Re: widgets with dynamic-choice

[Stefan Monnier]

> * what should it look like? Just a callable symbol or a form or
>   something else?

As you may know I abhor `eval`, so I'd rather not have a "form" there,
but a function instead.

> * when should the widget get updated?

When we need to display it?

> * how do we deal with outliers like a dynamic 100000 element list?

The widget probably shouldn't try to do anything special for that.
The same problem already exists with `choice` after all.

> * how are errors handled? do we empty the list or go back to the last
>   good version?

I wouldn't try to be clever here either.  Just let the signal percolate.

> * should this just be a way to provide 'choice and 'radio, or do we want
>   a more generic facility that can handle the other composite types?

I think we should start with a dynamic version of `choice` and see from
there if it can be easily generalized or not.


        Stefan