Function undo

behavioral/command/main.rs:46–52

Pops the last command and executes an undo action.

(app: &mut Cursive)

/// Pops the last command and executes an undo action.
fn undo(app: &mut Cursive) {
    let mut context = app.take_user_data::<AppContext>().unwrap();
    if let Some(mut command) = context.history.pop() {
        command.undo(app)
    }
    app.set_user_data(context);
}