(block-comment-start, block-comment-end): New vars.

(indent-for-comment): Handle them.

diff --git a/lisp/simple.el b/lisp/simple.el
index 8fd370cf71bdb6ed48593cae848b032de81b2517..b8442fd9b6809f99ad131be10aa575f25639d7a7 100644 (file)
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -1902,7 +1902,7 @@ can set the value for a particular mode using that mode's hook.")
 (make-variable-buffer-local 'comment-column)
 
 (defconst comment-start nil
-  "*String to insert to start a new comment, or nil if no comment syntax defined.")
+  "*String to insert to start a new comment, or nil if no comment syntax.")
 
 (defconst comment-start-skip nil
   "*Regexp to match the start of a comment plus everything up to its body.
@@ -1924,47 +1924,62 @@ the comment's starting delimiter.")
 This function is called with no args with point at the beginning of
 the comment's starting delimiter.")
 
+(defconst block-comment-start nil
+  "*String to insert to start a new comment on a line by itself.
+If nil, use `comment-start' instead.
+Note that the regular expression `comment-start-skip' should skip this string
+as well as the `comment-start' string.")
+
+(defconst block-comment-end nil
+  "*String to insert to end a new comment on a line by itself.
+Should be an empty string if comments are terminated by end-of-line.
+If nil, use `comment-end' instead.")
+
 (defun indent-for-comment ()
   "Indent this line's comment to comment column, or insert an empty comment."
   (interactive "*")
   (beginning-of-line 1)
-  (if (null comment-start)
-      (error "No comment syntax defined")
-    (let* ((eolpos (save-excursion (end-of-line) (point)))
-          cpos indent begpos)
-      (if (re-search-forward comment-start-skip eolpos 'move)
-         (progn (setq cpos (point-marker))
-                ;; Find the start of the comment delimiter.
-                ;; If there were paren-pairs in comment-start-skip,
-                ;; position at the end of the first pair.
-                (if (match-end 1)
-                    (goto-char (match-end 1))
-                  ;; If comment-start-skip matched a string with
-                  ;; internal whitespace (not final whitespace) then
-                  ;; the delimiter start at the end of that
-                  ;; whitespace.  Otherwise, it starts at the
-                  ;; beginning of what was matched.
-                  (skip-syntax-backward " " (match-beginning 0))
-                  (skip-syntax-backward "^ " (match-beginning 0)))))
-      (setq begpos (point))
-      ;; Compute desired indent.
-      (if (= (current-column)
-            (setq indent (if comment-indent-hook
-                             (funcall comment-indent-hook)
-                           (funcall comment-indent-function))))
-         (goto-char begpos)
-       ;; If that's different from current, change it.
-       (skip-chars-backward " \t")
-       (delete-region (point) begpos)
-       (indent-to indent))
-      ;; An existing comment?
-      (if cpos 
-         (progn (goto-char cpos)
-                (set-marker cpos nil))
-       ;; No, insert one.
-       (insert comment-start)
-       (save-excursion
-         (insert comment-end))))))
+  (let* ((empty (save-excursion (beginning-of-line)
+                               (looking-at "[ \t]*$")))
+        (starter (or (and empty block-comment-start) comment-start))
+        (ender (or (and empty block-comment-end) comment-end)))
+    (if (null starter)
+       (error "No comment syntax defined")
+      (let* ((eolpos (save-excursion (end-of-line) (point)))
+            cpos indent begpos)
+       (if (re-search-forward comment-start-skip eolpos 'move)
+           (progn (setq cpos (point-marker))
+                  ;; Find the start of the comment delimiter.
+                  ;; If there were paren-pairs in comment-start-skip,
+                  ;; position at the end of the first pair.
+                  (if (match-end 1)
+                      (goto-char (match-end 1))
+                    ;; If comment-start-skip matched a string with
+                    ;; internal whitespace (not final whitespace) then
+                    ;; the delimiter start at the end of that
+                    ;; whitespace.  Otherwise, it starts at the
+                    ;; beginning of what was matched.
+                    (skip-syntax-backward " " (match-beginning 0))
+                    (skip-syntax-backward "^ " (match-beginning 0)))))
+       (setq begpos (point))
+       ;; Compute desired indent.
+       (if (= (current-column)
+              (setq indent (if comment-indent-hook
+                               (funcall comment-indent-hook)
+                             (funcall comment-indent-function))))
+           (goto-char begpos)
+         ;; If that's different from current, change it.
+         (skip-chars-backward " \t")
+         (delete-region (point) begpos)
+         (indent-to indent))
+       ;; An existing comment?
+       (if cpos 
+           (progn (goto-char cpos)
+                  (set-marker cpos nil))
+         ;; No, insert one.
+         (insert starter)
+         (save-excursion
+           (insert ender)))))))
 
 (defun set-comment-column (arg)
   "Set the comment column based on point.