The standard function
close
is implemented as a generic function. All external resources used by the stream should be freed and true returned when that has been done. The result value for
close
is as per the Common Lisp ANSI specification.
When
stream
is an instance of a subclass of buffered-stream, if
abort
is true then any remaining data in the buffer can be discarded. There are two built-in methods on buffered-stream. The primary method specialized on buffered-stream returns
t
. The other, an
:around
method specialized on buffered-stream, flushes the stream buffer if
abort
is
nil
, calls the next method and marks the stream as closed if that method returns true. Thus the only requirement for a primary method specialized on a subclass of buffered-stream is that it must close any underlying data source and return true.
The
close
method on the
fundamental-stream class sets a flag for open-stream-p