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

(indent-for-comment): Handle them.

1 files changed, 53 insertions, 38 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 8fd370cf71b..b8442fd9b68 100644
--- 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.