ecs: Add world query, make it possible to request resources from function systems

lyra-ecs/src/query/borrow.rs

@@ -1,6 +1,6 @@
 use std::{marker::PhantomData, ptr::NonNull, cell::{Ref, RefMut}};
 
-use crate::{world::World, ComponentColumn, DynTypeId, Tick};
+use crate::{world::World, ComponentColumn, DynTypeId, Tick, Component};
 
 use super::{Fetch, Query, AsQuery};
 
@@ -97,11 +97,11 @@ where
     }
 }
 
-impl<T: 'static> AsQuery for QueryBorrow<T> {
+impl<T: Component> AsQuery for QueryBorrow<T> {
     type Query = Self;
 }
 
-impl<T: 'static> AsQuery for &T {
+impl<T: Component> AsQuery for &T {
     type Query = QueryBorrow<T>;
 }
 
@@ -209,11 +209,11 @@ where
     }
 }
 
-impl<T: 'static> AsQuery for QueryBorrowMut<T> {
+impl<T: Component> AsQuery for QueryBorrowMut<T> {
     type Query = Self;
 }
 
-impl<T: 'static> AsQuery for &mut T {
+impl<T: Component> AsQuery for &mut T {
     type Query = QueryBorrowMut<T>;
 }
 
@@ -244,7 +244,7 @@ mod tests {
             _phantom: std::marker::PhantomData,
         };
         let archetypes: Vec<&Archetype> = world.archetypes.values().collect();
-        let v = View::new(&world, borrow, archetypes);
+        let v = View::<QueryBorrow<Vec2>>::new(&world, borrow, archetypes);
 
         for e in v.into_iter() {
             println!("Found entity at {:?}", e);
@@ -260,7 +260,7 @@ mod tests {
             _phantom: std::marker::PhantomData,
         };
         let archetypes: Vec<&Archetype> = world.archetypes.values().collect();
-        let v = View::new(&world, borrow, archetypes);
+        let v = View::<QueryBorrowMut<Vec2>>::new(&world, borrow, archetypes);
 
         let mut orig = vec![];
 
@@ -277,7 +277,7 @@ mod tests {
             _phantom: std::marker::PhantomData,
         };
         let archetypes: Vec<&Archetype> = world.archetypes.values().collect();
-        let v = View::new(&world, borrow, archetypes);
+        let v = View::<QueryBorrow<Vec2>>::new(&world, borrow, archetypes);
 
         for (new, orig) in v.into_iter().zip(orig.iter()) {
             assert!(new.x - orig.x == 10.0);

lyra-ecs/src/query/mod.rs

@@ -23,6 +23,10 @@ pub mod tick;
 #[allow(unused_imports)]
 pub use tick::*;
 
+pub mod world;
+#[allow(unused_imports)]
+pub use world::*;
+
 pub mod dynamic;
 
 /// A [`Fetch`]er implementation gets data out of an archetype.
@@ -100,7 +104,7 @@ mod tests {
 
         let archetypes: Vec<&Archetype> = world.archetypes.values().collect();
 
-        let v = View::new(&world, entities, archetypes);
+        let v = View::<Entities>::new(&world, entities, archetypes);
 
         for e in v.into_iter() {
             println!("Got entity! {:?}", e);

lyra-ecs/src/query/resource.rs

@@ -10,7 +10,7 @@ pub struct FetchResource<'a, T> {
 }
 
 impl<'a, T: 'a + 'static> Fetch<'a> for FetchResource<'a, T> {
-    type Item = Ref<'a, T>;
+    type Item = Res<'a, T>;
 
     fn dangling() -> Self {
         Self {
@@ -25,7 +25,7 @@ impl<'a, T: 'a + 'static> Fetch<'a> for FetchResource<'a, T> {
 
     unsafe fn get_item(&mut self, _entity: crate::world::ArchetypeEntityId) -> Self::Item {
         let w = self.world.unwrap();
-        w.get_resource::<T>()
+        Res(w.get_resource::<T>())
     }
 
 }
@@ -34,7 +34,7 @@ impl<'a, T: 'a + 'static> Fetch<'a> for FetchResource<'a, T> {
 pub struct QueryResource<T: ResourceObject> {
     _phantom: PhantomData<T>
 }
-pub type Resource<T> = QueryResource<T>;
+//pub type Resource<T> = QueryResource<T>;
 
 impl<T: ResourceObject> Copy for QueryResource<T> {}
 
@@ -45,7 +45,7 @@ impl<T: ResourceObject> Clone for QueryResource<T> {
 }
 
 impl<T: ResourceObject + 'static> Query for QueryResource<T> {
-    type Item<'a> = Ref<'a, T>;
+    type Item<'a> = Res<'a, T>;
 
     type Fetch<'a> = FetchResource<'a, T>;
 
@@ -78,13 +78,28 @@ impl<R: ResourceObject> AsQuery for QueryResource<R> {
     type Query = QueryResource<R>;
 }
 
+/// A struct used for querying resources from the World.
+pub struct Res<'a, T>(Ref<'a, T>);
+
+impl<'a, T: ResourceObject> std::ops::Deref for Res<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.deref()
+    }
+}
+
+impl<'a, T: ResourceObject> AsQuery for Res<'a, T> {
+    type Query = QueryResource<T>;
+}
+
 pub struct FetchResourceMut<'a, T> {
     world: Option<&'a World>,
     _phantom: PhantomData<T>,
 }
 
 impl<'a, T: 'a + 'static> Fetch<'a> for FetchResourceMut<'a, T> {
-    type Item = RefMut<'a, T>;
+    type Item = ResMut<'a, T>;
 
     fn dangling() -> Self {
         Self {
@@ -99,7 +114,7 @@ impl<'a, T: 'a + 'static> Fetch<'a> for FetchResourceMut<'a, T> {
 
     unsafe fn get_item(&mut self, _entity: crate::world::ArchetypeEntityId) -> Self::Item {
         let w = self.world.unwrap();
-        w.get_resource_mut::<T>()
+        ResMut(w.get_resource_mut::<T>())
     }
 
 }
@@ -109,8 +124,6 @@ pub struct QueryResourceMut<T: ResourceObject> {
     _phantom: PhantomData<T>
 }
 
-pub type ResourceMut<T> = QueryResourceMut<T>;
-
 impl<T: ResourceObject> Copy for QueryResourceMut<T> {}
 
 impl<T: ResourceObject> Clone for QueryResourceMut<T> {
@@ -120,7 +133,7 @@ impl<T: ResourceObject> Clone for QueryResourceMut<T> {
 }
 
 impl<T: ResourceObject + 'static> Query for QueryResourceMut<T> {
-    type Item<'a> = RefMut<'a, T>;
+    type Item<'a> = ResMut<'a, T>;
 
     type Fetch<'a> = FetchResourceMut<'a, T>;
 
@@ -152,8 +165,33 @@ impl<T: ResourceObject + 'static> Query for QueryResourceMut<T> {
 impl<R: ResourceObject> AsQuery for QueryResourceMut<R> {
     type Query = QueryResourceMut<R>;
 }
+
+/// A struct used for querying resources from the World.
+pub struct ResMut<'a, T>(RefMut<'a, T>);
+
+impl<'a, T: ResourceObject> std::ops::Deref for ResMut<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.deref()
+    }
+}
+
+impl<'a, T: ResourceObject> std::ops::DerefMut for ResMut<'a, T> {
+
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.0.deref_mut()
+    }
+}
+
+impl<'a, T: ResourceObject> AsQuery for ResMut<'a, T> {
+    type Query = QueryResourceMut<T>;
+}
+
 #[cfg(test)]
 mod tests {
+    use std::ops::{Deref, DerefMut};
+
     use crate::{world::World, tests::{Vec2, Vec3}, query::QueryResourceMut};
 
     use super::QueryResource;
@@ -171,6 +209,7 @@ mod tests {
 
         let mut res_iter = world.view_iter::<QueryResource<SomeCounter>>();
         let res = res_iter.next().unwrap();
+        let res = res.deref();
         assert_eq!(res.0, 0);
     }
 
@@ -195,7 +234,7 @@ mod tests {
         assert_eq!(i.count(), 3);
 
         for (res, e) in world.view_iter::<(QueryResource<SomeCounter>, &Vec2)>() {
-            println!("Got res {}! and entity at {:?}", res.0, e);
+            println!("Got res {}! and entity at {:?}", res.deref().0, e);
         }
 
         let i = world.view_iter::<QueryResource<SomeCounter>>();
@@ -214,12 +253,14 @@ mod tests {
         {
             let mut resmut_iter = world.view_iter::<QueryResourceMut<SomeCounter>>();
             let mut resmut = resmut_iter.next().unwrap();
+            let resmut = resmut.deref_mut();
             assert_eq!(resmut.0, 0);
             resmut.0 += 20;
         }
 
         let mut res_iter = world.view_iter::<QueryResource<SomeCounter>>();
         let res = res_iter.next().unwrap();
+        let res = res.deref();
         assert_eq!(res.0, 20);
     }
 }

lyra-ecs/src/query/view.rs

@@ -2,19 +2,19 @@ use std::ops::Range;
 
 use crate::{archetype::Archetype, world::{ArchetypeEntityId, World}, EntityId, Tick};
 
-use super::{Query, Fetch};
+use super::{Query, Fetch, AsQuery};
 
-pub struct View<'a, Q: Query> {
+pub struct View<'a, Q: AsQuery> {
     world: &'a World,
-    query: Q,
+    query: Q::Query,
     archetypes: Vec<&'a Archetype>,
 }
 
 impl<'a, Q> View<'a, Q>
 where
-    Q: Query,
+    Q: AsQuery,
 {
-    pub fn new(world: &'a World, query: Q, archetypes: Vec<&'a Archetype>) -> Self {
+    pub fn new(world: &'a World, query: Q::Query, archetypes: Vec<&'a Archetype>) -> Self {
         Self {
             world,
             query,
@@ -25,14 +25,14 @@ where
 
 impl<'a, Q> IntoIterator for View<'a, Q>
 where
-    Q: Query,
+    Q: AsQuery,
 {
-    type Item = Q::Item<'a>;
+    type Item = <Q::Query as Query>::Item<'a>;
 
-    type IntoIter = ViewIter<'a, Q>;
+    type IntoIter = ViewIter<'a, Q::Query>;
 
     fn into_iter(self) -> Self::IntoIter {
-        let tick = self.world.tick_tracker().tick_when(Q::MUTATES);
+        let tick = self.world.tick_tracker().tick_when(Q::Query::MUTATES);
 
         ViewIter {
             world: self.world,

lyra-ecs/src/query/world.rs

@@ -0,0 +1,140 @@
+use std::ptr::NonNull;
+
+use crate::World;
+
+use super::{Fetch, Query, AsQuery};
+
+pub struct FetchWorldRef<'a> {
+    world: &'a World
+}
+
+impl<'a> Fetch<'a> for FetchWorldRef<'a> {
+    type Item = &'a World;
+
+    fn dangling() -> Self {
+        unreachable!()
+    }
+
+    fn can_visit_item(&mut self, _entity: crate::ArchetypeEntityId) -> bool {
+        true
+    }
+
+    unsafe fn get_item(&mut self, _entity: crate::world::ArchetypeEntityId) -> Self::Item {
+        self.world
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct QueryWorldRef;
+
+impl Default for QueryWorldRef {
+    fn default() -> Self {
+        Self
+    }
+}
+
+impl Query for QueryWorldRef {
+    type Item<'a> = &'a World;
+
+    type Fetch<'a> = FetchWorldRef<'a>;
+
+    const ALWAYS_FETCHES: bool = true;
+
+    fn new() -> Self {
+        QueryWorldRef
+    }
+
+    fn can_visit_archetype(&self, _archetype: &crate::archetype::Archetype) -> bool {
+        true
+    }
+
+    unsafe fn fetch<'a>(&self, world: &'a World, _archetype: &'a crate::archetype::Archetype, _tick: crate::Tick) -> Self::Fetch<'a> {
+        FetchWorldRef {
+            world
+        }
+    }
+
+    unsafe fn fetch_world<'a>(&self, world: &'a World) -> Option<Self::Fetch<'a>> {
+        Some(FetchWorldRef {
+            world,
+        })
+    }
+}
+
+impl AsQuery for QueryWorldRef {
+    type Query = Self;
+}
+
+impl AsQuery for &World {
+    type Query = QueryWorldRef;
+}
+
+pub struct FetchWorldRefMut<'a> {
+    world: &'a mut World
+}
+
+impl<'a> Fetch<'a> for FetchWorldRefMut<'a> {
+    type Item = &'a mut World;
+
+    fn dangling() -> Self {
+        unreachable!()
+    }
+
+    fn can_visit_item(&mut self, _entity: crate::ArchetypeEntityId) -> bool {
+        true
+    }
+
+    unsafe fn get_item(&mut self, _entity: crate::world::ArchetypeEntityId) -> Self::Item {
+        // safety: world outlives the fetcher
+        let mut world_ptr = NonNull::from(&self.world);
+        unsafe { world_ptr.as_mut() }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct QueryWorldRefMut;
+
+impl Default for QueryWorldRefMut {
+    fn default() -> Self {
+        Self
+    }
+}
+
+impl Query for QueryWorldRefMut {
+    type Item<'a> = &'a mut World;
+
+    type Fetch<'a> = FetchWorldRefMut<'a>;
+
+    const ALWAYS_FETCHES: bool = true;
+
+    fn new() -> Self {
+        QueryWorldRefMut
+    }
+
+    fn can_visit_archetype(&self, _archetype: &crate::archetype::Archetype) -> bool {
+        true
+    }
+
+    unsafe fn fetch<'a>(&self, world: &'a World, _archetype: &'a crate::archetype::Archetype, _tick: crate::Tick) -> Self::Fetch<'a> {
+        self.fetch_world(world).unwrap()
+    }
+
+    unsafe fn fetch_world<'a>(&self, world: &'a World) -> Option<Self::Fetch<'a>> {
+        // safety: the queries are expected to be executed by an executor that would
+        // not cause multiple mutable borrows
+        let mut world_ptr = NonNull::from(world);
+        let world = unsafe { world_ptr.as_mut() };
+
+        Some(FetchWorldRefMut {
+            world,
+        })
+    }
+}
+
+impl AsQuery for QueryWorldRefMut {
+    type Query = Self;
+}
+
+impl AsQuery for &mut World {
+    type Query = QueryWorldRefMut;
+}

lyra-ecs/src/resource.rs

@@ -1,8 +1,8 @@
 use std::{any::{TypeId, Any}, cell::{RefCell, Ref, RefMut}};
 
 /// Shorthand for `Send + Sync + 'static`, so it never needs to be implemented manually.
-pub trait ResourceObject: Send + Sync + 'static {}
+pub trait ResourceObject: 'static {}
-impl<T: Send + Sync + 'static> ResourceObject for T {}
+impl<T: 'static> ResourceObject for T {}
 
 /// A type erased storage for a Resource.
 pub struct ResourceData {

lyra-ecs/src/system/graph.rs

@@ -108,7 +108,7 @@ impl GraphExecutor {
 mod tests {
     use std::ptr::NonNull;
 
-    use crate::{world::World, query::{ResourceMut, View}, system::IntoSystem};
+    use crate::{world::World, query::{ResMut, View}, system::IntoSystem};
 
     use super::GraphExecutor;
 
@@ -120,7 +120,7 @@ mod tests {
 
         let mut exec = GraphExecutor::new();
 
-        let a_system = |view: View<ResourceMut<Vec<String>>>| -> anyhow::Result<()> {
+        let a_system = |view: View<ResMut<Vec<String>>>| -> anyhow::Result<()> {
             println!("System 'a' ran!");
             
             let mut order = view.into_iter().next().unwrap();
@@ -129,7 +129,7 @@ mod tests {
             Ok(())
         };
 
-        let b_system = |view: View<ResourceMut<Vec<String>>>| -> anyhow::Result<()> {
+        let b_system = |view: View<ResMut<Vec<String>>>| -> anyhow::Result<()> {
             println!("System 'b' ran!");
 
             let mut order = view.into_iter().next().unwrap();
@@ -138,7 +138,7 @@ mod tests {
             Ok(())
         };
 
-        let c_system = |view: View<ResourceMut<Vec<String>>>| -> anyhow::Result<()> {
+        let c_system = |view: View<ResMut<Vec<String>>>| -> anyhow::Result<()> {
             println!("System 'c' ran!");
 
             let mut order = view.into_iter().next().unwrap();

lyra-ecs/src/system/mod.rs

@@ -1,6 +1,6 @@
 use std::{ptr::NonNull, marker::PhantomData, cell::{Ref, RefMut}};
 
-use crate::{world::World, Access, ResourceObject, query::{Query, View}};
+use crate::{world::World, Access, ResourceObject, query::{Query, View, AsQuery}};
 
 pub mod graph;
 pub use graph::*;
@@ -131,20 +131,20 @@ impl_fn_system_tuple!{ A, B, C, D, E, F2, G, H, I, J, K, L, M, N, O }
 impl_fn_system_tuple!{ A, B, C, D, E, F2, G, H, I, J, K, L, M, N, O, P }
 
 /// An ArgFetcher implementation for query [`View`]s
-pub struct ViewArgFetcher<Q> {
+pub struct ViewArgFetcher<Q: AsQuery> {
-    query: Q
+    query: Q::Query
 }
 
-impl<'a, Q: Query> FnArg for View<'a, Q> {
+impl<'a, Q: AsQuery> FnArg for View<'a, Q> {
     type Fetcher = ViewArgFetcher<Q>;
 }
 
-impl<Q: Query> FnArgFetcher for ViewArgFetcher<Q> {
+impl<Q: AsQuery> FnArgFetcher for ViewArgFetcher<Q> {
     type Arg<'a> = View<'a, Q>;
 
     fn new() -> Self {
         ViewArgFetcher {
-            query: Q::new(),
+            query: <Q::Query as Query>::new(),
         }
     }
 

lyra-ecs/src/world.rs

@@ -213,7 +213,7 @@ impl World {
     /// View into the world for a set of entities that satisfy the queries.
     pub fn view_iter<T: 'static + AsQuery>(&self) -> ViewIter<T::Query> {
         let archetypes = self.archetypes.values().collect();
-        let v = View::new(self, T::Query::new(), archetypes);
+        let v = View::<T>::new(self, T::Query::new(), archetypes);
         v.into_iter()
     }