feat(ecs): add error handlingHEADmaster

1 files changed, 37 insertions, 7 deletions

diff --git a/ecs/src/system.rs b/ecs/src/system.rs
index ff3437a..5d3e0bf 100644
--- a/ecs/src/system.rs
+++ b/ecs/src/system.rs
@@ -4,6 +4,7 @@ use ecs_macros::Component;
 use seq_macro::seq;
 
 use crate::World;
+use crate::error::Error;
 use crate::uid::Uid;
 
 pub mod initializable;
@@ -28,10 +29,11 @@ pub trait System<'world, Impl>: 'static
 macro_rules! impl_system {
     ($c: tt) => {
         seq!(I in 0..$c {
-            impl<'world, Func, #(TParam~I,)*> System<'world, fn(#(TParam~I,)*)>
+            impl<'world, Func, Ret, #(TParam~I,)*> System<'world, fn(#(TParam~I,)*) -> Ret>
                 for Func
             where
-                Func: Fn(#(TParam~I,)*) + Copy + 'static,
+                Func: Fn(#(TParam~I,)*) -> Ret + 'static,
+                Ret: ReturnValue,
                 #(TParam~I: Param<'world, Input = ()>,)*
             {
                 type Callbacks = NoCallbacks;
@@ -48,8 +50,9 @@ macro_rules! impl_system {
 
                             self(#({
                                 TParam~I::new(world, &metadata)
-                            },)*);
+                            },)*).into_result()
                         }),
+                        name: std::any::type_name::<Self>()
                     };
 
                     (type_erased, NoCallbacks)
@@ -73,6 +76,7 @@ pub trait Into<'world, Impl>
 pub struct TypeErased
 {
     run: Box<TypeErasedRunFn>,
+    name: &'static str,
 }
 
 impl TypeErased
@@ -81,9 +85,14 @@ impl TypeErased
     ///
     /// # Safety
     /// `world_data` must live at least as long as the [`World`] the system belongs to.
-    pub unsafe fn run(&self, world: &World, metadata: Metadata)
+    pub unsafe fn run(&self, world: &World, metadata: Metadata) -> Result<(), Error>
     {
-        (self.run)(world, metadata);
+        (self.run)(world, metadata)
+    }
+
+    pub fn name(&self) -> &'static str
+    {
+        self.name
     }
 }
 
@@ -95,8 +104,26 @@ impl Debug for TypeErased
     }
 }
 
-/// Function in [`TypeErased`] used to run the system.
-type TypeErasedRunFn = dyn Fn(&World, Metadata);
+pub trait ReturnValue
+{
+    fn into_result(self) -> Result<(), Error>;
+}
+
+impl ReturnValue for ()
+{
+    fn into_result(self) -> Result<(), Error>
+    {
+        Ok(())
+    }
+}
+
+impl ReturnValue for Result<(), Error>
+{
+    fn into_result(self) -> Result<(), Error>
+    {
+        self
+    }
+}
 
 /// A parameter to a [`System`].
 pub trait Param<'world>
@@ -126,3 +153,6 @@ pub(crate) struct SystemComponent
 {
     pub(crate) system: TypeErased,
 }
+
+/// Function in [`TypeErased`] used to run the system.
+type TypeErasedRunFn = dyn Fn(&World, Metadata) -> Result<(), Error>;