Re: with-output-to-temp-buffer [Re: reverting CJK input methods]

[Richard Stallman <rms@gnu.org>]

    Well, we had this already.  If the user is supposed to be allowed to
    call erase-buffer (and I don't see anything that would make this a
    sensible proposition), then the overlays should have the 'evaporate
    property set.  Now your complaint was that user editable fields
    should probably not evaporate when empty, but the user editable
    fields are not read-only in the first place!

The user-editable fields are not read only, and they can be empty,
so the overlays must be set not to evaporate.  So this solution
does not work.

I am not sure it is necessary for Custom to work using overlays.
Maybe text properties would do the job.  They would get eliminated
too, if the whole text is deleted.

    > I think it is better for erase-buffer to get an error in the Custom
    > buffer.

    Even if you think so, I don't think that putting some read-only text
    in as a side effect is the right way to achieve this.

I think it makes sense.  To have user-editable fields in a buffer
implies that there are non-editable parts too.

    Anyway, it might be a good idea if erase-buffer also kills all
    overlays, after giving them a chance with modification-hooks and
    evaporate and whatever else there is in way of notification.

That might actually be a good idea.  I am not sure, though.