mirror of https://github.com/rust-lang/rust
33 lines
646 B
Rust
33 lines
646 B
Rust
//@ check-pass
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use std::iter::FromIterator;
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struct DynamicAlt<P>(P);
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impl<P> FromIterator<P> for DynamicAlt<P> {
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fn from_iter<T: IntoIterator<Item = P>>(_iter: T) -> Self {
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loop {}
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}
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}
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fn owned_context<I, F>(_: F) -> impl FnMut(I) -> I {
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|i| i
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}
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trait Parser<I> {}
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impl<T, I> Parser<I> for T where T: FnMut(I) -> I {}
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fn alt<I, P: Parser<I>>(_: DynamicAlt<P>) -> impl FnMut(I) -> I {
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|i| i
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}
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fn rule_to_parser<'c>() -> impl Parser<&'c str> {
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move |input| {
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let v: Vec<()> = vec![];
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alt(v.iter().map(|()| owned_context(rule_to_parser())).collect::<DynamicAlt<_>>())(input)
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}
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}
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fn main() {}
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