1 files changed, 22 insertions, 2 deletions
diff --git a/ecs/src/system.rs b/ecs/src/system.rs
index ecf1885..8f4d0b0 100644
--- a/ecs/src/system.rs
+++ b/ecs/src/system.rs
@@ -1,14 +1,21 @@
 use std::any::Any;
+use std::convert::Infallible;
 use std::fmt::Debug;
 
 use crate::component::Sequence as ComponentSequence;
 use crate::{ComponentStorage, Query};
 
+pub mod stateful;
+
 pub trait System<Impl>: 'static
 {
     type Query<'a>;
 
-    fn run(&self, component_storage: &mut ComponentStorage);
+    type Input;
+
+    fn initialize(self, input: Self::Input) -> Self;
+
+    fn run(&mut self, component_storage: &mut ComponentStorage);
 
     fn into_type_erased(self) -> TypeErased;
 }
@@ -18,9 +25,15 @@ where
     Func: Fn(Query<Comps>) + 'static,
     Comps: ComponentSequence,
 {
+    type Input = Infallible;
     type Query<'a> = Query<'a, Comps>;
 
-    fn run(&self, component_storage: &mut ComponentStorage)
+    fn initialize(self, _input: Self::Input) -> Self
+    {
+        self
+    }
+
+    fn run(&mut self, component_storage: &mut ComponentStorage)
     {
         self(Query::new(component_storage));
     }
@@ -38,6 +51,13 @@ where
     }
 }
 
+pub trait Into<Impl>
+{
+    type System;
+
+    fn into_system(self) -> Self::System;
+}
+
 pub struct TypeErased
 {
     data: Box<dyn Any>,