Returns whether the given backreference is a strict backreference.
Strict backreferences are backreferences that are always matched after the referenced group was matched. If there
exists any path that goes through a backreference but not through the referenced capturing group, that backreference
is not strict.
Returns whether the given backreference is a strict backreference.
Strict backreferences are backreferences that are always matched after the referenced group was matched. If there exists any path that goes through a backreference but not through the referenced capturing group, that backreference is not strict.
Examples
In the follow examples,
\1is a strict backreference:/(a)\1//(a)(?:b|\1)//(a)\1?//(?<=\1(a))b/In the follow examples,
\1is not a strict backreference:/(a)|\1//(?:(a)|b)\1//(a)?\1//(?<=(a)\1)b//(?!(a)).\1/