[lobster_johnson]

I have high hopes for Nimrod [1] in that regard. Unlike Rust and Go, Nimrod is able to be almost as fast as C/C++ without sacrificing syntax; Nimrod's syntax often looks entirely like Python. For example, here's the example from the Nimrod home page:

    # compute average line length
    var count = 0
    var sum = 0

    for line in stdin.lines:
      count += 1
      sum += line.len

    echo "Average line length: ",
      if count > 0: sum / count else: 0

Type inference ensures that this uses efficient types internally, and is compiled to something very close to the efficiency of C. Here [2] is the generated C code, minus line tracing and stack trace frame generation. (Nimrod does things like bounds checking and overflow checking; without them, the program obviously becomes faster; the AddInt() function, for example, is replaced with a simple "+=".)

[1] http://nimrod-lang.org

[2] https://gist.github.com/atombender/f50e47c573f865d000ec

[bjz_]

Nimrod is a great language, but it has different goals to Rust. You get better expressiveness, and cleaner code, but you don't get the huge benefits of Rust's static type system. It depends on which you value more - I think there is a place for them both though.

[lobster_johnson]

Nimrod's static type system looks comparable to Rust's; are you referring to Rust's safety guarantees?

If so, I believe Nimrod's support for immutability gets you pretty far, but I have not looked very deeply at it. For example, implements an explicit "IO taint" mechanism reminiscent of Haskell.