p4raw-id: //depot/perl@505
n = ARG(scan); /* which paren pair */
s = regstartp[n];
if (*reglastparen < n || !s)
- break; /* Zero length always matches */
+ sayNO; /* Do not match unless seen CLOSEn. */
if (s == regendp[n])
break;
/* Inline the first character, for speed. */
^(a\1?){4}$ aaaaaaaaaa y $1 aaaa
^(a\1?){4}$ aaaaaaaaa n - -
^(a\1?){4}$ aaaaaaaaaaa n - -
-^(a\1){4}$ aaaaaaaaaa y $1 aaaa
-^(a\1){4}$ aaaaaaaaa n - -
-^(a\1){4}$ aaaaaaaaaaa n - -
+^(a(?(1)\1)){4}$ aaaaaaaaaa y $1 aaaa
+^(a(?(1)\1)){4}$ aaaaaaaaa n - -
+^(a(?(1)\1)){4}$ aaaaaaaaaaa n - -
(?:(f)(o)(o)|(b)(a)(r))* foobar y $1:$2:$3:$4:$5:$6 f:o:o:b:a:r
(?<=a)b ab y $& b
(?<=a)b cb n - -