Yog Script (.ys, .yns) analyzed: its lexer, parser and syntax tree, names resolved, the class index model — what the build and the editors read a source with.
namespace System.Collections.Generic;
/// Items in order, read by their index.
[Intrinsic]
public interface IReadOnlyList<out T> : IReadOnlyCollection<T> {
T this[i32 index] { get; }
}