The things that make rust “functional” are features like a type system that supports sum and product types and functions as typed values that can be passed arou

The things that make rust “functional” are features like a type system that supports sum and product types and functions as typed values that can be passed around. It really is a functional language (in the original ML sense of the word) but with another orthogonal type system bolted on (borrow checker). It’s missing some features like higher kinded types but it’s functional nonetheless. I’m interested to hear what your definition of functional is - it’s always interesting because it’s such a vague term, really.