On 25/08/2015 07:05, Joseph Wright wrote: > On 26/08/2015 00:44, aparsloe wrote: >> (1) I wanted to use \tl_replace_all:Nnn on a token list that might >> contain braced groups. Using \tl_set_rescan:Nnn to change the category >> codes of { and } seemed the most direct way of proceeding. (Then >> resetting the category codes after replacement with an empty setup.) > > I see what you mean (I have a similar case in siunitx, for historical > reasons). We'll explore what we can do with this: there are > mapping-based approaches one can imagine that will enter brace groups. > (We do that for \tl_lower_case:n, for example). However, for a general > 'search and replace' I'd be slightly wary as the TeX convention that > stuff in brace groups is 'special' is quite prevalent. (Depending on > performance requirements, you might also look at l3regex if you are > doing the replacement only very rarely.) It would be useful here to see what your real use case is, as that's often illustrative. -- Joseph Wright