mkFunTys arg_tys $
res_ty
-dataConInstArgTys :: DataCon
+dataConInstArgTys :: DataCon -- A datacon with no existentials or equality constraints
+ -- However, it can have a dcTheta (notably it can be a
+ -- class dictionary, with superclasses)
-> [Type] -- Instantiated at these types
- -- NB: these INCLUDE the existentially quantified arg types
-> [Type] -- Needs arguments of these types
- -- NB: these INCLUDE the existentially quantified dict args
+ -- NB: these INCLUDE any dict args
-- but EXCLUDE the data-decl context which is discarded
-- It's all post-flattening etc; this is a representation type
-dataConInstArgTys dc@(MkData {dcRepArgTys = arg_tys,
- dcUnivTyVars = univ_tvs,
+dataConInstArgTys dc@(MkData {dcRepArgTys = rep_arg_tys,
+ dcUnivTyVars = univ_tvs, dcEqSpec = eq_spec,
dcExTyVars = ex_tvs}) inst_tys
- = ASSERT2 ( length tyvars == length inst_tys
- , ptext SLIT("dataConInstArgTys") <+> ppr dc $$ ppr tyvars $$ ppr inst_tys)
-
- map (substTyWith tyvars inst_tys) arg_tys
- where
- tyvars = univ_tvs ++ ex_tvs
-
-
--- And the same deal for the original arg tys
-dataConInstOrigArgTys :: DataCon -> [Type] -> [Type]
+ = ASSERT2 ( length univ_tvs == length inst_tys
+ , ptext SLIT("dataConInstArgTys") <+> ppr dc $$ ppr univ_tvs $$ ppr inst_tys)
+ ASSERT2 ( null ex_tvs && null eq_spec, ppr dc )
+ map (substTyWith univ_tvs inst_tys) rep_arg_tys
+
+dataConInstOrigArgTys
+ :: DataCon -- Works for any DataCon
+ -> [Type] -- Includes existential tyvar args, but NOT
+ -- equality constraints or dicts
+ -> [Type] -- Returns just the instsantiated *value* arguments
+-- For vanilla datacons, it's all quite straightforward
+-- But for the call in MatchCon, we really do want just the value args
dataConInstOrigArgTys dc@(MkData {dcOrigArgTys = arg_tys,
dcUnivTyVars = univ_tvs,
dcExTyVars = ex_tvs}) inst_tys
- = ASSERT2( length tyvars == length inst_tys
+ = ASSERT2( length tyvars == length inst_tys
, ptext SLIT("dataConInstOrigArgTys") <+> ppr dc $$ ppr tyvars $$ ppr inst_tys )
- map (substTyWith tyvars inst_tys) arg_tys
- where
- tyvars = univ_tvs ++ ex_tvs
+ map (substTyWith tyvars inst_tys) arg_tys
+ where
+ tyvars = univ_tvs ++ ex_tvs
\end{code}
These two functions get the real argument types of the constructor,