Highlight color problem

[ezksd]

The highlight color of function pure is not right, this code has no compiling error or warning.

Developer tool screenshot is under below if it helps.

This is the whole code，the wrong highlight color Snippet is in the last line.

#[allow(dead_code)]
enum List<T> {
    Cons(T, Box<List<T>>),
    Nil,
}

use List::{Cons,Nil};
#[allow(dead_code)]
impl<A: Copy> List<A> {
    fn cons(x: A, xs: List<A>) -> List<A> {
        Cons(x, Box::new(xs))
    }

    fn pure(x: A) -> List<A> {
        List::cons(x, Nil)
    }

    fn fold_left<B>(&self, init: B, f: impl Fn(B, A) -> B) -> B {
        match self {
            Cons(item, ref rest) => rest.fold_left(f(init, *item), f),
            Nil => init,
        }
    }

    fn fold_right<B>(&self, init: B, f: impl Fn(A, B) -> B) -> B {
        self.reverse().fold_left(init, |b, a| f(a, b))
    }

    fn reverse(&self) -> List<A> {
        self.fold_left(Nil, |b, a| Cons(a, Box::new(b)))
    }

    fn concat(&self, right: List<A>) -> List<A> {
        self.fold_right(right, |a, b| Cons(a, Box::new(b)))
    }

    fn map<B: Copy>(&self, f: impl Fn(A) -> B) -> List<B> {
        self.fold_left(Nil, |b, a| Cons(f(a), Box::new(b)))
            .reverse()
    }

    fn flat_map<B: Copy>(&self, f: impl Fn(A) -> List<B>) -> List<B> {
        self.fold_right(Nil, |a, b| f(a).concat(b))
    }

    fn filter(&self, f: impl Fn(A) -> bool) -> List<A> {
        self.flat_map(|x| if f(x) { List::pure(x) } else { Nil })
    }
}

[Xanewok]

IIRC this might've been a reserved keyword some time ago and the grammar files are quite dated at this time. Currently, VSCode ships with the Rust grammar files already - if we were to change that, we'd probably have to modify those and ship them ourselves.