如何解析类INI格式歌曲内容为关联数组并按指定序列拼接歌曲

我正在开发一个歌曲数据库应用，数据库的contents列存储类INI格式的歌曲内容：

[chorus]
And all will surely agree,
There's nothing like PHP.
[1]
It may not be the best way,
But it isn't going away.
[2]
When you don't appear to hack it,
Check for a closing bracket.
[bridge]
Oh, if you don't like this ode,
Then please don't look at my code.

sequence列存储歌曲播放顺序，例如1,c,2,c,b,1,c（数字对应verse编号，b代表bridge，c代表chorus）。我需要读取数据库后，按正确顺序拼接歌曲内容，各部分之间用空行分隔。

我原本想用parse_ini_string()函数处理，因为内容有[]格式的段头，但这个函数要求段头后必须是var=something;格式的行，显然不符合我的场景。我计划先把歌曲内容转成关联数组，再遍历序列拼接对应内容，另外我有一个序列缩写与段头的映射数组：

$sequenceCodes = array(
    "1" => "verse 1",
    "2" => "verse 2",
    "3" => "verse 3",
    // ... 其他映射
    "p" => "prechorus",
    "c" => "chorus",
    "b" => "bridge",
    "e" => "ending",
);

请问该如何实现需求？

步骤1：解析contents为关联数组 #

自己写解析逻辑，逐行处理类INI内容，提取段头和对应歌词：

function parseSongContents($contents) {
    $lines = explode("\n", trim($contents));
    $songParts = [];
    $currentSection = null;

    foreach ($lines as $line) {
        $line = trim($line);
        // 跳过空行
        if (empty($line)) continue;

        // 识别段头（[xxx]格式）
        if (preg_match('/^\[(.*?)\]$/', $line, $matches)) {
            $currentSection = $matches[1];
            $songParts[$currentSection] = [];
            continue;
        }

        // 非段头行，添加到当前段
        if ($currentSection !== null) {
            $songParts[$currentSection][] = $line;
        }
    }

    // 将每个段的数组转成换行分隔的字符串
    foreach ($songParts as &$part) {
        $part = implode("\n", $part);
    }
    unset($part);

    return $songParts;
}

步骤2：处理序列并拼接歌词 #

利用映射数组将序列缩写转为段头，再从解析后的数组中取出对应内容拼接：

// 示例数据
$contents = "[chorus]\nAnd all will surely agree,\nThere's nothing like PHP.\n[1]\nIt may not be the best way,\nBut it isn't going away.\n[2]\nWhen you don't appear to hack it,\nCheck for a closing bracket.\n[bridge]\nOh, if you don't like this ode,\nThen please don't look at my code.";
$sequence = "1,c,2,c,b,1,c";
$sequenceCodes = array(
    "1" => "1",  // 注意：映射值要和contents里的段头完全匹配
    "2" => "2",
    "c" => "chorus",
    "b" => "bridge",
);

// 解析内容
$songParts = parseSongContents($contents);

// 拆分序列
$sequenceItems = explode(",", $sequence);

// 拼接最终歌词
$finalLyrics = [];
foreach ($sequenceItems as $item) {
    // 通过映射找到对应的段头
    $section = $sequenceCodes[$item] ?? null;
    if ($section && isset($songParts[$section])) {
        $finalLyrics[] = $songParts[$section];
    }
}

// 各部分用空行分隔
$finalLyrics = implode("\n\n", $finalLyrics);

// 输出结果
echo $finalLyrics;

关键说明 #

• 解析函数会跳过空行，确保关联数组里的歌词无多余空白内容
• 映射数组$sequenceCodes的值必须和contents里的段头完全匹配（比如原内容段是[1]，映射值就写"1"；段是[chorus]，映射值写"chorus"）
• 拼接时用\n\n分隔各部分，符合需求的格式

内容的提问来源于stack exchange，提问作者Transistor