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