From b69e7bfacd629ee4c25ffb873a80f49518deb43c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonathan=20M=C3=BCller?= <git@foonathan.net>
Date: Tue, 31 Oct 2017 18:28:18 +0100
Subject: [PATCH] Add enum_to_string example

---
 example/CMakeLists.txt     |  1 +
 example/enum_to_string.cpp | 61 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 example/enum_to_string.cpp

diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
index 928bdfb..a831176 100644
--- a/example/CMakeLists.txt
+++ b/example/CMakeLists.txt
@@ -9,3 +9,4 @@ endfunction()
 
 _cppast_example(ast_printer)
 _cppast_example(documentation_generator)
+_cppast_example(enum_to_string)
diff --git a/example/enum_to_string.cpp b/example/enum_to_string.cpp
new file mode 100644
index 0000000..ec1428a
--- /dev/null
+++ b/example/enum_to_string.cpp
@@ -0,0 +1,61 @@
+// 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.
+
+/// \file
+/// Generates enum `to_string()` code.
+
+#include <iostream>
+
+#include <cppast/cpp_enum.hpp> // cpp_enum
+#include <cppast/visitor.hpp>  // visit()
+
+#include "example_parser.hpp"
+
+void generate_to_string(const cppast::cpp_file& file)
+{
+    cppast::visit(file,
+                  [](const cppast::cpp_entity& e) {
+                      // only visit enums that have the attribute set
+                      return (e.kind() == cppast::cpp_entity_kind::enum_t
+                              && cppast::has_attribute(e, "generate::to_string"))
+                             // or all namespaces
+                             || e.kind() == cppast::cpp_entity_kind::namespace_t;
+                  },
+                  [](const cppast::cpp_entity& e, const cppast::visitor_info& info) {
+                      if (e.kind() == cppast::cpp_entity_kind::enum_t && !info.is_old_entity())
+                      {
+                          // a new enum, generate to string function
+                          auto& enum_ = static_cast<const cppast::cpp_enum&>(e);
+
+                          // write function header
+                          std::cout << "const char* to_string(const " << enum_.name() << "& e) {\n";
+
+                          // generate switch
+                          std::cout << "  switch (e) {\n";
+                          for (const auto& enumerator : enum_)
+                          {
+                              std::cout << "  case " << enum_.name() << "::" << enumerator.name()
+                                        << ":\n";
+                              std::cout << "    return \"" << enumerator.name() << "\";\n";
+                          }
+                          std::cout << "  }\n";
+
+                          std::cout << "}\n\n";
+                      }
+                      else if (e.kind() == cppast::cpp_entity_kind::namespace_t)
+                      {
+                          if (info.event == cppast::visitor_info::container_entity_enter)
+                              // open namespace
+                              std::cout << "namespace " << e.name() << " {\n\n";
+                          else // if (info.event == cppast::visitor_info::container_entity_exit)
+                              // close namespace
+                              std::cout << "}\n";
+                      }
+                  });
+}
+
+int main(int argc, char* argv[])
+{
+    return example_main(argc, argv, {}, &generate_to_string);
+}