quick game of life

game.js

const parseGrid = ([str]) => str
    .split('\n')
    .map(row => row.trim())
    .filter(row => row.length > 0)
    .map(row => row.split('').map(char => char !== '.'))

const formatGrid = rows => rows
    .map(row => row.map(cell => cell ? '#' : '.').join(''))
    .join('\n')


const calcNextGridState = grid => grid.map((row, y) => row.map((cell, x) => calcNextCellState(grid, cell, x, y)))

const calcNextCellState = (grid, cell, x, y) => {
    const neighbours = [
        [x - 1, y - 1],
        [x - 1, y],
        [x - 1, y + 1],
        [x, y - 1],
        [x, y + 1],
        [x + 1, y - 1],
        [x + 1, y],
        [x + 1, y + 1]
    ]
    const nbNeighboursAlive = neighbours
        .filter(([x, y]) => x >= 0 && y >= 0 && y < grid.length && x < grid[y].length && grid[y][x])
        .length
    // une cellule morte possédant exactement trois voisines vivantes devient vivante
    if (!cell && nbNeighboursAlive === 3) return true
    // une cellule vivante possédant deux ou trois voisines vivantes le reste,
    if (cell && (nbNeighboursAlive === 2 || nbNeighboursAlive === 3)) return true;
    // sinon elle meurt
    return false
}


(function loop(grid, t = 1) {
    const out = formatGrid(grid)
    console.log(`Turn ${t}\n${out}`)
    if (t < 100 && out.includes('#')) setTimeout(() => {
        loop(calcNextGridState(grid), ++t)
    }, 1000)
})(parseGrid`
....................
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....................
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......#.#...........
......#.#.#.........
......#####.........
....................
....................
....................
`)