获取两个分隔符之间的匹配项(如果可能嵌套)

Question

我的情况的具体分隔符是左括号和右括号。 当不嵌套时，我可以获取它们之间的文本，如下所示：

$input = 'sometext(moretext)andmoretext(somemoretext)andevenmoretext(andmore)';
preg_match_all('#((.*?))#', $input, $match);
echo('<pre>'.print_r($match[1],1).'</pre>');
Array
(
    [0] => moretext
    [1] => somemoretext
    [2] => andmore
)

但是，当我有嵌套字符时，我会遇到一些障碍，并得到以下内容。

$input = 'sometext(moretext)andmoretext(somemore(with(bitof(littletext)text)more(andmore)text)text)andevenmoretext(andmore)';
preg_match_all('#((.*?))#', $input, $match);
echo('<pre>'.print_r($match[1],1).'</pre>');
Array
(
    [0] => moretext
    [1] => somemore(with(bitof(littletext
    [2] => andmore
    [3] => andmore
)

如何在分隔符之间返回整个字符串：

Array
(
    [0] => moretext
    [1] => somemore(with(bitof(littletext)text)more(andmore)text)text
    [2] => andmore
)

附言。 最终，我将使用递归 PHP 在任何也包含括号的顶级匹配项上执行相同的任务。

Answer 1

您可以使用此递归正则表达式模式来匹配匹配(...)：

preg_match_all('/( ( (?: [^()]* | (?R) )* ) )/x', $input, $m);
print_r($m[1]);

正则表达式演示

(?R)递归整个模式。

输出：

Array
(
    [0] => moretext
    [1] => somemore(with(bitof(littletext)text)more(andmore)text)text
    [2] => andmore
)

Answer 2

为了做到这一点，这里有一个非正则表达式解决方案。

function delimeterSplit( $input )
{
    $str = '';
    $output = array();
    $op = 0;
    $cp = 0;
    foreach( str_split( $input ) as $k => $v )
    {
        if( $v === '(' )
        {
            ++$op;
        }
        if( $input[ $k ] === ')' )
        {
            ++$cp;
        }
        if( ( ( $op === 1 && $v !== '(' ) || $op > 1 ) && $op !== $cp )
        {
            $str .= $v;
        }
        if( $op > 0 && $op === $cp )
        {
            $op = 0;
            $cp = 0;
            $output[] = $str;
            $str = '';
        }
    }
    return $output;
}
echo '<pre>'.print_r( delimeterSplit( 'sometext(moretext)andmoretext(somemoretext)andevenmoretext(andmore)' ), true ).'</pre>';
echo '<pre>'.print_r( delimeterSplit( 'sometext(moretext)andmoretext(somemore(with(bitof(littletext)text)more(andmore)text)text)andevenmoretext(andmore)' ), true ).'</pre>';

输出：

Array
(
    [0] => moretext
    [1] => somemoretext
    [2] => andmore
)
Array
(
    [0] => moretext
    [1] => somemore(with(bitof(littletext)text)more(andmore)text)text
    [2] => andmore
)