Le 01/10/14 à 17h10, Joseph Wright <[log in to unmask]> a écrit :

> On 30/09/2014 19:00, Denis Bitouzé wrote:
>>> At present, key properties mainly apply to individual keys in a 'stand
>>> alone' sense. This request is different as it's actually about an entire
>>> set of keys.
>> 
>> No, maybe I was unclear: my question concerned the "requireness" of
>> a single (or maybe several but treated separately) key property.
>
> On the other hand, a requirement to set some key can only be tested at
> the end of \keys_set:nn, once you know what keys were set. Moreover,
> it's potentially ambiguous as
>
>   \keys_set:nn { foo } { required = value }
>   \keys_set:nn { foo } { other-key }
>
> doesn't have the "required" key in the second setting: is it required
> here or not?

Maybe that's a nonsense idea, but couldn't it be possible to check the
key has been used \AtEndDocument?
-- 
Denis