use std::collections::HashSet;
use pest::Parser;
use pest_derive::Parser;
#[derive(Parser)]
#[grammar = "./src/rev_mapper/grammar.pest"]
pub struct MistMapperParser;
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct MistMap(pub usize, pub usize);
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct RustMap(pub usize, pub usize);
pub fn get_mapping(input: &str) -> HashSet<(RustMap, MistMap)> {
let mut mapping = HashSet::new();
let pairs = MistMapperParser::parse(Rule::mapping, input)
.unwrap()
.next()
.unwrap()
.into_inner();
for pair in pairs {
if pair.as_rule() == Rule::map {
let rs = pair.as_span().start_pos().line_col();
let mut inner = pair.into_inner();
let (line, col) = (
inner.next().unwrap().as_str().parse().unwrap(),
inner.next().unwrap().as_str().parse().unwrap(),
);
mapping.insert((RustMap(rs.0, rs.1), MistMap(line, col)));
}
}
mapping
}
pub fn find_mapping(
mapping: &HashSet<(RustMap, MistMap)>,
target: &RustMap,
) -> Option<(RustMap, MistMap)> {
mapping
.iter()
.copied()
.filter(|(rust, _)| rust <= target)
.max_by_key(|(rust, _)| *rust)
}