interactive-stream-p

interactive-stream-p stream → generalized-boolean

stream — a stream.

generalized-boolean — a generalized boolean.

Returns true if stream is an interactive stream; otherwise, returns false.

(when (> measured limit) 
  (let ((error (round (* (- measured limit) 100) 
                      limit))) 
    (unless (if (interactive-stream-p *query-io*) 
                (yes-or-no-p "The frammis is out of tolerance by ~D%.~@ 
                              Is it safe to proceed? " error) 
                (< error 15))  ;15% is acceptable 
      (error "The frammis is out of tolerance by ~D%." error))))

Should signal an error of type type-error if stream is not a stream.

Section 21.1 (Stream Concepts)