bug#25929: 25.2; map-delete doesn't delete permanently 1st alist elt

[Stefan Monnier]

>> The problem is how to make it extensible to user-defined types
>> via something like cl-generic.el (e.g. add support for avl-tree.el
>> without having to make map.el aware of avl-tree.el).

> Hm...  I haven't used cl-generic.el, but having map-delete be something
> like this work?

> (defmacro map-delete (map elem)
>   (if (symbolp map)
>       `(setq ,map (map-delete-1 ,map ,elem))
>     `(map-delete-1 ,map ,elem)))

It would work, yes.  I think the resulting semantics is pretty ugly, but
it's just a question of taste.


        Stefan