Lists are strictly [list_type | final_type] and there’s no additional granularity available.
There’s also some tricky “bugs”? in the spec, like nonempty improper lists are usually tagged as any for the final type, which technically includes the empty list, which is “not correct”
That is precisely what I am trying to tackle with the library i just published,
Look at the types t:all/0 and t:all_but_empty_list/0 (commented out)
https://github.com/eksperimental/extended_types/blob/53a86539296796ad7843ba4f8de641b2b93ec52c/lib/extended_types/types.ex#L116-L159
I am thinking of creating a function/macro that can generate custom types where certain types are excluded from any().
Edit: It is covered in these lines:
@type any_but_list :: ...
https://github.com/eksperimental/extended_types/blob/07594b8acf45b78112e08ad56c6ad867e8f0b675/lib/extended_types/types.ex#L146-L156
@type improper_list :: nonempty_improper_list(any, any_but_list)
https://github.com/eksperimental/extended_types/blob/07594b8acf45b78112e08ad56c6ad867e8f0b675/lib/extended_types/types.ex#L192-L197
