Re: Emacs 22 branch created.

[Richard Stallman]

    >     And of course very inefficient when you'll constantly be editing a 
very
    >     large rmail buffer.
    > Not really, because the gap makes such operations efficient.

    It just reduces the inefficiency.

It makes them plenty efficient enough.  Remember, the same issue
arises in Rmail, and it isn't a problem.

    > The other approach also needs peculiar changes in lower-level features
    > to work right.  Various operations on the message buffer would have to
    > operate on the file buffer as well.  These include set-buffer-file-name,
    > rename-buffer, as well as saving.

    Those other features can all be done at the UI-level, where they belong, not
    at a low level.  At the very least, it's all done in elisp, without any need
    to fiddle with C code.

I don't think that is true.  Changes in set-buffer-file-name and rename-buffer
would have to be done at the C level.  And I expect we would find other
low-level facilities that would need such changing.

With my approach, we can be sure that only the operating of writing a file
needs changing.