Python で書いた何の変哲もない 3 目ならべ。 技術的に特別なことは何もしていない。 ただ、これを Wrap して Console -> Web API -> Web Application としていくにはどういう設計がいいか、 どうしたら美しく書けるか、を考えながら書いていた。

tictactoe.py

# -*- coding: utf-8 -*-

from __future__ import unicode_literals
from __future__ import print_function


def enum(**enums):
    return type(str('Enum'), (), enums)


class TicTacToeException(Exception):
    pass


class TicTacToe(object):

    STATUS = enum(INIT=0, MAIN=1, GAMEOVER=2)
    MARK = enum(EMPTY=0, A=1, B=2)

    def __init__(
        self,
        size=3,
        state=STATUS.INIT,
        current=MARK.A,
        winner=None,
        board=None,
    ):
        if board is None:
            board = self.plain_board(size=size)
        self.size = size
        self.state = state
        self.current = current
        self.winner = winner
        self.board = board

    @classmethod
    def plain_board(cls, size=3, fillwith=MARK.EMPTY):
        range_ = range(size)
        return [[fillwith for _ in range_] for __ in range_]

    def start(self):
        if self.state != self.STATUS.INIT:
            raise TicTacToeException()
        self.state = self.STATUS.MAIN

    def is_puttable(self, i, j):
        try:
            return self.board[i][j] == self.MARK.EMPTY
        except Exception:
            return False

    def put(self, i, j):
        if self.state != self.STATUS.MAIN:
            raise TicTacToeException()
        if not self.is_puttable(i, j):
            raise TicTacToeException()
        self.board[i][j] = self.current

    def board_lines(self):
        board = self.board
        size = self.size
        horizonal = [tuple(line) for line in board]
        vertical = zip(*board)
        diagonal = [
            tuple(board[x][x] for x in range(size)),
            tuple(board[x][size - 1 - x] for x in range(size)),
        ]
        return tuple(horizonal + vertical + diagonal)

    def judge(self):
        all_lines = self.board_lines()
        if (self.MARK.A, ) * self.size in all_lines:
            winner = self.MARK.A
        elif (self.MARK.B, ) * self.size in all_lines:
            winner = self.MARK.B
        else:
            return
        self.winner = winner
        self.state = self.STATUS.GAMEOVER

    def next_turn(self):
        if self.current == self.MARK.A:
            next = self.MARK.B
        elif self.current == self.MARK.B:
            next = self.MARK.A
        self.current = next

    def dump(self):
        return {
            'state': self.state,
            'current': self.current,
            'winner': self.winner,
            'board': self.board,
        }

    @classmethod
    def load(cls, data):
        return cls(**data)

if __name__ == '__main__':
    '''
    実際のゲームの流れをテスト
    '''
    t = TicTacToe()
    print(t.dump())
    t.start()
    putting = (
        (0, 1),
        (1, 2),
        (1, 1),
        (2, 2),
        (1, 0),
        (0, 0),
        (2, 1),
    )

    for i, j in putting:
        if t.is_puttable(i, j):
            t.put(i, j)
            t.judge()
            if t.winner is None:
                t.next_turn()
            print(t.dump())
    print(t.winner)