introduce toplevel object main; close #327

include/mruby/class.h

@@ -39,6 +39,8 @@ mrb_class(mrb_state *mrb, mrb_value v)
     return mrb->fixnum_class;
   case MRB_TT_FLOAT:
     return mrb->float_class;
+  case MRB_TT_MAIN:
+    return mrb->object_class;
 
 #ifdef ENABLE_REGEXP
   case MRB_TT_REGEX:

include/mruby/value.h

@@ -34,7 +34,8 @@ enum mrb_vtype {
   MRB_TT_FILE,        /*  21 */
   MRB_TT_ENV,         /*  22 */
   MRB_TT_DATA,        /*  23 */
-  MRB_TT_MAXDEFINE    /*  24 */
+  MRB_TT_MAIN,        /*  24 */
+  MRB_TT_MAXDEFINE    /*  25 */
 };
 
 typedef struct mrb_value {
@@ -94,7 +95,8 @@ enum mrb_vtype {
   MRB_TT_FILE,        /*  22 */
   MRB_TT_ENV,         /*  23 */
   MRB_TT_DATA,        /*  24 */
-  MRB_TT_MAXDEFINE    /*  25 */
+  MRB_TT_MAIN,        /*  25 */
+  MRB_TT_MAXDEFINE    /*  26 */
 };
 
 #ifdef MRB_ENDIAN_BIG

src/kernel.c

@@ -64,6 +64,9 @@ mrb_obj_inspect(mrb_state *mrb, mrb_value obj)
   else if (mrb_nil_p(obj)) {
     return mrb_str_new(mrb, "nil", 3);
   }
+  else if (mrb_type(obj) == MRB_TT_MAIN) {
+    return mrb_str_new(mrb, "main", 4);
+  }
   return mrb_funcall(mrb, obj, "to_s", 0, 0);
 }
 

src/state.c

@@ -97,6 +97,8 @@ mrb_add_irep(mrb_state *mrb, int idx)
 mrb_value
 mrb_top_self(mrb_state *mrb)
 {
-  // for now
-  return mrb_nil_value();
+  mrb_value v;
+
+  MRB_SET_VALUE(v, MRB_TT_MAIN, value.i, 0);
+  return v;
 }

test/t/kernel.rb

@@ -338,5 +338,5 @@ end
 
 assert('Kernel#to_s', '15.3.1.3.46') do
   # TODO looks strange..
-  to_s == ''
+  nil.to_s == ''
 end