没有编号数组的 PHP 子模式

将preg_match与子模式一起使用总是返回具有相同数据的双键数组，一个带有子模式名称，另一个带有数字标记。因为我匹配的是数十万行，每行只有几千字节，所以恐怕数字数组占用了额外的内存。有没有正确的方法可以禁止数字标签数组返回？

例：

<?php
header('Content-Type: text/plain');
$data = <<<START
I go to school.
He goes to funeral.
START;
preg_match_all('@^(?<who>.*?) go(es)* to (?<place>.*?)$@m', $data, $matches);
print_r($matches);
?>

输出：

Array
(
    [0] => Array
        (
            [0] => I go to school.
            [1] => He goes to funeral.
        )
    [who] => Array
        (
            [0] => I
            [1] => He
        )
    [1] => Array
        (
            [0] => I
            [1] => He
        )
    [2] => Array
        (
            [0] => 
            [1] => es
        )
    [place] => Array
        (
            [0] => school.
            [1] => funeral.
        )
    [3] => Array
        (
            [0] => school.
            [1] => funeral.
        )
)