Add visit operation

src/visitor.cpp

@@ -0,0 +1,57 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#include <cppast/visitor.hpp>
+
+#include <cppast/cpp_entity.hpp>
+#include <cppast/cpp_entity_type.hpp>
+#include <cppast/cpp_enum.hpp>
+#include <cppast/cpp_file.hpp>
+#include <cppast/cpp_namespace.hpp>
+
+using namespace cppast;
+
+namespace
+{
+    template <typename T>
+    bool handle_container(const cpp_entity& e, detail::visitor_callback_t cb, void* functor)
+    {
+        auto& container = static_cast<const T&>(e);
+
+        auto handle_children = cb(functor, container, visitor_info::container_entity_enter);
+        if (handle_children)
+        {
+            for (auto& child : container)
+                if (!detail::visit(child, cb, functor))
+                    return false;
+        }
+
+        return cb(functor, container, visitor_info::container_entity_exit);
+    }
+}
+
+bool detail::visit(const cpp_entity& e, detail::visitor_callback_t cb, void* functor)
+{
+    switch (e.type())
+    {
+    case cpp_entity_type::file_t:
+        return handle_container<cpp_file>(e, cb, functor);
+    case cpp_entity_type::namespace_t:
+        return handle_container<cpp_namespace>(e, cb, functor);
+    case cpp_entity_type::enum_t:
+        return handle_container<cpp_enum>(e, cb, functor);
+
+    case cpp_entity_type::namespace_alias_t:
+    case cpp_entity_type::using_directive_t:
+    case cpp_entity_type::using_declaration_t:
+    case cpp_entity_type::enum_value_t:
+        return cb(functor, e, visitor_info::leave_entity);
+
+    case cpp_entity_type::count:
+        break;
+    }
+
+    DEBUG_UNREACHABLE(detail::assert_handler{});
+    return true;
+}