an example for functional programming

race.js

// a functional race game

race({
  time: 100,
  positions: [1,1,1,1,1]
});

function race(state){
  draw(state);
  if(state.time){
    race(step(state, move));
  } else {
    winner(state.positions)
  }
}

function draw(state){
  console.log('');
  console.log(state.positions.map(times).join('\n'));
}

function times(position){
  return new Array(position + 1).join('-')
}

function step(state, fn){
  return {
    time: state.time - 1,
    positions: state.positions.map(fn)
  }
}

function move(position){
  return position + (Math.random() > 0.3 ? 1 : 0)
}

function winner(positions){
  console.log("winner is", positions.indexOf(Math.max.apply(Math, positions)) + 1)
}