Type-safe signals #1000
Type-safe signals #1000
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Adds three APIs to classes that contain at least one #[signal] decl: - self.signals() - self.funcs() - Self::static_funcs() The idea is to use generated symbols for type-safe connecting (signal -> func) as well as emitting. This is still WIP.
Bromeon
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API docs are being generated and will be shortly available at: https://godot-rust.github.io/docs/gdext/pr-1000 |
| pub trait ParamTuple { | ||
| fn to_variant_array(&self) -> Vec<Variant>; | ||
| fn from_variant_array(array: &[&Variant]) -> Self; | ||
| } |
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i wonder if this is something we could reuse in Ptr/VarcallSignatureTuple?
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Yes, I was wondering the same, the similarities are hard to overlook 🙂 It could even be a foundation for a potential builder API one day, if we allow users to register their own methods....
One thing that would be interesting, but very hard to measure, is how compile-time is impacted by different approaches (e.g. more code in declarative macros vs. procedural macros vs. traits/generics) 🤔
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One thing that would be interesting, but very hard to measure, is how compile-time is impacted by different approaches (e.g. more code in declarative macros vs. procedural macros vs. traits/generics) 🤔
I can imagine it would also vary a lot depending on exactly what lies where too
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| /// Extracted syntax info for a declared signal. | ||
| struct SignalDetails<'a> { | ||
| /// `fn my_signal(i: i32, s: GString)` |
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I would change these from docstrings /// to normal comments // - IDE highlights might be a bit too confusing in isolation.
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Not sure how you mean this -- these types are only used during codegen of the macro and won't be visible to the user.
Using /// has the advantage that hovering over the fields (elsewhere) shows some example formats, plus there's syntax highlighting for the `...` backticked parts 🙂
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Seeing this MR gave me a smile for the whole day. Thanks. :) |
Closes #8.
Closes #620.
Early draft for a type-safe signal system. Largely backwards compatible with the current syntax.
The following...
...expands to code that can then be used like this (inside
impl MyClass):Note that this is explicitly not limited to functions declared via
#[func]. I had an earlier draft with a generatedfuncs()API which would route the calls via Godot reflection, but this seems more flexible, since you can keep signal recipients private in Rust. On the downside, it may be harder to disconnect such signals.Compatibility
#[signal]now requires aBase<T>field.As far as I can see, that's the only breakage. It might also be possible to opt in to the new type-safe signals via something like
#[godot_api(signals)]or so.This feature is only available on Godot 4.2+, since it requires custom callables.
Work to do
There's a ton that can still be added, in either this or future PRs:
sig.connect_obj(obj, Class::method)impl)gd.signals().my_signal()#[signal]pubetc).AsArginemit()&selfmethods