Added SMETHREF

compile.c

@@ -4524,7 +4524,7 @@ defined_expr0(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
       case NODE_ATTRASGN:{
 	const int explicit_receiver =
 	    (type == NODE_CALL || type == NODE_OPCALL ||
-             type == NODE_METHREF ||
+             (type == NODE_METHREF && node->nd_recv) ||
 	     (type == NODE_ATTRASGN && !private_recv_p(node)));
 
 	if (!lfinish[1] && (node->nd_args || explicit_receiver)) {
@@ -7499,7 +7499,12 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, in
 	break;
       }
       case NODE_METHREF:
-        CHECK(COMPILE_(ret, "receiver", node->nd_recv, popped));
+        if (node->nd_recv) {
+            CHECK(COMPILE_(ret, "receiver", node->nd_recv, popped));
+        }
+        else {
+	    ADD_INSN(ret, line, putself);
+        }
         ADD_ELEM(ret, &new_insn_body(iseq, line, BIN(methodref), 1, ID2SYM(node->nd_mid))->link);
         break;
       default:

node.c

@@ -938,7 +938,12 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
 	ANN("method reference");
 	ANN("format: [nd_recv].:[nd_mid]");
 	ANN("example: foo.:method");
-	F_NODE(nd_recv, "receiver");
+        if (node->nd_recv) {
+            F_NODE(nd_recv, "receiver");
+        }
+        else {
+	    F_MSG(nd_recv, "implicit self", "omitted receiver");
+        }
 	LAST_NODE;
 	F_ID(nd_mid, "method name");
 	return;

parse.y

@@ -900,6 +900,7 @@ static void token_info_warn(struct parser_params *p, const char *token, token_in
 %token tDSTAR		"**arg"
 %token tAMPER		"&"
 %token tLAMBDA		"->"
+%token tSMETHREF	"(.:name)"
 %token tSYMBEG tSTRING_BEG tXSTRING_BEG tREGEXP_BEG tWORDS_BEG tQWORDS_BEG tSYMBOLS_BEG tQSYMBOLS_BEG
 %token tSTRING_DBEG tSTRING_DEND tSTRING_DVAR tSTRING_END tLAMBEG tLABEL_END
 
@@ -2718,6 +2719,13 @@ primary		: literal
 		    /*% %*/
 		    /*% ripper: methref!($1, $3) %*/
 		    }
+		| tSMETHREF operation2
+		    {
+		    /*%%%*/
+			$$ = NEW_METHREF(0, $2, &@$);
+		    /*% %*/
+		    /*% ripper: methref!(Qnil, $2) %*/
+		    }
 		;
 
 primary_value	: primary
@@ -8078,7 +8086,7 @@ parser_yylex(struct parser_params *p)
 	  case ':':
 	    if ((c = nextc(p)) != -1 && parser_is_identchar(p)) {
 		pushback(p, c);
-		return tMETHREF;
+		return IS_lex_state_for(last_state, EXPR_BEG) ? tSMETHREF : tMETHREF;
 	    }
 	    pushback(p, c);
 	    c = ':';