diff --git a/docs/index.js b/docs/index.js
index bacadac..f8cad8d 100644
--- a/docs/index.js
+++ b/docs/index.js
@@ -45,7 +45,11 @@ function generateErrorListHTML(errors) {
   let html = '<ul>';
 
   html += $.map(errors, function (x) {
-    return '<li data-ln="' + x.ln + '" data-col="' + x.col + '"><span>' + x.ln + ':' + x.col + '</span> <span>' + escapeHtml(x.msg) + '</span></li>';
+    if (x.gln && x.gcol) {
+      return `<li data-ln="${x.ln}" data-col="${x.col}" data-gln="${x.gln}" data-gcol="${x.gcol}"><span>${x.ln}:${x.col}</span> <span>${escapeHtml(x.msg)}</span></li>`;
+    } else {
+      return `<li data-ln="${x.ln}" data-col="${x.col}"><span>${x.ln}:${x.col}</span> <span>${escapeHtml(x.msg)}</span></li>`;
+    }
   }).join('');
 
   html += '<ul>';
@@ -149,6 +153,11 @@ function makeOnClickInInfo(editor) {
     editor.navigateTo(el.data('ln') - 1, el.data('col') - 1);
     editor.scrollToLine(el.data('ln') - 1, true, false, null);
     editor.focus();
+
+    if(el.data('gln') && el.data('gcol')) {
+      grammar.navigateTo(el.data('gln') - 1, el.data('gcol') - 1);
+      grammar.scrollToLine(el.data('gln') - 1, true, false, null);
+    }
   }
 };
 $('#grammar-info').on('click', 'li', makeOnClickInInfo(grammar));
diff --git a/docs/native.cpp b/docs/native.cpp
index 4777274..815682e 100644
--- a/docs/native.cpp
+++ b/docs/native.cpp
@@ -18,15 +18,24 @@ std::string escape_json(const std::string &s) {
   return o.str();
 }
 
-std::function<void(size_t, size_t, const std::string &)>
-makeJSONFormatter(std::string &json, bool &init) {
+std::function<void(size_t, size_t, const std::string &, const std::string &)>
+makeJSONFormatter(peg::parser &peg, std::string &json, bool &init) {
   init = true;
-  return [&](size_t ln, size_t col, const std::string &msg) mutable {
+  return [&](size_t ln, size_t col, const std::string &msg, const std::string &rule) mutable {
     if (!init) { json += ","; }
     json += "{";
     json += R"("ln":)" + std::to_string(ln) + ",";
     json += R"("col":)" + std::to_string(col) + ",";
     json += R"("msg":")" + escape_json(msg) + R"(")";
+    if (!rule.empty()) {
+      auto it = peg.get_grammar().find(rule);
+      if (it != peg.get_grammar().end()) {
+        auto [gln, gcol] = it->second.line_;
+        json += ",";
+        json += R"("gln":)" + std::to_string(gln) + ",";
+        json += R"("gcol":)" + std::to_string(gcol);
+      }
+    }
     json += "}";
 
     init = false;
@@ -36,7 +45,7 @@ makeJSONFormatter(std::string &json, bool &init) {
 bool parse_grammar(const std::string &text, peg::parser &peg,
                    std::string &json) {
   bool init;
-  peg.set_logger(makeJSONFormatter(json, init));
+  peg.set_logger(makeJSONFormatter(peg, json, init));
   json += "[";
   auto ret = peg.load_grammar(text.data(), text.size());
   json += "]";
@@ -47,7 +56,7 @@ bool parse_code(const std::string &text, peg::parser &peg, std::string &json,
                 std::shared_ptr<peg::Ast> &ast) {
   peg.enable_ast();
   bool init;
-  peg.set_logger(makeJSONFormatter(json, init));
+  peg.set_logger(makeJSONFormatter(peg, json, init));
   json += "[";
   auto ret = peg.parse_n(text.data(), text.size(), ast);
   json += "]";
diff --git a/docs/native.wasm b/docs/native.wasm
index c11f203..80970ce 100755
Binary files a/docs/native.wasm and b/docs/native.wasm differ
diff --git a/peglib.h b/peglib.h
index fe4f092..ad7b2d7 100644
--- a/peglib.h
+++ b/peglib.h
@@ -2328,6 +2328,7 @@ public:
 
   std::string name;
   const char *s_ = nullptr;
+  std::pair<size_t, size_t> line_ = {1, 1};
 
   std::function<bool(const SemanticValues &vs, const std::any &dt,
                      std::string &msg)>
@@ -2557,6 +2558,9 @@ inline void ErrorInfo::output_log(const Log &log, const char *s, size_t n) {
               msg += "'";
             } else {
               msg += "<" + error_rule->name + ">";
+              if (label.empty()) {
+                label = error_rule->name;
+              }
             }
             first_item = false;
           }
@@ -2937,12 +2941,10 @@ inline size_t Recovery::parse_core(const char *s, size_t n,
   // Custom error message
   if (c.log) {
     auto label = dynamic_cast<Reference *>(rule.args_[0].get());
-    if (label) {
-      if (!label->rule_->error_message.empty()) {
-        c.error_info.message_pos = s;
-        c.error_info.message = label->rule_->error_message;
-        c.error_info.label = label->rule_->name;
-      }
+    if (label && !label->rule_->error_message.empty()) {
+      c.error_info.message_pos = s;
+      c.error_info.message = label->rule_->error_message;
+      c.error_info.label = label->rule_->name;
     }
   }
 
@@ -3481,13 +3483,14 @@ private:
         rule <= ope;
         rule.name = name;
         rule.s_ = vs.sv().data();
+        rule.line_ = line_info(vs.ss, rule.s_);
         rule.ignoreSemanticValue = ignore;
         rule.is_macro = is_macro;
         rule.params = params;
 
         if (data.start.empty()) {
-          data.start = name;
-          data.start_pos = vs.sv().data();
+          data.start = rule.name;
+          data.start_pos = rule.s_;
         }
       } else {
         data.duplicates_of_definition.emplace_back(name, vs.sv().data());
@@ -4549,13 +4552,7 @@ public:
 
   const Definition &operator[](const char *s) const { return (*grammar_)[s]; }
 
-  std::vector<std::string> get_rule_names() const {
-    std::vector<std::string> rules;
-    for (auto &[name, _] : *grammar_) {
-      rules.push_back(name);
-    }
-    return rules;
-  }
+  const Grammar &get_grammar() const { return *grammar_; }
 
   void disable_eoi_check() {
     if (grammar_ != nullptr) {
diff --git a/test/test1.cc b/test/test1.cc
index 3139dda..1f6e801 100644
--- a/test/test1.cc
+++ b/test/test1.cc
@@ -901,7 +901,8 @@ TEST(GeneralTest, Semantic_values_test) {
         x <- 'x'
     )");
 
-  for (const auto &rule : parser.get_rule_names()) {
+  for (const auto &item : parser.get_grammar()) {
+    const auto &rule = item.first;
     parser[rule.data()] = [rule](const SemanticValues &vs, std::any &) {
       if (rule == "term") {
         EXPECT_EQ("a at 0", std::any_cast<std::string>(vs[0]));