Ruby-level fixes

* Fix `Variant#method_missing` circular causes
* Correct `Object#__get_class` encoding
  * Create `String#to_sym`
* Stub `#_frame`, might be useful later according to the error spam

lib/godot/object.rb

@@ -11,7 +11,7 @@ class Object < Variant
     private def __get_class
       script = get_script #: RubyScript[Object]?
       # TODO: could also be scripts from other languages…
-      script&.klass or Godot.const_get get_class, false
+      script&.klass or Godot.const_get get_class.to_sym, false
     end
   end
 end

lib/godot/ruby_language.rb

@@ -34,6 +34,9 @@ def _add_named_global_constant(name, value) = RubyScript::Autoloads.const_set(na
     def _remove_named_global_constant(name) = RubyScript::Autoloads.remove_const(name)
 
     def _create_script = RubyScript.new
+
+    # ??
+    def _frame = nil
     # !
     # Dictionary _get_global_class_name ( String path ) virtual const
     # 

lib/godot/variant.rb

@@ -35,20 +35,23 @@ def method_missing(name, *args)
       when '?'
         godot_send("is_#{name[..-1]}", *args)
       else
+        no_method_error = NoMethodError #: _Exception # https://github.com/soutaro/steep/issues/919
     # First, check methods (if checking `attr_reader`s first, #[] can return a {Callable})
         begin
-          godot_send(name, *args) # `rescue` attaches `KeyError` cause if this raises
+          return godot_send(name, *args) # `rescue` attaches `KeyError` cause if this raises
         rescue NoMethodError => no_method_error
-          # Second, check `attr_reader`s
-          attr_reader_error = nil
-          if args.empty? # necessary condition for `attr_reader`
-            begin
-              return self[name]
-            rescue StandardError => attr_reader_error
-              # fall-through
-            end
+          # fall-through, clear {$!} to prevent circular causes
+        end
+        # @ t ype var no_method_error NoMethodError[self]
+        # Second, check `attr_reader`s
+        if args.empty? # necessary condition for `attr_reader`
+          begin
+            return self[name]
+          rescue => e # `attr_reader`s doesn’t work either: re-raise
+            raise no_method_error, cause: e
           end
-          raise no_method_error, cause: attr_reader_error # `attr_reader`s doesn’t work: re-raise
+        else
+          raise no_method_error
         end
       end
     end

sig/ruby_language.rbs

@@ -18,6 +18,8 @@ module Godot
     def self._remove_named_global_constant: (interned name) -> top
 
     def _create_script: () -> RubyScript[Object]
+    def _frame: () -> void
+
     INSTANCE: RubyLanguage
   end
 

src/ruby/string.c

@@ -44,11 +44,15 @@ VALUE godot_rb_cString_i_to_str(VALUE self) {
 }
 //FIXME: possible multiplication and casting overflows (though one should use buffers instead if they need 2GiB strings)
 
+/** Serialize into a UTF-8 Symbol */
+VALUE godot_rb_cString_i_to_sym(VALUE self) { return rb_str_intern(godot_rb_cString_i_to_s(self)); }
+
 init(String, STRING)
   // Endian test for UTF-32 -> `char[]`
   volatile char32_t sample = 1;
   godot_rb_encoding_UTF32 = rb_enc_find(RB_LIKELY(*(char*)&sample) ? "UTF-32LE" : "UTF-32BE");
   rb_gc_register_mark_object(encoding_UTF32 = rb_enc_from_encoding(godot_rb_encoding_UTF32));
   rb_define_method(cString, "to_s"  , godot_rb_cString_i_to_s  , 0);
   rb_define_method(cString, "to_str", godot_rb_cString_i_to_str, 0);
+  rb_define_method(cString, "to_sym", godot_rb_cString_i_to_sym, 0);
 }