;; (SMURF) prints 300 characters around the current position in INFILE.
;; It's useful when you get a dot-context error or other error while
;; loading a file.  Just do (SMURF) and it'll print out the vicinity
;; of the error.  2/3 of the printing will be before the error, 1/3
;; after.  If you want to see more context, just call it on the number
;; of characters you'd like to see instead of 300.
;; This function is my version of a long-existing function who's origin
;; is lost in the murky depths of history.  You'll have to play historian
;; if you want to know why it's named SMURF! --RWK

(HERALD SMURF)

(defun smurf (&optional (chars-wanted 300))
  (cond ((and (filep infile) (memq 'filepos (status filemode infile)))
	 (terpri tyo)
	 (let ((old-filepos (filepos infile))
	       (pre-chars (// (* 2 chars-wanted) 3)))
	      (let ((new-filepos (max 0 (- old-filepos pre-chars)))
		    (post-chars (- chars-wanted pre-chars)))
		   (filepos infile new-filepos)
		   (smurf-em (min old-filepos pre-chars))
		   (filepos infile old-filepos)
		   (princ '|===>>> Error Occured Here <<<===| tyo)
		   (smurf-em post-chars))))
	(T (terpri tyo)
	   (princ '|Can't FILEPOS with INFILE = | tyo)
	   (prin1 infile tyo)
	   (terpri tyo))))

(defun smurf-em (chars-wanted)
       (DO ((num chars-wanted (1- num))
	    (char (tyi infile nil)
		  (tyi infile nil)))
	   ((or (= num 0)
		(null char)))
	   (tyo char tyo)))