On Fri, Sep 19, 2008 at 1:32 AM, Joseph Wright <[log in to unmask]> wrote: > I should point out that this was, implicitly, a two-part questions. Part > one was about the primitives, part two is how to execute: > > \tlp_gset:Nx \g_siunitx_tmpa_tlp {\etex_scantokens:D {#1}} > > while _ is active (and I guess ideally : is "other"). In my current setup, > I only have to worry about @, which I just accept will be a letter. But I > have to have _ active. Ah :) Bit of a pickle. I guess I'd do something like \def:Npn \siunitxtmp { \tlp_gset:Nx \g_siunitx_tmpa_tlp {\etex_scantokens:D {#1}}} \char_make_active:N \_ \siunitxtmp (unless my brain hasn't woken up yet...I think that will work) Will