Haskell standard library mostly use haskell and NOT C or C--. If you use C to implement your language any small language in C can strongly impact yours, nobody wants that. By the way the purpose of C-- is the GHC(because you don't want to be tightly coupled with C).
All variables in make which are not target-specific, are global. That 100 % non functionnal.
> And even then, make is mostly declarative.
The docker API is declarative but the reality is not, so everybody somehow use docker shell to do dirty stuff.
And even then, make is mostly declarative.
And even then, Haskell is totally implemented on top of imperative tools (formerly C, C--, and now LLVM bytecode). It's still a functional language.