JavaScript 关键字快速匹配

来源：

http://www.cnblogs.com/index-html/archive/2013/04/17/js_keyword_match.html

http://www.etherdream.com/funnyscript/Keyword/Keyword.html

 适用于多关键字、大文本匹配，若关键字只有一个，则只是最朴素的字符串匹配（逐个匹配），没显示作用。

var treeSearch = {
    makeTree: function(strKeys) {
        "use strict";
        var tblCur = {},
            tblRoot,
            key,
            str_key,
            Length,
            j,
            i
            ;
        tblRoot = tblCur;
        for ( j = strKeys.length - 1; j >= 0; j -= 1) {
            str_key = strKeys[j];
            Length = str_key.length;
            for ( i = 0; i < Length; i += 1) {
                key = str_key.charAt(i);
                if (tblCur.hasOwnProperty(key)) { //生成子节点 
                    tblCur = tblCur[key];
                } else {
                    tblCur = tblCur[key] = {};
                }
            }
            tblCur.end = true; //最后一个关键字没有分割符
            tblCur = tblRoot;
        }
        return tblRoot;
    },
    search: function(content, tblRoot) {
        "use strict";
        var tblCur,
            p_star = 0,
            n = content.length,
            p_end,
            match,  //是否找到匹配
            match_key,
            match_str,
            arrMatch = [],  //存储结果
            arrLength = 0   //arrMatch的长度索引
            ;
 
        while (p_star < n) {
            tblCur = tblRoot; //回溯至根部
            p_end = p_star;
            match_str = "";
            match = false;
            do {
                match_key = content.charAt(p_end);
                if (!(tblCur = tblCur[match_key])) { //本次匹配结束
                    p_star += 1;
                    break;
                }else{
                    match_str += match_key;
                }
                p_end += 1;
                if (tblCur.end === true) //是否匹配到尾部  //找到匹配关键字
                {
                    match = true;
                }
            } while (true);
 
            if (match === true) { //最大匹配
                arrMatch[arrLength] = { //增强可读性
                    key: match_str,
                    begin: p_star - 1,
                    end: p_end
                };
                arrLength += 1;
                p_star = p_end;
            }
        }
        return arrMatch;
    }
};

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