RE: Making `interactive' conditional

[Herring, Davis]

>>> (and (not read-only) visiting-file)
>>
>> So now you can't invoke it in *scratch*?
>
> I don't expect to use Lisp predicates, no. Allowing those when the
> filtering is executed has unbounded time complexity.

I didn't mean "the object that describes the applicability conditions is not a 
form"; I meant that a command defined with that constraint would not be usable 
in *scratch* because it would fail the "visiting-file" condition.

> Filtering out editing commands when the buffer is not meant to be edited
> in any case enters into the "the user plausibly is not looking for this
> command" category.

Like `kill-line', which is totally useless in a read-only buffer, right?

Again, I'm not claiming these problems are insurmountable -- just that it's 
very hard to get right, because the exceptional cases are numerous.

Davis