[haberman]

> This is true for static and dynamic typing as well: they exist in degrees. Rust can verify type proofs that other languages can't regarding memory safety. Some languages can verify that integer indexes into an array won't go out of bounds. Thus it's not the case that a given language is either statically typed or dynamically typed

Memory safety and static/dynamic typing are orthogonal. C is statically typed but memory unsafe. Rust is statically typed but memory safe (except in unsafe blocks). Lua is dynamically-typed but memory safe.

I agree that it's possible to mix elements of static and dynamic typing in a single language. C++ is generally statically typed, but also supports dynamic_cast<>.

But generally speaking, static and dynamic typing have a very precise definition. Something that carries around type information at runtime is dynamically typed. Something that does type analysis at compile time so that the runtime doesn't need to carry type information is statically typed.