arbitrary line endings in vim?

Question

Is there any way to tell vim to use the NUL character as the end-of-line marker instead of LF, CR/LF, or CR?

More generally, is it possible to use any arbitrary character or sequence of characters as the EOL marker?

NOTE: I do not want to convert line endings. I know how to do that, I've been doing it for years. I have some pseudo-XML files that use NUL as the "line" separator and want to edit them as they are, without vim treating the file as one huge long line (which is difficult to read and painfully slow to navigate and edit) and without mangling the files by accidentally converting some or all NULs to LFs.

Answer 1

If you look at the buf_write() function in fileio.c ("abandon all hope ye who enter here", we see (slightly simplified):

if (fileformat == EOL_UNIX)
    *s++ = NL;
else
{
    *s++ = CAR;                 /* EOL_MAC or EOL_DOS: write CR */
    if (fileformat == EOL_DOS)  /* write CR-NL */
        *s++ = NL;
}

Full source here.

While you could easily add a NULL byte to the end of lines with a BufWritePre autocommand, I see no functionality to not write a NL or CRNL here, so you'd end up with NULL + NL.