PECL-Gen Help

Hi, I am using PECL_Gen to develop a php binding to a library that I wrote, and I was wondering if it is possible to set up the public functions with variable number of arguments or do I have to do this after I have finished creating the prototype with PECL_Gen Also are there any good working example of using pecl-gen and the format of the xml? The manual seems a little lite in some areas. Thanks in advance Gordon.