Here's an example. The other day I needed to number the lines of some code examples in notes I was writing up. Not a built-in editor feature, but a few minutes' hacking in the One True Editor yielded:
(defun my-number-region (beg end)
(interactive "r")
(save-excursion
(let ((end (progn (goto-char end) (beginning-of-line 2) (point-mar
+ker))))
(goto-char beg)
(beginning-of-line)
(loop for i = 1 then (1+ i)
while (< (point) (marker-position end))
do (progn
(insert (format "%-6d" i))
(beginning-of-line 2))))))
Being able to do this sort of simple customization without knowing about "plugin architectures" and what-not is what I think Emacs got fundamentally right, and is why I never have the patience for Eclipse.
