HsBinds(..), HsType(..), HsStmtContext(..),
unguardedRHS, mkSimpleMatch, mkMonoBind, andMonoBindList, placeHolderType
)
-import RdrName ( RdrName, mkUnqual, nameRdrName, getRdrName )
+import RdrName ( RdrName, mkUnqual, mkRdrUnqual, nameRdrName, getRdrName )
import RdrHsSyn ( mkHsOpApp, RdrNameMonoBinds, RdrNameHsExpr, RdrNamePat, mkHsDo )
import BasicTypes ( RecFlag(..), Fixity(..), FixityDirection(..)
, maxPrecedence
maybeTyConSingleCon, tyConFamilySize, tyConTyVars
)
import TcType ( isUnLiftedType, tcEqType, Type )
-import TysPrim ( charPrimTy, intPrimTy, wordPrimTy, addrPrimTy,
- floatPrimTy, doublePrimTy
- )
+import TysPrim ( charPrimTy, intPrimTy, wordPrimTy, addrPrimTy, floatPrimTy, doublePrimTy )
+import TysWiredIn ( charDataCon, intDataCon, floatDataCon, doubleDataCon, wordDataCon )
import Util ( zipWithEqual, isSingleton,
zipWith3Equal, nOfThem, zipEqual )
import Panic ( panic, assertPanic )
\end{itemize}
-deriveEq :: RdrName -- Class
- -> RdrName -- Type constructor
- -> [ (RdrName, [RdrType]) ] -- Constructors
- -> (RdrContext, -- Context for the inst decl
- [RdrBind], -- Binds in the inst decl
- [RdrBind]) -- Extra value bindings outside
-
-deriveEq clas tycon constrs
- = (context, [eq_bind, ne_bind], [])
- where
- context = [(clas, [ty]) | (_, tys) <- constrs, ty <- tys]
-
- ne_bind = mkBind
- (nullary_cons, non_nullary_cons) = partition is_nullary constrs
- is_nullary (_, args) = null args
-
\begin{code}
gen_Eq_binds :: TyCon -> RdrNameMonoBinds
nested_eq_expr tys as bs
= foldl1 and_Expr (zipWith3Equal "nested_eq" nested_eq tys as bs)
where
- nested_eq ty a b = HsPar (eq_Expr ty (HsVar a) (HsVar b))
+ nested_eq ty a b = HsPar (eq_Expr tycon ty (HsVar a) (HsVar b))
\end{code}
%************************************************************************
tys_needed = dataConOrigArgTys data_con
nested_compare_expr [ty] [a] [b]
- = careful_compare_Case ty eqTag_Expr (HsVar a) (HsVar b)
+ = careful_compare_Case tycon ty eqTag_Expr (HsVar a) (HsVar b)
nested_compare_expr (ty:tys) (a:as) (b:bs)
= let eq_expr = nested_compare_expr tys as bs
- in careful_compare_Case ty eq_expr (HsVar a) (HsVar b)
+ in careful_compare_Case tycon ty eq_expr (HsVar a) (HsVar b)
default_rhs | null nullary_cons = impossible_Expr -- Keep desugarer from complaining about
-- inexhaustive patterns
in
HsCase
(genOpApp (HsVar dh_RDR) minusInt_RDR (HsVar ah_RDR))
- [mkSimpleMatch [VarPat c_RDR] rhs placeHolderType tycon_loc]
+ [mk_triv_Match (VarPat c_RDR) rhs]
tycon_loc
))
) {-else-} (
data_con
= case maybeTyConSingleCon tycon of -- just checking...
Nothing -> panic "get_Ix_binds"
- Just dc -> if (any isUnLiftedType (dataConOrigArgTys dc)) then
- error ("ERROR: Can't derive Ix for a single-constructor type with primitive argument types: "++tycon_str)
- else
- dc
+ Just dc | any isUnLiftedType (dataConOrigArgTys dc)
+ -> pprPanic "Can't derive Ix for a single-constructor type with primitive argument types:" (ppr tycon)
+ | otherwise -> dc
con_arity = dataConSourceArity data_con
data_con_RDR = getRdrName data_con
prefix_stmts -- T a b c
= [bindLex (ident_pat (data_con_str data_con))]
- ++ map read_arg as_needed
+ ++ read_args
++ [result_stmt data_con as_needed]
infix_stmts -- a %% b
- = [read_arg a1,
+ = [read_a1,
bindLex (symbol_pat (data_con_str data_con)),
- read_arg a2,
+ read_a2,
result_stmt data_con [a1,a2]]
lbl_stmts -- T { f1 = a, f2 = b }
dc_nm = getName data_con
is_infix = isDataSymOcc (getOccName dc_nm)
as_needed = take con_arity as_RDRs
- (a1:a2:_) = as_needed
+ read_args = zipWithEqual "gen_Read_binds" read_arg as_needed (dataConOrigArgTys data_con)
+ (read_a1:read_a2:_) = read_args
+ (a1:a2:_) = as_needed
prec = getPrec is_infix get_fixity dc_nm
------------------------------------------------------------------------
data_con_str con = mkHsString (occNameUserString (getOccName con))
read_punc c = bindLex (punc_pat c)
- read_arg a = BindStmt (VarPat a) (mkHsVarApps step_RDR [readPrec_RDR]) loc
+ read_arg a ty
+ | isUnLiftedType ty = pprPanic "Error in deriving:" (text "Can't read unlifted types yet:" <+> ppr ty)
+ | otherwise = BindStmt (VarPat a) (mkHsVarApps step_RDR [readPrec_RDR]) loc
read_field lbl a = read_lbl lbl ++
[read_punc "=",
data_con_RDR = getRdrName data_con
con_arity = dataConSourceArity data_con
bs_needed = take con_arity bs_RDRs
+ arg_tys = dataConOrigArgTys data_con -- Correspond 1-1 with bs_needed
con_pat = mkConPat data_con_RDR bs_needed
nullary_con = con_arity == 0
labels = dataConFieldLabels data_con
where
occ_nm = getOccName (fieldLabelName l)
nm = occNameUserString occ_nm
-
is_op = isSymOcc occ_nm -- Legal, but rare.
- the_name
- | is_op = '(':nm ++ ")"
- | otherwise = nm
+ the_name | is_op = '(':nm ++ ")"
+ | otherwise = nm
- show_args = [ mkHsApps showsPrec_RDR [HsLit (HsInt arg_prec), HsVar b]
- | b <- bs_needed ]
+ show_args = zipWith show_arg bs_needed arg_tys
(show_arg1:show_arg2:_) = show_args
- show_prefix_args = intersperse (HsVar showSpace_RDR) show_args
+ show_prefix_args = intersperse (HsVar showSpace_RDR) show_args
-- Assumption for record syntax: no of fields == no of labelled fields
-- (and in same order)
| (lbl,arg) <- zipEqual "gen_Show_binds"
labels show_args ]
+ -- Generates (showsPrec p x) for argument x, but it also boxes
+ -- the argument first if necessary. Note that this prints unboxed
+ -- things without any '#' decorations; could change that if need be
+ show_arg b arg_ty = mkHsApps showsPrec_RDR [HsLit (HsInt arg_prec),
+ box_if_necy "Show" tycon (HsVar b) arg_ty]
+
-- Fixity stuff
is_infix = isDataSymOcc dc_occ_nm
con_prec_plus_one = 1 + getPrec is_infix get_fixity dc_nm
we generate
- instance (Data a, Data b) => Data (T a b) where
- gfoldl k z (T1 a b) = z T `k` a `k` b
- gfoldl k z T2 = z T2
- -- ToDo: add gmapT,Q,M, gfoldr
-
- gunfold k z _ (Constr "T1") = k (k (z T1))
- gunfold k z _ (Constr "T2") = z T2
- gunfold _ _ e _ = e
+ $cT1 = mkConstr 1 "T1" Prefix
+ $cT2 = mkConstr 2 "T2" Prefix
+ $dT = mkDataType [$con_T1, $con_T2]
- conOf (T1 _ _) = Constr "T1"
- conOf T2 = Constr "T2"
-
- consOf _ = [Constr "T1", Constr "T2"]
-
-ToDo: generate auxiliary bindings for the Constrs?
+ instance (Data a, Data b) => Data (T a b) where
+ gfoldl k z (T1 a b) = z T `k` a `k` b
+ gfoldl k z T2 = z T2
+ -- ToDo: add gmapT,Q,M, gfoldr
+
+ fromConstr c = case conIndex c of
+ I# 1# -> T1 undefined undefined
+ I# 2# -> T2
+
+ toConstr (T1 _ _) = $cT1
+ toConstr T2 = $cT2
+
+ dataTypeOf _ = $dT
\begin{code}
-gen_Data_binds :: TyCon -> RdrNameMonoBinds
-gen_Data_binds tycon
- = andMonoBindList [gfoldl_bind, gunfold_bind, conOf_bind, consOf_bind]
+gen_Data_binds :: FixityEnv
+ -> TyCon
+ -> (RdrNameMonoBinds, -- The method bindings
+ RdrNameMonoBinds) -- Auxiliary bindings
+gen_Data_binds fix_env tycon
+ = (andMonoBindList [gfoldl_bind, fromCon_bind, toCon_bind, dataTypeOf_bind],
+ -- Auxiliary definitions: the data type and constructors
+ datatype_bind `AndMonoBinds` andMonoBindList (map mk_con_bind data_cons))
where
tycon_loc = getSrcLoc tycon
data_cons = tyConDataCons tycon
as_needed = take (dataConSourceArity con) as_RDRs
mk_k_app e v = HsPar (mkHsOpApp e k_RDR (HsVar v))
- ------------ gunfold
- gunfold_bind = mk_FunMonoBind tycon_loc gunfold_RDR (map gunfold_eqn data_cons ++ [catch_all])
- gunfold_eqn con = ([VarPat k_RDR, VarPat z_RDR, wildPat,
- ConPatIn constr_RDR (PrefixCon [LitPat (mk_constr_string con)])],
- apN (dataConSourceArity con)
- (\e -> HsVar k_RDR `HsApp` e)
- (z_Expr `HsApp` HsVar (getRdrName con)))
- catch_all = ([wildPat, wildPat, VarPat e_RDR, wildPat], HsVar e_RDR)
- mk_constr_string con = mkHsString (occNameUserString (getOccName con))
-
- ------------ conOf
- conOf_bind = mk_FunMonoBind tycon_loc conOf_RDR (map conOf_eqn data_cons)
- conOf_eqn con = ([mkWildConPat con], mk_constr con)
-
- ------------ consOf
- consOf_bind = mk_easy_FunMonoBind tycon_loc consOf_RDR [wildPat] []
- (ExplicitList placeHolderType (map mk_constr data_cons))
- mk_constr con = HsVar constr_RDR `HsApp` (HsLit (mk_constr_string con))
+ ------------ fromConstr
+ fromCon_bind = mk_FunMonoBind tycon_loc fromConstr_RDR [([c_Pat], from_con_rhs)]
+ from_con_rhs = HsCase (HsVar conIndex_RDR `HsApp` c_Expr)
+ (map from_con_alt data_cons) tycon_loc
+ from_con_alt dc = mk_triv_Match (ConPatIn mkInt_RDR (PrefixCon [LitPat (HsIntPrim (toInteger (dataConTag dc)))]))
+ (mkHsVarApps (getRdrName dc)
+ (replicate (dataConSourceArity dc) undefined_RDR))
+
+ ------------ toConstr
+ toCon_bind = mk_FunMonoBind tycon_loc toConstr_RDR (map to_con_eqn data_cons)
+ to_con_eqn dc = ([mkWildConPat dc], HsVar (mkConstrName dc))
+
+ ------------ dataTypeOf
+ dataTypeOf_bind = mk_easy_FunMonoBind tycon_loc dataTypeOf_RDR [wildPat]
+ [] (HsVar data_type_name)
+
+ ------------ $dT
+ data_type_name = mkDataTypeName tycon
+ datatype_bind = mkVarMonoBind tycon_loc data_type_name
+ (HsVar mkDataType_RDR `HsApp`
+ ExplicitList placeHolderType constrs)
+ constrs = [HsVar (mkConstrName con) | con <- data_cons]
+
+ ------------ $cT1 etc
+ mk_con_bind dc = mkVarMonoBind tycon_loc (mkConstrName dc)
+ (mkHsApps mkConstr_RDR (constr_args dc))
+ constr_args dc = [mkHsIntLit (toInteger (dataConTag dc)), -- Tag
+ HsLit (mkHsString (occNameUserString dc_occ)), -- String name
+ HsVar fixity] -- Fixity
+ where
+ dc_occ = getOccName dc
+ is_infix = isDataSymOcc dc_occ
+ fixity | is_infix = infix_RDR
+ | otherwise = prefix_RDR
+
+gfoldl_RDR = varQual_RDR gENERICS_Name FSLIT("gfoldl")
+fromConstr_RDR = varQual_RDR gENERICS_Name FSLIT("fromConstr")
+toConstr_RDR = varQual_RDR gENERICS_Name FSLIT("toConstr")
+dataTypeOf_RDR = varQual_RDR gENERICS_Name FSLIT("dataTypeOf")
+mkConstr_RDR = varQual_RDR gENERICS_Name FSLIT("mkConstr")
+mkDataType_RDR = varQual_RDR gENERICS_Name FSLIT("mkDataType")
+conIndex_RDR = varQual_RDR gENERICS_Name FSLIT("conIndex")
+prefix_RDR = dataQual_RDR gENERICS_Name FSLIT("Prefix")
+infix_RDR = dataQual_RDR gENERICS_Name FSLIT("Infix")
+
+mkDataTypeName :: TyCon -> RdrName -- $tT
+mkDataTypeName tc = mkRdrUnqual (mkDataTOcc (getOccName tc))
+
+mkConstrName :: DataCon -> RdrName -- $cT1
+mkConstrName con = mkRdrUnqual (mkDataCOcc (getOccName con))
apN :: Int -> (a -> a) -> a -> a
-- "recursive" MonoBinds, and it is its job to sort things out
-- from there.
+mk_triv_Match pat expr = mkSimpleMatch [pat] expr placeHolderType generatedSrcLoc
+
mk_FunMonoBind :: SrcLoc -> RdrName
-> [([RdrNamePat], RdrNameHsExpr)]
-> RdrNameMonoBinds
-> RdrNameHsExpr -> RdrNameHsExpr
-> RdrNameHsExpr
careful_compare_Case :: -- checks for primitive types...
- Type
+ TyCon -- The tycon we are deriving for
+ -> Type
-> RdrNameHsExpr -- What to do for equality
-> RdrNameHsExpr -> RdrNameHsExpr
-> RdrNameHsExpr
= HsApp (HsApp (HsVar compare_RDR) a) b -- Simple case
compare_gen_Case eq a b -- General case
= HsCase (HsPar (HsApp (HsApp (HsVar compare_RDR) a) b)) {-of-}
- [mkSimpleMatch [mkNullaryConPat ltTag_RDR] ltTag_Expr placeHolderType generatedSrcLoc,
- mkSimpleMatch [mkNullaryConPat eqTag_RDR] eq placeHolderType generatedSrcLoc,
- mkSimpleMatch [mkNullaryConPat gtTag_RDR] gtTag_Expr placeHolderType generatedSrcLoc]
+ [mk_triv_Match (mkNullaryConPat ltTag_RDR) ltTag_Expr,
+ mk_triv_Match (mkNullaryConPat eqTag_RDR) eq,
+ mk_triv_Match (mkNullaryConPat gtTag_RDR) gtTag_Expr]
generatedSrcLoc
-careful_compare_Case ty eq a b
- | not (isUnLiftedType ty) =
- compare_gen_Case eq a b
- | otherwise =
- -- we have to do something special for primitive things...
- HsIf (genOpApp a relevant_eq_op b)
- eq
- (HsIf (genOpApp a relevant_lt_op b) ltTag_Expr gtTag_Expr generatedSrcLoc)
- generatedSrcLoc
+careful_compare_Case tycon ty eq a b
+ | not (isUnLiftedType ty)
+ = compare_gen_Case eq a b
+ | otherwise -- We have to do something special for primitive things...
+ = HsIf (genOpApp a relevant_eq_op b)
+ eq
+ (HsIf (genOpApp a relevant_lt_op b) ltTag_Expr gtTag_Expr generatedSrcLoc)
+ generatedSrcLoc
where
- relevant_eq_op = assoc_ty_id eq_op_tbl ty
- relevant_lt_op = assoc_ty_id lt_op_tbl ty
-
-assoc_ty_id tyids ty
- = if null res then panic "assoc_ty"
- else head res
+ relevant_eq_op = assoc_ty_id "Ord" tycon eq_op_tbl ty
+ relevant_lt_op = assoc_ty_id "Ord" tycon lt_op_tbl ty
+
+
+box_if_necy :: String -- The class involved
+ -> TyCon -- The tycon involved
+ -> RdrNameHsExpr -- The argument
+ -> Type -- The argument type
+ -> RdrNameHsExpr -- Boxed version of the arg
+box_if_necy cls_str tycon arg arg_ty
+ | isUnLiftedType arg_ty = HsApp (HsVar box_con) arg
+ | otherwise = arg
+ where
+ box_con = assoc_ty_id cls_str tycon box_con_tbl arg_ty
+
+assoc_ty_id :: String -- The class involved
+ -> TyCon -- The tycon involved
+ -> [(Type,a)] -- The table
+ -> Type -- The type
+ -> a -- The result of the lookup
+assoc_ty_id cls_str tycon tbl ty
+ | null res = pprPanic "Error in deriving:" (text "Can't derive" <+> text cls_str <+>
+ text "for primitive type" <+> ppr ty)
+ | otherwise = head res
where
- res = [id | (ty',id) <- tyids, ty `tcEqType` ty']
+ res = [id | (ty',id) <- tbl, ty `tcEqType` ty']
eq_op_tbl =
[(charPrimTy, eqChar_RDR)
,(doublePrimTy, ltDouble_RDR)
]
+box_con_tbl =
+ [(charPrimTy, getRdrName charDataCon)
+ ,(intPrimTy, getRdrName intDataCon)
+ ,(wordPrimTy, getRdrName wordDataCon)
+ ,(addrPrimTy, addrDataCon_RDR)
+ ,(floatPrimTy, getRdrName floatDataCon)
+ ,(doublePrimTy, getRdrName doubleDataCon)
+ ]
+
-----------------------------------------------------------------------
and_Expr, append_Expr :: RdrNameHsExpr -> RdrNameHsExpr -> RdrNameHsExpr
-----------------------------------------------------------------------
-eq_Expr :: Type -> RdrNameHsExpr -> RdrNameHsExpr -> RdrNameHsExpr
-eq_Expr ty a b = genOpApp a eq_op b
+eq_Expr :: TyCon -> Type -> RdrNameHsExpr -> RdrNameHsExpr -> RdrNameHsExpr
+eq_Expr tycon ty a b = genOpApp a eq_op b
where
eq_op
| not (isUnLiftedType ty) = eq_RDR
| otherwise =
-- we have to do something special for primitive things...
- assoc_ty_id eq_op_tbl ty
+ assoc_ty_id "Eq" tycon eq_op_tbl ty
\end{code}
untag_Expr tycon [] expr = expr
untag_Expr tycon ((untag_this, put_tag_here) : more) expr
= HsCase (HsPar (HsApp (con2tag_Expr tycon) (HsVar untag_this))) {-of-}
- [mkSimpleMatch [VarPat put_tag_here] (untag_Expr tycon more expr) placeHolderType generatedSrcLoc]
+ [mk_triv_Match (VarPat put_tag_here) (untag_Expr tycon more expr)]
generatedSrcLoc
cmp_tags_Expr :: RdrName -- Comparison op