server/www/lib.js

function Lib(ws) {
  return {
    clearElement: clearElement,
    defaultCompare: defaultCompare,
    funMap: funMap,
    insert: insert,
    send: send
  };

  function clearElement(elem) {
    while(elem.firstChild) {
      elem.removeChild(elem.firstChild);
    }
  }

  function insert(obj, t, compare, min, max) {
    min = min == undefined ? 0 : min;
    max = max == undefined ? t.length : max;
    compare = compare == undefined ? defaultCompare : compare;
    if(max - min < 1) {
      return min;
    }
    var avg = Math.floor((max + min) / 2);
    if (compare(obj, t[avg]) < 0) {
      return insert(obj, t, compare, min, avg);
    } else {
      return insert(obj, t, compare, avg+1, max);
    }
  }

  function defaultCompare(a, b) {
    if(a < b) {
      return -1;
    } else if(a > b) {
      return 1;
    } else {
      return 0;
    }
  }

  function funMap(projector, f) {
    return function() {
      var args = Array.prototype.map.call(arguments, projector);
      return f.apply(null, args);
    }
  }

  function send(o) {
    ws.send(JSON.stringify(o));
  }
}