Re: require-hard-newlines to use newline

[Chong Yidong]

> Anyway, what about my other suggestion?  The suggestion to make
> longlines.el use after-change-functions to discover all new text inserted
> in the buffer, and do longlines processing on that text?

I am already making longlines.el use post-command-hook to process text
yanked *into* the longlines buffer.  But I need a separate mechanism to
process text yanked *out of* the buffer, and neither post-command-hook nor
after-change-functions are suitable for this.  By the time the hook is
called, the text has already been put into the kill ring and clipboard.

> No, buffer-substring should not call them.  That's why I said "a
> variant of buffer-substring".  Some places would call this new
> variant, but some would continue to call the existing, ordinary
> buffer-substring function.

In that case, I don't think our ideas are so different.  I'll alter my
patch to implement the `kill-filters' variable, and make the appropriate
functions use it before calling buffer-substring.  So far, these functions
are `kill-region', `copy-region-as-kill', and `copy-to-register'; are
there others?