Nick Montfort's Taroko Gorge Engine

taroko.js

var t = 0;
var n = 0;
var paths = 0;
var above = "brow,mist,shape,layer,the crag,stone,forest,height".split(",");
var below = "flow,basin,shape,vein,rippling,stone,cove,rock".split(",");
var trans = "command,pace,roam,trail,frame,sweep,exercise,range".split(",");
var imper = "track,shade,translate,stamp,progress through,direct,run,enter";
imper = imper.split(",");
var intrans = "linger,dwell,rest,relax,hold,dream,hum".split(",");
var s = "s,".split(",");
var texture = "rough,fine".split(",");
function rand_range(max) {
  return Math.floor(Math.random() * (max + 1));
}
function choose(array) {
  return array[rand_range(array.length - 1)];
}
function path() {
  var p = rand_range(1);
  var words = choose(above);
  if (words == "forest" && rand_range(3) == 1) {
    words = "monkeys " + choose(trans);
  } else {
    words += s[p] + " " + choose(trans) + s[(p + 1) % 2];
  }
  words += " the " + choose(below) + choose(s) + ".";
  return words;
}
function site() {
  var words = "";
  if (rand_range(2) == 1) {
    words += choose(above);
  } else {
    words += choose(below);
  }
  words += "s " + choose(intrans) + ".";
  return words;
}
function cave() {
  var adjs = (
    "encompassing," +
    choose(texture) +
    ",sinuous,straight,objective,arched,cool,clear,dim,driven"
  ).split(",");
  var target = 1 + rand_range(3);
  while (adjs.length > target) {
    adjs.splice(rand_range(adjs.length), 1);
  }
  var words = "\u00a0\u00a0" + choose(imper) + " the " + adjs.join(" ") + " \u2014";
  return words;
}
function do_line() {
  var main = document.getElementById("main");
  if (t <= 25) {
    t += 1;
  } else {
    main.removeChild(document.getElementById("main").firstChild);
  }
  if (n === 0) {
    text = " ";
  } else if (n == 1) {
    paths = 2 + rand_range(2);
    text = path();
  } else if (n < paths) {
    text = site();
  } else if (n == paths) {
    text = path();
  } else if (n == paths + 1) {
    text = " ";
  } else if (n == paths + 2) {
    text = cave();
  } else {
    text = " ";
    n = 0;
  }
  n += 1;
  text = text.substring(0, 1).toUpperCase() + text.substring(1, text.length);
  last = document.createElement("div");
  last.appendChild(document.createTextNode(text));
  main.appendChild(last);
}
function poem() {
  setInterval(do_line, 1200);
}