> (defun smart-operator-backspace ()
>   (interactive)
>   (cond ((looking-back "hello"))
>      (save-excursion
>         (replace-regexp-in-string ".*hello" "" (match-string 1))))
>      (t
>         (delete-char 1))))

> However, (delete-char) never works for me. The reason is another minor mode
> remapped the backspace key to function 'autopair-backspace'. Then, I
> realized that I need a method to fetch the function by given keymap and get
> it called rather thant have hardcoded deletion executed.

> How can I do that with elisp code?

> > How can I do that with elisp code?

> You don't want to dig through the keymaps yourself.  Just take your
> minor-mode out of the lookup chain and use `key-binding'.

> This is what I do here:

> https://github.com/lewang/rebox2/blob/master/rebox2.el#L2363

> The deeper problem is that I have a chain of 3 functions from
> different minor-modes all bound to backspace.  They share the key
> happily, but Emacs lacks the mechanism to document this calling chain
> when I ask about <BACKSPACE> with C-h k.  I described the need to
> solve this as a feature request
> http://lists.gnu.org/archive/html/help-gnu-emacs/2012-10/msg00465.html
> , but there wasn't much interest.  :(