Game of Life : Node.JS

life.js

const _ = require("iotdb-helpers")

const Board = _size => {
    const self = Object.assign({})

    let _d = {}
    const _key = (x, y) => `${x}//${y}`
    const _set = (d, x, y, v) => d[_key(x,y)] = v
    const _get = (d, x, y) => d[_key(x,y)] || 0

    self.print = () => {
        for (let y = 0; y < _size; y++) {
            const row = []
            for (let x = 0; x < _size; x++) {
                row.push(_get(_d, x, y) ? "X " : ". ")
            }
            console.log(row.join(""))
        }
    }

    self.seed = n => {
        for (let i = 0; i < n; i++) {
            _set(_d, _.random.integer(_size), _.random.integer(_size), true)
        }
    }

    self.evolve = () => {
        const _cd = {}

        for (let y = 0; y < _size; y++) {
            for (let x = 0; x < _size; x++) {
                _set(_cd, x, y, 0)
            }
        }

        for (let y = 0; y < _size; y++) {
            for (let x = 0; x < _size; x++) {
                if (!_get(_d, x, y)) {
                    continue
                }

                _cd[_key(x - 1, y - 1)] += 1
                _cd[_key(x - 1, y)] += 1
                _cd[_key(x - 1, y + 1)] += 1

                _cd[_key(x, y - 1)] += 1
                _cd[_key(x, y + 1)] += 1

                _cd[_key(x + 1, y - 1)] += 1
                _cd[_key(x + 1, y)] += 1
                _cd[_key(x + 1, y + 1)] += 1
            }
        }

        const _nd = {}
        for (let y = 0; y < _size; y++) {
            for (let x = 0; x < _size; x++) {
                const alive = !!_get(_d, x, y)
                const count = _get(_cd, x, y)

                if (alive && ((count === 2) || (count === 3))) {
                    _set(_nd, x, y, true)
                } else if (!alive && (count === 3)) {
                    _set(_nd, x, y, true)
                }
            }
        }

        _d = _nd
    }

    return self
}

function sleep(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}

const size = 30
const seed = 200
const generations = 3000
const delay = 100

async function main() {
    const board = Board(size)
    board.seed(seed)

    for (let i = 0; i < generations; i++) {
        console.clear()
        console.log("--", i, "--")
        board.print()
        board.evolve()

        await sleep(delay);
    }
}

main()