function inherit(p){
  if(p==null){
    throw TypeError();
  }
  if(Object.create){
    return Object.create(p);
  }
  var t=typeof p;
  if(t!==‘object‘&&t!==‘function‘){
    throw TypeError();
  }
  function f(){};
  f.prototype=p;
  return new f();
}

function range(from,to){
  var r=inherit(range.methods);
  r.from=from;
  r.to=to;
  return r;
}

range.methods={
  includes:function(x){
    return this.from<=x&&x<=this.to;
  },
  foreach:function(f){
    for(var x=Math.ceil(this.from);x<=this.to;x++) f(x);
  },
  toString:function(){
    return "("+this.from+‘...‘+this.to+‘)‘;
  }
};

var r=range(1,3);

r.includes(2);
r.foreach(console.log);
r.toString();

Object.create(prototype, descriptors)