/*
 * call-seq:
 *  parse_io(io, encoding)
 *
 * Parse +io+ object with +encoding+
 */
static VALUE parse_io(VALUE klass, VALUE io, VALUE encoding)
{
  xmlCharEncoding enc = (xmlCharEncoding)NUM2INT(encoding);

  xmlParserCtxtPtr ctxt = xmlCreateIOParserCtxt(
      NULL,
      NULL,
      (xmlInputReadCallback)io_read_callback,
      (xmlInputCloseCallback)io_close_callback,
      (void *)io,
      enc
  );

  return Data_Wrap_Struct(klass, NULL, deallocate, ctxt);
}