Function run

examples/mini_repl.rs:36–85

(vm: &vm::VirtualMachine)

}

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(())
}