[echion]

It describes calculations or operations, so functional code still seems to perform or describe some actions.

Constraint logic programs seem more of the grey area I think you're talking about. Is a set of constraints "code" (c.f. https://en.wikibooks.org/wiki/Prolog/Solving_a_Logic_Puzzle#... )?

[mseepgood]

What if I perform calculations with C++ type declarations? C++ templates are Turing-complete after all.