regex - PCRE(递归)模式匹配包含正确括号子字符串的字符串。为什么这个会失败？

Question

好吧，还有其他方法(嗯……或者更确切地说是可行的方法)来做到这一点，但问题是为什么这个方法会失败？

/
\A              # start of the string
(               # group 1
(?:             # group 2
[^()]*          # something other than parentheses (greedy)
|               # or
\( (?1) \)      # parenthesized group 1
)               # -group 2
+               # at least once (greedy)
)               # -group 1
\Z              # end of the string
/x

无法匹配带有嵌套括号的字符串:“(())”

Answer 1

它不会失败

$ perl junk.pl
matched junk >(())<

$ cat junk.pl
my $junk = qr/
\A              # start of the string
(               # group 1
(?:             # group 2
[^()]*          # something other than parentheses (greedy)
|               # or
\( (?1) \)      # parenthesized group 1
)               # -group 2
+               # at least once (greedy)
)               # -group 1
\Z              # end of the string
/x;

if( "(())" =~ $junk ){
    print "matched junk >$1<\n";
}