refactoring some codes.

1 files changed, 29 insertions, 0 deletions

diff --git a/MoonParser/ast.cpp b/MoonParser/ast.cpp
index 090f5ee..739e02c 100644
--- a/MoonParser/ast.cpp
+++ b/MoonParser/ast.cpp
@@ -11,6 +11,13 @@ static ast_container *_current = 0;
 int ast_type_id = 0;
 
 
+bool ast_node::visit(const std::function<bool (ast_node*)>& begin,
+                const std::function<bool (ast_node*)>& end)
+{
+        return begin(this) || end(this);
+}
+
+
 /** sets the container under construction to be this.
  */
 ast_container::ast_container() {
@@ -41,6 +48,28 @@ void ast_container::construct(ast_stack &st) {
     }
 }
 
+bool ast_container::visit(const std::function<bool (ast_node*)>& begin,
+                const std::function<bool (ast_node*)>& end)
+{
+        bool result = begin(this);
+        if (result) return true;
+        const auto& members = this->members();
+        for (auto member : members) {
+                if (_ast_ptr* ptr = ast_cast<_ast_ptr>(member)) {
+                        if (ptr->get() && ptr->get()->visit(begin, end)) {
+                                return true;
+                        }
+                } else if (_ast_list* list = ast_cast<_ast_list>(member)) {
+                        for (auto obj : list->objects()) {
+                                if (obj->visit(begin, end)) {
+                                        return true;
+                                }
+                        }
+                }
+        }
+        return end(this);
+}
+
 
 //register the AST member to the current container.
 void ast_member::_init() {