基于纯 PHP 的字符串布尔搜索 [英] Pure PHP based boolean search for strings

问题描述

我有一个项目，需要在纯 PHP 中进行一些基本的布尔搜索.这意味着我有简单的字符串，我想对它们提供一些简单的布尔搜索.不涉及数据库或其他索引引擎，所以请不要参考 MySQL 布尔搜索或 lucene.

I have a project where I need some basic boolean search in pure PHP. It means I have plain strings I want to offer some simple boolean search on them. No database or other indexing engine is involved, so please don't refer to MySQL boolean search or lucene.

最后，类似于以下代码的内容应该打印 contains 和 not found.

At the end something like the following code should print contains and not found.

$search = 'foo -bar "must have" -"must not have"';
$contentFound = 'This is some foo text you must have.';
$contentNotFound = 'This is some bar text you must have.';

if ($this->booleanSearch($contentFound, $search)) {
    echo 'contains';
} else {
    echo 'not found';
}
if ($this->booleanSearch($contentNotFound, $search)) {
    echo 'contains';
} else {
    echo 'not found';
}

推荐答案

对于一个简单的实现，您可以只拆分条件(考虑引号)并遍历每个条件以查看它是否匹配:

For a simple implementation you could just split the criteria (taking into account the quotes) and iterate over each criterion to see whether it matches or not:

function booleanSearch($content, $search) {
    $criteria = str_getcsv($search, ' ');

    while ($criteria) {
        $not = false;
        $q = array_shift($criteria);

        if (substr($q, 0, 2) === '-"') {
            $not = true;

            while (substr($q, -1) != '"') {
                $q .= " " . array_shift($criteria);
            }

            $q = substr($q, 2, -1);
        }
        else if (substr($q, 0, 1) === '-' && strpos($q, ' ') === false) {
            $not = true;
            $q = substr($q, 1);
        }

        $found = strpos($content, $q) !== false;

        if ($found === $not) {
            return false;
        }
    }

    return true;
}

这篇关于基于纯 PHP 的字符串布尔搜索的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！