[XeTeX] Bidipoem for dialogue poetry

[Gareth Hughes]

Paul Isambert wrote:
>  Le 10/10/2010 14:16, Philip Taylor (Webmaster, Ret'd) a écrit :
>> Paul, in which dialect(s) of TeX does \quitvmode exist ?
>>
>> Paul Isambert wrote:
>>
>>> \def\persona#1{%
>>> \quitvmode\llap{\hbox to <some length>{#1\hfil}}%
>>> }
>>
> 
> Oh, right.
> Gareth, you should use \leavevmode instead of \quitvmode, which is a
> pdfTeX primitive that doesn't exist in XeTeX.
> 
> Paul

Yes, I spotted that \leavevmode was intended. Thank you, Paul, that
works like a dream and means that I don't have to use \phantom boxes
repeatedly.

Does anyone have any thoughts how line numbers might be handled in this
bidipoem environment? None of the usual packages that provide line
numbering play nicely, and I can't work out from the code how best to do it.

Gareth.