util-junk.el

;; kill-region or backward-kill-word

(defun kill-region-or-backward-kill-word ()
  (interactive)
  (if (region-active-p)
      (kill-region (point) (mark))
    (backward-kill-word 1)))

;; swap quotes

(defvar swap-quotes-list
  '((?\" ?\') (?\' ?\`) (?\` ?\")))

(defun transpose-chars-or-swap-quotes (arg)
  (interactive "p")
  (or (swap-quotes) (transpose-chars arg)))

(defun swap-quotes ()
  (interactive)
  (catch 'break
    (dolist (i swap-quotes-list)
      (let ((target-char (car i))
            (replaced-char (cadr i))
            (prev-pos (point)))
        (if (= (char-after (point)) target-char)
            (save-excursion
              (forward-char 1)
              (let ((next-pos (re-search-forward (char-to-string target-char))))
                (if next-pos
                    (subst-char-in-region prev-pos next-pos target-char replaced-char)
                  (message "The corresponding quote is not found.")))
              (throw 'break t)))))
    nil))

(defun kill-word-or-delete-horizontal-space (arg)
  (interactive "p")
  (let ((pos (point)))
    (if (and (not (eobp))
             (= (char-syntax (char-after pos)) 32)
             (= (char-syntax (char-after (1+ pos))) 32))
        (prog1 (delete-horizontal-space) 
          (unless (memq (char-after pos) '(?( ?) ?{ ?} ?[ ?]))
            (insert " ")))
      (kill-word arg))))

(defun eval-last-sexp-or-region (&optional args)
  (interactive "P")
  (let (output-buffer)
    (if (region-active-p)
        (eval-region 
         (region-beginning) (region-end) t)
      (eval-last-sexp args))))