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21 lines
329 B
21 lines
329 B
3 years ago
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use crate::List::{Cons, Nil};
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use std::cell::RefCell;
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use std::rc::Rc;
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#[derive(Debug)]
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enum List {
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Cons(i32, RefCell<Rc<List>>),
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Nil,
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}
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impl List {
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fn tail(&self) -> Option<&RefCell<Rc<List>>> {
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match self {
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Cons(_, item) => Some(item),
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Nil => None,
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}
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}
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}
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fn main() {}
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