refactor(ecs): move ArchetypeComponentsHash to archetype::Id

1 files changed, 27 insertions, 0 deletions

diff --git a/ecs/src/archetype.rs b/ecs/src/archetype.rs
new file mode 100644
index 0000000..a33de66
--- /dev/null
+++ b/ecs/src/archetype.rs
@@ -0,0 +1,27 @@
+use std::hash::{DefaultHasher, Hash, Hasher};
+
+use crate::component::Id as ComponentId;
+
+/// Archetype ID.
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Id
+{
+    hash: u64,
+}
+
+impl Id
+{
+    /// Returns the ID of a archetype with the given components.
+    pub fn new(component_ids: impl IntoIterator<Item = ComponentId>) -> Self
+    {
+        let mut hasher = DefaultHasher::new();
+
+        for component_id in component_ids {
+            component_id.hash(&mut hasher);
+        }
+
+        let hash = hasher.finish();
+
+        Self { hash }
+    }
+}