Changes a list of oks into {:ok, list_of_values}

If any element of the list is an error, returns this error element.

If all elements are oks, takes the first non-tag value from each of them for the list. (in the case of :ok, nothing is added to the resulting list.)

iex> combine([{:ok, 1}, {:ok, "a", %{meta: "this will be dropped"}}, {:ok, :asdf}])
{:ok, [1, "a", :asdf]}
iex> combine([{:ok, 1}, {:ok, 2}, {:error, 3}])
{:error, 3}
iex> combine([{:ok, 1}, {:ok, 2}, {:error, 3, 4, 5}])
{:error, 3, 4, 5}

Returns a list of the values of all error-type elements in the enumerable.

Note that the 'value' is taken to be the first element:

iex> error_vals([{:error, 1}, {:error, 2,3,4,5}])
[1, 2]

Returns a list of the tuple-values of all error-type elements in the enumerable.

The 'tuple-value' consists of all elements in the error-type element, except for the initial :error tag.

iex> error_valstuples([{:error, 1}, {:error, 2,3,4,5}])
[{1}, {2,3,4,5}]

Returns a list of only all error-type elements in the enumerable.

iex> errors([{:ok, 1}, {:error, 2}, {:ok, 3}])
[{:error, 2}]

Returns a list of the values of all ok-type elements in the enumerable.

Note that the 'value' is taken to be the first element:

iex> ok_vals([{:ok, 1}, {:ok, 2,3,4,5}])
[1, 2]

Returns a list of the tuple-values of all ok-type elements in the enumerable.

The 'tuple-value' consists of all elements in the ok-type element, except for the initial :ok tag.

iex> ok_valstuples([{:ok, 1}, {:ok, 2,3,4,5}])
[{1}, {2,3,4,5}]

Returns a list of only all ok-type elements in the enumerable.

iex> oks([{:ok, 1}, {:error, 2}, {:ok, 3}])
[{:ok, 1}, {:ok, 3}]