> couldn't one get there with, say,
> sequence-before(sequence, item+)
> and the corresponding sequence-after,
> by analogy to substring?
>
> One could then write,
>    sequence-before($sequence, $sequence[some-expr])

...I think you could do that now with subsequence and index-of eg:

subsequence($seq, 1, index-of($seq, some-expr))





-- 
Andrew Welch
http://andrewjwelch.com
Kernow: http://kernowforsaxon.sf.net/