Nil and typespec primitives - is it redundant to write integer() | nil?

[kanishka]

Is it redundant to write integer() | nil? Which primitives allow for nil?

[al2o3cr]

nil is an atom:

iex(1)> is_atom(nil)
true

so any typespec that allows atoms through will also permit nil - atom() for instance.

[kanishka]

I thought nil was treated specially. So essentially, integer, String.t, and anything besides atom does not include nil?

[benwilson512]

@kanishka

So essentially, integer, String.t, and anything besides atom does not include nil?

Correct.

@kanishka

I thought nil was treated specially.

No, nil doees not get any special typespec treatment.