;(function(g){
	var D = document,
		  _tag = function(tag,p){
		    return p.getElementsByTagName(tag || "*");
	    };
  var _queryMethod = {
		"#":function(q){ 
			var bits = q.split("#"),
				  tagName = bits[0],
				  id = bits[1],
				  element = D.getElementById(id);
			return tagName && element.tagName.toLowerCase() != tagName ? [] : [element];
		},
		".":function(q,p){
			var bits = q.split("."),
				  tagName = bits[0],
				  cn=bits[1],
				  elems = null,
				  returnEl = [],
				  index = 0;
		  for(var i=0,l = p.length;i<l;i++){
				elems = _tag(tagName,p[i]);
				var tmp = null;
				for(var j =0,m = elems.length;j<m;j++){
					if(!/\S/.test((tmp = elems[j]).nodeValue)) continue;
					if(new RegExp("\\b"+cn+"\\b").test(tmp.className)){
						returnEl[index++] = tmp;
					}
				}
			}
			return returnEl;
		},
		"tag":function(q,p){
			var found,returnEl = [],index=0;
			q = q;
			for(var i=0,l=p.length;i<l;i++){
				found = _tag(q,p[i]);
				for(var j =0,m=found.length;j<m;j++){
					returnEl[index++] = found[j];
				}
			}
			return returnEl;
		},
		"attr":function(operation,tag,attr,attrValue,p){
			var found =[],returnEl = [],index=fIndex=0;

			for(var i=0,l=p.length;i<l;i++){
				var tmp = _tag(tag,p[i]);
				for(var j=0,m=tmp.length;j<m;j++){
					found[index++]=tmp[j];
				}
			}

			//不错吧？ ^_^
			var checkFn = {
				'=':function(e) { return (e.getAttribute(attr) == attrValue); },
		    '~':function(e) { return (e.getAttribute(attr).match(new RegExp('\\b'+attrValue+'\\b'))); },
		    '|':function(e) { return (e.getAttribute(attr).match(new RegExp('^'+attrValue+'-?'))); },
		    '^':function(e) { return (e.getAttribute(attr).indexOf(attrValue) == 0); },
		    '$':function(e) { return (e.getAttribute(attr).lastIndexOf(attrValue) == e.getAttribute(attr).length - attrValue.length); },
		    '*':function(e) { return (e.getAttribute(attr).indexOf(attrValue) > -1); },
		    'a':function(e) { return e.getAttribute(attr);}
			}[operation];

			for(var i=0,l=found.length;i<l;i++){
				if(checkFn(found[i])){
					returnEl[fIndex++] = found[i];
				}
			}
			return returnEl;
		}
  }

	//处理每一个token
	var _querySelector = function(q,p){
		var elements = /#/.test(q) ? _queryMethod["#"](q) : /\./.test(q) ? _queryMethod["."](q,p) : [];
		if(elements.length) return elements;
		if(!elements.length && q.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/)){
			return _queryMethod["attr"](RegExp.$3 || "a",RegExp.$1,RegExp.$2,RegExp.$4,p);
	  }
		if(!elements.length){
			return _queryMethod["tag"](q,p);
		}
		return elements;
	}

	var _query = function(q){
		if(document.querySelectorAll){return document.querySelectorAll(q);}
		var tokens = q.split(' '),token,elems=[D];
		for(var i=0,l=tokens.length;i<l;i++){
			elems=_querySelector(tokens[i],elems);
		}
		return elems;
	}
	g.query=_query || {};
})(this);