Ada and SPARK predate Rust by decades. For Rust to come on the scene and start influencing them and their well-established community is something that reflects favorably on Rust.
By contrast, when a modern language adopts something from Lisp, that doesn't really say anything new about Lisp. It's been around forever and everyone who actually bothers to learn about the history of programming languages knows Lisp has a lot to teach those who bother to learn. When a new language borrows from Lisp, that says more about the state of the new language author's education than about Lisp itself.
> Ada and SPARK predate Rust by decades. For Rust to come on the scene and start influencing them and their well-established community is something that reflects favorably on Rust.
It definitely does ! And FWIW I work at AdaCore, and even though Rust did not invent those features, I can safely say that the work we do on safe pointer is very directly inspired by Rust.
By contrast, when a modern language adopts something from Lisp, that doesn't really say anything new about Lisp. It's been around forever and everyone who actually bothers to learn about the history of programming languages knows Lisp has a lot to teach those who bother to learn. When a new language borrows from Lisp, that says more about the state of the new language author's education than about Lisp itself.