diff --git a/ext/rbs_extension/constants.c b/ext/rbs_extension/constants.c
index 57ec73ee3..e4f04832a 100644
--- a/ext/rbs_extension/constants.c
+++ b/ext/rbs_extension/constants.c
@@ -40,6 +40,7 @@ VALUE RBS_AST_Members_MethodDefinition;
 VALUE RBS_AST_Members_MethodDefinition_Overload;
 VALUE RBS_AST_Members_Prepend;
 VALUE RBS_AST_Members_Private;
+VALUE RBS_AST_Members_Protected;
 VALUE RBS_AST_Members_Public;
 
 VALUE RBS_Namespace;
@@ -118,6 +119,7 @@ void rbs__init_constants(void) {
   IMPORT_CONSTANT(RBS_AST_Members_MethodDefinition_Overload, RBS_AST_Members_MethodDefinition, "Overload");
   IMPORT_CONSTANT(RBS_AST_Members_Prepend, RBS_AST_Members, "Prepend");
   IMPORT_CONSTANT(RBS_AST_Members_Private, RBS_AST_Members, "Private");
+  IMPORT_CONSTANT(RBS_AST_Members_Protected, RBS_AST_Members, "Protected");
   IMPORT_CONSTANT(RBS_AST_Members_Public, RBS_AST_Members, "Public");
 
   IMPORT_CONSTANT(RBS_Namespace, RBS, "Namespace");
diff --git a/ext/rbs_extension/constants.h b/ext/rbs_extension/constants.h
index 978bc32d0..a05bf15cd 100644
--- a/ext/rbs_extension/constants.h
+++ b/ext/rbs_extension/constants.h
@@ -39,6 +39,7 @@ extern VALUE RBS_AST_Members_MethodDefinition;
 extern VALUE RBS_AST_Members_MethodDefinition_Overload;
 extern VALUE RBS_AST_Members_Prepend;
 extern VALUE RBS_AST_Members_Private;
+extern VALUE RBS_AST_Members_Protected;
 extern VALUE RBS_AST_Members_Public;
 
 extern VALUE RBS_MethodType;
diff --git a/ext/rbs_extension/lexer.c b/ext/rbs_extension/lexer.c
index 040d537a0..f555bac7d 100644
--- a/ext/rbs_extension/lexer.c
+++ b/ext/rbs_extension/lexer.c
@@ -1,5 +1,5 @@
-/* Generated by re2c 3.1 */
-#line 1 "ext/rbs_extension/lexer.re"
+/* Generated by re2c 3.1 on Fri Feb  9 14:01:57 2024 */
+#line 1 "lexer.re"
 #include "rbs_extension.h"
 
 token rbsparser_next_token(lexstate *state) {
@@ -9,7 +9,7 @@ token rbsparser_next_token(lexstate *state) {
   backup = *state;
 
   
-#line 13 "ext/rbs_extension/lexer.c"
+#line 13 "<stdout>"
 {
 	unsigned int yych;
 	unsigned int yyaccept = 0;
@@ -116,15 +116,15 @@ token rbsparser_next_token(lexstate *state) {
 	}
 yy1:
 	rbs_skip(state);
-#line 145 "ext/rbs_extension/lexer.re"
+#line 146 "lexer.re"
 	{ return next_token(state, pEOF); }
-#line 122 "ext/rbs_extension/lexer.c"
+#line 122 "<stdout>"
 yy2:
 	rbs_skip(state);
 yy3:
-#line 146 "ext/rbs_extension/lexer.re"
+#line 147 "lexer.re"
 	{ return next_token(state, ErrorToken); }
-#line 128 "ext/rbs_extension/lexer.c"
+#line 128 "<stdout>"
 yy4:
 	rbs_skip(state);
 	yych = peek(state);
@@ -136,18 +136,18 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych == ' ') goto yy4;
 	}
 yy5:
-#line 144 "ext/rbs_extension/lexer.re"
+#line 145 "lexer.re"
 	{ state->start = state->current; goto start; }
-#line 142 "ext/rbs_extension/lexer.c"
+#line 142 "<stdout>"
 yy6:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych == '=') goto yy23;
 	if (yych == '~') goto yy23;
 yy7:
-#line 49 "ext/rbs_extension/lexer.re"
+#line 49 "lexer.re"
 	{ return next_token(state, tOPERATOR); }
-#line 151 "ext/rbs_extension/lexer.c"
+#line 151 "<stdout>"
 yy8:
 	yyaccept = 0;
 	rbs_skip(state);
@@ -161,14 +161,14 @@ token rbsparser_next_token(lexstate *state) {
 	if (yych <= 0x00000000) goto yy10;
 	if (yych != '\n') goto yy9;
 yy10:
-#line 60 "ext/rbs_extension/lexer.re"
+#line 60 "lexer.re"
 	{
         return next_token(
           state,
           state->first_token_of_line ? tLINECOMMENT : tCOMMENT
         );
       }
-#line 172 "ext/rbs_extension/lexer.c"
+#line 172 "<stdout>"
 yy11:
 	rbs_skip(state);
 	yych = peek(state);
@@ -224,9 +224,9 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy7;
 yy13:
 	rbs_skip(state);
-#line 34 "ext/rbs_extension/lexer.re"
+#line 34 "lexer.re"
 	{ return next_token(state, pAMP); }
-#line 230 "ext/rbs_extension/lexer.c"
+#line 230 "<stdout>"
 yy14:
 	yyaccept = 0;
 	rbs_skip(state);
@@ -236,21 +236,21 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy75;
 yy15:
 	rbs_skip(state);
-#line 25 "ext/rbs_extension/lexer.re"
+#line 25 "lexer.re"
 	{ return next_token(state, pLPAREN); }
-#line 242 "ext/rbs_extension/lexer.c"
+#line 242 "<stdout>"
 yy16:
 	rbs_skip(state);
-#line 26 "ext/rbs_extension/lexer.re"
+#line 26 "lexer.re"
 	{ return next_token(state, pRPAREN); }
-#line 247 "ext/rbs_extension/lexer.c"
+#line 247 "<stdout>"
 yy17:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych == '*') goto yy79;
-#line 36 "ext/rbs_extension/lexer.re"
+#line 36 "lexer.re"
 	{ return next_token(state, pSTAR); }
-#line 254 "ext/rbs_extension/lexer.c"
+#line 254 "<stdout>"
 yy18:
 	rbs_skip(state);
 	yych = peek(state);
@@ -260,9 +260,9 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy7;
 yy19:
 	rbs_skip(state);
-#line 31 "ext/rbs_extension/lexer.re"
+#line 31 "lexer.re"
 	{ return next_token(state, pCOMMA); }
-#line 266 "ext/rbs_extension/lexer.c"
+#line 266 "<stdout>"
 yy20:
 	rbs_skip(state);
 	yych = peek(state);
@@ -282,9 +282,9 @@ token rbsparser_next_token(lexstate *state) {
 	yych = peek(state);
 	if (yych == '.') goto yy81;
 yy22:
-#line 38 "ext/rbs_extension/lexer.re"
+#line 38 "lexer.re"
 	{ return next_token(state, pDOT); }
-#line 288 "ext/rbs_extension/lexer.c"
+#line 288 "<stdout>"
 yy23:
 	rbs_skip(state);
 	goto yy7;
@@ -295,9 +295,9 @@ token rbsparser_next_token(lexstate *state) {
 	if (yych <= '9') goto yy24;
 	if (yych == '_') goto yy24;
 yy25:
-#line 52 "ext/rbs_extension/lexer.re"
+#line 52 "lexer.re"
 	{ return next_token(state, tINTEGER); }
-#line 301 "ext/rbs_extension/lexer.c"
+#line 301 "<stdout>"
 yy26:
 	yyaccept = 3;
 	rbs_skip(state);
@@ -380,9 +380,9 @@ token rbsparser_next_token(lexstate *state) {
 		default: goto yy27;
 	}
 yy27:
-#line 45 "ext/rbs_extension/lexer.re"
+#line 45 "lexer.re"
 	{ return next_token(state, pCOLON); }
-#line 386 "ext/rbs_extension/lexer.c"
+#line 386 "<stdout>"
 yy28:
 	rbs_skip(state);
 	yych = peek(state);
@@ -390,9 +390,9 @@ token rbsparser_next_token(lexstate *state) {
 	if (yych <= '<') goto yy23;
 	if (yych <= '=') goto yy98;
 yy29:
-#line 47 "ext/rbs_extension/lexer.re"
+#line 47 "lexer.re"
 	{ return next_token(state, pLT); }
-#line 396 "ext/rbs_extension/lexer.c"
+#line 396 "<stdout>"
 yy30:
 	rbs_skip(state);
 	yych = peek(state);
@@ -404,9 +404,9 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych == '~') goto yy23;
 	}
 yy31:
-#line 44 "ext/rbs_extension/lexer.re"
+#line 44 "lexer.re"
 	{ return next_token(state, pEQ); }
-#line 410 "ext/rbs_extension/lexer.c"
+#line 410 "<stdout>"
 yy32:
 	rbs_skip(state);
 	yych = peek(state);
@@ -415,9 +415,9 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy7;
 yy33:
 	rbs_skip(state);
-#line 35 "ext/rbs_extension/lexer.re"
+#line 35 "lexer.re"
 	{ return next_token(state, pQUESTION); }
-#line 421 "ext/rbs_extension/lexer.c"
+#line 421 "<stdout>"
 yy34:
 	yyaccept = 0;
 	rbs_skip(state);
@@ -453,26 +453,26 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy36:
-#line 130 "ext/rbs_extension/lexer.re"
+#line 131 "lexer.re"
 	{ return next_token(state, tUIDENT); }
-#line 459 "ext/rbs_extension/lexer.c"
+#line 459 "<stdout>"
 yy37:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych == ']') goto yy106;
-#line 27 "ext/rbs_extension/lexer.re"
+#line 27 "lexer.re"
 	{ return next_token(state, pLBRACKET); }
-#line 466 "ext/rbs_extension/lexer.c"
+#line 466 "<stdout>"
 yy38:
 	rbs_skip(state);
-#line 28 "ext/rbs_extension/lexer.re"
+#line 28 "lexer.re"
 	{ return next_token(state, pRBRACKET); }
-#line 471 "ext/rbs_extension/lexer.c"
+#line 471 "<stdout>"
 yy39:
 	rbs_skip(state);
-#line 33 "ext/rbs_extension/lexer.re"
+#line 33 "lexer.re"
 	{ return next_token(state, pHAT); }
-#line 476 "ext/rbs_extension/lexer.c"
+#line 476 "<stdout>"
 yy40:
 	rbs_skip(state);
 	yych = peek(state);
@@ -494,9 +494,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy41:
-#line 133 "ext/rbs_extension/lexer.re"
+#line 134 "lexer.re"
 	{ return next_token(state, tULLIDENT); }
-#line 500 "ext/rbs_extension/lexer.c"
+#line 500 "<stdout>"
 yy42:
 	yyaccept = 4;
 	rbs_skip(state);
@@ -509,9 +509,9 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych != ':') goto yy113;
 	}
 yy43:
-#line 40 "ext/rbs_extension/lexer.re"
+#line 40 "lexer.re"
 	{  return next_token(state, tOPERATOR); }
-#line 515 "ext/rbs_extension/lexer.c"
+#line 515 "<stdout>"
 yy44:
 	rbs_skip(state);
 	yych = peek(state);
@@ -524,9 +524,9 @@ token rbsparser_next_token(lexstate *state) {
 		goto yy52;
 	}
 yy45:
-#line 129 "ext/rbs_extension/lexer.re"
+#line 130 "lexer.re"
 	{ return next_token(state, tLIDENT); }
-#line 530 "ext/rbs_extension/lexer.c"
+#line 530 "<stdout>"
 yy46:
 	rbs_skip(state);
 	yych = peek(state);
@@ -633,19 +633,19 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy52;
 yy62:
 	rbs_skip(state);
-#line 29 "ext/rbs_extension/lexer.re"
+#line 29 "lexer.re"
 	{ return next_token(state, pLBRACE); }
-#line 639 "ext/rbs_extension/lexer.c"
+#line 639 "<stdout>"
 yy63:
 	rbs_skip(state);
-#line 32 "ext/rbs_extension/lexer.re"
+#line 32 "lexer.re"
 	{ return next_token(state, pBAR); }
-#line 644 "ext/rbs_extension/lexer.c"
+#line 644 "<stdout>"
 yy64:
 	rbs_skip(state);
-#line 30 "ext/rbs_extension/lexer.re"
+#line 30 "lexer.re"
 	{ return next_token(state, pRBRACE); }
-#line 649 "ext/rbs_extension/lexer.c"
+#line 649 "<stdout>"
 yy65:
 	rbs_skip(state);
 	yych = peek(state);
@@ -687,9 +687,9 @@ token rbsparser_next_token(lexstate *state) {
 	}
 yy68:
 	rbs_skip(state);
-#line 107 "ext/rbs_extension/lexer.re"
+#line 108 "lexer.re"
 	{ return next_token(state, tDQSTRING); }
-#line 693 "ext/rbs_extension/lexer.c"
+#line 693 "<stdout>"
 yy69:
 	rbs_skip(state);
 	yych = peek(state);
@@ -726,9 +726,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy71:
-#line 140 "ext/rbs_extension/lexer.re"
+#line 141 "lexer.re"
 	{ return next_token(state, tGIDENT); }
-#line 732 "ext/rbs_extension/lexer.c"
+#line 732 "<stdout>"
 yy72:
 	rbs_skip(state);
 	goto yy71;
@@ -767,9 +767,9 @@ token rbsparser_next_token(lexstate *state) {
 yy76:
 	rbs_skip(state);
 yy77:
-#line 108 "ext/rbs_extension/lexer.re"
+#line 109 "lexer.re"
 	{ return next_token(state, tSQSTRING); }
-#line 773 "ext/rbs_extension/lexer.c"
+#line 773 "<stdout>"
 yy78:
 	rbs_skip(state);
 	yych = peek(state);
@@ -783,14 +783,14 @@ token rbsparser_next_token(lexstate *state) {
 	}
 yy79:
 	rbs_skip(state);
-#line 37 "ext/rbs_extension/lexer.re"
+#line 37 "lexer.re"
 	{ return next_token(state, pSTAR2); }
-#line 789 "ext/rbs_extension/lexer.c"
+#line 789 "<stdout>"
 yy80:
 	rbs_skip(state);
-#line 42 "ext/rbs_extension/lexer.re"
+#line 42 "lexer.re"
 	{ return next_token(state, pARROW); }
-#line 794 "ext/rbs_extension/lexer.c"
+#line 794 "<stdout>"
 yy81:
 	rbs_skip(state);
 	yych = peek(state);
@@ -802,9 +802,9 @@ token rbsparser_next_token(lexstate *state) {
 	if (yych == '=') goto yy86;
 	if (yych == '~') goto yy86;
 yy83:
-#line 127 "ext/rbs_extension/lexer.re"
+#line 128 "lexer.re"
 	{ return next_token(state, tSYMBOL); }
-#line 808 "ext/rbs_extension/lexer.c"
+#line 808 "<stdout>"
 yy84:
 	rbs_skip(state);
 	yych = peek(state);
@@ -888,9 +888,9 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy83;
 yy90:
 	rbs_skip(state);
-#line 46 "ext/rbs_extension/lexer.re"
+#line 46 "lexer.re"
 	{ return next_token(state, pCOLON2); }
-#line 894 "ext/rbs_extension/lexer.c"
+#line 894 "<stdout>"
 yy91:
 	rbs_skip(state);
 	yych = peek(state);
@@ -944,9 +944,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy96:
-#line 123 "ext/rbs_extension/lexer.re"
+#line 124 "lexer.re"
 	{ return next_token(state, tSYMBOL); }
-#line 950 "ext/rbs_extension/lexer.c"
+#line 950 "<stdout>"
 yy97:
 	rbs_skip(state);
 	yych = peek(state);
@@ -964,9 +964,9 @@ token rbsparser_next_token(lexstate *state) {
 	goto yy7;
 yy100:
 	rbs_skip(state);
-#line 43 "ext/rbs_extension/lexer.re"
+#line 43 "lexer.re"
 	{ return next_token(state, pFATARROW); }
-#line 970 "ext/rbs_extension/lexer.c"
+#line 970 "<stdout>"
 yy101:
 	rbs_skip(state);
 	yych = peek(state);
@@ -995,26 +995,26 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy103:
-#line 137 "ext/rbs_extension/lexer.re"
+#line 138 "lexer.re"
 	{ return next_token(state, tAIDENT); }
-#line 1001 "ext/rbs_extension/lexer.c"
+#line 1001 "<stdout>"
 yy104:
 	rbs_skip(state);
-#line 134 "ext/rbs_extension/lexer.re"
+#line 135 "lexer.re"
 	{ return next_token(state, tBANGIDENT); }
-#line 1006 "ext/rbs_extension/lexer.c"
+#line 1006 "<stdout>"
 yy105:
 	rbs_skip(state);
-#line 135 "ext/rbs_extension/lexer.re"
+#line 136 "lexer.re"
 	{ return next_token(state, tEQIDENT); }
-#line 1011 "ext/rbs_extension/lexer.c"
+#line 1011 "<stdout>"
 yy106:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych == '=') goto yy23;
-#line 48 "ext/rbs_extension/lexer.re"
+#line 48 "lexer.re"
 	{ return next_token(state, pAREF_OPR); }
-#line 1018 "ext/rbs_extension/lexer.c"
+#line 1018 "<stdout>"
 yy107:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1036,9 +1036,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy109:
-#line 131 "ext/rbs_extension/lexer.re"
+#line 132 "lexer.re"
 	{ return next_token(state, tULLIDENT); }
-#line 1042 "ext/rbs_extension/lexer.c"
+#line 1042 "<stdout>"
 yy110:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1059,9 +1059,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy111:
-#line 132 "ext/rbs_extension/lexer.re"
+#line 133 "lexer.re"
 	{ return next_token(state, tULIDENT); }
-#line 1065 "ext/rbs_extension/lexer.c"
+#line 1065 "<stdout>"
 yy112:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1098,9 +1098,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy116:
-#line 97 "ext/rbs_extension/lexer.re"
+#line 98 "lexer.re"
 	{ return next_token(state, kAS); }
-#line 1104 "ext/rbs_extension/lexer.c"
+#line 1104 "<stdout>"
 yy117:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1168,9 +1168,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy125:
-#line 78 "ext/rbs_extension/lexer.re"
+#line 78 "lexer.re"
 	{ return next_token(state, kIN); }
-#line 1174 "ext/rbs_extension/lexer.c"
+#line 1174 "<stdout>"
 yy126:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1189,66 +1189,71 @@ token rbsparser_next_token(lexstate *state) {
 yy129:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy186;
-	if (yych == 'i') goto yy187;
-	goto yy52;
+	if (yych <= 'h') {
+		if (yych == 'e') goto yy186;
+		goto yy52;
+	} else {
+		if (yych <= 'i') goto yy187;
+		if (yych == 'o') goto yy188;
+		goto yy52;
+	}
 yy130:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'b') goto yy188;
+	if (yych == 'b') goto yy189;
 	goto yy52;
 yy131:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy189;
+	if (yych == 'l') goto yy190;
 	goto yy52;
 yy132:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'n') goto yy190;
+	if (yych == 'n') goto yy191;
 	goto yy52;
 yy133:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'p') goto yy191;
+	if (yych == 'p') goto yy192;
 	goto yy52;
 yy134:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'u') goto yy193;
+	if (yych == 'u') goto yy194;
 	goto yy52;
 yy135:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'p') goto yy194;
+	if (yych == 'p') goto yy195;
 	goto yy52;
 yy136:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy195;
-	if (yych == 't') goto yy196;
+	if (yych == 'c') goto yy196;
+	if (yych == 't') goto yy197;
 	goto yy52;
 yy137:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy197;
+	if (yych == 'e') goto yy198;
 	goto yy52;
 yy138:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'i') goto yy199;
+	if (yych == 'i') goto yy200;
 	goto yy52;
 yy139:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy200;
+		if (yych <= '9') goto yy201;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy200;
+		if (yych <= 'F') goto yy201;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy200;
+		if (yych <= 'f') goto yy201;
 		goto yy67;
 	}
 yy140:
@@ -1263,31 +1268,31 @@ token rbsparser_next_token(lexstate *state) {
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 0x00000000) goto yy67;
-	if (yych == ')') goto yy201;
+	if (yych == ')') goto yy202;
 	goto yy141;
 yy142:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 0x00000000) goto yy67;
-	if (yych == '>') goto yy202;
+	if (yych == '>') goto yy203;
 	goto yy142;
 yy143:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 0x00000000) goto yy67;
-	if (yych == ']') goto yy203;
+	if (yych == ']') goto yy204;
 	goto yy143;
 yy144:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 0x00000000) goto yy67;
-	if (yych == '}') goto yy204;
+	if (yych == '}') goto yy205;
 	goto yy144;
 yy145:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 0x00000000) goto yy67;
-	if (yych == '|') goto yy205;
+	if (yych == '|') goto yy206;
 	goto yy145;
 yy146:
 	yyaccept = 5;
@@ -1304,19 +1309,19 @@ token rbsparser_next_token(lexstate *state) {
 	}
 yy147:
 	rbs_skip(state);
-#line 39 "ext/rbs_extension/lexer.re"
+#line 39 "lexer.re"
 	{ return next_token(state, pDOT3); }
-#line 1310 "ext/rbs_extension/lexer.c"
+#line 1315 "<stdout>"
 yy148:
 	rbs_skip(state);
-#line 109 "ext/rbs_extension/lexer.re"
+#line 110 "lexer.re"
 	{ return next_token(state, tDQSYMBOL); }
-#line 1315 "ext/rbs_extension/lexer.c"
+#line 1320 "<stdout>"
 yy149:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'u') goto yy206;
-	if (yych == 'x') goto yy207;
+	if (yych == 'u') goto yy207;
+	if (yych == 'x') goto yy208;
 	goto yy84;
 yy150:
 	rbs_skip(state);
@@ -1348,25 +1353,25 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy151:
-#line 126 "ext/rbs_extension/lexer.re"
+#line 127 "lexer.re"
 	{ return next_token(state, tSYMBOL); }
-#line 1354 "ext/rbs_extension/lexer.c"
+#line 1359 "<stdout>"
 yy152:
 	rbs_skip(state);
 	goto yy151;
 yy153:
 	rbs_skip(state);
 yy154:
-#line 110 "ext/rbs_extension/lexer.re"
+#line 111 "lexer.re"
 	{ return next_token(state, tSQSYMBOL); }
-#line 1363 "ext/rbs_extension/lexer.c"
+#line 1368 "<stdout>"
 yy155:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '\'') {
 		if (yych <= 0x00000000) goto yy67;
 		if (yych <= '&') goto yy87;
-		goto yy208;
+		goto yy209;
 	} else {
 		if (yych == '\\') goto yy155;
 		goto yy87;
@@ -1386,11 +1391,11 @@ token rbsparser_next_token(lexstate *state) {
 	yych = peek(state);
 	if (yych <= '^') {
 		if (yych <= '@') goto yy67;
-		if (yych <= 'Z') goto yy209;
+		if (yych <= 'Z') goto yy210;
 		goto yy67;
 	} else {
 		if (yych == '`') goto yy67;
-		if (yych <= 'z') goto yy209;
+		if (yych <= 'z') goto yy210;
 		goto yy67;
 	}
 yy159:
@@ -1398,14 +1403,14 @@ token rbsparser_next_token(lexstate *state) {
 	yych = peek(state);
 	if (yych <= '>') {
 		if (yych <= '/') {
-			if (yych == '!') goto yy211;
+			if (yych == '!') goto yy212;
 		} else {
 			if (yych <= '9') goto yy159;
-			if (yych == '=') goto yy211;
+			if (yych == '=') goto yy212;
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '?') goto yy211;
+			if (yych <= '?') goto yy212;
 			if (yych <= '@') goto yy160;
 			if (yych <= 'Z') goto yy159;
 		} else {
@@ -1414,9 +1419,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy160:
-#line 124 "ext/rbs_extension/lexer.re"
+#line 125 "lexer.re"
 	{ return next_token(state, tSYMBOL); }
-#line 1420 "ext/rbs_extension/lexer.c"
+#line 1425 "<stdout>"
 yy161:
 	rbs_skip(state);
 	goto yy96;
@@ -1436,33 +1441,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy163:
-#line 138 "ext/rbs_extension/lexer.re"
+#line 139 "lexer.re"
 	{ return next_token(state, tA2IDENT); }
-#line 1442 "ext/rbs_extension/lexer.c"
+#line 1447 "<stdout>"
 yy164:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'o') goto yy212;
+	if (yych == 'o') goto yy213;
 	goto yy108;
 yy165:
 	rbs_skip(state);
-#line 41 "ext/rbs_extension/lexer.re"
+#line 41 "lexer.re"
 	{ return next_token(state, tQIDENT); }
-#line 1452 "ext/rbs_extension/lexer.c"
+#line 1457 "<stdout>"
 yy166:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'a') goto yy213;
+	if (yych == 'a') goto yy214;
 	goto yy52;
 yy167:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'r') goto yy214;
+	if (yych == 'r') goto yy215;
 	goto yy52;
 yy168:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy215;
+	if (yych == 'l') goto yy216;
 	goto yy52;
 yy169:
 	rbs_skip(state);
@@ -1484,13 +1489,13 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy170:
-#line 72 "ext/rbs_extension/lexer.re"
+#line 72 "lexer.re"
 	{ return next_token(state, kBOT); }
-#line 1490 "ext/rbs_extension/lexer.c"
+#line 1495 "<stdout>"
 yy171:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 's') goto yy217;
+	if (yych == 's') goto yy218;
 	goto yy52;
 yy172:
 	rbs_skip(state);
@@ -1512,9 +1517,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy173:
-#line 74 "ext/rbs_extension/lexer.re"
+#line 74 "lexer.re"
 	{ return next_token(state, kDEF); }
-#line 1518 "ext/rbs_extension/lexer.c"
+#line 1523 "<stdout>"
 yy174:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1535,38 +1540,38 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy175:
-#line 75 "ext/rbs_extension/lexer.re"
+#line 75 "lexer.re"
 	{ return next_token(state, kEND); }
-#line 1541 "ext/rbs_extension/lexer.c"
+#line 1546 "<stdout>"
 yy176:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy218;
+	if (yych == 'e') goto yy219;
 	goto yy52;
 yy177:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 's') goto yy219;
+	if (yych == 's') goto yy220;
 	goto yy52;
 yy178:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy220;
+	if (yych == 'l') goto yy221;
 	goto yy52;
 yy179:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 't') goto yy221;
+	if (yych == 't') goto yy222;
 	goto yy52;
 yy180:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy222;
+	if (yych == 'e') goto yy223;
 	goto yy52;
 yy181:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'u') goto yy223;
+	if (yych == 'u') goto yy224;
 	goto yy52;
 yy182:
 	rbs_skip(state);
@@ -1588,9 +1593,9 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy183:
-#line 83 "ext/rbs_extension/lexer.re"
+#line 83 "lexer.re"
 	{ return next_token(state, kNIL); }
-#line 1594 "ext/rbs_extension/lexer.c"
+#line 1599 "<stdout>"
 yy184:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1611,35 +1616,40 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	}
 yy185:
-#line 84 "ext/rbs_extension/lexer.re"
+#line 84 "lexer.re"
 	{ return next_token(state, kOUT); }
-#line 1617 "ext/rbs_extension/lexer.c"
+#line 1622 "<stdout>"
 yy186:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'p') goto yy224;
+	if (yych == 'p') goto yy225;
 	goto yy52;
 yy187:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'v') goto yy225;
+	if (yych == 'v') goto yy226;
 	goto yy52;
 yy188:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy226;
+	if (yych == 't') goto yy227;
 	goto yy52;
 yy189:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'f') goto yy227;
+	if (yych == 'l') goto yy228;
 	goto yy52;
 yy190:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'g') goto yy229;
+	if (yych == 'f') goto yy229;
 	goto yy52;
 yy191:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'g') goto yy231;
+	goto yy52;
+yy192:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1651,22 +1661,17 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy192;
+			if (yych <= '@') goto yy193;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy192;
+			if (yych == '`') goto yy193;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy192:
-#line 90 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, kTOP); }
-#line 1665 "ext/rbs_extension/lexer.c"
 yy193:
-	rbs_skip(state);
-	yych = peek(state);
-	if (yych == 'e') goto yy230;
-	goto yy52;
+#line 91 "lexer.re"
+	{ return next_token(state, kTOP); }
+#line 1675 "<stdout>"
 yy194:
 	rbs_skip(state);
 	yych = peek(state);
@@ -1675,14 +1680,19 @@ token rbsparser_next_token(lexstate *state) {
 yy195:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'h') goto yy234;
+	if (yych == 'e') goto yy234;
 	goto yy52;
 yy196:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'y') goto yy235;
+	if (yych == 'h') goto yy236;
 	goto yy52;
 yy197:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'y') goto yy237;
+	goto yy52;
+yy198:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1694,74 +1704,74 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy198;
+			if (yych <= '@') goto yy199;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy198;
+			if (yych == '`') goto yy199;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy198:
-#line 96 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, kUSE); }
-#line 1708 "ext/rbs_extension/lexer.c"
 yy199:
+#line 97 "lexer.re"
+	{ return next_token(state, kUSE); }
+#line 1718 "<stdout>"
+yy200:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy236;
+	if (yych == 'd') goto yy238;
 	goto yy52;
-yy200:
+yy201:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy238;
+		if (yych <= '9') goto yy240;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy238;
+		if (yych <= 'F') goto yy240;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy238;
+		if (yych <= 'f') goto yy240;
 		goto yy67;
 	}
-yy201:
-	rbs_skip(state);
-#line 55 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, tANNOTATION); }
-#line 1731 "ext/rbs_extension/lexer.c"
 yy202:
 	rbs_skip(state);
-#line 58 "ext/rbs_extension/lexer.re"
+#line 55 "lexer.re"
 	{ return next_token(state, tANNOTATION); }
-#line 1736 "ext/rbs_extension/lexer.c"
+#line 1741 "<stdout>"
 yy203:
 	rbs_skip(state);
-#line 56 "ext/rbs_extension/lexer.re"
+#line 58 "lexer.re"
 	{ return next_token(state, tANNOTATION); }
-#line 1741 "ext/rbs_extension/lexer.c"
+#line 1746 "<stdout>"
 yy204:
 	rbs_skip(state);
-#line 54 "ext/rbs_extension/lexer.re"
+#line 56 "lexer.re"
 	{ return next_token(state, tANNOTATION); }
-#line 1746 "ext/rbs_extension/lexer.c"
+#line 1751 "<stdout>"
 yy205:
 	rbs_skip(state);
-#line 57 "ext/rbs_extension/lexer.re"
+#line 54 "lexer.re"
 	{ return next_token(state, tANNOTATION); }
-#line 1751 "ext/rbs_extension/lexer.c"
+#line 1756 "<stdout>"
 yy206:
 	rbs_skip(state);
+#line 57 "lexer.re"
+	{ return next_token(state, tANNOTATION); }
+#line 1761 "<stdout>"
+yy207:
+	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy239;
+		if (yych <= '9') goto yy241;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy239;
+		if (yych <= 'F') goto yy241;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy239;
+		if (yych <= 'f') goto yy241;
 		goto yy67;
 	}
-yy207:
+yy208:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '/') goto yy67;
@@ -1769,7 +1779,7 @@ token rbsparser_next_token(lexstate *state) {
 	if (yych <= '`') goto yy67;
 	if (yych <= 'f') goto yy84;
 	goto yy67;
-yy208:
+yy209:
 	yyaccept = 6;
 	rbs_skip(state);
 	backup = *state;
@@ -1782,49 +1792,49 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych == '\\') goto yy155;
 		goto yy87;
 	}
-yy209:
+yy210:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '>') {
 		if (yych <= '/') {
-			if (yych == '!') goto yy240;
+			if (yych == '!') goto yy242;
 		} else {
-			if (yych <= '9') goto yy209;
-			if (yych == '=') goto yy240;
+			if (yych <= '9') goto yy210;
+			if (yych == '=') goto yy242;
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '?') goto yy240;
-			if (yych <= '@') goto yy210;
-			if (yych <= 'Z') goto yy209;
+			if (yych <= '?') goto yy242;
+			if (yych <= '@') goto yy211;
+			if (yych <= 'Z') goto yy210;
 		} else {
-			if (yych == '`') goto yy210;
-			if (yych <= 'z') goto yy209;
+			if (yych == '`') goto yy211;
+			if (yych <= 'z') goto yy210;
 		}
 	}
-yy210:
-#line 125 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, tSYMBOL); }
-#line 1809 "ext/rbs_extension/lexer.c"
 yy211:
+#line 126 "lexer.re"
+	{ return next_token(state, tSYMBOL); }
+#line 1819 "<stdout>"
+yy212:
 	rbs_skip(state);
 	goto yy160;
-yy212:
+yy213:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy241;
+	if (yych == 'd') goto yy243;
 	goto yy108;
-yy213:
+yy214:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 's') goto yy242;
+	if (yych == 's') goto yy244;
 	goto yy52;
-yy214:
+yy215:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == '_') goto yy244;
+	if (yych == '_') goto yy246;
 	goto yy52;
-yy215:
+yy216:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1836,68 +1846,73 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy216;
+			if (yych <= '@') goto yy217;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy216;
+			if (yych == '`') goto yy217;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy216:
-#line 71 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, kBOOL); }
-#line 1850 "ext/rbs_extension/lexer.c"
 yy217:
-	rbs_skip(state);
-	yych = peek(state);
-	if (yych == 's') goto yy245;
-	goto yy52;
+#line 71 "lexer.re"
+	{ return next_token(state, kBOOL); }
+#line 1860 "<stdout>"
 yy218:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'n') goto yy247;
+	if (yych == 's') goto yy247;
 	goto yy52;
 yy219:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy248;
+	if (yych == 'n') goto yy249;
 	goto yy52;
 yy220:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'u') goto yy250;
+	if (yych == 'e') goto yy250;
 	goto yy52;
 yy221:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'a') goto yy251;
+	if (yych == 'u') goto yy252;
 	goto yy52;
 yy222:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'r') goto yy252;
+	if (yych == 'a') goto yy253;
 	goto yy52;
 yy223:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy253;
+	if (yych == 'r') goto yy254;
 	goto yy52;
 yy224:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy254;
+	if (yych == 'l') goto yy255;
 	goto yy52;
 yy225:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'a') goto yy255;
+	if (yych == 'e') goto yy256;
 	goto yy52;
 yy226:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'i') goto yy256;
+	if (yych == 'a') goto yy257;
 	goto yy52;
 yy227:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'e') goto yy258;
+	goto yy52;
+yy228:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'i') goto yy259;
+	goto yy52;
+yy229:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1909,23 +1924,23 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy228;
+			if (yych <= '@') goto yy230;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy228;
+			if (yych == '`') goto yy230;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy228:
-#line 88 "ext/rbs_extension/lexer.re"
+yy230:
+#line 89 "lexer.re"
 	{ return next_token(state, kSELF); }
-#line 1923 "ext/rbs_extension/lexer.c"
-yy229:
+#line 1938 "<stdout>"
+yy231:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'l') goto yy257;
+	if (yych == 'l') goto yy260;
 	goto yy52;
-yy230:
+yy232:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1937,18 +1952,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy231;
+			if (yych <= '@') goto yy233;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy231;
+			if (yych == '`') goto yy233;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy231:
-#line 91 "ext/rbs_extension/lexer.re"
+yy233:
+#line 92 "lexer.re"
 	{ return next_token(state, kTRUE); }
-#line 1951 "ext/rbs_extension/lexer.c"
-yy232:
+#line 1966 "<stdout>"
+yy234:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1960,28 +1975,28 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy233;
+			if (yych <= '@') goto yy235;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy233;
+			if (yych == '`') goto yy235;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy233:
-#line 92 "ext/rbs_extension/lexer.re"
+yy235:
+#line 93 "lexer.re"
 	{ return next_token(state, kTYPE); }
-#line 1974 "ext/rbs_extension/lexer.c"
-yy234:
+#line 1989 "<stdout>"
+yy236:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy258;
+	if (yych == 'e') goto yy261;
 	goto yy52;
-yy235:
+yy237:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'p') goto yy259;
+	if (yych == 'p') goto yy262;
 	goto yy52;
-yy236:
+yy238:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -1993,52 +2008,52 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy237;
+			if (yych <= '@') goto yy239;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy237;
+			if (yych == '`') goto yy239;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy237:
-#line 95 "ext/rbs_extension/lexer.re"
+yy239:
+#line 96 "lexer.re"
 	{ return next_token(state, kVOID); }
-#line 2007 "ext/rbs_extension/lexer.c"
-yy238:
+#line 2022 "<stdout>"
+yy240:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy260;
+		if (yych <= '9') goto yy263;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy260;
+		if (yych <= 'F') goto yy263;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy260;
+		if (yych <= 'f') goto yy263;
 		goto yy67;
 	}
-yy239:
+yy241:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy261;
+		if (yych <= '9') goto yy264;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy261;
+		if (yych <= 'F') goto yy264;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy261;
+		if (yych <= 'f') goto yy264;
 		goto yy67;
 	}
-yy240:
+yy242:
 	rbs_skip(state);
-	goto yy210;
-yy241:
+	goto yy211;
+yy243:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'o') goto yy262;
+	if (yych == 'o') goto yy265;
 	goto yy108;
-yy242:
+yy244:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2050,29 +2065,29 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy243;
+			if (yych <= '@') goto yy245;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy243;
+			if (yych == '`') goto yy245;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy243:
-#line 67 "ext/rbs_extension/lexer.re"
+yy245:
+#line 67 "lexer.re"
 	{ return next_token(state, kALIAS); }
-#line 2064 "ext/rbs_extension/lexer.c"
-yy244:
+#line 2079 "<stdout>"
+yy246:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= 'q') {
-		if (yych == 'a') goto yy263;
+		if (yych == 'a') goto yy266;
 		goto yy52;
 	} else {
-		if (yych <= 'r') goto yy264;
-		if (yych == 'w') goto yy265;
+		if (yych <= 'r') goto yy267;
+		if (yych == 'w') goto yy268;
 		goto yy52;
 	}
-yy245:
+yy247:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2084,23 +2099,23 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy246;
+			if (yych <= '@') goto yy248;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy246;
+			if (yych == '`') goto yy248;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy246:
-#line 73 "ext/rbs_extension/lexer.re"
+yy248:
+#line 73 "lexer.re"
 	{ return next_token(state, kCLASS); }
-#line 2098 "ext/rbs_extension/lexer.c"
-yy247:
+#line 2113 "<stdout>"
+yy249:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy266;
+	if (yych == 'd') goto yy269;
 	goto yy52;
-yy248:
+yy250:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2112,56 +2127,46 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy249;
+			if (yych <= '@') goto yy251;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy249;
+			if (yych == '`') goto yy251;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy249:
-#line 77 "ext/rbs_extension/lexer.re"
-	{ return next_token(state, kFALSE); }
-#line 2126 "ext/rbs_extension/lexer.c"
-yy250:
-	rbs_skip(state);
-	yych = peek(state);
-	if (yych == 'd') goto yy268;
-	goto yy52;
 yy251:
-	rbs_skip(state);
-	yych = peek(state);
-	if (yych == 'n') goto yy269;
-	goto yy52;
+#line 77 "lexer.re"
+	{ return next_token(state, kFALSE); }
+#line 2141 "<stdout>"
 yy252:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'f') goto yy270;
+	if (yych == 'd') goto yy271;
 	goto yy52;
 yy253:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy271;
+	if (yych == 'n') goto yy272;
 	goto yy52;
 yy254:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'n') goto yy273;
+	if (yych == 'f') goto yy273;
 	goto yy52;
 yy255:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 't') goto yy274;
+	if (yych == 'e') goto yy274;
 	goto yy52;
 yy256:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy275;
+	if (yych == 'n') goto yy276;
 	goto yy52;
 yy257:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy277;
+	if (yych == 't') goto yy277;
 	goto yy52;
 yy258:
 	rbs_skip(state);
@@ -2171,9 +2176,24 @@ token rbsparser_next_token(lexstate *state) {
 yy259:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy279;
+	if (yych == 'c') goto yy279;
 	goto yy52;
 yy260:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'e') goto yy281;
+	goto yy52;
+yy261:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'c') goto yy282;
+	goto yy52;
+yy262:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'e') goto yy283;
+	goto yy52;
+yy263:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
@@ -2186,40 +2206,40 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych <= 'f') goto yy65;
 		goto yy67;
 	}
-yy261:
+yy264:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
 		if (yych <= '/') goto yy67;
-		if (yych <= '9') goto yy280;
+		if (yych <= '9') goto yy284;
 		goto yy67;
 	} else {
-		if (yych <= 'F') goto yy280;
+		if (yych <= 'F') goto yy284;
 		if (yych <= '`') goto yy67;
-		if (yych <= 'f') goto yy280;
+		if (yych <= 'f') goto yy284;
 		goto yy67;
 	}
-yy262:
+yy265:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == '_') goto yy281;
+	if (yych == '_') goto yy285;
 	goto yy108;
-yy263:
+yy266:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy282;
+	if (yych == 'c') goto yy286;
 	goto yy52;
-yy264:
+yy267:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy283;
+	if (yych == 'e') goto yy287;
 	goto yy52;
-yy265:
+yy268:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'r') goto yy284;
+	if (yych == 'r') goto yy288;
 	goto yy52;
-yy266:
+yy269:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2231,33 +2251,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy267;
+			if (yych <= '@') goto yy270;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy267;
+			if (yych == '`') goto yy270;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy267:
-#line 76 "ext/rbs_extension/lexer.re"
+yy270:
+#line 76 "lexer.re"
 	{ return next_token(state, kEXTEND); }
-#line 2245 "ext/rbs_extension/lexer.c"
-yy268:
+#line 2265 "<stdout>"
+yy271:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy285;
+	if (yych == 'e') goto yy289;
 	goto yy52;
-yy269:
+yy272:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy287;
+	if (yych == 'c') goto yy291;
 	goto yy52;
-yy270:
+yy273:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'a') goto yy288;
+	if (yych == 'a') goto yy292;
 	goto yy52;
-yy271:
+yy274:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2269,28 +2289,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy272;
+			if (yych <= '@') goto yy275;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy272;
+			if (yych == '`') goto yy275;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy272:
-#line 82 "ext/rbs_extension/lexer.re"
+yy275:
+#line 82 "lexer.re"
 	{ return next_token(state, kMODULE); }
-#line 2283 "ext/rbs_extension/lexer.c"
-yy273:
+#line 2303 "<stdout>"
+yy276:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy289;
+	if (yych == 'd') goto yy293;
 	goto yy52;
-yy274:
+yy277:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy291;
+	if (yych == 'e') goto yy295;
 	goto yy52;
-yy275:
+yy278:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 't') goto yy297;
+	goto yy52;
+yy279:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2302,33 +2327,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy276;
+			if (yych <= '@') goto yy280;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy276;
+			if (yych == '`') goto yy280;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy276:
-#line 87 "ext/rbs_extension/lexer.re"
+yy280:
+#line 88 "lexer.re"
 	{ return next_token(state, kPUBLIC); }
-#line 2316 "ext/rbs_extension/lexer.c"
-yy277:
+#line 2341 "<stdout>"
+yy281:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 't') goto yy293;
+	if (yych == 't') goto yy298;
 	goto yy52;
-yy278:
+yy282:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'k') goto yy294;
+	if (yych == 'k') goto yy299;
 	goto yy52;
-yy279:
+yy283:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy295;
+	if (yych == 'd') goto yy300;
 	goto yy52;
-yy280:
+yy284:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '@') {
@@ -2341,27 +2366,27 @@ token rbsparser_next_token(lexstate *state) {
 		if (yych <= 'f') goto yy84;
 		goto yy67;
 	}
-yy281:
+yy285:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == '_') goto yy297;
+	if (yych == '_') goto yy302;
 	goto yy108;
-yy282:
+yy286:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy299;
+	if (yych == 'c') goto yy304;
 	goto yy52;
-yy283:
+yy287:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'a') goto yy300;
+	if (yych == 'a') goto yy305;
 	goto yy52;
-yy284:
+yy288:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'i') goto yy301;
+	if (yych == 'i') goto yy306;
 	goto yy52;
-yy285:
+yy289:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2373,28 +2398,28 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy286;
+			if (yych <= '@') goto yy290;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy286;
+			if (yych == '`') goto yy290;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy286:
-#line 79 "ext/rbs_extension/lexer.re"
+yy290:
+#line 79 "lexer.re"
 	{ return next_token(state, kINCLUDE); }
-#line 2387 "ext/rbs_extension/lexer.c"
-yy287:
+#line 2412 "<stdout>"
+yy291:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy302;
+	if (yych == 'e') goto yy307;
 	goto yy52;
-yy288:
+yy292:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'c') goto yy304;
+	if (yych == 'c') goto yy309;
 	goto yy52;
-yy289:
+yy293:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2406,18 +2431,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy290;
+			if (yych <= '@') goto yy294;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy290;
+			if (yych == '`') goto yy294;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy290:
-#line 85 "ext/rbs_extension/lexer.re"
+yy294:
+#line 85 "lexer.re"
 	{ return next_token(state, kPREPEND); }
-#line 2420 "ext/rbs_extension/lexer.c"
-yy291:
+#line 2445 "<stdout>"
+yy295:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2429,28 +2454,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy292;
+			if (yych <= '@') goto yy296;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy292;
+			if (yych == '`') goto yy296;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy292:
-#line 86 "ext/rbs_extension/lexer.re"
+yy296:
+#line 86 "lexer.re"
 	{ return next_token(state, kPRIVATE); }
-#line 2443 "ext/rbs_extension/lexer.c"
-yy293:
+#line 2468 "<stdout>"
+yy297:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'o') goto yy305;
+	if (yych == 'e') goto yy310;
 	goto yy52;
-yy294:
+yy298:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy306;
+	if (yych == 'o') goto yy311;
 	goto yy52;
-yy295:
+yy299:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'e') goto yy312;
+	goto yy52;
+yy300:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2462,18 +2492,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy296;
+			if (yych <= '@') goto yy301;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy296;
+			if (yych == '`') goto yy301;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy296:
-#line 94 "ext/rbs_extension/lexer.re"
+yy301:
+#line 95 "lexer.re"
 	{ return next_token(state, kUNTYPED); }
-#line 2476 "ext/rbs_extension/lexer.c"
-yy297:
+#line 2506 "<stdout>"
+yy302:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2485,33 +2515,33 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy298;
+			if (yych <= '@') goto yy303;
 			if (yych <= 'Z') goto yy107;
 		} else {
-			if (yych == '`') goto yy298;
+			if (yych == '`') goto yy303;
 			if (yych <= 'z') goto yy107;
 		}
 	}
-yy298:
-#line 98 "ext/rbs_extension/lexer.re"
+yy303:
+#line 99 "lexer.re"
 	{ return next_token(state, k__TODO__); }
-#line 2499 "ext/rbs_extension/lexer.c"
-yy299:
+#line 2529 "<stdout>"
+yy304:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy307;
+	if (yych == 'e') goto yy313;
 	goto yy52;
-yy300:
+yy305:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy308;
+	if (yych == 'd') goto yy314;
 	goto yy52;
-yy301:
+yy306:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 't') goto yy309;
+	if (yych == 't') goto yy315;
 	goto yy52;
-yy302:
+yy307:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2523,48 +2553,53 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy303;
+			if (yych <= '@') goto yy308;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy303;
+			if (yych == '`') goto yy308;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy303:
-#line 80 "ext/rbs_extension/lexer.re"
+yy308:
+#line 80 "lexer.re"
 	{ return next_token(state, kINSTANCE); }
-#line 2537 "ext/rbs_extension/lexer.c"
-yy304:
+#line 2567 "<stdout>"
+yy309:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy310;
+	if (yych == 'e') goto yy316;
 	goto yy52;
-yy305:
+yy310:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'n') goto yy312;
+	if (yych == 'd') goto yy318;
 	goto yy52;
-yy306:
+yy311:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'd') goto yy314;
+	if (yych == 'n') goto yy320;
 	goto yy52;
-yy307:
+yy312:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 's') goto yy316;
+	if (yych == 'd') goto yy322;
 	goto yy52;
-yy308:
+yy313:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy317;
+	if (yych == 's') goto yy324;
 	goto yy52;
-yy309:
+yy314:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'e') goto yy318;
+	if (yych == 'e') goto yy325;
 	goto yy52;
-yy310:
+yy315:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych == 'e') goto yy326;
+	goto yy52;
+yy316:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2576,18 +2611,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy311;
+			if (yych <= '@') goto yy317;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy311;
+			if (yych == '`') goto yy317;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy311:
-#line 81 "ext/rbs_extension/lexer.re"
+yy317:
+#line 81 "lexer.re"
 	{ return next_token(state, kINTERFACE); }
-#line 2590 "ext/rbs_extension/lexer.c"
-yy312:
+#line 2625 "<stdout>"
+yy318:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2599,18 +2634,41 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy313;
+			if (yych <= '@') goto yy319;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy313;
+			if (yych == '`') goto yy319;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy313:
-#line 89 "ext/rbs_extension/lexer.re"
+yy319:
+#line 87 "lexer.re"
+	{ return next_token(state, kPROTECTED); }
+#line 2648 "<stdout>"
+yy320:
+	rbs_skip(state);
+	yych = peek(state);
+	if (yych <= '=') {
+		if (yych <= '/') {
+			if (yych == '!') goto yy104;
+		} else {
+			if (yych <= '9') goto yy51;
+			if (yych >= '=') goto yy105;
+		}
+	} else {
+		if (yych <= '^') {
+			if (yych <= '@') goto yy321;
+			if (yych <= 'Z') goto yy51;
+		} else {
+			if (yych == '`') goto yy321;
+			if (yych <= 'z') goto yy51;
+		}
+	}
+yy321:
+#line 90 "lexer.re"
 	{ return next_token(state, kSINGLETON); }
-#line 2613 "ext/rbs_extension/lexer.c"
-yy314:
+#line 2671 "<stdout>"
+yy322:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2622,38 +2680,38 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy315;
+			if (yych <= '@') goto yy323;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy315;
+			if (yych == '`') goto yy323;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy315:
-#line 93 "ext/rbs_extension/lexer.re"
+yy323:
+#line 94 "lexer.re"
 	{ return next_token(state, kUNCHECKED); }
-#line 2636 "ext/rbs_extension/lexer.c"
-yy316:
+#line 2694 "<stdout>"
+yy324:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 's') goto yy319;
+	if (yych == 's') goto yy327;
 	goto yy52;
-yy317:
+yy325:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'r') goto yy320;
+	if (yych == 'r') goto yy328;
 	goto yy52;
-yy318:
+yy326:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'r') goto yy322;
+	if (yych == 'r') goto yy330;
 	goto yy52;
-yy319:
+yy327:
 	rbs_skip(state);
 	yych = peek(state);
-	if (yych == 'o') goto yy324;
+	if (yych == 'o') goto yy332;
 	goto yy52;
-yy320:
+yy328:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2665,18 +2723,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy321;
+			if (yych <= '@') goto yy329;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy321;
+			if (yych == '`') goto yy329;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy321:
-#line 69 "ext/rbs_extension/lexer.re"
+yy329:
+#line 69 "lexer.re"
 	{ return next_token(state, kATTRREADER); }
-#line 2679 "ext/rbs_extension/lexer.c"
-yy322:
+#line 2737 "<stdout>"
+yy330:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych <= '=') {
@@ -2688,18 +2746,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy323;
+			if (yych <= '@') goto yy331;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy323;
+			if (yych == '`') goto yy331;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy323:
-#line 70 "ext/rbs_extension/lexer.re"
+yy331:
+#line 70 "lexer.re"
 	{ return next_token(state, kATTRWRITER); }
-#line 2702 "ext/rbs_extension/lexer.c"
-yy324:
+#line 2760 "<stdout>"
+yy332:
 	rbs_skip(state);
 	yych = peek(state);
 	if (yych != 'r') goto yy52;
@@ -2714,18 +2772,18 @@ token rbsparser_next_token(lexstate *state) {
 		}
 	} else {
 		if (yych <= '^') {
-			if (yych <= '@') goto yy325;
+			if (yych <= '@') goto yy333;
 			if (yych <= 'Z') goto yy51;
 		} else {
-			if (yych == '`') goto yy325;
+			if (yych == '`') goto yy333;
 			if (yych <= 'z') goto yy51;
 		}
 	}
-yy325:
-#line 68 "ext/rbs_extension/lexer.re"
+yy333:
+#line 68 "lexer.re"
 	{ return next_token(state, kATTRACCESSOR); }
-#line 2728 "ext/rbs_extension/lexer.c"
+#line 2786 "<stdout>"
 }
-#line 147 "ext/rbs_extension/lexer.re"
+#line 148 "lexer.re"
 
 }
diff --git a/ext/rbs_extension/lexer.h b/ext/rbs_extension/lexer.h
index 9e4228d81..fbc2be5a9 100644
--- a/ext/rbs_extension/lexer.h
+++ b/ext/rbs_extension/lexer.h
@@ -49,6 +49,7 @@ enum TokenType {
   kOUT,             /* out */
   kPREPEND,         /* prepend */
   kPRIVATE,         /* private */
+  kPROTECTED,       /* protected */
   kPUBLIC,          /* public */
   kSELF,            /* self */
   kSINGLETON,       /* singleton */
diff --git a/ext/rbs_extension/lexer.re b/ext/rbs_extension/lexer.re
index 1547f96f6..65a0b409a 100644
--- a/ext/rbs_extension/lexer.re
+++ b/ext/rbs_extension/lexer.re
@@ -84,6 +84,7 @@ start:
       "out"           { return next_token(state, kOUT); }
       "prepend"       { return next_token(state, kPREPEND); }
       "private"       { return next_token(state, kPRIVATE); }
+      "protected"     { return next_token(state, kPROTECTED); }
       "public"        { return next_token(state, kPUBLIC); }
       "self"          { return next_token(state, kSELF); }
       "singleton"     { return next_token(state, kSINGLETON); }
diff --git a/ext/rbs_extension/lexstate.c b/ext/rbs_extension/lexstate.c
index 0f7c2f454..3d96bb700 100644
--- a/ext/rbs_extension/lexstate.c
+++ b/ext/rbs_extension/lexstate.c
@@ -48,6 +48,7 @@ static const char *RBS_TOKENTYPE_NAMES[] = {
   "kOUT",             /* out */
   "kPREPEND",         /* prepend */
   "kPRIVATE",         /* private */
+  "kPROTECTED",       /* protected */
   "kPUBLIC",          /* public */
   "kSELF",            /* self */
   "kSINGLETON",       /* singleton */
diff --git a/ext/rbs_extension/parser.c b/ext/rbs_extension/parser.c
index 15400209e..1d48fd31b 100644
--- a/ext/rbs_extension/parser.c
+++ b/ext/rbs_extension/parser.c
@@ -36,6 +36,7 @@
   case kATTRACCESSOR: \
   case kPUBLIC: \
   case kPRIVATE: \
+  case kPROTECTED: \
   case kUNTYPED: \
   case kUSE: \
   case kAS: \
@@ -1495,6 +1496,7 @@ InstanceSingletonKind parse_instance_singleton_kind(parserstate *state, bool all
  * def_member ::= {kDEF} method_name `:` <method_types>
  *              | {kPRIVATE} kDEF method_name `:` <method_types>
  *              | {kPUBLIC} kDEF method_name `:` <method_types>
+ *              | {kPROTECTED} kDEF method_name `:` <method_types>
  *
  * method_types ::= {} <method_type>
  *                | {} <`...`>
@@ -1531,6 +1533,12 @@ VALUE parse_member_def(parserstate *state, bool instance_only, bool accept_overl
     member_range.start = visibility_range.start;
     parser_advance(state);
     break;
+  case kPROTECTED:
+    visibility_range = state->current_token.range;
+    visibility = ID2SYM(rb_intern("protected"));
+    member_range.start = visibility_range.start;
+    parser_advance(state);
+    break;
   default:
     visibility_range = NULL_RANGE;
     visibility = Qnil;
@@ -1915,6 +1923,7 @@ VALUE parse_variable_member(parserstate *state, position comment_pos, VALUE anno
 /*
   visibility_member ::= {<`public`>}
                       | {<`private`>}
+                      | {<`protected`>}
 */
 VALUE parse_visibility_member(parserstate *state, VALUE annotations) {
   if (rb_array_len(annotations) > 0) {
@@ -1935,6 +1944,9 @@ VALUE parse_visibility_member(parserstate *state, VALUE annotations) {
   case kPRIVATE:
     klass = RBS_AST_Members_Private;
     break;
+  case kPROTECTED:
+    klass = RBS_AST_Members_Protected;
+    break;
   default:
     rbs_abort();
   }
@@ -1953,7 +1965,7 @@ VALUE parse_visibility_member(parserstate *state, VALUE annotations) {
 
   attr_keyword ::= `attr_reader` | `attr_writer` | `attr_accessor`
 
-  visibility ::= `public` | `private`
+  visibility ::= `public` | `private` | `protected`
 
   attr_var ::=                    # empty
              | `(` tAIDENT `)`    # Ivar name
@@ -1991,6 +2003,11 @@ VALUE parse_attribute_member(parserstate *state, position comment_pos, VALUE ann
     visibility_range = state->current_token.range;
     parser_advance(state);
     break;
+  case kPROTECTED:
+    visibility = ID2SYM(rb_intern("protected"));
+    visibility_range = state->current_token.range;
+    parser_advance(state);
+    break;
   default:
     visibility = Qnil;
     visibility_range = NULL_RANGE;
@@ -2217,6 +2234,7 @@ VALUE parse_nested_decl(parserstate *state, const char *nested_in, position anno
                   | attribute_member
                   | `public`
                   | `private`
+                  | `protected`
 */
 VALUE parse_module_members(parserstate *state) {
   VALUE members = rb_ary_new();
@@ -2260,6 +2278,7 @@ VALUE parse_module_members(parserstate *state) {
 
     case kPUBLIC:
     case kPRIVATE:
+    case kPROTECTED:
       if (state->next_token.range.start.line == state->current_token.range.start.line) {
         switch (state->next_token.type)
         {
diff --git a/lib/rbs/ast/members.rb b/lib/rbs/ast/members.rb
index 7888a1686..15eb6561b 100644
--- a/lib/rbs/ast/members.rb
+++ b/lib/rbs/ast/members.rb
@@ -394,6 +394,14 @@ def to_json(state = _ = nil)
         end
       end
 
+      class Protected < Base
+        include LocationOnly
+
+        def to_json(state = _ = nil)
+          { member: :protected, location: location }.to_json(state)
+        end
+      end
+
       class Alias < Base
         attr_reader :new_name
         attr_reader :old_name
diff --git a/lib/rbs/definition.rb b/lib/rbs/definition.rb
index 307a6e89e..83ce6834b 100644
--- a/lib/rbs/definition.rb
+++ b/lib/rbs/definition.rb
@@ -139,6 +139,14 @@ def private?
         @accessibility == :private
       end
 
+      def protected?
+        @accessibility == :protected
+      end
+
+      def undef?
+        @accessibility == :undef
+      end
+
       def sub(s)
         self.class.new(
           super_method: super_method&.sub(s),
diff --git a/lib/rbs/definition_builder/method_builder.rb b/lib/rbs/definition_builder/method_builder.rb
index f137aed4e..1e8721792 100644
--- a/lib/rbs/definition_builder/method_builder.rb
+++ b/lib/rbs/definition_builder/method_builder.rb
@@ -230,6 +230,8 @@ def each_member_with_accessibility(members, accessibility: :public)
             accessibility = :public
           when AST::Members::Private
             accessibility = :private
+          when AST::Members::Protected
+            accessibility = :protected
           else
             yield member, accessibility
           end
diff --git a/lib/rbs/parser_aux.rb b/lib/rbs/parser_aux.rb
index a243e7697..75a9065e1 100644
--- a/lib/rbs/parser_aux.rb
+++ b/lib/rbs/parser_aux.rb
@@ -60,6 +60,7 @@ def self.buffer(source)
       attr_accessor
       public
       private
+      protected
       untyped
       true
       false
diff --git a/lib/rbs/prototype/rb.rb b/lib/rbs/prototype/rb.rb
index d6d78dd64..3784d0b1a 100644
--- a/lib/rbs/prototype/rb.rb
+++ b/lib/rbs/prototype/rb.rb
@@ -761,6 +761,11 @@ def public
         @public ||= AST::Members::Public.new(location: nil)
       end
 
+      def protected
+        @protected ||= AST::Members::Public.new(location: nil)
+      end
+
+      # TODO
       def current_accessibility(decls, index = decls.size)
         slice = decls.slice(0, index) or raise
         idx = slice.rindex { |decl| decl == private || decl == public }
diff --git a/lib/rbs/sorter.rb b/lib/rbs/sorter.rb
index 2874f7703..b2035559a 100644
--- a/lib/rbs/sorter.rb
+++ b/lib/rbs/sorter.rb
@@ -47,9 +47,11 @@ def sort_decl!(decl)
           singleton_new_methods: [],
           public_singleton_methods: [],
           private_singleton_methods: [],
+          protected_singleton_methods: [],
           instance_initialize_methods: [],
           public_instance_methods: [],
           private_instance_methods: [],
+          protected_instance_methods: [],
         } #: partitioned
 
         decl.members.each { |m| sort_decl! m }
@@ -62,6 +64,8 @@ def sort_decl!(decl)
             :public
           when Members::Private
             :private
+          when Members::Protected
+            :protected
           when Members::MethodDefinition, Members::AttrReader, Members::AttrWriter, Members::AttrAccessor
             visibility_annotated_members << member.update(visibility: member.visibility || current_visibility)
             current_visibility
@@ -106,16 +110,20 @@ def sort_decl!(decl)
                 partitioned[:singleton_new_methods] << member.update(visibility: nil)
               elsif member.visibility == :public
                 partitioned[:public_singleton_methods] << member.update(visibility: nil)
-              else
+              elsif member.visibility == :private
                 partitioned[:private_singleton_methods] << member.update(visibility: nil)
+              else
+                partitioned[:protected_singleton_methods] << member.update(visibility: nil)
               end
             else
               if member.name == :initialize
                 partitioned[:instance_initialize_methods] << member.update(visibility: nil)
               elsif member.visibility == :public
                 partitioned[:public_instance_methods] << member.update(visibility: nil)
-              else
+              elsif member.visibility == :private
                 partitioned[:private_instance_methods] << member.update(visibility: nil)
+              else
+                partitioned[:protected_instance_methods] << member.update(visibility: nil)
               end
             end
           when Members::Alias
@@ -124,7 +132,7 @@ def sort_decl!(decl)
             else
               partitioned[:public_instance_methods] << member
             end
-          when Members::Public, Members::Private
+          when Members::Public, Members::Private, Members::Protected
             raise
           else
             partitioned[:other_decls] << member
@@ -145,8 +153,10 @@ def sort_decl!(decl)
         partitioned[:module_functions].sort_by! {|decl| decl.name.to_s }
         partitioned[:public_singleton_methods].sort_by! {|decl| decl.is_a?(Members::MethodDefinition) ? decl.name.to_s : decl.new_name.to_s }
         partitioned[:private_singleton_methods].sort_by! {|decl| decl.name.to_s }
+        partitioned[:protected_singleton_methods].sort_by! {|decl| decl.name.to_s }
         partitioned[:public_instance_methods].sort_by! {|decl| decl.is_a?(Members::MethodDefinition) ? decl.name.to_s : decl.new_name.to_s }
         partitioned[:private_instance_methods].sort_by! {|decl| decl.name.to_s }
+        partitioned[:protected_instance_methods].sort_by! {|decl| decl.name.to_s }
 
         members = [] #: Array[member]
         members.push(*partitioned[:type_alias_decls])
@@ -172,7 +182,13 @@ def sort_decl!(decl)
         end
         members.push(*partitioned[:private_singleton_methods])
 
-        if current_visibility == :private && !partitioned[:public_instance_methods].empty?
+        if !partitioned[:protected_singleton_methods].empty?
+          current_visibility = :protected
+          members.push Members::Protected.new(location: nil)
+        end
+        members.push(*partitioned[:protected_singleton_methods])
+
+        if current_visibility != :public && !partitioned[:public_instance_methods].empty?
           current_visibility = :public
           members.push Members::Public.new(location: nil)
         end
@@ -180,12 +196,18 @@ def sort_decl!(decl)
         members.push(*partitioned[:instance_initialize_methods])
         members.push(*partitioned[:public_instance_methods])
 
-        if current_visibility == :public && !partitioned[:private_instance_methods].empty?
+        if current_visibility != :private && !partitioned[:private_instance_methods].empty?
           current_visibility = :private
           members.push Members::Private.new(location: nil)
         end
         members.push(*partitioned[:private_instance_methods])
 
+        if current_visibility != :protected && !partitioned[:protected_instance_methods].empty?
+          current_visibility = :protected
+          members.push Members::Protected.new(location: nil)
+        end
+        members.push(*partitioned[:protected_instance_methods])
+
         members.push(*partitioned[:other_decls])
 
         decl.members.replace(_ = members)
diff --git a/lib/rbs/subtractor.rb b/lib/rbs/subtractor.rb
index fe97c9572..5514f6034 100644
--- a/lib/rbs/subtractor.rb
+++ b/lib/rbs/subtractor.rb
@@ -78,7 +78,7 @@ def call(minuend = @minuend, context: nil)
         cvar_exist?(owner, member.name)
       when AST::Members::Include, AST::Members::Extend, AST::Members::Prepend
         mixin_exist?(owner, member, context: context)
-      when AST::Members::Public, AST::Members::Private
+      when AST::Members::Public, AST::Members::Private, AST::Members::Protected
         # They should not be removed even if the subtrahend has them.
         false
       else
@@ -158,7 +158,7 @@ def call(minuend = @minuend, context: nil)
     end
 
     private def access_modifier?(decl)
-      decl.is_a?(AST::Members::Public) || decl.is_a?(AST::Members::Private)
+      decl.is_a?(AST::Members::Public) || decl.is_a?(AST::Members::Private) || decl.is_a?(AST::Members::Protected)
     end
 
     private def update_decl(decl, members:)
diff --git a/lib/rbs/writer.rb b/lib/rbs/writer.rb
index 8d80a4c05..6ec5d6c57 100644
--- a/lib/rbs/writer.rb
+++ b/lib/rbs/writer.rb
@@ -261,6 +261,8 @@ def write_member(member)
         puts "public"
       when AST::Members::Private
         puts "private"
+      when AST::Members::Protected
+        puts "protected"
       when AST::Members::Alias
         write_comment member.comment
         write_annotation member.annotations
diff --git a/test/rbs/parser_test.rb b/test/rbs/parser_test.rb
index ee52200fc..1efa92d91 100644
--- a/test/rbs/parser_test.rb
+++ b/test/rbs/parser_test.rb
@@ -200,6 +200,7 @@ def test_module_decl_public_private
 module Foo
   public
   private
+  protected
 end
     RBS
       decls[0].tap do |decl|
@@ -207,6 +208,7 @@ module Foo
 
         assert_instance_of RBS::AST::Members::Public, decl.members[0]
         assert_instance_of RBS::AST::Members::Private, decl.members[1]
+        assert_instance_of RBS::AST::Members::Protected, decl.members[2]
       end
     end
   end
diff --git a/test/rbs/signature_parsing_test.rb b/test/rbs/signature_parsing_test.rb
index 55855591e..5d81f4c7a 100644
--- a/test/rbs/signature_parsing_test.rb
+++ b/test/rbs/signature_parsing_test.rb
@@ -529,18 +529,19 @@ def foo: -> void
     end
   end
 
-  def test_private_public
+  def test_private_public_protected
     Parser.parse_signature(<<~SIG).tap do |_, _, decls|
       class Foo
         public
         private
+        protected
       end
     SIG
 
       decls[0].yield_self do |decl|
         assert_instance_of Declarations::Class, decl
 
-        assert_equal 2, decl.members.size
+        assert_equal 3, decl.members.size
 
         decl.members[0].yield_self do |m|
           assert_instance_of Members::Public, m
@@ -549,6 +550,10 @@ class Foo
         decl.members[1].yield_self do |m|
           assert_instance_of Members::Private, m
         end
+
+        decl.members[2].yield_self do |m|
+          assert_instance_of Members::Protected, m
+        end
       end
     end
   end
@@ -559,13 +564,14 @@ class Foo
         public def foo: () -> void
         private def bar: () -> void
         def baz: () -> void
+        protected def quux: () -> void
       end
     SIG
 
       decls[0].tap do |decl|
         assert_instance_of Declarations::Class, decl
 
-        assert_equal 3, decl.members.size
+        assert_equal 4, decl.members.size
 
         decl.members[0].tap do |m|
           assert_instance_of Members::MethodDefinition, m
@@ -584,6 +590,12 @@ def baz: () -> void
           assert_equal :baz, m.name
           assert_nil m.visibility
         end
+
+        decl.members[3].tap do |m|
+          assert_instance_of Members::MethodDefinition, m
+          assert_equal :quux, m.name
+          assert_equal :protected, m.visibility
+        end
       end
     end
   end
@@ -604,13 +616,14 @@ class Foo
         public attr_reader foo: String
         private attr_reader bar: String
         attr_reader baz: String
+        protected attr_reader quux: String
       end
     SIG
 
       decls[0].tap do |decl|
         assert_instance_of Declarations::Class, decl
 
-        assert_equal 3, decl.members.size
+        assert_equal 4, decl.members.size
 
         decl.members[0].tap do |m|
           assert_instance_of Members::AttrReader, m
@@ -629,6 +642,12 @@ class Foo
           assert_equal :baz, m.name
           assert_nil m.visibility
         end
+
+        decl.members[3].tap do |m|
+          assert_instance_of Members::AttrReader, m
+          assert_equal :quux, m.name
+          assert_equal :protected, m.visibility
+        end
       end
     end
   end
@@ -650,6 +669,8 @@ class Foo
 
         private
 
+        protected
+
         public    # comment can follow
       end
     SIG
@@ -704,6 +725,7 @@ def singleton: -> String
         def type: -> String
         def module: -> String
         def private: -> String
+        def protected: -> String
         def public: -> untyped
         def interface: -> untyped
         def super: -> untyped
@@ -747,6 +769,7 @@ def _foo!: -> untyped
         :type,
         :module,
         :private,
+        :protected,
         :public,
         :interface,
         :super,