Most likely, you already know that Perl is compiled to a tree of ops. pp_vec is one such op type -- corresponding to the Perl vec() function.

Now, you could create op structures from XS and inject them into the running program. B::Generate does stuff like that.

The one example I'm aware of where this actually works well is List::Util::shuffle. Instead of repeating what's happening there, check for yourself: List::Util XS code.

I tried to do something similar in order to get caller() in XS, but that experiment mostly failed. I would not suggest going down that route.

Cheers,
Steffen