Add game of life in JavaScript.

Closes #1377.

Author: legowerewolf

archive/j/javascript/game-of-life.js

@@ -0,0 +1,69 @@
+main();
+
+async function main() {
+	let parameters = {
+		dimension: 20,
+		fps: 4,
+		frameCount: 60,
+		spawnRate: 0.3,
+	};
+
+	for (let i = 0; i < process.argv.length - 1; i++) {
+		if (process.argv[i] == "--dimension") parameters.dimension = process.argv[++i];
+		else if (process.argv[i] == "--fps") parameters.fps = process.argv[++i];
+		else if (process.argv[i] == "--frameCount") parameters.frameCount = process.argv[++i];
+		else if (process.argv[i] == "--spawnRate") parameters.spawnRate = process.argv[++i];
+	}
+
+	// Initialize a board as a lifeless square array.
+	let board = new Array(parameters.dimension).fill(new Array(parameters.dimension).fill(false));
+
+	// Load up the array with trues (live) and falses (dead).
+	board = board.map((row) => row.map(() => Math.random() < parameters.spawnRate));
+
+	for (let i = 0; i < parameters.frameCount; i++) {
+		printBoard(board);
+
+		// Mutate the board
+		board = board.map((row, rowIndex) =>
+			row.map((cell, colIndex) => {
+				prevRowIndex = rowIndex - 1 < 0 ? parameters.dimension - 1 : rowIndex - 1;
+				nextRowIndex = rowIndex + 1 > parameters.dimension - 1 ? 0 : rowIndex + 1;
+				prevColIndex = colIndex - 1 < 0 ? parameters.dimension - 1 : colIndex - 1;
+				nextColIndex = colIndex + 1 > parameters.dimension - 1 ? 0 : colIndex + 1;
+
+				// Get the count of neighbors that are alive
+				neighbors = [
+					[prevRowIndex, prevColIndex],
+					[prevRowIndex, colIndex],
+					[prevRowIndex, nextColIndex],
+					[rowIndex, prevColIndex],
+					[rowIndex, nextColIndex],
+					[nextRowIndex, prevColIndex],
+					[nextRowIndex, colIndex],
+					[nextRowIndex, nextColIndex],
+				].reduce((sum, indices) => sum + (board[indices[0]][indices[1]] ? 1 : 0), 0);
+
+				// Mutate the current cell
+				if (cell && (neighbors < 2 || neighbors > 3)) return false;
+				if (!cell && neighbors == 3) return true;
+				return cell;
+			})
+		);
+
+		await sleep((1 / parameters.fps) * 1000);
+	}
+}
+
+function printBoard(board) {
+	console.clear();
+	board.forEach((row) => {
+		console.log(row.reduce((prev, curr) => prev.concat(curr ? "█" : " "), ""));
+	});
+}
+
+function sleep(time) {
+	return new Promise((resolve) => {
+		setTimeout(resolve, time);
+	});
+}