Re: Extended menu items, when are :enable and :filter computed?

[Lennart Borgman]

Richard Stallman wrote:
> I think this optimization is not needed any more, so I don't want to
> put it in etc/TODO.  I don't want to do it at all, unless people show
> there is a real need for it today.  Not just a theoretical need, but a
> substantial practical need.  Not just a speculation but actual facts.
>   
I do not know if my example is important, but here is how this problem 
came to my mind:

I am trying to use the excellent nxml-mode to build a web authoring 
environment in Emacs. This mode can tell what tags are allowed at a 
certain position in an XHTML document. This information could be used 
for building menus which perhaps would be good for beginners. However 
there are some computations required for that of course.

In this web authoring environment there are also cases when the 
existence of certain files could make difference for what to enable in 
the menus.

I realize this is not a very strong case. I could for example use a 
popup menu instead to show what tags are allowed. And the normal way to 
check this in nxhtml-mode is just completion the normal way in Emacs.