On 13/11/2008, at 4:04 PM, Joseph Wright wrote:

> I see that expl3 has \tlist_head_i:n and \tlist_head_iii:n, but no
> \tlist_head_ii:n.  For at least one or two things, it would be  
> handy.  Is
> there a reason for this selection of head functions?

I suspect \tlist_head_iii was just added for use in xparse. It would  
make sense, I think, to add the "ii" variation as well.

I wonder if it's necessary to provide the aliases \tlist_head:w and so  
on. I guess using them is a bit nicer than \use_i_delimit_by_q_nil:w.  
As a matter of style, should we also define  
\use_iii_delimit_by_q_nil:w as a counterpart to \tlist_head_iii:w ?

W