我的第五代选择器Icarus
Icarus是我目前匹配精度最高（通过470个单元测试保证精度)，速度最快（IE67下力压jQuery，其他浏览器都是使用querySelectorAll不分上下）的选择器，并且它全面支持CSS3的所有新增伪类，支持jQuery所有自定义伪类，并且支持对XML的查找，支持XML带命名空间的元素的查找（jQuery只能支持不带命名空间的，并且非常容易报错）。
Icarus与jQuery1.7在slickspeed中的速度比赛结果（数值最大代表越慢）：
| Icarus | jQuery1.7 | 比率 | |
| IE7 | 443 | 657 | 1.5 |
| IE6 | 975 | 1570 | 1.6 |
如果对比早期的jQuery.42就更不用说了，是其两倍以上。
Icarus最大亮点是对XML的完美支持，为此它用得到xpath与getElementsByTagName，对于命名空间的支持，请使用"aaa\\:bbb"方式来查找。
以下就是Icarus用到原生查找API：
- getElementById
- getElementsByTagName
- getElementsByTagNameNS
- getElementsByClassName
- evaluate (xpath)
- selectNodes (xpath)
- querySelectorAll
Icarus的代码量为930行（不依赖dom的其他模块），jQuery的Sizzle为1500行。
Icarus对CSS3伪类是按W3C的规范来查找，比如:not反选伪类，只支持单个表达式，如div:not(.a)，不能用div:not(.a.b)，要用就需要多个的反选，div:not(.a):not(.b)。
Icarus虽然支持jQuery的自定义伪类，但并不提倡使用，如位置伪类(:first,:last,:even,:odd,:eq...)，我们完全可以使用标准的子元素过滤伪类要代替（:last-child,:first-child,:nth-child(even)...），对于jQuery的自定义表单伪类（:text,:radio....），我们也完全可以使用属性选择器来代替(input[type=text],input[type=radio]....)。总之，不标准的东西活不长，希望大家切记。
//dom.query v5 开发代号Icarus
(function(global,DOC){
var dom = global[DOC.URL.replace(/(#.+|\W)/g,'')];
dom.define("query", function(){
dom.mix(dom,{
//http://www.cnblogs.com/rubylouvre/archive/2010/03/14/1685360.
isXML : function(el){
var doc = el.ownerDocument || el
return doc.createElement("p").nodeName !== doc.createElement("P").nodeName;
},
// 第一个节点是否包含第二个节点
contains:function(a, b){
if(a.compareDocumentPosition){
return !!(a.compareDocumentPosition(b) & 16);
}else if(a.contains){
return a !== b && (a.contains ? a.contains(b) : true);
}
while ((b = b.parentNode))
if (a === b) return true;
return false;
},
//获取某个节点的文本，如果此节点为元素节点，则取其childNodes的所有文本，
//为了让结果在所有浏览器下一致，忽略所有空白节点，因此它非元素的innerText或textContent
getText : function() {
return function getText( nodes ) {
for ( var i = 0, ret = "",node; node = nodes[i++]; ) {
// 对得文本节点与CDATA的内容
if ( node.nodeType === 3 || node.nodeType === 4 ) {
ret += node.nodeValue;
//取得元素节点的内容
} else if ( node.nodeType !== 8 ) {
ret += getText( node.childNodes );
}
}
return ret;
}
}(),
unique :function(nodes){
if(nodes.length < 2){
return nodes;
}
var result = [], array = [], uniqResult = {}, node = nodes[0],index, ri = 0
//如果支持sourceIndex我们将使用更为高效的节点排序
//http://www.cnblogs.com/jkisjk/archive/2011/01/28/array_quickly_sortby.html
if(node.sourceIndex){//IE opera
for(var i = 0 , n = nodes.length; i< n; i++){
node = nodes[i];
index = node.sourceIndex+1e8;
if(!uniqResult[index]){
(array[ri++] = new String(index))._ = node;
uniqResult[index] = 1
}
}
array.sort();
while( ri )
result[--ri] = array[ri]._;
return result;
}else {
var sortOrder = node.compareDocumentPosition ? sortOrder1 : sortOrder2;
nodes.sort( sortOrder );
if (sortOrder.hasDuplicate ) {
for ( i = 1; i < nodes.length; i++ ) {
if ( nodes[i] === nodes[ i - 1 ] ) {
nodes.splice( i--, 1 );
}
}
}
sortOrder.hasDuplicate = false;
return nodes;
}
}
});
var reg_combinator = /^\s*([>+~,\s])\s*(\*|(?:[-\w*]|[^\x00-\xa0]|\\.)*)/
var trimLeft = /^\s+/;
var trimRight = /\s+$/;
var reg_quick = /^(^|[#.])((?:[-\w]|[^\x00-\xa0]|\\.)+)$/;
var reg_comma = /^\s*,\s*/;
var reg_sequence = /^([#\.:]|\[\s*)((?:[-\w]|[^\x00-\xa0]|\\.)+)/;
var reg_pseudo = /^\(\s*("([^"]*)"|'([^']*)'|[^\(\)]*(\([^\(\)]*\))?)\s*\)/;
var reg_attrib = /^\s*(?:(\S?=)\s*(?:(['"])(.*?)\2|(#?(?:[\w\u00c0-\uFFFF\-]|\\.)*)|)|)\s*\]/
var reg_attrval = /\\([0-9a-fA-F]{2,2})/g;
var reg_sensitive = /^(title|id|name|class|for|href|src)$/
var reg_backslash = /\\/g;
var reg_tag = /^((?:[-\w\*]|[^\x00-\xa0]|\\.)+)/;//能使用getElementsByTagName处理的CSS表达式
if ( trimLeft.test( "\xA0" ) ) {
trimLeft = /^[\s\xA0]+/;
trimRight = /[\s\xA0]+$/;
}
var hash_operator = {
"=": 1,
"!=": 2,
"|=": 3,
"~=": 4,
"^=": 5,
"$=": 6,
"*=": 7
}
function sortOrder1( a, b ) {
if ( a === b ) {
sortOrder1.hasDuplicate = true;
return 0;
}
if ( !a.compareDocumentPosition || !b.compareDocumentPosition ) {
return a.compareDocumentPosition ? -1 : 1;
}
return a.compareDocumentPosition(b) & 4 ? -1 : 1;
};
function sortOrder2( a, b ) {//处理旧式的标准浏览器与XML
if ( a === b ) {
sortOrder2.hasDuplicate = true;
return 0;
}
var al, bl,
ap = [],
bp = [],
aup = a.parentNode,
bup = b.parentNode,
cur = aup;
//如果是属于同一个父节点，那么就比较它们在childNodes中的位置
if ( aup === bup ) {
return siblingCheck( a, b );
// If no parents were found then the nodes are disconnected
} else if ( !aup ) {
return -1;
} else if ( !bup ) {
return 1;
}
// Otherwise they're somewhere else in the tree so we need
// to build up a full list of the parentNodes for comparison
while ( cur ) {
ap.unshift( cur );
cur = cur.parentNode;
}
cur = bup;
while ( cur ) {
bp.unshift( cur );
cur = cur.parentNode;
}
al = ap.length;
bl = bp.length;
// Start walking down the tree looking for a discrepancy
for ( var i = 0; i < al && i < bl; i++ ) {
if ( ap[i] !== bp[i] ) {
return siblingCheck( ap[i], bp[i] );
}
}
// We ended someplace up the tree so do a sibling check
return i === al ?
siblingCheck( a, bp[i], -1 ) :
siblingCheck( ap[i], b, 1 );
};
function siblingCheck( a, b, ret ) {
if ( a === b ) {
return ret;
}
var cur = a.nextSibling;
while ( cur ) {
if ( cur === b ) {
return -1;
}
cur = cur.nextSibling;
}
return 1;
};
var slice = Array.prototype.slice;
function makeArray( nodes, result, flag_multi ) {
nodes = slice.call( nodes, 0 );
if ( result ) {
result.push.apply( result, nodes );
}else{
result = nodes;
}
return flag_multi ? dom.unique(result) : result;
};
//IE56789无法使用数组方法转换节点集合
try {
slice.call( dom.html.childNodes, 0 )[0].nodeType;
} catch( e ) {
function makeArray( nodes, result ,flag_multi) {
var ret = result || [], ri = ret.length;
for(var i = 0,el ; el = nodes[i++];){
ret[ri++] = el
}
return flag_multi ? dom.unique(ret) : ret;
}
}
function _toHex(x, y) {
return String.fromCharCode(parseInt(y, 16));
}
function parse_nth(expr) {
var orig = expr
expr = expr.replace(/^\+|\s*/g, '');//清除无用的空白
var match = (expr === "even" && "2n" || expr === "odd" && "2n+1" || !/\D/.test(expr) && "0n+" + expr || expr).match(/(-?)(\d*)n([-+]?\d*)/);
return parse_nth[ orig ] = {
a: (match[1] + (match[2] || 1)) - 0,
b: match[3] - 0
};
}
function getElementsByTagName(tagName, els, flag_xml) {
var method = "getElementsByTagName", elems = [], uniqResult = {}, prefix
if(flag_xml && tagName.indexOf(":") > 0 && els.length && els[0].lookupNamespaceURI){
var arr = tagName.split(":");
prefix = arr[0];
tagName = arr[1];
method = "getElementsByTagNameNS";
prefix = els[0].lookupNamespaceURI(prefix);
}
switch (els.length) {
case 0:
return elems;
case 1:
//在IE67下，如果存在一个name为length的input元素，下面的all.length返回此元素，而不是长度值
var all = prefix ? els[0][method](prefix,tagName) : els[0][method](tagName);
for(var i = 0, ri = 0, el; el = all[i++];){
if(el.nodeType === 1){//防止混入注释节点
elems[ri++] = el
}
}
return elems;
default:
for(i = 0, ri = 0; el = els[i++];){
var nodes = prefix ? el[method](prefix,tagName) : el[method](tagName)
for (var j = 0, node; node = nodes[j++];) {
var uid = dom.getUid(node);
if (!uniqResult[uid]) {
uniqResult[uid] = elems[ri++] = node;
}
}
}
return elems;
}
}
//IE9 以下的XML文档不能直接设置自定义属性
var attrURL = dom.oneObject('action,cite,codebase,data,href,longdesc,lowsrc,src,usemap', 2);
var bools = dom["@bools"] = "autofocus,autoplay,async,checked,controls,declare,disabled,defer,defaultChecked,"+
"contentEditable,ismap,loop,multiple,noshade,open,noresize,readOnly,selected"
var boolOne = dom.oneObject(bools.toLowerCase() );
var getHTMLText = new Function("els","return els[0]."+ (dom.html.textContent ? "textContent" : "innerText") );
//检测各种BUG（fixGetAttribute，fixHasAttribute，fixById，fixByTag）
var fixGetAttribute,fixHasAttribute,fixById,fixByTag;
new function(){
var select = DOC.createElement("select");
var option = select.appendChild( DOC.createElement("option") );
option.setAttribute("selected","selected")
option.className ="x"
fixGetAttribute = option.getAttribute("class") != "x";
select.appendChild( DOC.createComment("") );
fixByTag = select.getElementsByTagName("*").length == 2
var all = DOC.getElementsByTagName("*"), node, nodeType, comments = [], i = 0, j = 0;
while ( (node = all[i++]) ) {
nodeType = node.nodeType;
nodeType === 1 ? dom.getUid(node) :
nodeType === 8 ? comments.push(node) : 0;
}
while ( (node = comments[j++]) ) {
node.parentNode.removeChild(node);
}
fixHasAttribute = select.hasAttribute ? !option.hasAttribute('selected') :true;
var form = DOC.createElement("div"),
id = "fixId" + (new Date()).getTime(),
root = dom.html;
form.innerHTML = "<a name='" + id + "'/>";
root.insertBefore( form, root.firstChild );
fixById = !!DOC.getElementById( id ) ;
root.removeChild(form )
};
//http://www.atmarkit.co.jp/fxml/tanpatsu/24bohem/01.html
//http://msdn.microsoft.com/zh-CN/library/ms256086.aspx
//https://developer.mozilla.org/cn/DOM/document.evaluate
//http://d.hatena.ne.jp/javascripter/20080425/1209094795
function getElementsByXPath(xpath,context,doc) {
var result = [];
try{
if(global.DOMParser){//IE9支持DOMParser，但我们不能使用doc.evaluate!global.DOMParser
var nodes = doc.evaluate(xpath, context, null, 7, null);
for (var i = 0, n = nodes.snapshotLength; i < n; i++){
result[i] = nodes.snapshotItem(i)
}
}else{
nodes = context.selectNodes(xpath);
for (i = 0, n = nodes.length; i < n; i++){
result[i] = nodes[i]
}
}
}catch(e){
return false;
}
return result;
};
/**
* 选择器
* @param {String} expr CSS表达式
* @param {Node} context 上下文（可选）
* @param {Array} result 结果集(内部使用)
* @param {Array} lastResult 上次的结果集(内部使用)
* @param {Boolean}flag_xml 是否为XML文档(内部使用)
* @param {Boolean}flag_multi 是否出现并联选择器(内部使用)
* @param {Boolean}flag_dirty 是否出现通配符选择器(内部使用)
* @return {Array} result
*/
//http://webbugtrack.blogspot.com/
var Icarus = dom.query = function(expr, contexts, result, lastResult, flag_xml,flag_multi,flag_dirty){
result = result || [];
contexts = contexts || DOC;
var pushResult = makeArray;
if(!contexts.nodeType){//实现对多上下文的支持
contexts = pushResult(contexts);
if(!contexts.length)
return result
}else{
contexts = [contexts];
}
var rrelative = reg_combinator,//保存到本地作用域
rquick = reg_quick,
rBackslash = reg_backslash, rcomma = reg_comma,//用于切割并联选择器
context = contexts[0],
doc = context.ownerDocument || context,
rtag = reg_tag,
flag_all, uniqResult, elems, nodes, tagName, last, ri, uid;
//将这次得到的结果集放到最终结果集中
//如果要从多个上下文中过滤孩子
expr = expr.replace(trimLeft, "").replace(trimRight, "");
flag_xml = flag_xml !== void 0 ? flag_xml : dom.isXML(doc);
if (!flag_xml && doc.querySelectorAll2) {
var query = expr;
if(contexts.length > 2 || doc.documentMode == 8 && context.nodeType == 1 ){
if(contexts.length > 2 )
context = doc;
query = ".fix_icarus_sqa "+query;//IE8也要使用类名确保查找范围
for(var i = 0, node; node = contexts[i++];){
if(node.nodeType === 1){
node.className = "fix_icarus_sqa " + node.className;
}
}
}
if(doc.documentMode !== 8 || context.nodeName.toLowerCase() !== "object"){
try{
return pushResult( context.querySelectorAll(query), result, flag_multi);
}catch(e){
}finally{
if(query.indexOf(".fix_icarus_sqa") === 0 ){//如果为上下文添加了类名，就要去掉类名
for(i = 0; node = contexts[i++];){
if(node.nodeType === 1){
node.className = node.className.replace("fix_icarus_sqa ","");
}
}
}
}
}
}
var match = expr.match(rquick);
if(match ){//对只有单个标签，类名或ID的选择器进行提速
var value = match[2].replace(rBackslash,""), key = match[1];
if ( key == "") {//tagName;
nodes = getElementsByTagName(value,contexts,flag_xml);
} else if ( key === "." && contexts.length === 1 ) {//className，并且上下文只有1个
if(flag_xml){//如果XPATH查找失败，就会返回字符，那些我们就使用普通方式去查找
nodes = getElementsByXPath("//*[@class='"+value+"']", context, doc);
}else if(context.getElementsByClassName){
nodes = context.getElementsByClassName( value );
}
}else if ( key === "#" && contexts.length === 1){//ID，并且上下文只有1个
if( flag_xml){
nodes = getElementsByXPath("//*[@id='"+value+"']", context, doc);
//基于document的查找是不安全的，因为生成的节点可能还没有加入DOM树，比如dom("<div id=\"A'B~C.D[E]\"><p>foo</p></div>").find("p")
}else if(context.nodeType == 9){
node = doc.getElementById(value);
//IE67 opera混淆表单元素，object以及链接的ID与NAME
//http://webbugtrack.blogspot.com/2007/08/bug-152-getelementbyid-returns.html
nodes = !node ? [] : !fixById ? [node] : node.getAttributeNode("id").nodeValue === value ? [node] : false;
}
}
if(nodes ){
return pushResult( nodes, result, flag_multi );
}
}
//执行效率应该是内大外小更高一写
lastResult = contexts;
if(lastResult.length){
loop:
while (expr && last !== expr) {
flag_dirty = false;
elems = null;
uniqResult = {};
//处理夹在中间的关系选择器（取得连接符及其后的标签选择器或通配符选择器）
if (match = expr.match(rrelative)) {
expr = RegExp.rightContext;
elems = [];
tagName = (flag_xml ? match[2] : match[2].toUpperCase()).replace(rBackslash,"") || "*";
i = 0;
ri = 0;
flag_all = tagName === "*";// 表示无需判定tagName
switch (match[1]) {//根据连接符取得种子集的亲戚，组成新的种子集
case " "://后代选择器
if(expr.length || match[2]){//如果后面还跟着东西或最后的字符是通配符
elems = getElementsByTagName(tagName, lastResult, flag_xml);
}else{
elems = lastResult;
break loop
}
break;
case ">"://亲子选择器
while((node = lastResult[i++])){
for (node = node.firstChild; node; node = node.nextSibling){
if (node.nodeType === 1 && (flag_all || tagName === node.nodeName)){
elems[ri++] = node;
}
}
}
break;
case "+"://相邻选择器
while((node = lastResult[i++])){
while((node = node.nextSibling)){
if (node.nodeType === 1) {
if (flag_all || tagName === node.nodeName)
elems[ri++] = node;
break;
}
}
}
break;
case "~"://兄长选择器
while((node = lastResult[i++])){
while((node = node.nextSibling)){
if (node.nodeType === 1 && (flag_all || tagName === node.nodeName)) {
uid = dom.getUid(node);
if (uniqResult[uid]){
break;
}else {
uniqResult[uid] = elems[ri++] = node;
}
}
}
}
elems = dom.unique(elems);
break;
}
}else if(match = expr.match(rtag)){//处理位于最开始的或并联选择器之后的标签选择器或通配符
expr = RegExp.rightContext;
elems = getElementsByTagName(match[1].replace(rBackslash,""), lastResult, flag_xml);
}
if(expr){
var arr = Icarus.filter(expr, elems, lastResult, doc, flag_xml);
expr = arr[0];
elems = arr[1];
if (!elems) {
flag_dirty = true;
elems = getElementsByTagName("*", lastResult, flag_xml);
}
if (match = expr.match(rcomma)) {
expr = RegExp.rightContext;
pushResult(elems, result);
return Icarus(expr, contexts, result, [], flag_xml, true, flag_dirty);
}else{
lastResult = elems;
}
}
}
}
if (flag_multi) {
if (elems.length){
return pushResult(elems, result,flag_multi);
}
}else if (DOC !== doc || fixByTag && flag_dirty) {
for (result = [], ri = 0, i = 0; node = elems[i++]; )
if (node.nodeType === 1)
result[ri++] = node;
return result
}
return elems;
}
var onePosition = dom.oneObject("eq|gt|lt|first|last|even|odd".split("|"));
dom.mix(Icarus, {
//getAttribute总会返回字符串
//http://reference.sitepoint.com/javascript/Element/getAttribute
getAttribute : !fixGetAttribute ?
function(elem, name) {
return elem.getAttribute(name) || '';
} :
function(elem, name, flag_xml) {
if(flag_xml)
return elem.getAttribute(name) || '';
name = name.toLowerCase();
//http://jsfox.cn/blog/javascript/get-right-href-attribute.html
if(attrURL[name]){//得到href属性里原始链接，不自动转绝对地址、汉字和符号都不编码
return elem.getAttribute(name, 2) || ''
}
if(elem.tagName === "INPUT" && name == "type"){
return elem.getAttribute("type") || elem.type;//IE67无法辩识HTML5添加添加的input类型，如input[type=search]，不能使用el.type与el.getAttributeNode去取。
}
//布尔属性，如果为true时则返回其属性名，否则返回空字符串，其他一律使用getAttributeNode
var attr = boolOne[name] ? (elem.getAttribute(name) ? name : '') :
(elem = elem.getAttributeNode(name)) && elem.value || '';
return reg_sensitive.test(name)? attr :attr.toLowerCase();
},
hasAttribute : !fixHasAttribute ?
function(elem, name, flag_xml) {
return flag_xml ? !!elem.getAttribute(name) :elem.hasAttribute(name);
} :
function(elem, name) {
//http://help.dottoro.com/ljnqsrfe.php
name = name.toLowerCase();
//如果这个显式设置的属性是""，即使是outerHTML也寻不见其踪影
elem = elem.getAttributeNode(name);
return !!(elem && (elem.specified || elem.nodeValue));
},
filter : function(expr, elems, lastResult, doc, flag_xml, flag_get){
var rsequence = reg_sequence,
rattrib = reg_attrib ,
rpseudo = reg_pseudo,
rBackslash = reg_backslash,
rattrval = reg_attrval,
pushResult = makeArray,
toHex = _toHex,
_hash_op = hash_operator,
parseNth = parse_nth,
match ,key, tmp;
while ( match = expr.match(rsequence)) {//主循环
expr = RegExp.rightContext;
key = ( match[2]|| "").replace(rBackslash,"");
if (!elems) {//取得用于过滤的元素
if (lastResult.length === 1 && lastResult[0] === doc){
switch (match[1]) {
case "#":
if (!flag_xml) {//FF chrome opera等XML文档中也存在getElementById，但不能用
tmp = doc.getElementById(key);
if (!tmp) {
elems = [];
continue;
}
//处理拥有name值为"id"的控件的form元素
if (fixById ? tmp.id === key : tmp.getAttributeNode("id").nodeValue === key) {
elems = [tmp];
continue;
}
}
break;
case ":":
switch (key) {
case "root":
elems = [doc.documentElement];
continue;
case "link":
elems = pushResult(doc.links || []);
continue;
}
break;
}
}
elems = getElementsByTagName("*", lastResult, flag_xml);//取得过滤元
}
//取得用于过滤的函数，函数参数或数组
var filter = 0, flag_not = false, args;
switch (match[1]) {
case "#"://ID选择器
filter = ["id", "=", key];
break;
case "."://类选择器
filter = ["class", "~=", key];
break;
case ":"://伪类选择器
tmp = Icarus.pseudoAdapter[key];
if (match = expr.match(rpseudo)) {
expr = RegExp.rightContext;
if(!!~key.indexOf("nth")){
args = parseNth[match[1]] || parseNth(match[1]);
}else{
args = match[3] || match[2] || match[1]
}
}
if (tmp){
filter = tmp;
}else if (key === "not") {
flag_not = true;
if (args === "*"){//处理反选伪类中的通配符选择器
elems = [];
}else if(reg_tag.test(args)){//处理反选伪类中的标签选择器
tmp = [];
match = flag_xml ? args : args.toUpperCase();
for (var i = 0, ri = 0, elem; elem = elems[i++];)
if (match !== elem.nodeName)
tmp[ri++] = elem;
elems = tmp;
}else{
var obj = Icarus.filter(args, elems, lastResult, doc, flag_xml, true) ;
filter = obj.filter;
args = obj.args;
}
}
else{
throw 'An invalid or illegal string was specified : "'+ key+'"!'
}
break
default:
filter = [key.toLowerCase()];
if (match = expr.match(rattrib)) {
expr = RegExp.rightContext;
if (match[1]) {
filter[1] = match[1];//op
filter[2] = match[3] || match[4];//对值进行转义
filter[2] = filter[2] ? filter[2].replace(rattrval, toHex).replace(rBackslash,"") : "";
}
}
break;
}
if(flag_get){
return {
filter:filter,
args:args
}
}
//如果条件都俱备，就开始进行筛选
if (elems.length && filter) {
tmp = [];
i = 0;
ri = 0;
if (typeof filter === "function") {//如果是一些简单的伪类
if(onePosition[key]){
//如果args为void则将集合的最大索引值传进去，否则将exp转换为数字
args = args === void 0 ? elems.length - 1 : ~~args;
for (; elem = elems[i];){
if(filter(i++, args) ^ flag_not)
tmp[ri++] = elem;
}
}else{
while((elem = elems[i++])){
if ((!!filter(elem, args)) ^ flag_not)
tmp[ri++] = elem;
}
}
}else if (typeof filter.exec === "function"){//如果是子元素过滤伪类
tmp = filter.exec({
not: flag_not,
xml: flag_xml
}, elems, args, doc);
} else {
var name = filter[0], op = _hash_op[filter[1]], val = filter[2]||"", flag, attr;
if (!flag_xml && name === "class" && op === 4) {//如果是类名
val = " " + val + " ";
while((elem = elems[i++])){
var className = elem.className;
if (!!(className && (" " + className + " ").indexOf(val) > -1) ^ flag_not){
tmp[ri++] = elem;
}
}
} else {
if(!flag_xml && op && val && !reg_sensitive.test(name)){
val = val.toLowerCase();
}
if (op === 4){
val = " " + val + " ";
}
while((elem = elems[i++])){
if(!op){
flag = Icarus.hasAttribute(elem,name,flag_xml);//[title]
}else if(val === "" && op > 3){
flag = false
}else{
attr = Icarus.getAttribute(elem,name,flag_xml);
switch (op) {
case 1:// = 属性值全等于给出值
flag = attr === val;
break;
case 2://!= 非标准，属性值不等于给出值
flag = attr !== val;
break;
case 3://|= 属性值以“-”分割成两部分，给出值等于其中一部分，或全等于属性值
flag = attr === val || attr.substr(0, val.length + 1) === val + "-";
break;
case 4://~= 属性值为多个单词，给出值为其中一个。
flag = attr && (" " + attr + " ").indexOf(val) >= 0;
break;
case 5://^= 属性值以给出值开头
flag = attr && attr.indexOf(val) === 0 ;
break;
case 6://$= 属性值以给出值结尾
flag = attr &&attr.substr(attr.length - val.length) === val;
break;
case 7://*= 属性值包含给出值
flag = attr && attr.indexOf(val) >= 0;
break;
}
}
if (flag ^ flag_not)
tmp[ri++] = elem;
}
}
}
elems = tmp;
}
}
return [expr, elems];
}
});
//===================构建处理伪类的适配器=====================
var filterPseudoHasExp = function(strchild,strsibling, type){
return {
exec:function(flags,lastResult,args){
var result = [], flag_not = flags.not,child = strchild, sibling = strsibling,
ofType = type, cache = {},lock = {},a = args.a, b = args.b, i = 0, ri = 0, el, found ,diff,count;
if(!ofType && a === 1 && b === 0 ){
return flag_not ? [] : lastResult;
}
var checkName = ofType ? "nodeName" : "nodeType";
for (; el = lastResult[i++];) {
var parent = el.parentNode;
var pid = dom.getUid(parent);
if (!lock[pid]){
count = lock[pid] = 1;
var checkValue = ofType ? el.nodeName : 1;
for(var node = parent[child];node;node = node[sibling]){
if(node[checkName] === checkValue){
pid = dom.getUid(node);
cache[pid] = count++;
}
}
}
diff = cache[dom.getUid(el)] - b;
found = a === 0 ? diff === 0 : (diff % a === 0 && diff / a >= 0 );
(found ^ flag_not) && (result[ri++] = el);
}
return result;
}
};
};
function filterPseudoNoExp(name, isLast, isOnly) {
var A = "var result = [], flag_not = flags.not, node, el, tagName, i = 0, ri = 0, found = 0; for (; node = el = lastResult[i++];found = 0) {"
var B = "{0} while (!found && (node=node.{1})) { (node.{2} === {3}) && ++found; }";
var C = " node = el;while (!found && (node = node.previousSibling)) { node.{2} === {3} && ++found; }";
var D = "!found ^ flag_not && (result[ri++] = el); } return result";
var start = isLast ? "nextSibling" : "previousSibling";
var fills = {
type: [" tagName = el.nodeName;", start, "nodeName", "tagName"],
child: ["", start, "nodeType", "1"]
}
[name];
var body = A+B+(isOnly ? C: "")+D;
var fn = new Function("flags","lastResult",body.replace(/{(\d)}/g, function ($, $1) {
return fills[$1];
}));
return {
exec:fn
}
}
function filterProp(str_prop, flag) {
return {
exec: function (flags, elems) {
var result = [], prop = str_prop, flag_not = flag ? flags.not : !flags.not;
for (var i = 0,ri = 0, elem; elem = elems[i++];)
if ( elem[prop] ^ flag_not)
result[ri++] = elem;//&& ( !flag || elem.type !== "hidden" )
return result;
}
};
};
Icarus.pseudoAdapter = {
root: function (el) {//标准
return el === (el.ownerDocument || el.document).documentElement;
},
target: {//标准
exec: function (flags, elems,_,doc) {
var result = [], flag_not = flags.not;
var win = doc.defaultView || doc.parentWindow;
var hash = win.location.hash.slice(1);
for (var i = 0,ri = 0, elem; elem = elems[i++];)
if (((elem.id || elem.name) === hash) ^ flag_not)
result[ri++] = elem;
return result;
}
},
"first-child" : filterPseudoNoExp("child", false, false),
"last-child" : filterPseudoNoExp("child", true, false),
"only-child" : filterPseudoNoExp("child", true, true),
"first-of-type" : filterPseudoNoExp("type", false, false),
"last-of-type" : filterPseudoNoExp("type", true, false),
"only-of-type" : filterPseudoNoExp("type", true, true),//name, isLast, isOnly
"nth-child" : filterPseudoHasExp("firstChild", "nextSibling", false),//标准
"nth-last-child" : filterPseudoHasExp("lastChild", "previousSibling", false),//标准
"nth-of-type" : filterPseudoHasExp("firstChild", "nextSibling", true),//标准
"nth-last-of-type": filterPseudoHasExp("lastChild", "previousSibling", true),//标准
empty: {//标准
exec: function (flags, elems) {
var result = [], flag_not = flags.not, check
for (var i = 0, ri = 0, elem; elem = elems[i++];) {
if(elem.nodeType == 1){
if (!elem.firstChild ^ flag_not)
result[ri++] = elem;
}
}
return result;
}
},
link: {//标准
exec: function (flags, elems) {
var links = (elems[0].ownerDocument || elems[0].document).links;
if (!links) return [];
var result = [],
checked = {},
flag_not = flags.not;
for (var i = 0, ri = 0,elem; elem = links[i++];)
checked[dom.getUid(elem) ] = 1;
for (i = 0; elem = elems[i++]; )
if (checked[dom.getUid(elem)] ^ flag_not)
result[ri++] = elem;
return result;
}
},
lang: {//标准 CSS2链接伪类
exec: function (flags, elems, arg) {
var result = [], reg = new RegExp("^" + arg, "i"), flag_not = flags.not;
for (var i = 0, ri = 0, elem; elem = elems[i++]; ){
var tmp = elem;
while (tmp && !tmp.getAttribute("lang"))
tmp = tmp.parentNode;
tmp = !!(tmp && reg.test(tmp.getAttribute("lang")));
if (tmp ^ flag_not)
result[ri++] = elem;
}
return result;
}
},
active: function(el){
return el === el.ownerDocument.activeElement;
},
focus:function(el){
return (el.type|| el.href) && el === el.ownerDocument.activeElement;
},
indeterminate : function(node){//标准
return node.indeterminate === true && node.type === "checkbox"
},
//http://www.w3.org/TR/css3-selectors/#UIstates
enabled: filterProp("disabled", false),//标准
disabled: filterProp("disabled", true),//标准
checked: filterProp("checked", true),//标准
contains: {
exec: function (flags, elems, arg) {
var res = [], elem = elems[0], fn = flags.xml ? dom.getText: getHTMLText,
flag_not = flags.not;
for (var i = 0, ri = 0, elem; elem = elems[i++]; ){
if ((!!~fn( [elem] ).indexOf(arg)) ^ flag_not)
res[ri++] = elem;
}
return res;
}
},
//自定义伪类
selected : function(el){
el.parentNode.selectedIndex;//处理safari的bug
return el.selected === true;
},
header : function(el){
return /h\d/i.test( el.nodeName );
},
button : function(el){
return "button" === el.type || el.nodeName === "BUTTON";
},
input: function(el){
return /input|select|textarea|button/i.test(el.nodeName);
},
parent : function( el ) {
return !!el.firstChild;
},
has : function(el, expr){//孩子中是否拥有匹配expr的节点
return !!dom.query(expr,[el]).length;
},
//与位置相关的过滤器
first: function(index){
return index === 0;
},
last: function(index, num){
return index === num;
},
even: function(index){
return index % 2 === 0;
},
odd: function(index){
return index % 2 === 1;
},
lt: function(index, num){
return index < num;
},
gt: function(index, num){
return index > num;
},
eq: function(index, num){
return index === num;
},
hidden : function( el ) {
return el.type === "hidden" || (!el.offsetWidth && !el.offsetHeight) || (el.currentStyle && el.currentStyle.display === "none") ;
}
}
Icarus.pseudoAdapter.visible = function(el){
return !Icarus.pseudoAdapter.hidden(el);
}
"text,radio,checkbox,file,password,submit,image,reset".replace(dom.rword, function(name){
Icarus.pseudoAdapter[name] = function(el){
return (el.getAttribute("type") || el.type) === name;//避开HTML5新增类型导致的BUG，不直接使用el.type === name;
}
});
});
})(this,this.document);
//2011.10.25重构dom.unique
//2011.10.26支持对拥有name值为id的控件的表单元素的查找，添加labed语句，让元素不存在时更快跳出主循环
//2011.10.30让属性选择器支持拥有多个中括号与转义符的属性表达式，如‘input[name=brackets\\[5\\]\\[\\]]’
//2011.10.31重构属性选择器处理无操作部分，使用hasAttribute来判定用户是否显示使用此属性，并支持checked, selected, disabled等布尔属性
//2011.10.31重构关系选择器部分，让后代选择器也出现在switch分支中
//2011.11.1 重构子元素过滤伪类的两个生成函数filterPseudoHasExp filterPseudoNoExp
//2011.11.2 FIX处理 -of-type家族的BUG
//2011.11.3 添加getAttribute hasAttribute API
//2011.11.4 属性选择器对给出值或属性值为空字符串时进行快速过滤
//2011.11.5 添加getElementsByXpath 增加对XML的支持
//2011.11.6 重构getElementsByTagName 支持带命名空间的tagName
//2011.11.6 处理IE67与opera9在getElementById中的BUG
//2011.11.7 支持多上下文,对IE678的注释节点进行清除,优化querySelectorAll的使用
//2011.11.8 处理分解nth-child参数的BUG，修正IE67下getAttribute对input[type=search]的支持，重构sortOrder标准浏览器的部分
//调整swich...case中属性选择器的分支，因为reg_sequence允许出现"[ "的情况，因此会匹配不到，需要改为default
//修改属性选择器$=的判定，原先attr.indexOf(val) == attr.length - val.length，会导致"PWD".indexOf("bar]")也有true
//2011.11.9 增加getText 重构 getElementById与过滤ID部分
//2011.11.10 exec一律改为match,对parseNth的结果进行缓存
下面是Icarus对命名空间的支持演示，例子是inline SVG，由于IE9不支持，请在高版本的标准浏览器中看。在IE10支持SVG后，SVG的应用就大大增多了，因此命名空间的支持是必须的。
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<head>
<title>icarus svg by 司徒正美</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script src="https://files.cnblogs.com/rubylouvre/icarus.js"></script>
<script>
window.onload = function(){
alert(dom.query("svg\\:feOffset:first")[0].tagName)
}
</script>
</head>
<body>
<svg:svg height="0">
<!-- Create the filter. Make sure it uses the sRGB colorspace or you're in for some nasty surprises. -->
<svg:filter color-interpolation-filters="sRGB" id="perspDisp" filterUnits="userSpaceOnUse" x="0%" y="0%" width="512" height="512" >
<!-- Move the video 128px to the bottom/right so that the displacement filter can reach 128px to the top/left without reaching beyond the image -->
<svg:feOffset
x="128" y="128" width="256" height="256"
dx="128" dy="128"
result="displacement"
/>
<!-- This actually loads our texture-->
<svg:feImage
id="textureLoader"
x="0" y="0" width="256" height="256"
xlink:href="texture.tinman.png"
/>
<!-- Tile the texture to fill the whole viewport so that the displacement filter can also reach 128px to the bottom/right without leaving the texture -->
<svg:feTile
x="0" y="0" width="512" height="512"
result="texture"
/>
<!-- Apply the displacement -->
<svg:feDisplacementMap
x="128" y="128" width="256" height="256"
in="texture" in2="displacement"
scale="255"
xChannelSelector="R" yChannelSelector="G"
/>
<!-- Apply the alpha of the displacement map to the final image, so that whatever is transparent in the map is also transparent in the final image -->
<svg:feComposite
in2="displacement"
operator="in"
/>
<!-- Move the image back to the top/left -->
<svg:feOffset
x="0" y="0" width="256" height="256"
dx="-128" dy="-128"
/>
</svg:filter>
</svg:svg>
</body>
</html>
后话，javascript的选择器基本是为了兼容IE678（IE8的querySelectoAll支持种类太少），以后的选择器基本上是用querySelectorAll与evaluate与matchesSelector来写了，CSS4也很快到来了，带来更多伪类，因此jQuery的自定义伪类基本没有存在的必要。
相关链接：
机器瞎学/数据掩埋/模式混淆/人工智障/深度遗忘/神经掉线/计算机幻觉/专注单身二十五年
