[wgsl-in] An 'expected one of ..' lexer error system would be nice

[expenses]

With this wgsl code:

struct Foo {
  xxx: array<f32; 3>;
};
fn bar() -> Foo {
  return Foo(array<f32;3>(1.0, 2.0, 3.0));
}

we get the error:

error: expected paren, found `;`
  ┌─ wgsl:2:17
  │
2 │   xxx: array<f32; 3>;
  │                 ^ expected paren

thread 'main' panicked at 'unable to parse WGSL', bin/naga.rs:122:21

While a > parenthesis could go in that slot, a , comma could as well, which is the seperator between an array type and the number of items.
Ideally we'd have something like what rust does:

error: expected one of `>` `,`, found `;`
  ┌─ wgsl:2:17
  │
2 │   xxx: array<f32; 3>;
  │                 ^ expected one of `>` `,`

thread 'main' panicked at 'unable to parse WGSL', bin/naga.rs:122:21

[kvark]

I agree it would be great to be that precise, but it's a tough one to do. The expectations are sort of dynamic in the code, they depend on the implementation of a particular branch of logic...