I'm not sure what you mean about "repairing ... code". This command
simply inserts ')', ']', or '}' (and perhaps '>' or so) to match the
most recent unclosed ([{<.
(If it is "really useful", know that it's not my idea; you just quoted
my reimplementation of Florian's code.)
But yours is much cleaner, I like it. Thanks for that.
Here is a small example to illustrate what it does:
If you are writing a nested expression, like the following, and '_' is
your cursor,
{ (a * [(b) - (c) _
and you have bound ')' to paren-close-dwim (dwim = do what I mean),
three succeeding presses of ')' will produce the sequence: ])}. Or in
other words: ')' will produce the correct next matching closing
bracket regarding the position of your cursor.
Florian