make target an associated type

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Evan Almloff committed 2024-02-07 08:53:21 -06:00
1 parent ef101dd876
commit 1af8f56e89
11 files changed
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@@ -3,112 +3,105 @@ use crate::CopyValue;
use crate::Signal;
use crate::SignalData;
use dioxus_core::ScopeId;
use generational_box::AnyStorage;
use generational_box::Storage;
use generational_box::UnsyncStorage;
use std::fmt::Debug;
use std::fmt::Display;
/// A read only signal that has been mapped to a new type.
pub struct MappedSignal<U: 'static + ?Sized> {
origin_scope: ScopeId,
mapping: CopyValue<Box<dyn Fn() -> U>>,
pub struct MappedSignal<U: ?Sized + 'static, S: AnyStorage = UnsyncStorage> {
mapping: CopyValue<Box<dyn Fn() -> S::Ref<U>>>,
}
impl MappedSignal<()> {
/// Create a new mapped signal.
pub fn new<T, S, U>(
signal: Signal<T, S>,
mapping: impl Fn(&T) -> &U + 'static,
) -> MappedSignal<S::Ref<U>>
pub fn new<R, T, S, U>(readable: R, mapping: impl Fn(&T) -> &U + 'static) -> MappedSignal<U, S>
where
S: Storage<SignalData<T>>,
U: ?Sized,
{
MappedSignal {
origin_scope: signal.origin_scope(),
mapping: CopyValue::new(Box::new(move || S::map(signal.read(), &mapping))),
}
todo!()
// MappedSignal {
// mapping: CopyValue::new(Box::new(move || S::map(signal.read(), &mapping))),
// }
}
}
impl<U> MappedSignal<U> {
/// Get the scope that the signal was created in.
pub fn origin_scope(&self) -> ScopeId {
self.origin_scope
}
// impl<U: ?Sized> MappedSignal<U> {
// /// Get the current value of the signal. This will subscribe the current scope to the signal.
// pub fn read(&self) -> U {
// (self.mapping.read())()
// }
/// Get the current value of the signal. This will subscribe the current scope to the signal.
pub fn read(&self) -> U {
(self.mapping.read())()
}
// /// Run a closure with a reference to the signal's value.
// pub fn with<O>(&self, f: impl FnOnce(U) -> O) -> O {
// f(self.read())
// }
// }
/// Run a closure with a reference to the signal's value.
pub fn with<O>(&self, f: impl FnOnce(U) -> O) -> O {
f(self.read())
}
}
// impl<U: ?Sized + Clone> MappedSignal<U> {
// /// Get the current value of the signal. This will subscribe the current scope to the signal.
// pub fn value(&self) -> U {
// self.read().clone()
// }
// }
impl<U: ?Sized + Clone> MappedSignal<U> {
/// Get the current value of the signal. This will subscribe the current scope to the signal.
pub fn value(&self) -> U {
self.read().clone()
}
}
// impl<U: ?Sized> PartialEq for MappedSignal<U> {
// fn eq(&self, other: &Self) -> bool {
// self.mapping == other.mapping
// }
// }
impl<U: ?Sized> PartialEq for MappedSignal<U> {
fn eq(&self, other: &Self) -> bool {
self.mapping == other.mapping
}
}
// impl<U> std::clone::Clone for MappedSignal<U> {
// fn clone(&self) -> Self {
// *self
// }
// }
impl<U> std::clone::Clone for MappedSignal<U> {
fn clone(&self) -> Self {
*self
}
}
// impl<U> Copy for MappedSignal<U> {}
impl<U> Copy for MappedSignal<U> {}
// impl<U: Display> Display for MappedSignal<U> {
// fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
// self.with(|v| Display::fmt(&v, f))
// }
// }
impl<U: Display> Display for MappedSignal<U> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
self.with(|v| Display::fmt(&v, f))
}
}
// impl<U: Debug> Debug for MappedSignal<U> {
// fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
// self.with(|v| Debug::fmt(&v, f))
// }
// }
impl<U: Debug> Debug for MappedSignal<U> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
self.with(|v| Debug::fmt(&v, f))
}
}
// impl<T> std::ops::Deref for MappedSignal<T> {
// type Target = dyn Fn() -> T;
impl<T> std::ops::Deref for MappedSignal<T> {
type Target = dyn Fn() -> T;
// fn deref(&self) -> &Self::Target {
// // https://github.com/dtolnay/case-studies/tree/master/callable-types
fn deref(&self) -> &Self::Target {
// https://github.com/dtolnay/case-studies/tree/master/callable-types
// // First we create a closure that captures something with the Same in memory layout as Self (MaybeUninit<Self>).
// let uninit_callable = std::mem::MaybeUninit::<Self>::uninit();
// // Then move that value into the closure. We assume that the closure now has a in memory layout of Self.
// let uninit_closure = move || Self::read(unsafe { &*uninit_callable.as_ptr() });
// First we create a closure that captures something with the Same in memory layout as Self (MaybeUninit<Self>).
let uninit_callable = std::mem::MaybeUninit::<Self>::uninit();
// Then move that value into the closure. We assume that the closure now has a in memory layout of Self.
let uninit_closure = move || Self::read(unsafe { &*uninit_callable.as_ptr() });
// // Check that the size of the closure is the same as the size of Self in case the compiler changed the layout of the closure.
// let size_of_closure = std::mem::size_of_val(&uninit_closure);
// assert_eq!(size_of_closure, std::mem::size_of::<Self>());
// Check that the size of the closure is the same as the size of Self in case the compiler changed the layout of the closure.
let size_of_closure = std::mem::size_of_val(&uninit_closure);
assert_eq!(size_of_closure, std::mem::size_of::<Self>());
// // Then cast the lifetime of the closure to the lifetime of &self.
// fn cast_lifetime<'a, T>(_a: &T, b: &'a T) -> &'a T {
// b
// }
// let reference_to_closure = cast_lifetime(
// {
// // The real closure that we will never use.
// &uninit_closure
// },
// // We transmute self into a reference to the closure. This is safe because we know that the closure has the same memory layout as Self so &Closure == &Self.
// unsafe { std::mem::transmute(self) },
// );
// Then cast the lifetime of the closure to the lifetime of &self.
fn cast_lifetime<'a, T>(_a: &T, b: &'a T) -> &'a T {
b
}
let reference_to_closure = cast_lifetime(
{
// The real closure that we will never use.
&uninit_closure
},
// We transmute self into a reference to the closure. This is safe because we know that the closure has the same memory layout as Self so &Closure == &Self.
unsafe { std::mem::transmute(self) },
);
// Cast the closure to a trait object.
reference_to_closure as &Self::Target
}
}
// // Cast the closure to a trait object.
// reference_to_closure as &Self::Target
// }
// }