Make C-M-RET insert \item[]

Question

In AUCTeX M-RET is bound to (LaTeX-insert-item) which makes a new properly indented line and inserts \item and a space after which the cursor is placed. I would like to extend this feature so that C-M-RET has similar functionality but for \item[description].

What I would like is for C-M-RET to

1. make a new properly indented line and insert \item[],
2. place the cursor between the square brackets, and
3. place the cursor one space after \item[] as Tab is pressed.

Answer 1

The following function is cribbed from latex.el, and modified slightly to call the argument-prompting version LaTeX-item-argument instead of just inserting the item directly.

(defun LaTeX-insert-item-arg ()
  "Insert a new item in an environment, prompting for an item label.
You may use `LaTeX-item-list' to change the routines used to insert the item."
  (interactive "*")
  (let ((environment (LaTeX-current-environment)))
    (when (and (TeX-active-mark)
           (> (point) (mark)))
      (exchange-point-and-mark))
    (unless (bolp) (LaTeX-newline))
    (if (assoc environment LaTeX-item-list)
    (funcall (cdr (assoc environment LaTeX-item-list)))
      (LaTeX-item-argument)) ;; ONLY THIS LINE IS DIFFERENT
    (indent-according-to-mode)))

You can bind that function to any key you like:

(add-hook 'LaTeX-mode-hook (lambda () 
    (local-set-key [(control return)] 'LaTeX-insert-item-arg)))

If you want M-C-RET, use (meta control return) instead, though it only seems to work with the Alt key, and not the Esc key (which usually behaves the same...)