code: function Op(o,l,r){
  	// set expression yes, no?
  	this._expression = false;
  	this._traversed = false;
  	this._parens = false;
  	this._cache = null;
  	this._invert = false;
  	this._opToken = o;
  	this._op = o && o._value || o;
  	
  	if (this._op == 'and') {
  		this._op = '&&';
  	} else if (this._op == 'or') {
  		this._op = '||';
  	} else if (this._op == 'is') {
  		this._op = '===';
  	} else if (this._op == 'isnt') {
  		this._op = '!==';
  	};
  	
  	
  	this._left = l;
  	this._right = r;
  	return this;
  }
docs: OPERATORS