defmodule Glicko.Result do @moduledoc """ Convenience functions for handling a result against an opponent. ## Usage iex> opponent = Player.new_v2 iex> Result.new(opponent, 1.0) {0.0, 2.014761872416068, 1.0} iex> Result.new(opponent, :draw) # With shortcut {0.0, 2.014761872416068, 0.5} """ alias Glicko.Player @type t :: {Player.rating, Player.rating_deviation, score} @type score :: float @type score_shortcut :: :loss | :draw | :win @score_shortcut_map %{loss: 0.0, draw: 0.5, win: 1.0} @score_shortcuts Map.keys(@score_shortcut_map) @doc """ Creates a new result from an opponent rating, opponent rating deviation and score. Supports passing either `:loss`, `:draw`, or `:win` as shortcuts. """ @spec new(Player.rating, Player.rating_deviation, score | score_shortcut) :: t def new(opponent_rating, opponent_rating_deviation, score) when is_number(score) do {opponent_rating, opponent_rating_deviation, score} end def new(opponent_rating, opponent_rating_deviation, score_type) when is_atom(score_type) and score_type in @score_shortcuts do {opponent_rating, opponent_rating_deviation, Map.fetch!(@score_shortcut_map, score_type)} end @doc """ Creates a new result from an opponent and score. Supports passing either `:loss`, `:draw`, or `:win` as shortcuts. """ @spec new(opponent :: Player.t, score :: score | score_shortcut) :: t def new(opponent, score) do new(Player.rating(opponent, :v2), Player.rating_deviation(opponent, :v2), score) end @doc """ Convenience function for accessing an opponent's rating. """ @spec opponent_rating(result :: Result.t) :: Player.rating def opponent_rating(_result = {rating, _, _}), do: rating @doc """ Convenience function for accessing an opponent's rating deviation. """ @spec opponent_rating_deviation(result :: Result.t) :: Player.rating_deviation def opponent_rating_deviation(_result = {_, rating_deviation, _}), do: rating_deviation @doc """ Convenience function for accessing the score. """ @spec score(result :: Result.t) :: score def score(_result = {_, _, score}), do: score end