Dummy tweaks (attempt 2) by nnethercote · Pull Request #121829 · rust-lang/rust (original) (raw)

DummyAstNode and DummyResult are quite different if you look closely.

• DummyAstNode is a trait, but DummyResult is a type.
• For expressions, DummyAstNode uses ExprKind::Dummy, but DummyResult uses ExprKind::Err or an empty ExprKind::Tup
• For types, DummyAstNode uses TyKind::Dummy, but DummyResult uses an empty TyKind::Tup.
• DummyAstNode can handle a single Item, Stmt, Block, or Crate, but DummyResult cannot.
• DummyResult can produce multiple items, statements, field, etc., but DummyAstNode cannot.

So the purpose is much the same, but the details vary greatly. This is why I removed the interdependency. You could probably frankenstein them into a single thing (trait? type?) that can be used in both cases, by adding extra parameters, but I think that would end up being less clear.