Re: Assignment of misc packages for emacs

["Stefan Monnier" <monnier+gnu/emacs@RUM.cs.yale.edu>]

> It seems to use _multiple_ keymaps (the MAPS and NMAPS parameters),

Yes, one might come from the global map, another from the local map,
yet others from various minor mode maps.

> which it merges to get all the menu entries.  Can any explain in what
> situation you end up with multiple keymaps that need to be merged like
> this?

They may all share the same prefix.

> Should the lisp function be passed a list of keymaps?

I think so, yes.

> It would also be nice to have some helper functions/forms to assist lisp
> code in manipulating the keymaps without caring too much about the
> details.
> 
> For this current application, for instance, I'd like:
> 
>   1) something to iterate over the keymaps
> 
>      E.g. perhaps (dobindings (VAR KEYMAP [PREDICATE]) BODY..)

XEmacs has map-keymap (and so does lucid.el).
CL has cl-map-keymap used internally for the `loop' macro where you can
loop over keybindings.
`map_keymap' (c|sh)ould also be used internally to avoid exposing the
internal representation of keymaps all over keyboard.c.

>   2) accessor functions of some sort for the tricky bits
> 
>      For menu-items, as I mentioned earlier, there's already this handy
>      C function `parse_menu_item' which could be used to do the bulk of
>      the work for any accessor function(s).
> 
>      I'm not sure what would be better though, a bunch of individual
>      accessor functions, e.g., (menu-item-help MENU-ITEM), or one big
>      accessor function like (menu-item-property MENU-ITEM :help).
> 
>      The second would probably be easier to implement, since
>      parse_menu_item fills in a table, so a general accessor funciton
>      like `menu-item-property' could just have a list of
>      keyword->table-index mappings.

How about (menu-item-property (parse-menu-item MENU-ITEM) :help) ?
Parsing can take a non-negligible time (it can run elisp code among
other things) so it would be good to be able to separate it from accessing
the actual data.


	Stefan