mass.query v3 发布

我想query v2这种设计思路已到瓶颈了，把选择器群组切割成最小颗粒，然后在循环中从文档对象找到一个或多个节点，然后再到下一个循环找到它们的孩子或直接从它们当中筛选……为此付出的代价也非常多——颗粒越多，循环次数也越多，虽然我在每个分支不断让指针向后移。但这也太累了，有些颗粒需要合并了才有意义。不过最令人痛心的问题是，也是所有从左到右选择的选择器不得不面临问题是，如果出现并联、亲子、兄长、相邻等选择器，得到的元素集合就很有可能不是按文档顺序排列。因此我下一版将尝试从右到左。不过从右到左最大的问题就是后代选择器，这种不断往上回溯的算法非常难，这也是jQuery在处理关系选择器容易出现错的原因。
其实无论是从左到右，还是从右到左，只要能把代码量压缩我都无怨言。因为很快就步入IE9的时代，querySelectorAll将支持更多的伪类(而且更有用)。因此这样人为的选择器只为向前兼容而存在，这样的代码我当然希望它占用我框架代码量的比重越少越好。我最近也想到几种方法，能让我的选择器跑得更快，但这也增加200多行代码，于是我不干了。
有人提出20/80原则，但这意味着一些选择器跑不了，但我宁愿慢一点也不愿放弃支持。其实选择一个或多个元素速度根本可以忽略不计，性能都耗在处理节点的各种操作上。
有人抱怨大循环的分支非常复杂，但明显易读性与执行效率往往不是一伙的，就像排序算法，越快的实现就越难看懂。这次把结构做好的，相对的，速度被拉下来了。
我知道，需要新的思路了……
/*
query selector version 2.4
Copyright 2010
Dual licensed under the MIT or GPL Version 2 licenses.
author "司徒正美(zhongqincheng)"
http://www.cnblogs.com/rubylouvre/
 */
(function(window,undefined){
    var parseNth = function (exp) {
        var match = reg_nth.exec(exp === "even" && "2n" || exp === "odd" && "2n+1" || !/\D/.test(exp) && "0n+" + exp || exp);
        return {
            a: (match[1] + (match[2] || 1)) - 0,
            b: match[3] - 0
        };
    }
    // "nth-child", "nth-last-child", "nth-of-type", "nth-last-of-type"
    var queryPseudoHasExp = function(start,next,flag_all){
        return {
            curry :function(lastResult,flag_not,getUID,name,exp){
                if ( exp === "n" && name.indexOf("child") > 0) {
                    return flag_not ? [] : lastResult;
                }
                var result = [],ri = 0,i = 0, uniqResult = {},p = parseNth(exp),a = p.a, b= p.b, c,  el, uid, find,tagName, node,
                flag_elem = "lastElementChild" in lastResult[0];
                start = flag_elem ? start : start.replace("Element","");
                next = flag_elem ? next : next.replace("Element","");
                while((el = lastResult[i++])){
                    uid = el.uniqueID || getUID(el);
                    find = uniqResult[uid];
                    if (find === void 0) {
                        for ( c = 0, node = el.parentNode[start], tagName = el.nodeName;node; node = node[next])
                            if ((flag_elem || node.nodeType === 1) && (flag_all || node.nodeName === tagName)) {
                                ++c;
                                uniqResult[getUID(node)] = a === 0 ? c === b : (c - b) % a === 0 && (c - b) / a >= 0;
                            }
                        find = uniqResult[uid];
                    }
                    if (find ^ flag_not)
                        result[ri++] = el;
                }
                return result;
            }
        }
    }
 
    var queryPseudoNoExp = function(direction,flag_all){
        return {
            curry : function(lastResult,flag_not){
                var result = [],ri = 0, i = 0,el,node,tagName,find,
                flag_elem = "lastElementChild" in lastResult[0],
                prop_prev = flag_elem ? prop_prev : "previousSibling",
                prop_next = flag_elem ? prop_prev : "nextSibling"
                while((el = lastResult[i++])){
                    tagName = flag_all || el.nodeName, find = null;
                    if (find === null && direction <= 0){
                        for (node = el[prop_prev]; node; node = node[prop_prev])
                            if ((flag_elem || node.nodeType === 1) && (flag_all || node.nodeName === tagName)) {
                                find = false;
                                break;
                            }
                    }
                    if (find === null && direction >= 0){
                        for (node = el[prop_next]; node; node = node[prop_next])
                            if ((flag_elem || node.nodeType === 1) && (flag_all || node.nodeName === tagName)) {
                                find = false;
                                break;
                            }
                    }
                    if (find === null)//如果本身就是first-child或last-child
                        find = true;
                    if (find ^ flag_not)//参与运算的两个值，如果两个相应bit位相同，则结果为0，否则为1。
                        result[ri++] = el;
                }
                return result;
            }
        }
    };
 
    var map_attr = {
        "accept-charset": "acceptCharset",
        accesskey: "accessKey",
        bgcolor: "bgColor",
        cellpadding: "cellPadding",
        cellspacing: "cellSpacing",
        "char": "ch",
        charoff: "chOff",
        "class": "className",
        codebase: "codeBase",
        codetype: "codeType",
        colspan: "colSpan",
        datetime: "dateTime",
        defaultchecked:"defaultChecked",
        defaultselected:"defaultSelected",
        defaultvalue:"defaultValue",
        "for": "htmlFor",
        frameborder: "frameBorder",
        "http-equiv": "httpEquiv",
        ismap: "isMap",
        longdesc: "longDesc",
        maxlength: "maxLength",
        marginwidth:"marginWidth",
        marginheight:'marginHeight',
        nohref: "noHref",
        noresize:"noResize",
        noshade: "noShade",
        readonly: "readOnly",
        rowspan: "rowSpan",
        tabindex: "tabIndex",
        usemap: "useMap",
        vspace: "vSpace",
        valuetype: "valueType"
    };
    var A_slice = Array.prototype.slice;
    window.dom = {
        UID:1,
        oneObject : function(array,val){
            var result = {},value = val !== void 0 ? val :1;
            for(var i=0,n=array.length;i < n;i++)
                result[array[i]] = value;
            return result;
        },
        slice:function(nodes,start,end){
            return A_slice.call(nodes,(start || 0),(end || nodes.length))
        },
        isXML : function(doc){
            return (!!doc.xmlVersion) || (!!doc.xml) || (Object.prototype.toString.call(doc) === '[object XMLDocument]') ||
            (doc.nodeType === 9 && doc.documentElement.nodeName !== 'HTML');
        },
 
        queryId : function (id, root) {
            var el = (root || document).getElementById(id);
            return el && [el] || []
        },
 
        queryTag : function (tagName, parents, getUID) {
            var result = [], ri = 0, uniqResult = {},i , node, uid ,n = parents.length;
            switch (n) {
                case 0:
                    return result;
                case 1:
                    var nodes =  parents[0].getElementsByTagName(tagName);
                    return  this.slice(nodes)
                default:
                    for (var k = 0 ; k < n ; k++) {
                        for (i = 0,nodes = parents[k].getElementsByTagName(tagName); node = nodes[i++];) {
                            if(dom.support.diffComment || node.nodeType === 1){
                                uid = node.uniqueID || getUID(node);
                                if (!uniqResult[uid]) {
                                    uniqResult[uid] = result[ri++] = node;
                                }
                            }
                        }
                    }
                    return result;
            }
        },
        _filters : { //伪类选择器的过滤器
            enabled: function(el){//标准
                return el.disabled === false && el.type !== "hidden";
            },
            disabled: function(el){//标准
                return el.disabled === true;
            },
            checked: function(el){//标准
                return el.checked === true;
            },
            indeterminate:function(el){//标准
                return el.indeterminate = true && el.type === "checkbox"
            },
            selected: function(el){
                el.parentNode.selectedIndex;//处理safari的bug
                return el.selected === true;
            },
            empty: function (el) {//标准
                return !el.firstChild;
            },
            lang: function (el, value) {//标准
                var reg = new RegExp("^" + value, "i")
                while (el && !el.getAttribute("lang"))
                    el = el.parentNode;
                return  !!(el && reg.test(el.getAttribute("lang")));
            },
            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);
            },
            hidden : function( el ) {
                return el.type === "hidden" || (el.offsetWidth === 0 ) || (!-[1,] && el.currentStyle.display === "none") ;
            },
            visible : function( el ) {
                return el.type !== "hidden" && (el.offsetWidth || el.offsetHeight || (!-[1,] && el.currentStyle.display !== "none"));
            },
            target:function(el,exp,context){//标准
                var id = context.location.hash.slice(1);
                return (el.id || el.name) === id;
            },
            parent : function( el ) {
                return !!el.firstChild;
            },
            contains: function(el, exp) {
                return (el.textContent||el.innerText||'').indexOf(exp) !== -1
            },
 
            has: function( el,exp ) {
                var a =  dom.query(exp, [el]).length;
                return !!a
            },
 
            "first-child":      queryPseudoNoExp(-1, true),//标准
            "last-child":       queryPseudoNoExp( 1, true),//标准
            "only-child":       queryPseudoNoExp( 0, true),//标准
            "first-of-type":    queryPseudoNoExp(-1, false),//标准
            "last-of-type":     queryPseudoNoExp( 1, false),//标准
            "only-of-type":     queryPseudoNoExp( 0 ,false),//标准
            "nth-child":        queryPseudoHasExp("firstElementChild", "nextElementSibling",     true),//标准
            "nth-last-child":   queryPseudoHasExp("lastElementChild",  "previousElementSibling", true),//标准
            "nth-of-type":      queryPseudoHasExp("firstElementChild", "nextElementSibling",     false),//标准
            "nth-last-of-type": queryPseudoHasExp("lastElementChild",  "previousElementSibling", false),//标准
            //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 & 1) === 0;
            },
            odd: function(index){
                return (index & 1) === 1;
            },
            lt: function(index, num){
                return index < num;
            },
            gt: function(index, num){
                return index > num;
            },
            eq: function(index, num){
                return index ===  num;
            },
            not:function(){}
        }
    }
    var reg_nth =  /(-?)(\d*)n([-+]?\d*)/;
    var reg_split = /(?:\(.*\)|[^,#:\.\s+>~[\](])+|[\.\[\]#:+>~,]|\s+/g
    var reg_id=  /^#([^,#:\.\s\xa0\u3000\+>~\[\(])+$/
    var reg_tag =  /[\w\u00c0-\uFFFF_-]+/;
    var reg_pseudo =  /^(\w[-\w]*)(\((.+)\))?$/
    var reg_href = /^(?:src|href|style)$/;
    var reg_blank = /\s*([>,\+\~=])\s*(?=(?:(?:[^"']*"[^"']*){2}|(?:[^"']*'[^"']*){2})*[^"']*$)/g;
    var reg_attribute = /\[\s*((?:[\w\u00c0-\uFFFF\-]|\\.)+)\s*(?:(\S?=)\s*(['"]*)(.*?)\3|)\s*\]/ ;
    var one_position = dom.oneObject("eq|gt|lt|first|last|even|odd".split("|"));
    "text|radio|checkbox|file|password|submit|image|reset".replace(/\w+/g, function(name){
        dom._filters[name] = function(el){
            return el.type = name;
        }
    });
    var queryAttribute = function(el,name){
        var special = map_attr[name];
        if(special)
            return el[special];
        var flag = reg_href.test(name) ? 2 : 0;
        return el.getAttribute(name,flag) || el[name];
    };
    var documentOrder = !-[1,] ? function (a, b) {
        return (a.sourceIndex - b.sourceIndex);
    }:function (a, b) {
        return (3 - (a.compareDocumentPosition(b) & 6));
    }
 
    dom.support = {
        sliceNodes : true
    };
    var HTML = document.documentElement;
    var div = document.createElement("div");
    HTML.insertBefore(div, HTML.firstChild);
    var id = new Date - 0
    div.innerHTML = '<a name="'+id+'"></a><b id="'+id+'"></b>';
    dom.support.diffName = document.getElementById(id) !== div.firstChild;
    try{//检测是否支持
        A_slice.call(div.childNodes)
    }catch(e){
        dom.support.sliceNodes = false;
    }
    div.appendChild(document.createComment(''))
    dom.support.diffComment = div.getElementsByTagName("*").length !== 3;
    HTML.removeChild(div)
    if(!dom.support.diffName){
        //如果浏览器的getElementById不能区分name与id
        dom.queryId = function(id,root){
            root = root || document;
            if(root.getElementById){
                var el = root.getElementById(id);
                return el && el.attributes['id'].value === id ? [el] :[]
            } else {
                var all = root.all[id];
                for(var i=0;el=all[i++];){
                    if(el.attributes['id'].value === id)
                        return [el]
                }
                return []
            }
        }
    }
    if(!dom.support.sliceNodes){
        //如果浏览器的getElementById不能区分name与id
        dom.slice = function(nodes,start,end){
            var i = nodes.length,result = [];
            while(i--){
                result[i] = nodes[i];
            }
            return  A_slice.call(result,(start || 0),(end || result.length));
        }
    }
 
    var getUIDHTML= function(node){
        return node.uniqueID || (node.uniqueID = dom.UID++);
    },
    getUIDXML = function(node){
        var uid = node.getAttribute("uniqueID");
        if (!uid){
            uid = dom.UID++;
            node.setAttribute("uniqueID", uid);
        }
        return uid;
    }
    //sss 为选择器群组,lastResult为undefined或纯数组
    dom.query = function(sss,lastResult,flag_not,flag_xml){
        if (typeof sss !== "string")
            return [];
        sss = sss.replace(/^[^#\(]*(#)/, "$1");
        lastResult = lastResult || [document];
        var match = lastResult[0],
        doc = match.nodeType === 9 ? match : (match.ownerDocument || match.document);
        flag_xml = flag_xml !== void 0 ? flag_xml : dom.isXML(doc),
        flag_not = !!flag_not;
        var result = [], ri = 0,  i = 0,flag_sort,flag_class,
        getUID = flag_xml? getUIDXML : getUIDHTML,
        flag_elem = "lastElementChild" in doc.documentElement ,
        prop = flag_elem ? "nextElementSibling" :"nextSibling",
        next,node,nodes,uniqResult,flag_all,uid,name,value;
        if(reg_id.test(sss))
            return dom.queryId(sss.slice(1),doc);
        if(/^\w+$/.test(sss)){
            return dom.queryTag(sss,lastResult,getUID);
        }
        if(doc.querySelectorAll && !flag_not){
            var flag_sqa = true;
            if(lastResult.length > 1)
                flag_sort = true;
            for (; node = lastResult[i];i++ ){
                node.id = node.id || node.uniqueID
                if( node.nodeType === 1 && node.uniqueID )
                    sss = "#"+node.id+" "+ sss;
                try {
                    result = result.concat(dom.slice(lastResult[i].querySelectorAll(sss)));
                } catch (e) {
                    flag_sqa = false;
                }finally{//IE8下querySelectorAll不在当前节点的孩子们中搜索
                    if (node.nodeType === 1 && node.uniqueID && node.id === node.uniqueID) {
                        node.removeAttribute( "id" );
                    }
                }
            }
            if(flag_sqa){
                return result
            }
        }
        sss = sss.replace(/^\s+|\s+$/g, '').replace(reg_blank,"$1").match(reg_split);
        var to_s = Object.prototype.toString,filter,tagName,not;
        for (var s = 0, ss ; ss = sss[s++];) {
            next = sss[s];
            uniqResult =  nodes = [];
            filter = flag_class = i = ri = 0
            switch(ss){
                case "#"://★★★★(1)ID选择器
                    if(!flag_xml && !flag_not){//XML不支持getElementById
                        nodes = dom.queryId(next, doc);
                    }else{
                        filter = ["id", "=", next];
                    }
                    s++;
                    break;
                case "."://★★★★(2)类选择器
                    s++;
                    if( lastResult.length === 1 && doc.getElementsByClassName && (!flag_not)){
                        nodes = dom.slice(lastResult[0].getElementsByClassName(next));
                    }else{
                        flag_class = true;
                        filter = ["class", "~=", next];
                    }
                    break;
                case "["://★★★★(3)属性选择器
                    while(next!=="]"){
                        ss += next;
                        next = sss[++s];
                    }
                    ss += next;
                    match = ss.match(reg_attribute);
                    filter = [match[1], match[2], match[4]];
                    s++;
                    break;
                case ","://★★★★(4)并联选择器
                    result = result.concat(lastResult);
                    lastResult = nodes = [doc];
                    flag_sort = true;
                    continue;
                case ">"://★★★★关系选择器
                case "+":
                case "~":
                    tagName = "*"
                    if (next && reg_tag.test(next)) {
                        tagName = flag_xml ? next : next.toUpperCase();
                        s++;
                    }
                    flag_all = tagName === "*";
                    flag_sort = true;
                    var els,el,j
                    switch (ss) {
                        case ">"://★★★(5)亲子选择器
                            while((el = lastResult[i++])){
                                els = el.children || el.childNodes;
                                for(j = 0; node = els[j++];)
                                    if(node.nodeType === 1 &&(flag_all || tagName === node.nodeName))
                                        nodes[ri++] = node;
                            }
                            break;
                        case "+"://★★★(6)相邻选择器
                            while((node = lastResult[i++])){
                                while((node = node[prop])){
                                    if(node.nodeType === 1){
                                        if (flag_all || tagName === node.nodeName)
                                            nodes[ri++] = node;
                                        break;
                                    }
                                }
                            }
                            break;
                        case "~":// ★★★(7)兄长选择器
                            while((node = lastResult[i++])){
                                while ((node = node[prop])){
                                    if(uniqResult[node.uniqueID] === node) break;
                                    if ( (flag_elem || node.nodeType === 1) && (flag_all || tagName === node.nodeName)) {
                                        uid = node.uniqueID || getUID(node);
                                        if(uniqResult[uid]){
                                            break;
                                        }else{
                                            nodes[ri++] = uniqResult[uid] = node;
                                        }
                                    }
                                }
                            }
                    }
                    break;
                case ":":
                    s++;
                    switch (next.slice(0,4)) {
                        case "scop"://直接查找不进行过滤
                            nodes = [doc];
                            break;
                        case "root"://直接查找不进行过滤
                            nodes = [doc.documentElement];
                            break;
                        case "link"://直接查找不进行过滤
                            match = doc.links;
                            if (match) {
                                nodes = dom.slice(match);
                                break
                            }
                        default:
                            match = next.match(reg_pseudo);
                            name = match[1],value = match[3], filter = dom._filters[name];
                    }
                    break;
                default://处理(9)通配符选择器(10)标签选择器与(11)后代选择器
                    tagName = ss === " "? next : ss;
                    match = reg_tag.test(tagName);
                    if( tagName !== ss && match ){
                        s++;
                    }
                    tagName = match ? tagName : "*"
                    tagName = flag_xml ? tagName : tagName.toUpperCase();
                    nodes = (flag_not  && (!match) && sss[s] === void 0) ? [] : dom.queryTag(tagName, lastResult, getUID);
                    break;
            }
            if(filter && !nodes.length ){
                not = flag_not && sss[s] === void 0;
                lastResult = lastResult[0] !== doc ? lastResult : dom.queryTag("*", lastResult, getUID);
                switch(to_s.call(filter||"")){
                    case "[object Function]":
                        if(one_position[name]){  //处理位置伪类
                            if(flag_sort)
                                lastResult = lastResult.sort(documentOrder);
                            //如果exp为空白则将集合的最大索引值传进去，否则将exp转换为数字
                            value = (value === ""|| value === void 0) ? lastResult.length - 1 : ~~value;
                            for (; node = lastResult[i];){
                                if(filter(i++, value) ^ not )
                                    nodes[ri++] = node;
                            }
                        }else if(name==="not"){
                            nodes = dom.query(value,lastResult,true,flag_xml);
                        }else{
                            //处理target root checked disabled empty enabled lang 等伪类
                            for (; node = lastResult[i++];){
                                if(!!filter(node, value, doc) ^ not)
                                    nodes[ri++] = node;
                            }
                        }
                        break;
                    case "[object Object]":
                        //处理结构伪类中的子元素过滤伪类
                        nodes = filter.curry(lastResult, not, getUID, name, value);
                    case "[object Array]":  //处理属性伪类
                        //处理属性伪类
                        var operator = filter[1], value = filter[2], attrib, flag;
                        for (; node = lastResult[i++];){
                            attrib = flag_class? node.className : queryAttribute(node, filter[0]);//取得元素的实际属性值
                            flag = (attrib != null) && (attrib !== "");
                            if(flag && operator){
                                switch (operator) {
                                    case "=":
                                        flag = attrib === value;
                                        break;
                                    case "!=":
                                        flag = attrib !== value;
                                        break;
                                    case "~=":
                                        flag = (" " + attrib + " ").indexOf(value) !== -1;
                                        break;
                                    case "^=":
                                        flag = attrib.indexOf(value) === 0;
                                        break;
                                    case "$=":
                                        flag = attrib.lastIndexOf(value) + value.length === attrib.length;
                                        break;
                                    case "*=":
                                        flag = attrib.indexOf(value) !== -1;
                                        break;
                                    case  "|=":
                                        flag = attrib === value || attrib.substring(0, value.length + 1) === value + "-";
                                        break;
                                }
                            }
                            if (!!flag  ^ not ){
                                nodes[ri++] = node;
                            }
                        }
                }
            }//结束过滤
            lastResult = nodes;
            if(!lastResult.length ) {
                break;
            }
        }
        result = result.concat(lastResult);
        if(result.length > 1 && flag_sort){
            i=ri=0,uniqResult = {},nodes= [];
            for(;node = result[i++];){
                uid = node.uniqueID || getUID(node);
                if (uniqResult[uid]){
                    break;
                }else {
                    uniqResult[uid] = nodes[ri++] = node;
                }
            }
            result = nodes.sort(documentOrder);
        }
        return result;
    }
 
})(window);