便宜上代入と呼ぶ • list = [1, 2, 3] • [1, b, 3] = [1, 2, 3] • [1, b, 4] = [1, 2, 3] ◦ これはマッチしないので例外が発生する • [ _, 2, 3] = [1, 2, 3] ◦ _ がつくと任意のものにマッチ • {:ok, message} = something() ◦ somethingが {:ok, 処理結果}を返す場合で正常系のみハンドリングをする場合 • [head | tail] = [1, 2, 3] ◦ head = 1, tail = [2, 3]