1 files changed, 123 insertions, 0 deletions
diff --git a/src/data/component_set.rs b/src/data/component_set.rs
new file mode 100644
index 0000000..6e0461c
--- /dev/null
+++ b/src/data/component_set.rs
@@ -0,0 +1,123 @@
+use crate::data::Index;
+
+// TODO ECS: use this to handle optional components properly.
+// pub trait OptionalComponentSet<T> {
+//     fn get(&self, handle: Index) -> Option<&T>;
+// }
+
+/// A set of optional elements of type `T`.
+pub trait ComponentSetOption<T>: Sync {
+    /// Get the element associated to the given `handle`, if there is one.
+    fn get(&self, handle: Index) -> Option<&T>;
+}
+
+/// A set of elements of type `T`.
+pub trait ComponentSet<T>: ComponentSetOption<T> {
+    /// The estimated number of elements in this set.
+    ///
+    /// This value is typically used for preallocating some arrays for
+    /// better performances.
+    fn size_hint(&self) -> usize;
+    // TODO ECS: remove this, its only needed by the query pipeline update
+    //           which should only take the modified colliders into account.
+    /// Iterate through all the elements on this set.
+    fn for_each(&self, f: impl FnMut(Index, &T));
+    /// Get the element associated to the given `handle`.
+    fn index(&self, handle: Index) -> &T {
+        self.get(handle).unwrap()
+    }
+}
+
+/// A set of mutable elements of type `T`.
+pub trait ComponentSetMut<T>: ComponentSet<T> {
+    /// Applies the given closure to the element associated to the given `handle`.
+    ///
+    /// Return `None` if the element doesn't exist.
+    fn map_mut_internal<Result>(
+        &mut self,
+        handle: crate::data::Index,
+        f: impl FnOnce(&mut T) -> Result,
+    ) -> Option<Result>;
+
+    /// Set the value of this element.
+    fn set_internal(&mut self, handle: crate::data::Index, val: T);
+}
+
+/// Helper trait to address multiple elements at once.
+pub trait BundleSet<'a, T> {
+    /// Access multiple elements from this set.
+    fn index_bundle(&'a self, handle: Index) -> T;
+}
+
+impl<'a, T, A, B> BundleSet<'a, (&'a A, &'a B)> for T
+where
+    T: ComponentSet<A> + ComponentSet<B>,
+{
+    #[inline(always)]
+    fn index_bundle(&'a self, handle: Index) -> (&'a A, &'a B) {
+        (self.index(handle), self.index(handle))
+    }
+}
+
+impl<'a, T, A, B, C> BundleSet<'a, (&'a A, &'a B, &'a C)> for T
+where
+    T: ComponentSet<A> + ComponentSet<B> + ComponentSet<C>,
+{
+    #[inline(always)]
+    fn index_bundle(&'a self, handle: Index) -> (&'a A, &'a B, &'a C) {
+        (self.index(handle), self.index(handle), self.index(handle))
+    }
+}
+
+impl<'a, T, A, B, C, D> BundleSet<'a, (&'a A, &'a B, &'a C, &'a D)> for T
+where
+    T: ComponentSet<A> + ComponentSet<B> + ComponentSet<C> + ComponentSet<D>,
+{
+    #[inline(always)]
+    fn index_bundle(&'a self, handle: Index) -> (&'a A, &'a B, &'a C, &'a D) {
+        (
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+        )
+    }
+}
+
+impl<'a, T, A, B, C, D, E> BundleSet<'a, (&'a A, &'a B, &'a C, &'a D, &'a E)> for T
+where
+    T: ComponentSet<A> + ComponentSet<B> + ComponentSet<C> + ComponentSet<D> + ComponentSet<E>,
+{
+    #[inline(always)]
+    fn index_bundle(&'a self, handle: Index) -> (&'a A, &'a B, &'a C, &'a D, &'a E) {
+        (
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+        )
+    }
+}
+
+impl<'a, T, A, B, C, D, E, F> BundleSet<'a, (&'a A, &'a B, &'a C, &'a D, &'a E, &'a F)> for T
+where
+    T: ComponentSet<A>
+        + ComponentSet<B>
+        + ComponentSet<C>
+        + ComponentSet<D>
+        + ComponentSet<E>
+        + ComponentSet<F>,
+{
+    #[inline(always)]
+    fn index_bundle(&'a self, handle: Index) -> (&'a A, &'a B, &'a C, &'a D, &'a E, &'a F) {
+        (
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+            self.index(handle),
+        )
+    }
+}