Am 15.02.2010 um 13:36 schrieb Frank Mittelbach:

> Philipp Stephani writes:
>>>> - \exp_arg_unbraced:No === \exp_after:wN
>>> You'd like this to exist, you mean?
>> Yes, I just think it fits better with the other _unbraced macros (it would
>> be the simplest of those). 
>> Please note that the three points you commented on are just related to
>> design or style decisions, there is nothing wrong with how it is currently
>> implemented in expl3. 
> for a start \exp_after:wN should normally not be needed except on very
> low-level programming (which should largely only happen in the kernel). For
> the rest the l3expan concept really provides a much more powerful and
> consistent interface.

In my case I need it indeed as a replacement of a high-level function: namely, a variant of \tl_map_inline that looks at three groups at a time. This is trivial with a macro that takes three undelimited and one "rest" argument, so perhaps l3tl could have \tl_map_function_ii, \lt_map_inline_ii and so on. Then I wouldn't need this any more.