Rust

  • String.push(char) takes char
  • Vec has reverse method where as iterator has rev method
  • String and &str both have chars method that convert string to Char
  • String and &str can be split_whitespace
    • they also can call split(pat: P) e.g split(' ') is equivalent to split by whitespace
  • NOTE: in rust usize -1 could overflow to max, this might causing algorithm not working properly
  • If we are dealing with linked list with Option<Box<Node>>, we can potentially using Box::clone() to overcome some limitation due to borrow checker. Box::clone should be relatively not expensive as mentioned in rust book: a box is a smart pointer to a heap allocated value of T.
  • Check if key in HashMap, use HashMap.contains_key(&key), HashMap.remove(&key) for delete, HashMap.insert(key, val) for insert key
  • *HashMap.entry(&key).or_insert(value) += 1 can be used as default map
  • Double side queue: VecDeque, we can push/pop_front and push/pop_back
  • char can be force convert to u8 if we want: 'a' as u8
  • Rc<RefCell<T>> can be get the internal &mut T by call borrow_mut()
  • &mut [T] can call &mut [T].clone/copy_from_slice(&[T]), but their length needs to be the same
  • &[T] has method to_vec that can clone it to a new vector
  • &mut [T] has rotate_left/right and reverse method
  • Vec<char> can be collect into string using x.chars().into_iter().collect<String>()
  • char can use to_uppercase/lowercase() convert to up/lower case characters.
  • char has is_ascii_alphabetic method
  • slice has method .split_at(usize) so the slice can be split into two parts
  • iter has fold method, which allows we to fold iterator. e.g.
    vec![1,1,1,2,3].iter().fold(HashMap::new(), |mut map, i|{
  let val = map.entry(i).or_insert(0); *val += 1; map
})`
// equals to HashMap{1:3, 2:1, 3:1}

Docker

  • Docker can be run with --network=host on windows, but as stated by reference, quote:

    The host networking driver only works on Linux hosts, and is not supported on Docker Desktop for Mac, Docker Desktop for Windows, or Docker EE for Windows Server.

    So, when you notice something wired, like cannot ping docker exported port from windows/wsl2. check if your docker container is launched using --network=host.