amnesia

#            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
#                    Version 2, December 2004
#
#            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
#   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
#
#  0. You just DO WHAT THE FUCK YOU WANT TO.

defmodule Options do
  @doc """
  Allows use of pipe operator to chain conditional updates
  to a keyword list. If the given value is nil, no update is
  done.

  Please note: mylist[:a][:b] will properly return nil even
  of mylist[:a] is already nil instead of crashing. This allows
  using even deeply nested values safely with this construct.
  """
  def update(args, key, value) do
    case value do
      nil  -> args
      _any -> Keyword.put(args, key, value)
    end
  end

  @doc "Turns parameter into a list, invariant when paramers is a list or nil."
  def normalize(data) when data |> is_list do
    data
  end

  def normalize(nil), do: nil

  def normalize(data) do
    [data]
  end
end