mirror of https://github.com/rust-lang/rust
25 lines
455 B
Rust
25 lines
455 B
Rust
//@ run-pass
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#![feature(box_patterns)]
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#[derive(Clone)]
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enum Noun
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{
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Atom(isize),
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Cell(Box<Noun>, Box<Noun>)
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}
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fn fas(n: &Noun) -> Noun
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{
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match n {
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&Noun::Cell(box Noun::Atom(2), box Noun::Cell(ref a, _)) => (**a).clone(),
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_ => panic!("Invalid fas pattern")
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}
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}
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pub fn main() {
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fas(
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&Noun::Cell(Box::new(Noun::Atom(2)),
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Box::new(Noun::Cell(Box::new(Noun::Atom(2)), Box::new(Noun::Atom(3)))))
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);
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}
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