Re: menu-bar: disable items when no frame visible

[Juri Linkov]

>     2. Why keymap variables are replaced with their values at the moment
>     of adding a menu item?  I.e. what changes like the following achieve?
>
>      (define-key menu-bar-edit-menu [bookmark]
>     -  '(menu-item "Bookmarks" menu-bar-bookmark-map
>     +  `(menu-item "Bookmarks" ,menu-bar-bookmark-map
>                 :help "Record positions and jump between them"))
>
> I think a symbol in such a position means to use its function
> definition, not its value.  Thus, unless I am misremembering, the
> first version would not work at all.  Was it ever really in use?

Actually, both versions work correctly.  I guess the first version works
because menu operations can read the value of the map variable, and the
second version works because functions that modify the menu operate
directly on the Lisp structure by modifying its cells.  I don't know
which of these two variants is more preferable.

-- 
Juri Linkov
http://www.jurta.org/emacs/