Implement Occur multi-line matches.

http://lists.gnu.org/archive/html/emacs-devel/2010-03/msg01044.html

* replace.el (occur): Doc fix.
(occur-engine): Set `begpt' to the beginning of the first line.
Set `endpt' to the end of the last match line.  At first, count
line numbers between `origpt' and `begpt'.  Split out code from
`out-line' variable to new let-bindings `match-prefix' and
`match-str'.  In `out-line' add non-numeric prefix to all
non-first lines of multi-line matches.  Finally, count lines
between `begpt' and `endpt' and add to `lines'.

3 files changed, 52 insertions, 25 deletions

diff --git a/etc/TODO b/etc/TODO
index a20ffdaa0d3..6ce2947bd93 100644
--- a/etc/TODO
+++ b/etc/TODO
@@ -105,9 +105,6 @@ for users to customize.
 
 ** erase-buffer should perhaps disregard read-only properties of text.
 
-** Make occur correctly handle matches that span more than one line,
-   as well as overlapping matches.
-
 ** Fix the kill/yank treatment of invisible text.  At the moment,
   invisible text is placed in the kill-ring, so that the contents of
   the ring may not correspond to the text as displayed to the user.
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b84b8436993..c417eb7246e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,19 @@
 2010-03-23  Juri Linkov  <juri@jurta.org>
 
+        Implement Occur multi-line matches.
+        http://lists.gnu.org/archive/html/emacs-devel/2010-03/msg01044.html
+
+        * replace.el (occur): Doc fix.
+        (occur-engine): Set `begpt' to the beginning of the first line.
+        Set `endpt' to the end of the last match line.  At first, count
+        line numbers between `origpt' and `begpt'.  Split out code from
+        `out-line' variable to new let-bindings `match-prefix' and
+        `match-str'.  In `out-line' add non-numeric prefix to all
+        non-first lines of multi-line matches.  Finally, count lines
+        between `begpt' and `endpt' and add to `lines'.
+
+2010-03-23  Juri Linkov  <juri@jurta.org>
+
         * replace.el (occur-accumulate-lines, occur-engine):
         Use `occur-engine-line' instead of duplicate code.
         (occur-engine-line): New function created from duplicate code
diff --git a/lisp/replace.el b/lisp/replace.el
index f2d49b4de1c..4a8b39dbca7 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -1045,7 +1045,7 @@ invoke `occur'."
 
 (defun occur (regexp &optional nlines)
   "Show all lines in the current buffer containing a match for REGEXP.
-This function can not handle matches that span more than one line.
+If a match spreads across multiple lines, all those lines are shown.
 
 Each line is displayed with NLINES lines before and after, or -NLINES
 before if NLINES is negative.
@@ -1210,11 +1210,14 @@ See also `multi-occur'."
                   (when (setq endpt (re-search-forward regexp nil t))
                     (setq matches (1+ matches)) ;; increment match count
                     (setq matchbeg (match-beginning 0))
-                    (setq lines (+ lines (1- (count-lines origpt endpt))))
+                    ;; Get beginning of first match line and end of the last.
                     (save-excursion
                       (goto-char matchbeg)
-                      (setq begpt (line-beginning-position)
-                            endpt (line-end-position)))
+                      (setq begpt (line-beginning-position))
+                      (goto-char endpt)
+                      (setq endpt (line-end-position)))
+                    ;; Sum line numbers up to the first match line.
+                    (setq lines (+ lines (count-lines origpt begpt)))
                     (setq marker (make-marker))
                     (set-marker marker matchbeg)
                     (setq curstring (occur-engine-line begpt endpt keep-props))
@@ -1234,24 +1237,33 @@ See also `multi-occur'."
                          curstring)
                         (setq start (match-end 0))))
                     ;; Generate the string to insert for this match
-                    (let* ((out-line
+                    (let* ((match-prefix
+                            ;; Using 7 digits aligns tabs properly.
+                            (apply #'propertize (format "%7d:" lines)
+                                   (append
+                                    (when prefix-face
+                                      `(font-lock-face prefix-face))
+                                    `(occur-prefix t mouse-face (highlight)
+                                                   occur-target ,marker follow-link t
+                                                   help-echo "mouse-2: go to this occurrence"))))
+                           (match-str
+                            ;; We don't put `mouse-face' on the newline,
+                            ;; because that loses.  And don't put it
+                            ;; on context lines to reduce flicker.
+                            (propertize curstring 'mouse-face (list 'highlight)
+                                        'occur-target marker
+                                        'follow-link t
+                                        'help-echo
+                                        "mouse-2: go to this occurrence"))
+                           (out-line
                             (concat
-                             ;; Using 7 digits aligns tabs properly.
-                             (apply #'propertize (format "%7d:" lines)
-                                    (append
-                                     (when prefix-face
-                                       `(font-lock-face prefix-face))
-                                     `(occur-prefix t mouse-face (highlight)
-                                       occur-target ,marker follow-link t
-                                       help-echo "mouse-2: go to this occurrence")))
-                             ;; We don't put `mouse-face' on the newline,
-                             ;; because that loses.  And don't put it
-                             ;; on context lines to reduce flicker.
-                             (propertize curstring 'mouse-face (list 'highlight)
-                                         'occur-target marker
-                                         'follow-link t
-                                         'help-echo
-                                         "mouse-2: go to this occurrence")
+                             match-prefix
+                             ;; Add non-numeric prefix to all non-first lines
+                             ;; of multi-line matches.
+                             (replace-regexp-in-string
+                              "\n"
+                              "\n       :"
+                              match-str)
                              ;; Add marker at eol, but no mouse props.
                              (propertize "\n" 'occur-target marker)))
                            (data
@@ -1270,7 +1282,11 @@ See also `multi-occur'."
                     (goto-char endpt))
                   (if endpt
                       (progn
-                        (setq lines (1+ lines))
+                        ;; Sum line numbers between first and last match lines.
+                        (setq lines (+ lines (count-lines begpt endpt)
+                                       ;; Add 1 for empty last match line since
+                                       ;; count-lines returns 1 line less.
+                                       (if (and (bolp) (eolp)) 1 0)))
                         ;; On to the next match...
                         (forward-line 1))
                     (goto-char (point-max))))))