What is this?

This is the MNK game (Tic-Tac-Toe but the field is M by N celss and the length of the winning sequence of X/O is K) implemented as a single line of Python code. No exec/eval magic or escaping newline characters. Truly an FP-style hell.

Why is this?

This was created for a ridiculous game jam where you had to write a game as one line of python code (not exceeding 4KB). exec and eval were banned, so you really had to cover yourself with lambdas.

How is this?

This was some hard to debug code written in one line using only lambdas, so at first I wrote a draft using regular python, but in a manner that would allow me to easily inline variables and lambda equivalents of the defined functions. The result of this can be found in this file and that's probably what you want to look at.

How to run this?

Well, you can just evaluate

_ = X

in interactive mode where X is all the code from this file.

Like this:

_ = print((lambda itertools, math: (lambda players, ask_user: (lambda m, n, k: (lambda board, format_board: next(itertools.dropwhile(lambda a: not a, map((lambda player: print(format_board(board)) or (lambda y, x: (board[y].__setitem__(x, player) or all(all(map('.'.__ne__, row)) for row in board) and f"{format_board(board)}\n\nDraw!" or any(map(lambda direction: ((lambda count: count(*direction) + count(-direction[0], -direction[1]) >= k - 1)(lambda dx, dy: len([*itertools.takewhile(lambda delta: (0 <= x + dx * delta < n and 0 <= y + dy * delta < m and board[y + dy * delta][x + dx * delta] == player), itertools.count(1))]))), [(0, 1), (1, 0), (1, 1), (1, -1)])) and f"{format_board(board)}\n\nPlayer {player} won!"))(*(c - 1 for c in ask_user(f"Player {player}, please, enter row and column", (lambda row, column: column < 1 and "Column should be >= 1" or row < 1 and "Row should be >= 1" or column > n and f"Column should be <= {n}" or row > m and f"Row should be <= {m}" or board[row - 1][column - 1] != '.' and "This cell is already occupied"))))), players))))([['.'] * n for _ in range(m)], lambda board: "\n".join(' '.join(map(("{:>" + str(math.floor(math.log(max(m, n), 10) + 1)) + "}").format, [row_no] + ([[*range(1, n + 1)]] + board)[row_no])) for row_no in range(m + 1))))(*ask_user("Enter MNK (M is height, N is width, K is the length of the winning sequence)", (lambda m, n, k: (min(m, n, k) <= 0 and "M, N, and K should be >0") or (k > max(m, n) and "K should not be bigger than both M and N")))))(itertools.cycle('XO'), lambda query, get_error: next(itertools.dropwhile(lambda t: (lambda something: (print(something) if something else something) or something)(get_error(*t)), ([*map(int, input(f"{query}:\n").split())] for _ in itertools.count())))))(__import__("itertools"), __import__("math")))