C is also a functional programming language

Why not? I can just avoid side-effects. I can also treat functions as first-order data using Function pointers.

>>18

I see nothing in this thread that can't be translated to BASIC or any other imperative programming language. There are ways around even the lack of function pointers, for example using a dispatch table, and once you allow manually closing over free variables with structures as "functional programming" I don't see what makes handcoding a dispatch table any different.