add dummy visibility methods (public/protected/private) that do nothing; ref #1357

src/class.c

@@ -908,6 +908,12 @@ mrb_mod_module_eval(mrb_state *mrb, mrb_value mod)
   return mrb_yield_internal(mrb, b, 0, 0, mod, c);
 }
 
+mrb_value
+mrb_mod_dummy_visibility(mrb_state *mrb, mrb_value mod)
+{
+  return mod;
+}
+
 mrb_value
 mrb_singleton_class(mrb_state *mrb, mrb_value v)
 {
@@ -1909,6 +1915,9 @@ mrb_init_class(mrb_state *mrb)
   mrb_define_method(mrb, mod, "instance_methods",        mrb_mod_instance_methods, MRB_ARGS_ANY());  /* 15.2.2.4.33 */
   mrb_define_method(mrb, mod, "method_defined?",         mrb_mod_method_defined,   MRB_ARGS_REQ(1)); /* 15.2.2.4.34 */
   mrb_define_method(mrb, mod, "module_eval",             mrb_mod_module_eval,      MRB_ARGS_ANY());  /* 15.2.2.4.35 */
+  mrb_define_method(mrb, mod, "private",                 mrb_mod_dummy_visibility, MRB_ARGS_ANY());  /* 15.2.2.4.36 */
+  mrb_define_method(mrb, mod, "protected",               mrb_mod_dummy_visibility, MRB_ARGS_ANY());  /* 15.2.2.4.37 */
+  mrb_define_method(mrb, mod, "public",                  mrb_mod_dummy_visibility, MRB_ARGS_ANY());  /* 15.2.2.4.38 */
   mrb_define_method(mrb, mod, "remove_class_variable",   mrb_mod_remove_cvar,      MRB_ARGS_REQ(1)); /* 15.2.2.4.39 */
   mrb_define_method(mrb, mod, "remove_method",           mrb_mod_remove_method,    MRB_ARGS_ANY());  /* 15.2.2.4.41 */
   mrb_define_method(mrb, mod, "to_s",                    mrb_mod_to_s,             MRB_ARGS_NONE());