jquery ready函数源代码研究

        try {
            // 这个地方标记一下,在后面解析(1)
            document.documentElement.doScroll(“left”);
        } catch( error ) {
//// 这个地方标记一下,在后面解析(2)
            setTimeout( arguments.callee, 0 );
            return;
        }
        // and execute any waiting functions
        jQuery.ready();
    })();
    if ( jQuery.browser.opera )
        document.addEventListener( “DOMContentLoaded”, function () {
            if (jQuery.isReady) return;
            for (var i = 0; i < document.styleSheets.length; i++) // 标记(3)
                if (document.styleSheets[i].disabled) {
                    setTimeout( arguments.callee, 0 );
                    return;
                }
            // and execute any waiting functions
            jQuery.ready();
        }, false);
    if ( jQuery.browser.safari ) {
        var numStyles;
        (function(){
            if (jQuery.isReady) return;
            if ( document.readyState != “loaded” && document.readyState != “complete” ) { // 标记(4)
                setTimeout( arguments.callee, 0 );
                return;
            }
            if ( numStyles === undefined )
                numStyles = jQuery(“style, link[rel=stylesheet]”).length;