




 
The generic function 
stream-check-eof-no-hang
 determines if the data source of the stream is at end of file, without hanging. 
stream should be an instance of a subclass of buffered-stream.
result
 is 
:eof
 if 
stream
 is at end of file and 
nil
 otherwise.
There is a built-in method specialized on buffered-stream which returns 
:eof
 in all cases.