Cypher based Game of Life implementation meets Java meets the terminal. xkcd 356 applies.

GoL.java

///usr/bin/env jbang "$0" "$@" ; exit $?
//JAVA 24
//PREVIEW
//DEPS org.neo4j:neo4j-jdbc:6.1.3

import java.sql.DriverManager;

import org.neo4j.jdbc.Neo4jPreparedStatement;

/**
 * See <a href="https://neo4j.com/blog/developer/cypher-game-of-life/">A Cypher Game of Life</a>.
 *
 * Run with
 * <pre>
 *     jbang https://gist.github.com/michael-simons/837577004840d6ee53085e1e2aa53d82
 * </pre>
 *
 * @throws Exception we just throw things around here
 */
void main() throws Exception {

	var height = 30;
	var width = 30;
	var sleep = Duration.ofMillis(500);

	var random = ThreadLocalRandom.current();
	var numAlive = (int) (height * width * 0.1);

	var cells = random.ints(numAlive * 2, 0, height).boxed().gather(Gatherers.windowSliding(2)).toList();

	try (var connection = DriverManager.getConnection("jdbc:neo4j://localhost:7687", "neo4j", "verysecret")) {
		try (var stmt = connection.prepareStatement("MATCH (c:Cell) DETACH DELETE c")) {
			stmt.executeUpdate();
		}
		try (var stmt = connection.prepareStatement("""
			UNWIND range(0,$height-1) AS row
			WITH row
			UNWIND range(0,$width-1) AS column
			WITH row, column
			CREATE (cell:Cell {coordinate: Point({x:column,y:row}), alive:false})
			WITH row, column, cell
			UNWIND [[row-1, column-1],[row-1, column],[row-1, column+1],[row, column-1]] AS neighbor
			MATCH (other:Cell {coordinate: Point({x:neighbor[1],y:neighbor[0]})})
			MERGE (other)-[:NEIGHBOUR_OF]->(cell)
			""").unwrap(Neo4jPreparedStatement.class)) {

			stmt.setInt("height", height);
			stmt.setInt("width", width);
			stmt.executeUpdate();
		}
		try (var stmt = connection.prepareStatement("""
			UNWIND $cells AS cell
			MATCH (c:Cell {coordinate: Point({x:cell[0],y:cell[1]})})
			SET c.alive = true
			"""
		).unwrap(Neo4jPreparedStatement.class)) {
			stmt.setObject("cells", cells);
			stmt.executeUpdate();
		}
		try (var stmt = connection.prepareStatement("""
			MATCH (cell:Cell)
			OPTIONAL MATCH (cell)-[:NEIGHBOUR_OF]-(:Cell {alive: true })
			WITH cell, COUNT(*) AS liveNeighbours
			SET cell.alive =
			CASE liveNeighbours
			  WHEN <= 1 THEN FALSE
			  WHEN >= 4 THEN FALSE
			  WHEN = 3 THEN TRUE
			  ELSE cell.alive
			END
			WITH cell ORDER BY cell.coordinate.y ASC, cell.coordinate.x ASC
			WITH collect(cell) AS cells
			RETURN reduce(res = "", cell IN cells |
			res +
			    CASE cell.coordinate.x = 0
			    WHEN true THEN "\\n"
			    ELSE ""
			  END +
			  CASE cell.alive
			    WHEN true THEN '\u001b[1;38;5;0;48;5;253m ■ \u001b[0m'
			    ELSE '\u001b[1;38;5;214;48;5;253m ■ \u001b[0m'
			  END) AS result
			""")) {
			var previous = "";
			while (true) {
				var rs = stmt.executeQuery();
				rs.next();
				var result = rs.getString("result");
				System.out.print("\033[H\033[2J");
				System.out.println(result);
				System.out.flush();
				Thread.sleep(sleep);
				if (result.equals(previous)) {
					break;
				}
				previous = result;
			}
		}
	}
}