Re: Get a command by its keybinding and also respecting key translation

[Tassilo Horn]

Stefan Monnier <address@hidden> writes:

Hi Stefan,

>>> (define-key outline-minor-mode-map
>>> (kdb "<tab>")
>>> `(menu-item "dummy" org-cycle
>>> :filter ,(lambda (cmd)
>>> (if (th-outline-context-p) cmd))))
>
>> Hm, just for educational purposes, could you please explain the
>> backquoting and the comma-substitution of the lambda?  I mean, I know
>> that `,' in a backquote triggers evaluation, but since a lambda evals
>> to itself, what's the point in doing so?
>
> Without backquote and comma, the whole menu-item is just a piece of
> data which happens to contain something that looks like a function.
> With the backquote and comma, it turns into something that contains a
> function, so tools can handle this `lambda' knowing that it *is* a
> function (e.g. it can be byte-compiled, can cause warnings if it uses
> obsolete functions, can be macro-expanded, ...).

Thanks!  So now the next question, how can I write a macro whose
expansion contains backticks and commas, and I'm still able to
comma-expand in the "inner" backquoted parts?

Or with an example:

(defmacro define-context-key (keymap key dispatch)
  `(define-key ,keymap ,key
     (backquote
      (menu-item "context-key" ignore
                 :filter (lambda (&optional ignored)
                           ,dispatch)))))

How do I smuggle a `,' before the lambda?

Bye,
Tassilo