Function: ediff-extract-diffs

ediff-extract-diffs is a byte-compiled function defined in ediff-diff.el.gz.

Signature

(ediff-extract-diffs DIFF-BUFFER WORD-MODE &optional BOUNDS)

Source Code

;; Defined in /usr/src/emacs/lisp/vc/ediff-diff.el.gz
;; BOUNDS specifies visibility bounds to use.
;; WORD-MODE tells whether we are in the word-mode or not.
;; If WORD-MODE, also construct vector of diffs using word numbers.
;; Else, use point values.
;; This function handles diff-2 jobs including the case of
;; merging buffers and files without ancestor.
(defun ediff-extract-diffs (diff-buffer word-mode &optional bounds)
  (let ((A-buffer ediff-buffer-A)
	(B-buffer ediff-buffer-B)
	(C-buffer ediff-buffer-C)
	(a-prev 1) ; this is needed to set the first diff line correctly
	(a-prev-pt nil)
	(b-prev 1)
	(b-prev-pt nil)
	(c-prev 1)
	(c-prev-pt nil)
	diff-list shift-A shift-B
	)

    ;; diff list contains word numbers, unless changed later
    (setq diff-list (cons (if word-mode 'words 'points)
			  diff-list))
    ;; we don't use visibility bounds for buffer C when merging
    (if bounds
	(setq shift-A
	      (ediff-overlay-start
	       (ediff-get-value-according-to-buffer-type 'A bounds))
	      shift-B
	      (ediff-overlay-start
	       (ediff-get-value-according-to-buffer-type 'B bounds))))

    ;; reset point in buffers A/B/C
    (ediff-with-current-buffer A-buffer
      (goto-char (if shift-A shift-A (point-min))))
    (ediff-with-current-buffer B-buffer
      (goto-char (if shift-B shift-B (point-min))))
    (if (ediff-buffer-live-p C-buffer)
	(ediff-with-current-buffer C-buffer
	  (goto-char (point-min))))

    (ediff-with-current-buffer diff-buffer
      (goto-char (point-min))
      (while (re-search-forward ediff-match-diff-line nil t)
       (let* ((a-begin (string-to-number (buffer-substring (match-beginning 1)
                                                           (match-end 1))))
	      (a-end  (let ((b (match-beginning 3))
			    (e (match-end 3)))
			(if b
			    (string-to-number (buffer-substring b e))
			  a-begin)))
	      (diff-type (buffer-substring (match-beginning 4) (match-end 4)))
	      (b-begin (string-to-number (buffer-substring (match-beginning 5)
                                                           (match-end 5))))
	      (b-end (let ((b (match-beginning 7))
			   (e (match-end 7)))
		       (if b
			   (string-to-number (buffer-substring b e))
			 b-begin)))
	      a-begin-pt a-end-pt b-begin-pt b-end-pt
	      c-begin c-end c-begin-pt c-end-pt)
	 ;; fix the beginning and end numbers, because diff is somewhat
	 ;; strange about how it numbers lines
	 (if (string-equal diff-type "a")
	     (setq b-end (1+ b-end)
		   a-begin (1+ a-begin)
		   a-end a-begin)
	   (if (string-equal diff-type "d")
	       (setq a-end (1+ a-end)
		     b-begin (1+ b-begin)
		     b-end b-begin)
	     ;; (string-equal diff-type "c")
	     (setq a-end (1+ a-end)
		   b-end (1+ b-end))))

	 (if (eq ediff-default-variant 'default-B)
	     (setq c-begin b-begin
		   c-end b-end)
	   (setq c-begin a-begin
		 c-end a-end))

	 ;; compute main diff vector
	 (if word-mode
	     ;; make diff-list contain word numbers
	     (setq diff-list
		   (nconc diff-list
			  (list
			   (if (ediff-buffer-live-p C-buffer)
			       (vector (- a-begin a-prev) (- a-end a-begin)
				       (- b-begin b-prev) (- b-end b-begin)
				       (- c-begin c-prev) (- c-end c-begin)
				       nil nil ; dummy ancestor
				       nil     ; state of diff
				       nil     ; state of merge
				       nil     ; state of ancestor
				       )
			     (vector (- a-begin a-prev) (- a-end a-begin)
				     (- b-begin b-prev) (- b-end b-begin)
				     nil nil ; dummy buf C
				     nil nil ; dummy ancestor
				     nil     ; state of diff
				     nil     ; state of merge
				     nil     ; state of ancestor
				     ))
			   ))
		   a-prev a-end
		   b-prev b-end
		   c-prev c-end)
	   ;; else convert lines to points
	   (ediff-with-current-buffer A-buffer
	     (goto-char (or a-prev-pt shift-A (point-min)))
	     (forward-line (- a-begin a-prev))
	     (setq a-begin-pt (point))
	     (forward-line (- a-end a-begin))
	     (setq a-end-pt (point)
		   a-prev a-end
		   a-prev-pt a-end-pt))
	   (ediff-with-current-buffer B-buffer
	     (goto-char (or b-prev-pt shift-B (point-min)))
	     (forward-line (- b-begin b-prev))
	     (setq b-begin-pt (point))
	     (forward-line (- b-end b-begin))
	     (setq b-end-pt (point)
		   b-prev b-end
		   b-prev-pt b-end-pt))
	   (if (ediff-buffer-live-p C-buffer)
	       (ediff-with-current-buffer C-buffer
		 (goto-char (or c-prev-pt (point-min)))
		 (forward-line (- c-begin c-prev))
		 (setq c-begin-pt (point))
		 (forward-line (- c-end c-begin))
		 (setq c-end-pt (point)
		       c-prev c-end
		       c-prev-pt c-end-pt)))
	   (setq diff-list
		 (nconc
		  diff-list
		  (list
		   (if (ediff-buffer-live-p C-buffer)
		       (vector
			a-begin-pt a-end-pt b-begin-pt b-end-pt
			c-begin-pt c-end-pt
			nil nil	; dummy ancestor
			;; state of diff
			;; shows which buff is different from the other two
			(if (eq ediff-default-variant 'default-B) 'A 'B)
			ediff-default-variant	; state of merge
			nil			; state of ancestor
			)
		     (vector a-begin-pt a-end-pt
			     b-begin-pt b-end-pt
			     nil nil	; dummy buf C
			     nil nil	; dummy ancestor
			     nil nil	; dummy state of diff & merge
			     nil	; dummy state of ancestor
			     )))
		  )))

	 ))) ; end ediff-with-current-buffer
    diff-list
    ))