Lars Hellström wrote:
>> }
>> \cs_generate_variant:Nn \foo_internal:n {V}
>
> I thought O was the appropriate variant for expanding a token list
> control sequence?
The re-factor saw us drop "O", and sort-of downgrade "o" (we use it
less). The V specifier lets you write both
\foo_internal:V \l_my_tl % A macro at the TeX level
and
\foo_internal:V \l_my_toks % A toks at the TeX level
whereas \foo_internal:o would need
\foo_internal:o {\l_my_tl}
\foo_internal:o { \toks_use:N \l_my_toks }
So V is preferred for accessing variables (as the internal structure is
not important), and o is meant for cases which go beyond simply getting
a variable value "out".
--
Joseph Wright