File: yui-throttle/js/throttle.js

            /**
            Throttles a call to a method based on the time between calls. This method is attached
            to the `Y` object and is <a href="../classes/YUI.html#method_throttle">documented there</a>.
            
                var fn = Y.throttle(function() {
                    counter++;
                });
            
                for (i; i< 35000; i++) {
                    out++;
                    fn();
                }
            
            
            @module yui
            @submodule yui-throttle
            */
            
            /*! Based on work by Simon Willison: http://gist.github.com/292562 */
            /**
             * Throttles a call to a method based on the time between calls.
             * @method throttle
             * @for YUI
             * @param fn {function} The function call to throttle.
             * @param ms {Number} The number of milliseconds to throttle the method call.
             * Can set globally with Y.config.throttleTime or by call. Passing a -1 will
             * disable the throttle. Defaults to 150.
             * @return {function} Returns a wrapped function that calls fn throttled.
             * @since 3.1.0
             */
            Y.throttle = function(fn, ms) {
                ms = (ms) ? ms : (Y.config.throttleTime || 150);
            
                if (ms === -1) {
                    return function() {
                        fn.apply(this, arguments);
                    };
                }
            
                var last = Y.Lang.now();
            
                return function() {
                    var now = Y.Lang.now();
                    if (now - last > ms) {
                        last = now;
                        fn.apply(this, arguments);
                    }
                };
            };