refactor(ecs): add component ID struct

1 files changed, 31 insertions, 6 deletions

diff --git a/ecs/src/component.rs b/ecs/src/component.rs
index 5c0b9ce..512c60d 100644
--- a/ecs/src/component.rs
+++ b/ecs/src/component.rs
@@ -15,7 +15,7 @@ pub(crate) mod storage;
 pub trait Component: SystemInput + Any + TypeName
 {
     /// The component type in question. Will usually be `Self`
-    type Component
+    type Component: Component
     where
         Self: Sized;
 
@@ -23,6 +23,9 @@ pub trait Component: SystemInput + Any + TypeName
     where
         Self: Sized;
 
+    /// Returns the ID of this component's type.
+    fn id(&self) -> Id;
+
     #[doc(hidden)]
     fn as_any_mut(&mut self) -> &mut dyn Any;
 
@@ -76,6 +79,11 @@ where
     type Component = ComponentT;
     type RefMut<'component> = Option<ComponentRefMut<'component, ComponentT>>;
 
+    fn id(&self) -> Id
+    {
+        Id::of::<Self>()
+    }
+
     fn as_any_mut(&mut self) -> &mut dyn Any
     {
         self
@@ -104,6 +112,23 @@ where
 
 impl<ComponentT> SystemInput for Option<ComponentT> where ComponentT: Component {}
 
+/// The ID of a [`Component`] type.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Id
+{
+    inner: TypeId,
+}
+
+impl Id
+{
+    pub fn of<ComponentT>() -> Self
+    where
+        ComponentT: Component,
+    {
+        Self { inner: TypeId::of::<ComponentT>() }
+    }
+}
+
 /// A sequence of components.
 pub trait Sequence
 {
@@ -113,7 +138,7 @@ pub trait Sequence
 
     fn into_vec(self) -> Vec<Box<dyn Component>>;
 
-    fn type_ids() -> Vec<(TypeId, IsOptional)>;
+    fn ids() -> Vec<(Id, IsOptional)>;
 
     fn from_components<'component>(
         components: impl Iterator<Item = &'component EntityComponent>,
@@ -145,7 +170,7 @@ impl From<bool> for IsOptional
 /// Will return `true` if the component is a [`Option`].
 pub fn is_optional<ComponentT: Component>() -> bool
 {
-    if TypeId::of::<ComponentT>() == TypeId::of::<Option<ComponentT::Component>>() {
+    if Id::of::<ComponentT>() == Id::of::<Option<ComponentT::Component>>() {
         return true;
     }
 
@@ -174,11 +199,11 @@ macro_rules! inner {
                     Vec::from_iter([#(Box::new(self.I) as Box<dyn Component>,)*])
                 }
 
-                fn type_ids() -> Vec<(TypeId, IsOptional)>
+                fn ids() -> Vec<(Id, IsOptional)>
                 {
                     vec![
                         #(
-                            (TypeId::of::<Comp~I>(), is_optional::<Comp~I>().into()),
+                            (Id::of::<Comp~I>(), is_optional::<Comp~I>().into()),
                         )*
                     ]
                 }
@@ -193,7 +218,7 @@ macro_rules! inner {
 
                     for comp in components {
                         #(
-                            if comp.id == TypeId::of::<Comp~I::Component>() {
+                            if comp.id == Id::of::<Comp~I::Component>() {
                                 comp_~I = Some(lock_component(comp));
                                 continue;
                             }