46 lines
956 B
Rust
46 lines
956 B
Rust
use crate::{
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lenses::{LensOver, LensView},
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Optics, OpticsTrait,
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};
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#[derive(Clone, Copy)]
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pub struct Combination<A, B>(A, B);
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impl<A, B> OpticsTrait for Combination<A, B> {}
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impl<A, B> std::ops::Add<Optics<B>> for Optics<A>
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where
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A: OpticsTrait,
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B: OpticsTrait,
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{
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type Output = Optics<Combination<Optics<A>, Optics<B>>>;
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fn add(self, rhs: Optics<B>) -> Self::Output {
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Optics(Combination(self, rhs))
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}
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}
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impl<A, B, T> LensView<T> for Combination<A, B>
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where
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A: LensView<T>,
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B: LensView<A::Field>,
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{
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type Field = B::Field;
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fn view(&self, thing: T) -> Self::Field {
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B::view(&self.1, A::view(&self.0, thing))
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}
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}
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impl<A, B, T> LensOver<T> for Combination<A, B>
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where
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A: LensOver<T>,
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B: LensOver<A::Field>,
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{
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fn over<F>(&self, thing: T, f: F) -> T
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where
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F: FnOnce(Self::Field) -> Self::Field,
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{
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A::over(&self.0, thing, |b| B::over(&self.1, b, f))
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}
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}
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