On 8/27/11, Will Robertson <[log in to unmask]> wrote:
> On 26/08/2011, at 3:04 AM, Ulrike Fischer wrote:
>
>> Now I want to define a "mirrored" key
>>
>> no-sym
>>
>> so that "no-sym = true" sets  \l_chessfss_sym_bool to false.
>>
>> Is there some easy way?
>
> Not directly as far as I know (using
>
>   .code:n = { \bool_set_false:N \l_chessfss_sym_bool }
>
> works of course but it's not the best interface), so I think this would be a
> good addition. (I seem to remember kvoptions has a similar feature.) Which
> do you think is best to name it?
>
>   no-sym .bool_unset:N = \l_chessfss_sym_bool
>   no-sym .bool_set_false:N = \l_chessfss_sym_bool
>   no-sym .bool_set_reverse:N = \l_chessfss_sym_bool

I find .bool_set_reverse:N more descriptive (cf. \reverse_if:N), as
no-sym = false is valid user input, I guess?
-- 
Bruno