diff --git a/peglib.h b/peglib.h
index 98c41aa..a54fb2e 100644
--- a/peglib.h
+++ b/peglib.h
@@ -459,6 +459,9 @@ struct SemanticValues : protected std::vector<any>
         return peg::line_info(ss, s_);
     }
 
+    // Choice count
+    size_t      choice_count() const { return choice_count_; }
+
     // Choice number (0 based index)
     size_t      choice() const { return choice_; }
 
@@ -480,7 +483,7 @@ struct SemanticValues : protected std::vector<any>
         return this->transform(beg, end, [](const any& v) { return v.get<T>(); });
     }
 
-    SemanticValues() : s_(nullptr), n_(0), choice_(0) {}
+    SemanticValues() : s_(nullptr), n_(0), choice_count_(0), choice_(0) {}
 
     using std::vector<any>::iterator;
     using std::vector<any>::const_iterator;
@@ -512,6 +515,7 @@ private:
 
     const char* s_;
     size_t      n_;
+    size_t      choice_count_;
     size_t      choice_;
 
     template <typename F>
@@ -532,6 +536,17 @@ private:
         }
         return r;
     }
+
+    void reset() {
+        path = nullptr;
+        ss = nullptr;
+        tokens.clear();
+
+        s_ = nullptr;
+        n_ = 0;
+        choice_count_ = 0;
+        choice_ = 0;
+    }
 };
 
 /*
@@ -846,11 +861,9 @@ public:
         if (!sv.empty()) {
             sv.clear();
         }
+        sv.reset();
         sv.path = path;
         sv.ss = s;
-        sv.s_ = nullptr;
-        sv.n_ = 0;
-        sv.tokens.clear();
         return sv;
     }
 
@@ -996,6 +1009,7 @@ public:
                 }
                 sv.s_ = chldsv.c_str();
                 sv.n_ = chldsv.length();
+                sv.choice_count_ = opes_.size();
                 sv.choice_ = id;
                 sv.tokens.insert(sv.tokens.end(), chldsv.tokens.begin(), chldsv.tokens.end());
 
@@ -2893,12 +2907,18 @@ inline constexpr unsigned int operator "" _(const char* s, size_t) {
 template <typename Annotation>
 struct AstBase : public Annotation
 {
-    AstBase(const char* a_path, size_t a_line, size_t a_column, const char* a_name, const std::vector<std::shared_ptr<AstBase>>& a_nodes)
+    AstBase(const char* a_path, size_t a_line, size_t a_column,
+            const char* a_name, size_t a_choice_count, size_t a_choice,
+            const std::vector<std::shared_ptr<AstBase>>& a_nodes)
         : path(a_path ? a_path : "")
         , line(a_line)
         , column(a_column)
         , name(a_name)
+        , choice_count(a_choice_count)
+        , choice(a_choice)
         , original_name(a_name)
+        , original_choice_count(a_choice_count)
+        , original_choice(a_choice)
 #ifndef PEGLIB_NO_CONSTEXPR_SUPPORT
         , tag(str2tag(a_name))
         , original_tag(tag)
@@ -2907,12 +2927,18 @@ struct AstBase : public Annotation
         , nodes(a_nodes)
     {}
 
-    AstBase(const char* a_path, size_t a_line, size_t a_column, const char* a_name, const std::string& a_token)
+    AstBase(const char* a_path, size_t a_line, size_t a_column,
+            const char* a_name, size_t a_choice_count, size_t a_choice,
+            const std::string& a_token)
         : path(a_path ? a_path : "")
         , line(a_line)
         , column(a_column)
         , name(a_name)
+        , choice_count(a_choice_count)
+        , choice(a_choice)
         , original_name(a_name)
+        , original_choice_count(a_choice_count)
+        , original_choice(a_choice)
 #ifndef PEGLIB_NO_CONSTEXPR_SUPPORT
         , tag(str2tag(a_name))
         , original_tag(tag)
@@ -2921,12 +2947,17 @@ struct AstBase : public Annotation
         , token(a_token)
     {}
 
-    AstBase(const AstBase& ast, const char* a_original_name)
+    AstBase(const AstBase& ast, const char* a_original_name,
+            size_t a_original_choice_count, size_t a_original_choise)
         : path(ast.path)
         , line(ast.line)
         , column(ast.column)
         , name(ast.name)
+        , choice_count(ast.choice_count)
+        , choice(ast.choice)
         , original_name(a_original_name)
+        , original_choice_count(a_original_choice_count)
+        , original_choice(a_original_choise)
 #ifndef PEGLIB_NO_CONSTEXPR_SUPPORT
         , tag(ast.tag)
         , original_tag(str2tag(a_original_name))
@@ -2942,7 +2973,11 @@ struct AstBase : public Annotation
     const size_t                      column;
 
     const std::string                 name;
+    const size_t                      choice_count;
+    const size_t                      choice;
     const std::string                 original_name;
+    const size_t                      original_choice_count;
+    const size_t                      original_choice;
 #ifndef PEGLIB_NO_CONSTEXPR_SUPPORT
     const unsigned int                tag;
     const unsigned int                original_tag;
@@ -2966,11 +3001,12 @@ void ast_to_s_core(
     for (auto i = 0; i < level; i++) {
         s += "  ";
     }
-    std::string name;
-    if (ast.name == ast.original_name) {
-        name = ast.name;
-    } else {
-        name = ast.original_name + "[" + ast.name + "]";
+    auto name = ast.original_name;
+    if (ast.original_choice_count > 0) {
+        name += "/" + std::to_string(ast.original_choice);
+    }
+    if (ast.name != ast.original_name) {
+        name += "[" + ast.name + "]";
     }
     if (ast.is_token) {
         s += "- " + name + " (" + ast.token + ")\n";
@@ -3009,7 +3045,8 @@ struct AstOptimizer
 
         if (opt && original->nodes.size() == 1) {
             auto child = optimize(original->nodes[0], parent);
-            return std::make_shared<T>(*child, original->name.c_str());
+            return std::make_shared<T>(
+                *child, original->name.c_str(), original->choice_count, original->choice);
         }
 
         auto ast = std::make_shared<T>(*original);
@@ -3199,10 +3236,16 @@ public:
                     auto line = line_info(sv.ss, sv.c_str());
 
                     if (rule.is_token()) {
-                        return std::make_shared<T>(sv.path, line.first, line.second, name.c_str(), sv.token());
+                        return std::make_shared<T>(
+                            sv.path, line.first, line.second,
+                            name.c_str(), sv.choice_count(), sv.choice(),
+                            sv.token());
                     }
 
-                    auto ast = std::make_shared<T>(sv.path, line.first, line.second, name.c_str(), sv.transform<std::shared_ptr<T>>());
+                    auto ast = std::make_shared<T>(
+                        sv.path, line.first, line.second,
+                        name.c_str(), sv.choice_count(), sv.choice(),
+                        sv.transform<std::shared_ptr<T>>());
 
                     for (auto node: ast->nodes) {
                         node->parent = ast;