59 lines
1.8 KiB
Rust
59 lines
1.8 KiB
Rust
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// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// pretty-expanded FIXME #23616
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fn main() {
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let _ = test(Some(0).into_iter());
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}
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trait Parser {
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type Input: Iterator;
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type Output;
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fn parse(self, input: Self::Input) -> Result<(Self::Output, Self::Input), ()>;
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fn chain<P>(self, p: P) -> Chain<Self, P> where Self: Sized {
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Chain(self, p)
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}
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}
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struct Token<T>(T::Item) where T: Iterator;
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impl<T> Parser for Token<T> where T: Iterator {
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type Input = T;
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type Output = T::Item;
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fn parse(self, _input: Self::Input) -> Result<(Self::Output, Self::Input), ()> {
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Err(())
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}
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}
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struct Chain<L, R>(L, R);
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impl<L, R> Parser for Chain<L, R> where L: Parser, R: Parser<Input = L::Input> {
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type Input = L::Input;
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type Output = (L::Output, R::Output);
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fn parse(self, _input: Self::Input) -> Result<(Self::Output, Self::Input), ()> {
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Err(())
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}
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}
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fn test<I>(i: I) -> Result<((), I), ()> where I: Iterator<Item = i32> {
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Chain(Token(0), Token(1))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.chain(Chain(Token(0), Token(1)))
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.parse(i)
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.map(|(_, i)| ((), i))
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}
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