Thank you for the great works of debuggex, I like it. My little tool didn't intend to act like a extreme powerful and multifunctional tool which debuggex is. I

Thank you for the great works of debuggex, I like it. My little tool didn't intend to act like a extreme powerful and multifunctional tool which debuggex is. I know debuggex need to conform existing regex engines,so it will be more useful and can be widely applied. But what my tool intended is another side,trying to point out errors strictly.Such as /\1(a)/ or /(\1)/ doesn't make sense, so I think the ability to report errors like this will be useful.Although js interpreter's regex engine still supports octal today,but I remove it radically(see the project README).Maybe this little feature is useful for someone. ;)