Check out Mercury! [1] - Strongly typed and integrates with other languages really really nicely. Besides the reference material on the official site, there's a lovely crash course [2] as well.

Prince's [3] base is Mercury and integrates Rust and C without fuss.

[1] https://mercurylang.org/ [2] https://mercury-in.space/crash.html [3] https://www.princexml.com/