70 lines
1.3 KiB
Markdown
70 lines
1.3 KiB
Markdown
# `Linked`
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Fix (many) errors to make this compile and pass tests:
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```rust
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# #[derive(Clone, Copy)]
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struct Node<'a> {
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next: Option<&'a Self>,
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value: &'a str,
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}
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struct Linked<'a, F> {
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node: Node<'a>,
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callback: &'a mut F,
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}
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impl<'a, F: FnMut(String)> Linked<'a, F> {
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# /*
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fn with(&mut self, value: &str) -> Linked<'_, F> {
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Self {
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node: Node {
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next: Some(self.node),
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# */
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# fn with<'b>(&'b mut self, value: &'b str) -> Linked<'b, F> {
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# Linked {
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# node: Node {
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# next: Some(&self.node),
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value,
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},
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callback: self.callback,
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}
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}
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fn call(&mut self) {
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let mut node = self.node;
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let mut value = node.value.to_string();
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while let Some(next) = node.next {
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value += next.value;
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# /*
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node = next;
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}
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self.callback(value);
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# */
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# node = *next; }
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# (self.callback)(value);
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}
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}
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// don't change anything below
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let mut vec = vec![];
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let mut linked = Linked {
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node: Node { next: None, value: "0" },
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callback: &mut |value| vec.push(value),
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};
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// why does removing code below cause the instantiation to fail?
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linked.call();
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{
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let mut linked = linked.with("1");
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linked.with("2").call();
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linked.with("3").call();
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}
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linked.with("4").call();
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assert_eq!(vec, ["0", "210", "310", "40"]);
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```
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