ANSI Common Lisp 21 Streams 21.2 Dictionary of Streams
- Arguments and Values:
input-stream - an input stream designator.
The default is standard input.
Clears any available input from input-stream.
If clear-input does not make sense for input-stream,
then clear-input does nothing.
;; The exact I/O behavior of this example might vary from implementation
;; to implementation depending on the kind of interactive buffering that
;; occurs. (The call to SLEEP here is intended to help even out the
;; differences in implementations which do not do line-at-a-time buffering.)
(defun read-sleepily (&optional (clear-p nil) (zzz 0))
(list (progn (print '>) (read))
;; Note that input typed within the first ZZZ seconds
;; will be discarded.
(progn (print '>)
(if zzz (sleep zzz))
(if clear-p (clear-input))
(read-sleepily t 10)
> 20 ; Some implementations won't echo typeahead here.
- Side Effects:
The input-stream is modified.
- Affected By:
- Exceptional Situations:
Should signal an error of type type-error if input-stream is not a stream designator.
- See Also:
- Allegro CL Implementation Details: