M&DE

Mirror Annotations & Default Extraction — a Scala 3 macro library that extends scala.deriving.Mirror with annotation metadata, default values, generated members, and transparent wrapper support.

Overview

Scala 3's built-in Mirror provides basic type-level information about case classes and enums, but it stops short of exposing annotations, default values, or computed members. M&DE fills that gap — it derives enriched mirrors at compile time that carry:

• Type-level annotation metadata — custom annotations on types and fields, queryable at both type level and runtime
• Default value extraction — from constructor defaults, @whenAbsent annotations, and @optionalParam markers
• Generated members — @generated vals and defs exposed as first-class elements of the mirror
• Transparent wrappers — @transparent single-field case classes with compile-time wrap/unwrap
• Custom labels — @name to override the label of a type or field

Made supports case classes, enums, sealed traits, objects, value classes, and higher-kinded types.

Acknowledgements

M&DE is inspired by:

• AVSystem commons by ghik
• ops-mirror by bishabosha