feat(ecs): add support for system local components

1 files changed, 76 insertions, 0 deletions

diff --git a/ecs/examples/with_local.rs b/ecs/examples/with_local.rs
new file mode 100644
index 0000000..d7af0e0
--- /dev/null
+++ b/ecs/examples/with_local.rs
@@ -0,0 +1,76 @@
+use ecs::component::Local;
+use ecs::system::{Into, System};
+use ecs::{Query, World};
+
+struct SomeData
+{
+    num: u64,
+}
+
+struct Name
+{
+    name: String,
+}
+
+struct SayHelloState
+{
+    cnt: usize,
+}
+
+fn say_hello(mut query: Query<(SomeData, String)>, mut state: Local<SayHelloState>)
+{
+    for (data, text) in query.iter_mut() {
+        println!("Hello there. Count {}: {}: {}", state.cnt, text, data.num);
+
+        state.cnt += 1;
+    }
+}
+
+fn say_whats_up(mut query: Query<(SomeData, Name)>, mut state: Local<SayHelloState>)
+{
+    for (data, name) in query.iter_mut() {
+        println!(
+            "Whats up, {}. Number is {}. Count {}",
+            name.name, data.num, state.cnt
+        );
+
+        state.cnt += 1;
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+enum Event
+{
+    Update,
+}
+
+fn main()
+{
+    let mut world = World::<Event>::new();
+
+    world.register_system(
+        Event::Update,
+        say_hello.into_system().initialize(SayHelloState { cnt: 0 }),
+    );
+
+    world.register_system(
+        Event::Update,
+        say_whats_up
+            .into_system()
+            .initialize(SayHelloState { cnt: 0 }),
+    );
+
+    world.create_entity((
+        SomeData { num: 987_654 },
+        "Yoo".to_string(),
+        Name { name: "Bob".to_string() },
+    ));
+
+    world.create_entity((SomeData { num: 345 }, "Haha".to_string()));
+
+    world.emit(&Event::Update);
+
+    println!("Haha");
+
+    world.emit(&Event::Update);
+}