jquery core refactoring

gistfile1.js

		// Handle HTML strings
		if ( typeof selector === "string" ) {
			var mode, id, tag;
			if (/^#[\w\-]*$/.test(selector)) { // single #id
				mode = "id";
				id = selector.substring(1);
			} else if (/^\s*<[\w\W]+>.*/.test(selector)) { // at least one html tag
				mode = "html";
			} else { // selector expr
				mode = "expr";
			}

			// simple #id selector without coutext
			if (mode === "id" && !context) {
				elem = document.getElementById( id );

				// Check parentNode to catch when Blackberry 4.6 returns
				// nodes that are no longer in the document #6963
				if ( elem && elem.parentNode ) {
					// Handle the case where IE and Opera return items
					// by name instead of ID
					if ( elem.id !== id ) {
						return rootjQuery.find( selector );
					}

					// Otherwise, we inject the element directly into the jQuery object
					this.length = 1;
					this[0] = elem;
				}

				this.context = document;
				this.selector = selector;
				return this;
			}

			// HANDLE: $(html) -> $(array)
			if ( mode === "html" ) {
				context = context instanceof jQuery ? context[0] : context;
				doc = ( context ? context.ownerDocument || context : document );

				// If a single string is passed in and it's a single tag
				// just do a createElement and skip the rest
				ret = rsingleTag.exec( selector );

				if ( ret ) {
					if ( jQuery.isPlainObject( context ) ) {
						selector = [ document.createElement( ret[1] ) ];
						jQuery.fn.attr.call( selector, context, true );

					} else {
						selector = [ doc.createElement( ret[1] ) ];
					}

				} else {
					tag = selector.match(/(<[\w\W]+>)[^>]*$/)[1];
					ret = jQuery.buildFragment( [ tag ], [ doc ] );
					selector = ( ret.cacheable ? jQuery.clone(ret.fragment) : ret.fragment ).childNodes;
				}

				return jQuery.merge( this, selector );
			}

			// HANDLE: $(expr, $(...))
			if ( !context || context.jquery ) {
				return ( context || rootjQuery ).find( selector );
			// HANDLE: $(expr, context)
			// (which is just equivalent to: $(context).find(expr)
			} else {
				return this.constructor( context ).find( selector );
			}

		// HANDLE: $(function)
		// Shortcut for document ready