Implement C++ pretty-printer

luprex/core/cpp/util.hpp

@@ -27,6 +27,9 @@ using IdVector = std::vector<int64_t>;
 // Return true if the string is a valid lua identifier.
 bool is_identifier(const std::string &str);
 
+// Output a string to a stream using Lua string escaping and quoting.
+void quote_string(const std::string &str, std::ostream *os);
+
 // ID vector quick create.
 IdVector id_vector_create(int64_t id1=-1, int64_t id2=-1, int64_t id3=-1, int64_t id4=-1);