| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // ignore-pretty |
| |
| #![allow(unknown_features)] |
| |
| struct Parser<'a, I, O> { |
| parse: Box<FnMut(I) -> Result<O, String> + 'a> |
| } |
| |
| impl<'a, I: 'a, O: 'a> Parser<'a, I, O> { |
| fn compose<K: 'a>(mut self, mut rhs: Parser<'a, O, K>) -> Parser<'a, I, K> { |
| // FIXME (#22405): Replace `Box::new` with `box` here when/if possible. |
| Parser { |
| parse: Box::new(move |x: I| { |
| match (self.parse)(x) { |
| Ok(r) => (rhs.parse)(r), |
| Err(e) => Err(e) |
| } |
| }) |
| } |
| } |
| } |
| |
| fn main() {} |
