Add initial APIs for getting world and commands for child_builders #15416
Conversation
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@benfrankel and @viridia could you take a look at this? Still quite noob at rust so it took me a bit to figure out and reason about the lifetimes properly. |
| /// }); | ||
| /// # } | ||
| /// ``` | ||
| impl<'a> ChildBuilder<'a> { |
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| impl<'a> ChildBuilder<'a> { | |
| impl ChildBuilder<'_> { |
I believe it should be possible to elide the lifetime here, and then return &mut Commands from commands_mut etc. with no lifetime specified.
| /// }); | ||
| /// } | ||
| /// ``` | ||
| impl<'w> WorldChildBuilder<'w> { |
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| impl<'w> WorldChildBuilder<'w> { | |
| impl WorldChildBuilder<'_> { |
Same lifetime elision.
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| #[test] | ||
| fn get_commands_from_child_builder() { | ||
| let world = World::default(); |
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Why World::default() here and World::new() in the other test?
| let mut _world_mut_clone = world_child_builder.world_mut(); | ||
| let _world_clone = world_child_builder.world(); |
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I'd add explicit type annotations here, like let mut _: &mut World = .... Same for the .commands() test.
| } | ||
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| /// Same as above, except non-mutable | ||
| pub fn commands(&self) -> &Commands<'a, 'a> { |
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I'm not sure there's a use-case for an immutable reference to a Commands. I think something like this might work?
pub fn commands(&mut self) -> Commands { self.commands.reborrow() }
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Agreed, I would just have the one method that returns a mutable commands.
Is there a reason we're not simply returning self.world.commands()?
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Since this is a method on ChildBuilder, there's no self.world.
alice-i-cecile
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worldandworld_mutmethods toWorldChildBuilder#15414Solution
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For those of you who asked for this, I'm trying to find a concrete use cases where these are useful? Is it because we'd be borrowing commands/world too often? I implemented this not knowing the actual use cases for this, which seemed straightforward, then when I was adding examples and what not I realized when does this actually get used?