Re: Emacs CC Mode's auto-newline facility: INFORMAL SURVEY

[Ben Pfaff <blp@cs.stanford.edu>]

Alan Mackenzie <acm@muc.de> writes:

> o Do you program with auto-newline switched on (e.g. do you get NLs
>   inserted automatically after typing a `;' or `{')?

Yes.

> o Did you configure this auto-newline setting yourself, and if not, are
>   you happy with it?

Yes.  I have some customization in my .emacs.  I don't know elisp
well enough to tell whether this code entirely makes sense, but
it seems to do what I want:

;; Returns true if the last character typed by the user was a
;; semicolon.  (This is a gross hack.)
(defun newline-if-semi ()
  (= last-command-char ?\;))

...
;; My style for C, based on GNU style.
(defconst blp-c-style
...
    ;; Insert a newline after a typed semicolon if the line after this
    ;; one is blank and we're not inside a set of parentheses.
    ;; Never insert a newline after a comma.
    (c-hanging-semi&comma-criteria . (c-semi&comma-no-newlines-before-nonblanks
				      c-semi&comma-inside-parenlist
				      newline-if-semi))
...

For what it's worth, I use this in conjunction with custom
keybindings to create and end {} blocks:

  ;; Simplifies braced blocks: just type M-{ at the beginning, type
  ;; some statements, type M-} to end it, and no need to worry about
  ;; anything else.
  (local-set-key [?\M-{] 'insert-brace)
  (local-set-key [?\M-}] 'move-past-brace-and-reindent)

  ;; Inserts a pair of braces {}, properly spacing them, and puts the
  ;; cursor between them.
  (defun insert-brace ()
    (interactive)
    (setq last-command-event ?{)
    (c-electric-brace nil)
    (c-indent-line)
    (save-excursion
      (insert "\n\n}")
      (c-indent-command)))

  (defun move-past-brace-and-reindent ()
    (interactive)
    (delete-all-blank-lines)
    (search-forward "}")
    (let ((save-point))
      (save-excursion
        (insert "\n")
        (c-indent-line)
        (setq save-point (point)))
      (funcall blink-paren-function)
      (goto-char save-point)))
  (defun delete-all-blank-lines ()
    "Delete all surrounding blank lines."
    (interactive "*")
    (save-excursion
      (beginning-of-line)
      (if (looking-at "[ \t]*$")
          (delete-region (if (re-search-backward "[^ \t\n]" nil t)
                             (progn (forward-line 1) (point))
                           (point-min))
                         (if (re-search-forward "[^ \t\n]" nil t)
                             (progn (beginning-of-line) (point))
                           (point-max))))))

> o Are you aware of the key binding C-c C-a to toggle this mode on and
>   off?

Yes.

> o How often do you use C-c C-a (or even C-c C-t) to toggle auto-newline
>   mode?

Hardly ever.

> o In which language(s) (C, C++, ....) do you program in (X)Emacs?

C mostly.  Fairly often Perl, Bourne shell.  Occasionally Java,
C++.
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