harper_core/expr/
longest_match_of.rs

1use crate::{Span, Token, expr::Expr};
2
3/// An [`Expr`] that returns the farthest offset of the longest match in a list of expressions.
4#[derive(Default)]
5pub struct LongestMatchOf {
6    exprs: Vec<Box<dyn Expr>>,
7}
8
9impl LongestMatchOf {
10    pub fn new(exprs: Vec<Box<dyn Expr>>) -> Self {
11        Self { exprs }
12    }
13
14    pub fn add(&mut self, expr: impl Expr + 'static) {
15        self.exprs.push(Box::new(expr));
16    }
17}
18
19impl Expr for LongestMatchOf {
20    fn run(&self, cursor: usize, tokens: &[Token], source: &[char]) -> Option<Span<Token>> {
21        let mut longest: Option<Span<Token>> = None;
22
23        for expr in self.exprs.iter() {
24            let Some(window) = expr.run(cursor, tokens, source) else {
25                continue;
26            };
27
28            if let Some(longest_window) = longest {
29                if window.len() > longest_window.len() {
30                    longest = Some(window);
31                }
32            } else {
33                longest = Some(window);
34            }
35        }
36
37        longest
38    }
39}
harper_core/expr/longest_match_of.rs

harper_core/expr/
longest_match_of.rs
