Re: buffer-substring-filter

[Chong Yidong]

> Using mapcar is a little wasteful, since it makes a list of the results
> only to throw them all away.  Better to use dolist.
>
> It would be good to move point to BEG, temporarily,
> so that the functions can tell where the text came from
> in case they care.

Yes, true.

> However, the real question is whether this is the right feature
> for doing the job.  Have you changed longlines.el to use it?
> Does it do what longlines needs?

Yes, I have changed longlines.el to use it, and I have confirmed that it
does what I need.