tada/src/desugar/basic.rs

36 lines
1.2 KiB
Rust

use crate::ast::Separated;
impl<E, S1, S2> Separated<E, S1, S2> {
pub fn desugar_elem(self, desugar_elem: impl Fn(E) -> (E, bool)) -> (Self, bool) {
match self {
Self::Empty(span) => (Self::Empty(span), false),
Self::NonEmpty {
first_elem,
last_elems,
trailing,
span,
} => {
let (new_first_elem, mut desugared) = desugar_elem(first_elem);
let mut new_last_elems = vec![];
for (separator, elem) in last_elems {
if desugared {
new_last_elems.push((separator, elem));
} else {
let (elem, elem_desugared) = desugar_elem(elem);
desugared = desugared || elem_desugared;
new_last_elems.push((separator, elem));
}
}
let new = Self::NonEmpty {
first_elem: new_first_elem,
last_elems: new_last_elems,
trailing,
span,
};
(new, desugared)
}
}
}
}