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
\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
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-} (
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
+ $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
+ 1 -> T1 undefined undefined
+ 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)
- gunfold_eqn con = ([VarPat k_RDR, VarPat z_RDR,
- ConPatIn constr_RDR (PrefixCon [LitPat (mk_constr_string con)])],
- apN (dataConSourceArity con)
- (\e -> HsVar k_RDR `HsApp` e)
- (z_Expr `HsApp` HsVar (getRdrName con)))
- 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 (LitPat (HsInt (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
+ (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
= 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 tycon ty eq a b
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