Function: ispell-filter

ispell-filter is a byte-compiled function defined in ispell.el.gz.

Signature

(ispell-filter PROCESS OUTPUT)

Documentation

Output filter function for ispell, grep, and look.

Source Code

;; Defined in /usr/src/emacs/lisp/textmodes/ispell.el.gz
;; "ispell-filter" is a list of output lines from the generating function.
;;   Each full line (ending with \n) is a separate item on the list.
;; "output" can contain multiple lines, part of a line, or both.
;; "start" and "end" are used to keep bounds on lines when "output" contains
;;   multiple lines.
;; "ispell-filter-continue" is true when we have received only part of a
;;   line as output from a generating function ("output" did not end with \n)
;; THIS FUNCTION WILL FAIL IF THE PROCESS OUTPUT DOESN'T END WITH \n!
;;   This is the case when a process dies or fails. The default behavior
;;   in this case treats the next input received as fresh input.

(defun ispell-filter (_process output)
  "Output filter function for ispell, grep, and look."
  (let ((start 0)
	(continue t)
	end)
    (while continue
      (setq end (string-search "\n" output start)) ; get text up to the newline.
      ;; If we get out of sync and ispell-filter-continue is asserted when we
      ;; are not continuing, treat the next item as a separate list.  When
      ;; ispell-filter-continue is asserted, ispell-filter *should* always be a
      ;; list!

      ;; Continue with same line (item)?
      (if (and ispell-filter-continue ispell-filter (listp ispell-filter))
	  ;; Yes.  Add it to the prev item
	  (setcar ispell-filter
		  (concat (car ispell-filter) (substring output start end)))
	;; No. This is a new line and item.
	(setq ispell-filter
	      (cons (substring output start end) ispell-filter)))
      (if (null end)
	  ;; We've completed reading the output, but didn't finish the line.
	  (setq ispell-filter-continue t continue nil)
	;; skip over newline, this line complete.
	(setq ispell-filter-continue nil end (1+ end))
	(if (= end (length output))	; No more lines in output
	    (setq continue nil)		;  so we can exit the filter.
	  (setq start end))))))		; else move start to next line of input