## Declare namespaces

Raptor can use namespace prefix/URIs to abbreviate syntax in some syntaxes such as Turtle or any XML syntax including RDF/XML, RSS1.0 and Atom 1.0. These are declared with `raptor_serialize_set_namespace()` using a prefix and URI argument pair like this:

      const unsigned char* prefix="ex";
      raptor_uri* uri=raptor_new_uri("http://example.org");

      raptor_serialize_set_namespace(rdf_serializer, prefix, uri);

or `raptor_serialize_set_namespace_from_namespace()` from an existing namespace. This can be useful when connected up the the namespace declarations that are generated from a parser via a namespace handler set with `raptor_set_namespace_handler()`

like this:

      static void
      relay_namespaces(void* user_data, raptor_namespace *nspace)
      {
        raptor_serialize_set_namespace_from_namespace(rdf_serializer, nspace);
      }

      rdf_parser=raptor_new_parser(syntax_name);
      raptor_set_namespace_handler(rdf_parser, rdf_serializer, relay_namespaces);