Der Sauspiel-Mischer

mischer.ex

defmodule Mischer do
  def deck do
    suits = ["s","h","g","e"]
    ranks = ["7","8","9","X","U","O","K","A"]
    for rank <- ranks, suit <- suits, do: rank <> suit
  end

  def shuffle(cards \\ deck) do
    card_count = Enum.count(cards)
    Enum.reduce 0..(card_count - 1), cards, fn(i, shuffled_cards) ->
      swap(shuffled_cards, i, rand_uniform(i, card_count))
    end
  end

  defp swap(list, i, j) do
    i_element = Enum.at(list, i)
    j_element = Enum.at(list, j)
    list |> List.replace_at(i, j_element) |> List.replace_at(j, i_element)
  end

  defp rand_uniform(lo, hi) do
    :crypto.rand_uniform(lo, hi)
  end
end

So werden auf Sauspiel die Schafkopf-Karten gemischt, siehe sauspiel.de/mischer.

Anleitung zum selber nachmischen: Elixir installieren und dann folgendes ausführen:

$ iex -r mischer.ex
Erlang/OTP 18 [erts-7.1] [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false]

Interactive Elixir (1.1.1) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> Mischer.shuffle
["Ag", "9h", "As", "Xg", "Ae", "7e", "9g", "7h", "Og", "Ug", "Kh", "Ue", "8g",
 "Xe", "Xs", "9e", "9s", "8h", "7g", "Ah", "7s", "Kg", "Ke", "Oh", "Us", "8s",
 "Xh", "Uh", "8e", "Oe", "Os", "Ks"]

Frohes Mischen!