Tag: raw-io	Event driven IO watcher. Feed it a file descriptor, and it'll call you when data arrives, or is ready to be sent.
Attrib Name	Type	Possible Values	Description
fd	integer	-1,*	Sepcify the file descripter to watch
oncanread	function	null	Function to call when the fd is ready for reading.
oncanwrite	function	null	Function to call when the fd is ready for writing.
onerror	function	null	Function to call when an exception occurs on the fd.