[chaley]

Originally Posted by ownedbycats

Question:

I had this proof-of-concept template for making different icons based on is_marked values.

program:
m = is_marked();

first_non_empty
   (
    contains(m, "invalid_author_sort", 'test.png', ''),
    contains(m, "invalid_title_sort", 'test2.png', ''),
   )

But how do I set a value for a non-defined mark?

Do you mean no marks or not one of the ones you have tested for? If you mean no marks then

program:
m = is_marked();

first_non_empty
   (
    contains(m, "invalid_author_sort", 'test.png', ''),
    contains(m, "invalid_title_sort", 'test2.png', ''),
    if !m then 'foo.png' fi
   )

If you mean any mark other than the ones above then remove the !.