Will Robertson wrote: > On 15/09/2008, at 3:42 PM, Joseph Wright wrote: > >> So my attempts to create a simple hook: >> >> \def:cpx {<key>} <arg spec.> {\exp_not:N\prehook <code> >> \exp_not:posthook} >> >> fail when the added code contains #1, #2, ... My current approach at >> least does not give a TeX error under these circumstances (I've added a >> custom one to warn of a problem). >> >> I'm sure I'm mossing something, but my knowledge of TeX's approach to >> doubling # characters, etc., is clearly insufficient to find it. > > Maybe as a pre-cursor to this work we should port patchcmd to expl3? > Even that package only handles "plain" argument specs, though. > > W That is a somewhat different issue, I think. As I said, the problem here is my lack of knowledge of how to get the "hooks" to reproduce exactly the input, including the "#1", etc., signs. Of course, \patchcmd would be nice for other things (as I've already said). -- Joseph Wright