1 files changed, 37 insertions, 7 deletions

diff --git a/MoonParser/ast.hpp b/MoonParser/ast.hpp
index 1077f5d..63dccba 100644
--- a/MoonParser/ast.hpp
+++ b/MoonParser/ast.hpp
@@ -63,7 +63,18 @@ public:
      */
         virtual traversal traverse(const std::function<traversal (ast_node*)>& func);
 
-        virtual ast_node* getByPath(std::initializer_list<size_t> paths);
+        template <typename... Ts>
+        struct select_last {
+                using type = typename decltype((std::enable_if<true,Ts>{}, ...))::type;
+        };
+        template <typename... Ts>
+        using select_last_t = typename select_last<Ts...>::type;
+
+        template <class ...Args>
+        select_last_t<Args...>* getByPath() {
+                int types[] = {ast_type<Args>()...};
+                return static_cast<select_last_t<Args...>*>(getByTypeIds(std::begin(types), std::end(types)));
+        }
 
         virtual bool visitChild(const std::function<bool (ast_node*)>& func);
 
@@ -82,6 +93,7 @@ public:
         virtual int get_type() { return ast_type<ast_node>(); }
 private:
         int _ref;
+        ast_node* getByTypeIds(int* begin, int* end);
     template <class T, bool OPT, bool MEM> friend class ast_ptr;
     template <class ...Args> friend class ast_choice;
     template <class T> friend class ast_list;
@@ -89,10 +101,16 @@ private:
 };
 
 template<class T>
-T* ast_cast(ast_node *node) {
+T* ast_cast(ast_node* node) {
         return node && ast_type<T>() == node->get_type() ? static_cast<T*>(node) : nullptr;
 }
 
+template<class T>
+T* ast_to(ast_node* node) {
+        assert(node->get_type() == ast_type<T>());
+        return static_cast<T*>(node);
+}
+
 template <class ...Args>
 bool ast_is(ast_node* node) {
         if (!node) return false;
@@ -132,8 +150,6 @@ public:
      */
     virtual void construct(ast_stack& st) override;
 
-        virtual ast_node* getByPath(std::initializer_list<size_t> paths) override;
-
         virtual traversal traverse(const std::function<traversal (ast_node*)>& func) override;
 
         virtual bool visitChild(const std::function<bool (ast_node*)>& func) override;
@@ -210,7 +226,7 @@ public:
 
         template <class T>
         T* to() const {
-                assert(m_ptr->getId() != ast_type<T>());
+                assert(m_ptr->get_type() == ast_type<T>());
                 return static_cast<T*>(m_ptr);
         }
 
@@ -380,6 +396,22 @@ public:
                 }
         }
 
+    void set_front(ast_node* node) {
+                if (accept(node)) {
+                        m_objects.front()->release();
+                        m_objects.front() = node;
+                        node->retain();
+                }
+        }
+
+    void set_back(ast_node* node) {
+                if (accept(node)) {
+                        m_objects.back()->release();
+                        m_objects.back() = node;
+                        node->retain();
+                }
+        }
+
          const container& objects() const {
         return m_objects;
     }
@@ -410,7 +442,6 @@ protected:
  */
 template <class T> class ast_list : public _ast_list {
 public:
-    ///the default constructor.
     ast_list() {}
 
     ast_list(const ast_list<T>& other) {
@@ -450,7 +481,6 @@ private:
 
 template <class ...Args> class ast_sel_list : public _ast_list {
 public:
-    ///the default constructor.
     ast_sel_list() {}
 
     ast_sel_list(const ast_sel_list<Args...>& other) {