pub trait Expr: LSend {
// Required method
fn run(
&self,
cursor: usize,
tokens: &[Token],
source: &[char],
) -> Option<Span>;
}
pub trait Expr: LSend {
// Required method
fn run(
&self,
cursor: usize,
tokens: &[Token],
source: &[char],
) -> Option<Span>;
}