| // build-pass (FIXME(62277): could be check-pass?) | |
| #![allow(dead_code)] | |
| struct Parser<'a, I, O> { | |
| parse: Box<dyn 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> { | |
| Parser { | |
| parse: Box::new(move |x: I| { | |
| match (self.parse)(x) { | |
| Ok(r) => (rhs.parse)(r), | |
| Err(e) => Err(e) | |
| } | |
| }) | |
| } | |
| } | |
| } | |
| fn main() {} |