> null is typically used as a flag value, but the meaning can be ambiguous Languages like Haskell or Rust handle this in a straightforward way by removing the

> null is typically used as a flag value, but the meaning can be ambiguous Languages like Haskell or Rust handle this in a straightforward way by removing the null and using sum types to replace them. > maybe it's the absence of a value Option<T> contains a possible value, or nothing. https://doc.rust-lang.org/std/option/ https://doc.rust-lang.org/std/option/ > maybe an error occured Result<T, E> contains either a value or an error. https://doc.rust-lang.org/std/result/index.html https://doc.rust-lang.org/std/result/index.html > Sometimes it has more than one meaning for the same type. Result<Option<T>, E> is a result that might have a value.