Various useful utility functions

findFirst.js

/**
 * Finds the first occurence of an element specified by the given function in a collection.
 *
 * @method  findFirst
 * @param  {Array} collection The collection to search.
 * @param  {Function} fn   The selector function used to find an element.
 * @return {*}  The first occurence of the element.
 */
function findFirst(collection) {
    return function(fn) {
      var result;
      collection.some(function(element, index){
        if(fn(element,index)) {
          result = element;
          return true;
        }
      });        
      return result;
    }
}

in-range.js

/**
 * Performs an operation for a given range of numbers.
 */
function inRange(start, end, modifier) {
    return Array.apply(null, {
        length: end - start + 1
    }).map(Number.call, function(e) {
        return modifier(e + start);
    });
}

set-zero-timeout.js

    // Only add setZeroTimeout to the window object, and hide everything
    // else in a closure.
    (function() {
        var timeouts = [];
        var messageName = "zero-timeout-message";

        // Like setTimeout, but only takes a function argument.  There's
        // no time argument (always zero) and no arguments (you have to
        // use a closure).
        function setZeroTimeout(fn) {
            timeouts.push(fn);
            window.postMessage(messageName, "*");
        }

        function handleMessage(event) {
            if (event.source == window && event.data == messageName) {
                event.stopPropagation();
                if (timeouts.length > 0) {
                    var fn = timeouts.shift();
                    fn();
                }
            }
        }

        window.addEventListener("message", handleMessage, true);

        // Add the one thing we want added to the window object.
        window.setZeroTimeout = setZeroTimeout;
    })();