hecs_schedule/
query.rs

1use std::any::type_name;
2
3use crate::{Error, Result};
4use hecs::{Entity, Query};
5
6/// Wraps the bulting QueryOne with a Result containing the entity and component instead of option
7pub struct QueryOne<'a, Q: Query> {
8    entity: Entity,
9    query: hecs::QueryOne<'a, Q>,
10}
11
12impl<'a, Q: Query> QueryOne<'a, Q> {
13    pub(crate) fn new(entity: Entity, query: hecs::QueryOne<'a, Q>) -> Self {
14        Self { entity, query }
15    }
16
17    /// Get the query result, or return an error if the entity does not satisfy the query
18    ///
19    /// Must be called at most once.
20    ///
21    /// Panics if called more than once or if it would construct a borrow that clashes with another
22    /// pre-existing borrow.
23    // Note that this uses self's lifetime, not 'a, for soundness.
24    pub fn get(&mut self) -> Result<Q::Item<'_>> {
25        match self.query.get() {
26            Some(val) => Ok(val),
27            None => Err(Error::UnsatisfiedQuery(self.entity, type_name::<Q>())),
28        }
29    }
30}
hecs_schedule/query.rs

hecs_schedule/
query.rs
