refactor(ecs): add & use component metadata struct

1 files changed, 26 insertions, 3 deletions

diff --git a/ecs/src/component.rs b/ecs/src/component.rs
index be5756f..67ae453 100644
--- a/ecs/src/component.rs
+++ b/ecs/src/component.rs
@@ -139,13 +139,33 @@ pub trait Sequence
 
     fn into_vec(self) -> Vec<Box<dyn Component>>;
 
-    fn ids() -> Vec<(Id, IsOptional)>;
+    fn metadata() -> Vec<Metadata>;
 
     fn from_components<'component>(
         components: impl Iterator<Item = &'component EntityComponent>,
     ) -> Self::Refs<'component>;
 }
 
+/// [`Component`] metadata.
+#[derive(Debug, Clone)]
+#[non_exhaustive]
+pub struct Metadata
+{
+    pub id: Id,
+    pub is_optional: IsOptional,
+}
+
+impl Metadata
+{
+    pub fn of<ComponentT: Component + ?Sized>(component: &ComponentT) -> Self
+    {
+        Self {
+            id: component.id(),
+            is_optional: component.is_optional().into(),
+        }
+    }
+}
+
 /// Whether or not a `Component` is optional.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum IsOptional
@@ -201,11 +221,14 @@ macro_rules! inner {
                     Vec::from_iter([#(Box::new(self.I) as Box<dyn Component>,)*])
                 }
 
-                fn ids() -> Vec<(Id, IsOptional)>
+                fn metadata() -> Vec<Metadata>
                 {
                     vec![
                         #(
-                            (Id::of::<Comp~I>(), is_optional::<Comp~I>().into()),
+                            Metadata {
+                                id: Id::of::<Comp~I>(),
+                                is_optional: is_optional::<Comp~I>().into()
+                            },
                         )*
                     ]
                 }