Lua file output

["Kevin Watters" <kwatters@...>]

I'd like to let Lua do the serialization for my game--it has access to all
the variables anyway so I thought it would be easy and robust to do a
foreach on each of the tables and write them to disk.  Unfortunately it
looks like the file I/O functions read and write only provide capability for
strings and numbers, NOT userdata. Is there a way around this?--or do I need
to write my own functions?