBind (getSrcSpan tycon) rdr_name
[([nlConVarPat intDataCon_RDR [a_RDR]],
noLoc (ExprWithTySig (nlHsApp (nlHsVar tagToEnum_RDR) a_Expr)
(nlHsTyVar (getRdrName tycon))))]
+ where
+ rdr_name = tag2con_RDR tycon
-gen_tag_n_con_monobind (rdr_name, tycon, GenMaxTag)
+genAuxBind (GenMaxTag tycon)
= mkVarBind (getSrcSpan tycon) 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)
-
\end{code}
%************************************************************************
projects / ghc-hetmet.git / blobdiff