[iimblack]

I see. I know nothing about Nim but I do see in their example they used var when declaring the function. This way seems like it's hidden to the consumer of the function but hopefully editor tooling helps with this.

[juki]

You have to declare the variable as `var` as well, eg.

    var arr1 = [4, 2, 3, 6]
    sort arr1

    # Doesn't work
    let arr2 = [4, 2, 3, 6]
    sort arr2

You'll get a warning about the latter from the compiler (and nimsuggest for editors).