| // pest. The Elegant Parser |
| // Copyright (c) 2018 DragoČ™ Tiselice |
| // |
| // 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. All files in the project carrying such notice may not be copied, |
| // modified, or distributed except according to those terms. |
| |
| // This structure serves to improve performance over Token objects in two ways: |
| // |
| // * it is smaller than a Token, leading to both less memory use when stored in the queue but also |
| // increased speed when pushing to the queue |
| // * it finds its pair in O(1) time instead of O(N), since pair positions are known at parse time |
| // and can easily be stored instead of recomputed |
| #[derive(Debug)] |
| pub enum QueueableToken<'i, R> { |
| Start { |
| /// Queue (as a vec) contains both `Start` token and `End` for the same rule. |
| /// This field is an index of corresponding `End` token in vec. |
| end_token_index: usize, |
| /// Position from which rule was tried to parse (or successfully parsed). |
| input_pos: usize, |
| }, |
| End { |
| /// Queue (as a vec) contains both `Start` token and `End` for the same rule. |
| /// This filed is an index of corresponding `Start` token in vec. |
| start_token_index: usize, |
| rule: R, |
| tag: Option<&'i str>, |
| /// Position at which successfully parsed rule finished (ended). |
| input_pos: usize, |
| }, |
| } |