You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mini_repl.rs
    path of file: ./repos/RustPython/examples
    
    the code of the file until where you have to start completion: ///! This example show cases a very simple REPL.
///! While a much better REPL can be found in ../src/shell,
///! This much smaller REPL is still a useful example because it showcases inserting
///! values and functions into the Python runtime's scope, and showcases use
///! of the compilation mode "Single".
use rustpython_vm as vm;
// these are needed for special memory shenanigans to let us share a variable with Python and Rust
use std::sync::atomic::{AtomicBool, Ordering};

// This has to be a macro because it uses the py_compile macro,
// which compiles python source to optimized bytecode at compile time, so that
// the program you're embedding this into doesn't take longer to start up.
macro_rules! add_python_function {
    ( $scope:ident, $vm:ident, $src:literal $(,)? ) => {{
        // compile the code to bytecode
        let code = vm::py_compile!(source = $src);
        // convert the rustpython_compiler_core::CodeObject to a PyRef<PyCode>
        let code = $vm.ctx.new_code(code);

        // run the python code in the scope to store the function
        $vm.run_code_obj(code, $scope.clone())
    }};
}

static ON: AtomicBool = AtomicBool::new(true);

fn on(b: bool) {
    ON.store(b, Ordering::Relaxed);
}

fn main() -> vm::PyResult<()> {
    vm::Interpreter::without_stdlib(Default::default()).enter(run)
}

fn run(vm: &vm::VirtualMachine) -> vm::PyResult<()> {
    let mut input = String::with_capacity(50);
    let stdin = std::io::stdin();

    let scope: vm::scope::Scope = vm.new_scope_with_builtins();

    // typing `quit()` is too long, let's mak
    
fn run(vm: &vm::VirtualMachine) -> vm::PyResult<()> {
    let mut input = String::with_capacity(50);
    let stdin = std::io::stdin();

    let scope: vm::scope::Scope = vm.new_scope_with_builtins();

    // typing `quit()` is too long, let's make `on(False)` work instead.
    scope
        .globals
        .set_item("on", vm.new_function("on", on).into(), vm)?;

    // let's include a fibonacci function, but let's be lazy and write it in Python
    add_python_function!(
        scope,
        vm,
        // a fun line to test this with is
        // ''.join( l * fib(i) for i, l in enumerate('supercalifragilistic') )
        r#"\
def fib(n):
    return n if n <= 1 else fib(n - 1) + fib(n - 2)
"#
    )?;

    while ON.load(Ordering::Relaxed) {
        input.clear();
        stdin
            .read_line(&mut input)
            .expect("Failed to read line of input");

        // this line also automatically prints the output
        // (note that this is only the case when compiler::Mode::Single is passed to vm.compile)
        match vm
            .compile(&input, vm::compiler::Mode::Single, "<embedded>".to_owned())
            .map_err(|err| vm.new_syntax_error(&err, Some(&input)))
            .and_then(|code_obj| vm.run_code_obj(code_obj, scope.clone()))
        {
            Ok(output) => {
                // store the last value in the "last" variable
                if !vm.is_none(&output) {
                    scope.globals.set_item("last", output, vm)?;
                }
            }
            Err(exc) => {
                vm.print_exception(exc);
            }
        }
    }

    Ok(())
}