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6 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Gino Valente
|
276dd04001
|
bevy_reflect: Function reflection (#13152)
# Objective
We're able to reflect types sooooooo... why not functions?
The goal of this PR is to make functions callable within a dynamic
context, where type information is not readily available at compile
time.
For example, if we have a function:
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
```
And two `Reflect` values we've already validated are `i32` types:
```rust
let left: Box<dyn Reflect> = Box::new(2_i32);
let right: Box<dyn Reflect> = Box::new(2_i32);
```
We should be able to call `add` with these values:
```rust
// ?????
let result: Box<dyn Reflect> = add.call_dynamic(left, right);
```
And ideally this wouldn't just work for functions, but methods and
closures too!
Right now, users have two options:
1. Manually parse the reflected data and call the function themselves
2. Rely on registered type data to handle the conversions for them
For a small function like `add`, this isn't too bad. But what about for
more complex functions? What about for many functions?
At worst, this process is error-prone. At best, it's simply tedious.
And this is assuming we know the function at compile time. What if we
want to accept a function dynamically and call it with our own
arguments?
It would be much nicer if `bevy_reflect` could alleviate some of the
problems here.
## Solution
Added function reflection!
This adds a `DynamicFunction` type to wrap a function dynamically. This
can be called with an `ArgList`, which is a dynamic list of
`Reflect`-containing `Arg` arguments. It returns a `FunctionResult`
which indicates whether or not the function call succeeded, returning a
`Reflect`-containing `Return` type if it did succeed.
Many functions can be converted into this `DynamicFunction` type thanks
to the `IntoFunction` trait.
Taking our previous `add` example, this might look something like
(explicit types added for readability):
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
And it also works on closures:
```rust
let add = |left: i32, right: i32| left + right;
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
As well as methods:
```rust
#[derive(Reflect)]
struct Foo(i32);
impl Foo {
fn add(&mut self, value: i32) {
self.0 += value;
}
}
let mut foo = Foo(2);
let mut function: DynamicFunction = Foo::add.into_function();
let args: ArgList = ArgList::new().push_mut(&mut foo).push_owned(2_i32);
function.call(args).unwrap();
assert_eq!(foo.0, 4);
```
### Limitations
While this does cover many functions, it is far from a perfect system
and has quite a few limitations. Here are a few of the limitations when
using `IntoFunction`:
1. The lifetime of the return value is only tied to the lifetime of the
first argument (useful for methods). This means you can't have a
function like `(a: i32, b: &i32) -> &i32` without creating the
`DynamicFunction` manually.
2. Only 15 arguments are currently supported. If the first argument is a
(mutable) reference, this number increases to 16.
3. Manual implementations of `Reflect` will need to implement the new
`FromArg`, `GetOwnership`, and `IntoReturn` traits in order to be used
as arguments/return types.
And some limitations of `DynamicFunction` itself:
1. All arguments share the same lifetime, or rather, they will shrink to
the shortest lifetime.
2. Closures that capture their environment may need to have their
`DynamicFunction` dropped before accessing those variables again (there
is a `DynamicFunction::call_once` to make this a bit easier)
3. All arguments and return types must implement `Reflect`. While not a
big surprise coming from `bevy_reflect`, this implementation could
actually still work by swapping `Reflect` out with `Any`. Of course,
that makes working with the arguments and return values a bit harder.
4. Generic functions are not supported (unless they have been manually
monomorphized)
And general, reflection gotchas:
1. `&str` does not implement `Reflect`. Rather, `&'static str`
implements `Reflect` (the same is true for `&Path` and similar types).
This means that `&'static str` is considered an "owned" value for the
sake of generating arguments. Additionally, arguments and return types
containing `&str` will assume it's `&'static str`, which is almost never
the desired behavior. In these cases, the only solution (I believe) is
to use `&String` instead.
### Followup Work
This PR is the first of two PRs I intend to work on. The second PR will
aim to integrate this new function reflection system into the existing
reflection traits and `TypeInfo`. The goal would be to register and call
a reflected type's methods dynamically.
I chose not to do that in this PR since the diff is already quite large.
I also want the discussion for both PRs to be focused on their own
implementation.
Another followup I'd like to do is investigate allowing common container
types as a return type, such as `Option<&[mut] T>` and `Result<&[mut] T,
E>`. This would allow even more functions to opt into this system. I
chose to not include it in this one, though, for the same reasoning as
previously mentioned.
### Alternatives
One alternative I had considered was adding a macro to convert any
function into a reflection-based counterpart. The idea would be that a
struct that wraps the function would be created and users could specify
which arguments and return values should be `Reflect`. It could then be
called via a new `Function` trait.
I think that could still work, but it will be a fair bit more involved,
requiring some slightly more complex parsing. And it of course is a bit
more work for the user, since they need to create the type via macro
invocation.
It also makes registering these functions onto a type a bit more
complicated (depending on how it's implemented).
For now, I think this is a fairly simple, yet powerful solution that
provides the least amount of friction for users.
---
## Showcase
Bevy now adds support for storing and calling functions dynamically
using reflection!
```rust
// 1. Take a standard Rust function
fn add(left: i32, right: i32) -> i32 {
left + right
}
// 2. Convert it into a type-erased `DynamicFunction` using the `IntoFunction` trait
let mut function: DynamicFunction = add.into_function();
// 3. Define your arguments from reflected values
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
// 4. Call the function with your arguments
let result: Return = function.call(args).unwrap();
// 5. Extract the return value
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
## Changelog
#### TL;DR
- Added support for function reflection
- Added a new `Function Reflection` example:
|
||
Alice Cecile
|
ec7b3490f6
|
Add on_unimplemented Diagnostics to Most Public Traits (#13347) (#13662)
# Objective - #13414 did not have the intended effect. - #13404 is still blocked ## Solution - Re-adds #13347. Co-authored-by: Zachary Harrold <zac@harrold.com.au> Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com> Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> |
||
|
Alice Cecile
|
ee6dfd35c9
|
Revert "Add on_unimplemented Diagnostics to Most Public Traits" (#13413)
# Objective - Rust 1.78 breaks all Android support, see https://github.com/bevyengine/bevy/issues/13331 - We should not bump the MSRV to 1.78 until that's resolved in #13366. ## Solution - Temporarily revert https://github.com/bevyengine/bevy/pull/13347 Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com> |
||
Zachary Harrold
|
11f0a2dcde
|
Add on_unimplemented Diagnostics to Most Public Traits (#13347)
# Objective - Fixes #12377 ## Solution Added simple `#[diagnostic::on_unimplemented(...)]` attributes to some critical public traits providing a more approachable initial error message. Where appropriate, a `note` is added indicating that a `derive` macro is available. ## Examples <details> <summary>Examples hidden for brevity</summary> Below is a collection of examples showing the new error messages produced by this change. In general, messages will start with a more Bevy-centric error message (e.g., _`MyComponent` is not a `Component`_), and a note directing the user to an available derive macro where appropriate. ### Missing `#[derive(Resource)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct MyResource; fn main() { App::new() .insert_resource(MyResource) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `MyResource` is not a `Resource` --> examples/app/empty.rs:7:26 | 7 | .insert_resource(MyResource) | --------------- ^^^^^^^^^^ invalid `Resource` | | | required by a bound introduced by this call | = help: the trait `Resource` is not implemented for `MyResource` = note: consider annotating `MyResource` with `#[derive(Resource)]` = help: the following other types implement trait `Resource`: AccessibilityRequested ManageAccessibilityUpdates bevy::bevy_a11y::Focus DiagnosticsStore FrameCount bevy::prelude::State<S> SystemInfo bevy::prelude::Axis<T> and 141 others note: required by a bound in `bevy::prelude::App::insert_resource` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:419:31 | 419 | pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self { | ^^^^^^^^ required by this bound in `App::insert_resource` ``` </details> ### Putting A `QueryData` in a `QueryFilter` Slot <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Component)] struct A; #[derive(Component)] struct B; fn my_system(_query: Query<&A, &B>) {} fn main() { App::new() .add_systems(Update, my_system) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `&B` is not a valid `Query` filter --> examples/app/empty.rs:9:22 | 9 | fn my_system(_query: Query<&A, &B>) {} | ^^^^^^^^^^^^^ invalid `Query` filter | = help: the trait `QueryFilter` is not implemented for `&B` = help: the following other types implement trait `QueryFilter`: With<T> Without<T> bevy::prelude::Or<()> bevy::prelude::Or<(F0,)> bevy::prelude::Or<(F0, F1)> bevy::prelude::Or<(F0, F1, F2)> bevy::prelude::Or<(F0, F1, F2, F3)> bevy::prelude::Or<(F0, F1, F2, F3, F4)> and 28 others note: required by a bound in `bevy::prelude::Query` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\query.rs:349:51 | 349 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> { | ^^^^^^^^^^^ required by this bound in `Query` ``` </details> ### Missing `#[derive(Component)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct A; fn my_system(mut commands: Commands) { commands.spawn(A); } fn main() { App::new() .add_systems(Startup, my_system) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `A` is not a `Bundle` --> examples/app/empty.rs:6:20 | 6 | commands.spawn(A); | ----- ^ invalid `Bundle` | | | required by a bound introduced by this call | = help: the trait `bevy::prelude::Component` is not implemented for `A`, which is required by `A: Bundle` = note: consider annotating `A` with `#[derive(Component)]` or `#[derive(Bundle)]` = help: the following other types implement trait `Bundle`: TransformBundle SceneBundle DynamicSceneBundle AudioSourceBundle<Source> SpriteBundle SpriteSheetBundle Text2dBundle MaterialMesh2dBundle<M> and 34 others = note: required for `A` to implement `Bundle` note: required by a bound in `bevy::prelude::Commands::<'w, 's>::spawn` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\commands\mod.rs:243:21 | 243 | pub fn spawn<T: Bundle>(&mut self, bundle: T) -> EntityCommands { | ^^^^^^ required by this bound in `Commands::<'w, 's>::spawn` ``` </details> ### Missing `#[derive(Asset)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct A; fn main() { App::new() .init_asset::<A>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `A` is not an `Asset` --> examples/app/empty.rs:7:23 | 7 | .init_asset::<A>() | ---------- ^ invalid `Asset` | | | required by a bound introduced by this call | = help: the trait `Asset` is not implemented for `A` = note: consider annotating `A` with `#[derive(Asset)]` = help: the following other types implement trait `Asset`: Font AnimationGraph DynamicScene Scene AudioSource Pitch bevy::bevy_gltf::Gltf GltfNode and 17 others note: required by a bound in `init_asset` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_asset\src\lib.rs:307:22 | 307 | fn init_asset<A: Asset>(&mut self) -> &mut Self; | ^^^^^ required by this bound in `AssetApp::init_asset` ``` </details> ### Mismatched Input and Output on System Piping <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; fn producer() -> u32 { 123 } fn consumer(_: In<u16>) {} fn main() { App::new() .add_systems(Update, producer.pipe(consumer)) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `fn(bevy::prelude::In<u16>) {consumer}` is not a valid system with input `u32` and output `_` --> examples/app/empty.rs:11:44 | 11 | .add_systems(Update, producer.pipe(consumer)) | ---- ^^^^^^^^ invalid system | | | required by a bound introduced by this call | = help: the trait `bevy::prelude::IntoSystem<u32, _, _>` is not implemented for fn item `fn(bevy::prelude::In<u16>) {consumer}` = note: expecting a system which consumes `u32` and produces `_` note: required by a bound in `pipe` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\mod.rs:168:12 | 166 | fn pipe<B, Final, MarkerB>(self, system: B) -> PipeSystem<Self::System, B::System> | ---- required by a bound in this associated function 167 | where 168 | B: IntoSystem<Out, Final, MarkerB>, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IntoSystem::pipe` ``` </details> ### Missing Reflection <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Component)] struct MyComponent; fn main() { App::new() .register_type::<MyComponent>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `MyComponent` does not provide type registration information --> examples/app/empty.rs:8:26 | 8 | .register_type::<MyComponent>() | ------------- ^^^^^^^^^^^ the trait `GetTypeRegistration` is not implemented for `MyComponent` | | | required by a bound introduced by this call | = note: consider annotating `MyComponent` with `#[derive(Reflect)]` = help: the following other types implement trait `GetTypeRegistration`: bool char isize i8 i16 i32 i64 i128 and 443 others note: required by a bound in `bevy::prelude::App::register_type` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:619:29 | 619 | pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::register_type` ``` </details> ### Missing `#[derive(States)]` Implementation <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash)] enum AppState { #[default] Menu, InGame { paused: bool, turbo: bool, }, } fn main() { App::new() .init_state::<AppState>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: the trait bound `AppState: FreelyMutableState` is not satisfied --> examples/app/empty.rs:15:23 | 15 | .init_state::<AppState>() | ---------- ^^^^^^^^ the trait `FreelyMutableState` is not implemented for `AppState` | | | required by a bound introduced by this call | = note: consider annotating `AppState` with `#[derive(States)]` note: required by a bound in `bevy::prelude::App::init_state` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:282:26 | 282 | pub fn init_state<S: FreelyMutableState + FromWorld>(&mut self) -> &mut Self { | ^^^^^^^^^^^^^^^^^^ required by this bound in `App::init_state` ``` </details> ### Adding a `System` with Unhandled Output <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; fn producer() -> u32 { 123 } fn main() { App::new() .add_systems(Update, consumer) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `fn() -> u32 {producer}` does not describe a valid system configuration --> examples/app/empty.rs:9:30 | 9 | .add_systems(Update, producer) | ----------- ^^^^^^^^ invalid system configuration | | | required by a bound introduced by this call | = help: the trait `IntoSystem<(), (), _>` is not implemented for fn item `fn() -> u32 {producer}`, which is required by `fn() -> u32 {producer}: IntoSystemConfigs<_>` = help: the following other types implement trait `IntoSystemConfigs<Marker>`: <Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)> as IntoSystemConfigs<()>> <NodeConfigs<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)>> as IntoSystemConfigs<()>> <(S0,) as IntoSystemConfigs<(SystemConfigTupleMarker, P0)>> <(S0, S1) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1)>> <(S0, S1, S2) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2)>> <(S0, S1, S2, S3) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3)>> <(S0, S1, S2, S3, S4) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4)>> <(S0, S1, S2, S3, S4, S5) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4, P5)>> and 14 others = note: required for `fn() -> u32 {producer}` to implement `IntoSystemConfigs<_>` note: required by a bound in `bevy::prelude::App::add_systems` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:342:23 | 339 | pub fn add_systems<M>( | ----------- required by a bound in this associated function ... 342 | systems: impl IntoSystemConfigs<M>, | ^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::add_systems` ``` </details> </details> ## Testing CI passed locally. ## Migration Guide Upgrade to version 1.78 (or higher) of Rust. ## Future Work - Currently, hints are not supported in this diagnostic. Ideally, suggestions like _"consider using ..."_ would be in a hint rather than a note, but that is the best option for now. - System chaining and other `all_tuples!(...)`-based traits have bad error messages due to the slightly different error message format. --------- Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> |
||
Brezak
|
423a4732c3
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Update compile test to use ui_test 0.23 (#13245)
# Objective Closes #13241 ## Solution Update test utils to use `ui_test` 0.23.0. ## Testing - Run compile tests for bevy_ecs. cc @BD103 |
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BD103
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bdb4899978
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Move compile fail tests (#13196)
# Objective
- Follow-up of #13184 :)
- We use `ui_test` to test compiler errors for our custom macros.
- There are four crates related to compile fail tests
- `bevy_ecs_compile_fail_tests`, `bevy_macros_compile_fail_tests`, and
`bevy_reflect_compile_fail_tests`, which actually test the macros.
-
[`bevy_compile_test_utils`](
|