OkThen.Result.is_none

You're seeing just the macro is_none, go back to OkThen.Result module for more information.
Link to this macro

is_none(value)

(macro)

Returns true if result is tagged :none.

Equivalent to is_tagged(value, :none). See is_tagged/2.

Examples

iex> Result.is_none(:none)
true

iex> Result.is_none({:ok, "hello"})
false

iex> Result.is_none({:error, "hello"})
false