OkThen.Result.error_filter

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

error_filter(result, check_function)

Specs

error_filter(result_input(), (any() -> as_boolean(any()))) :: result_input()

If result is tagged :error, passes the wrapped value into the provided function. If check_function returns a truthy value, result is returned unchanged. Otherwise, returns :none.

Equivalent to tagged_filter(result, :error, check_function). See tagged_filter/3.

Examples

iex> {:error, "hello"} |> Result.error_filter(&String.length(&1) == 5)
{:error, "hello"}

iex> {:error, "hello"} |> Result.error_filter(&String.length(&1) == 0)
:none

iex> :some |> Result.error_filter(&String.length(&1) == 0)
:some

iex> :ok |> Result.error_filter(&String.length(&1) == 0)
:ok

iex> nil |> Result.error_filter(&String.length(&1) == 0)
nil