On 08/03/2011, at 11:47 PM, Bruno Le Floch wrote: > Thank you Joseph for the quick bug fix. Let me propose the following > code for inclusion. The idea is similar to `\prg_new_map_functions`, > which defines a set of maps, some of which are expandable. Namely, > > \tl_gset_replacer:nnn {<name>} {<item1>} {<item2>} As an aside, based on the name of \prg_new_map_functions:Nn I think \prg_new_replace_functions:Nn would be better. > defines expandable replacement functions: > > \<name>_replace_aux:nwwn > \<name>_replace_some:nn > \<name>_replace_one:n > \<name>_replace_all:n > > which are all `f`-expandable. This sounds pretty good to me. How useful is the _some function? I'd be happy without it. Anyway, I'd vote for adding this to expl3. -- Will