Array.prototype.binaryIndexOf

/*  binary search of an array
    Performs a binary search on the host array. This method can either be
    injected into Array.prototype or called with a specified scope like this:
    binaryIndexOf.call(someArray, searchElement);
    http://jsperf.com/binaryindexof-and-indexof/3 */
   */

function binaryIndexOf(e){for(var b=0,c=this.length-1,a,d;b<=c;)if(a=(b+c)/2|0,d=this[a],d<e)b=a+1;else if(d>e)c=a-1;else return a;return-1}
Array.prototype.binaryIndexOf=binaryIndexOf;