53 lines
1.2 KiB
Rust
53 lines
1.2 KiB
Rust
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
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pub enum Either<A, B> {
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A(A),
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B(B),
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}
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impl<A, B> Either<A, B> {
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pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
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where
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F1: FnOnce(A) -> R,
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F2: FnOnce(B) -> R,
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{
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match self {
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Either::A(a) => f1(a),
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Either::B(b) => f2(b),
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}
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}
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pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
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where
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F1: FnOnce(A) -> U,
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F2: FnOnce(B) -> V,
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{
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match self {
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Either::A(a) => Either::A(f1(a)),
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Either::B(b) => Either::B(f2(b)),
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}
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}
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pub fn map_a<U, F>(self, f: F) -> Either<U, B>
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where
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F: FnOnce(A) -> U,
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{
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self.map(f, |it| it)
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}
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pub fn a(self) -> Option<A> {
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match self {
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Either::A(it) => Some(it),
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Either::B(_) => None,
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}
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}
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pub fn b(self) -> Option<B> {
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match self {
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Either::A(_) => None,
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Either::B(it) => Some(it),
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}
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}
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pub fn as_ref(&self) -> Either<&A, &B> {
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match self {
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Either::A(it) => Either::A(it),
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Either::B(it) => Either::B(it),
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}
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}
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}
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