On 30/06/2014 09:28, Joseph Wright wrote:
> On 30/06/2014 09:22, Joseph Wright wrote:
>>  - Brace groups/escaping: the current version takes an approach similar
>>    to BibTeX, treating all brace groups as 'preserved'. This is a
>>    clear rule but leaves open questions on how (if at all) to handle
>>    commands in 'text'. Notably, these functions are intended for 'text
>>    like' input, so this may not be an issue. Notice that math mode
>>    is given no special treatment but can be protected from case
>>    changing by bracing.
> To be clear, the operations do not case-change command sequence tokens:
> I was referring to commands with arguments, as the brace groups will
> prevent any case change:
>   \tl_upper_case:n { Some~\emph{text} } => "SOME~\emph{text}"

A particular question here is of course accents: something like

   \tl_upper_case:n { \'{e} }

will fail to case change but both

   \tl_upper_case:n { \'e }


   \tl_upper_case:n { é }

will work. There is a balance to be struck between convenient input
('all braces skipped' is easy to follow) and sufficient flexibility.
Thoughts most welcome.
Joseph Wright