-# A single argument of an annotation
-abstract class AAtArg
- super Prod
-end
-
-# A type-like argument of an annotation
-class ATypeAtArg
- super AAtArg
- var n_type: AType is writable, noinit
-end
-
-# An expression-like argument of an annotation
-class AExprAtArg
- super AAtArg
- var n_expr: AExpr is writable, noinit
-end
-
-# An annotation-like argument of an annotation
-class AAtAtArg
- super AAtArg
-end
-