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(ccmode)Customizing Semi-colons and Commas

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Customizing Semi-colons and Commas
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   You can also customize the insertion of newlines after semi-colons
and commas, when the auto-newline minor mode is enabled (Note: Minor
Modes).  This is controlled by the style variable
`c-hanging-semi&comma-criteria', which contains a list of functions
that are called in the order they appear.  Each function is called with
zero arguments, and is expected to return one of the following values:

   * non-`nil' -- A newline is inserted, and no more functions from the
     list are called.

   * `stop' -- No more functions from the list are called, but no
     newline is inserted.

   * `nil' -- No determination is made, and the next function in the
     list is called.


   If every function in the list is called without a determination being
made, then no newline is added. The default value for this variable is a
list containing a single function which inserts newlines only after
semi-colons which do not appear inside parenthesis lists (i.e. those
that separate `for'-clause statements).

   Here's an example of a criteria function, provided by CC Mode, that
will prevent newlines from being inserted after semicolons when there is
a non-blank following line.  Otherwise, it makes no determination.  To
use, add this to the front of the `c-hanging-semi&comma-criteria' list.


     (defun c-semi&comma-no-newlines-before-nonblanks ()
       (save-excursion
         (if (and (eq last-command-char ?\;)
                  (zerop (forward-line 1))
                  (not (looking-at "^[ \t]*$")))
             'stop
           nil)))

   The function `c-semi&comma-inside-parenlist' is what prevents
newlines from being inserted inside the parenthesis list of `for'
statements.  In addition to `c-semi&comma-no-newlines-before-nonblanks'
described above, CC Mode also comes with the criteria function
`c-semi&comma-no-newlines-for-oneline-inliners', which suppresses
newlines after semicolons inside one-line inline method definitions
(i.e. in C++ or Java).