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use crate::algorithms::{Queue, QueueType};
use crate::StateId;
#[derive(Debug, Default, Clone)]
pub struct TrivialQueue {
state: Option<StateId>,
}
impl Queue for TrivialQueue {
fn head(&mut self) -> Option<StateId> {
self.state
}
fn enqueue(&mut self, state: usize) {
self.state = Some(state);
}
fn dequeue(&mut self) {
self.state = None;
}
fn update(&mut self, _state: usize) {}
fn is_empty(&self) -> bool {
self.state.is_none()
}
fn clear(&mut self) {
self.state = None;
}
fn queue_type(&self) -> QueueType {
QueueType::TrivialQueue
}
}
#[cfg(test)]
mod test {
use super::*;
use anyhow::Result;
#[test]
fn test_trivial_queue() -> Result<()> {
let mut queue = TrivialQueue::default();
assert_eq!(queue.head(), None);
queue.enqueue(2);
queue.enqueue(3);
assert_eq!(queue.head(), Some(3));
queue.dequeue();
assert_eq!(queue.head(), None);
queue.enqueue(2);
queue.enqueue(3);
assert_eq!(queue.is_empty(), false);
assert_eq!(queue.head(), Some(3));
queue.clear();
assert_eq!(queue.head(), None);
assert_eq!(queue.is_empty(), true);
Ok(())
}
}