refactor: add SubEnum and EnumFromInner proc macros (#1109)

Adds two new proc macros, `SubEnum` and `EnumFromInner`, to generate `Container` subenum types and conversion implementations.

Author: Miitto

Cargo.lock

@@ -16,3 +16,5 @@ tokio-tungstenite = "0.26"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 uuid = { version = "1", features = ["v4", "serde"] }
+
+wm-macros = { path = "packages/wm-macros" }

Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "wm-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = "2.0.103"
+quote = "1.0"
+proc-macro2 = "1.0"

packages/wm-macros/Cargo.toml

@@ -0,0 +1,46 @@
+//! Utilities for working with [syn::Attribute]
+
+pub mod prelude {
+  pub use super::FindAttributes;
+}
+
+/// Trait for filtering lists of [syn::Attribute] by name and type.
+pub trait FindAttributes {
+  /// Find attributes by name. E.g. `#[name]`, `#[name(...)]` or `#[name =
+  /// <value>]`
+  fn find_attrs(
+    &self,
+    name: &str,
+  ) -> impl Iterator<Item = &syn::Attribute>;
+  /// Find list attributes by name. E.g. `#[name(...)]`
+  fn find_list_attrs(
+    &self,
+    name: &str,
+  ) -> impl Iterator<Item = &syn::MetaList> {
+    self
+      .find_attrs(name)
+      .filter_map(|attr| attr.meta.require_list().ok())
+  }
+}
+
+impl FindAttributes for Vec<syn::Attribute> {
+  fn find_attrs(
+    &self,
+    name: &str,
+  ) -> impl Iterator<Item = &syn::Attribute> {
+    self.iter().filter(move |attr| {
+      attr.path().get_ident().is_some_and(|ident| ident == name)
+    })
+  }
+}
+
+impl FindAttributes for &[syn::Attribute] {
+  fn find_attrs(
+    &self,
+    name: &str,
+  ) -> impl Iterator<Item = &syn::Attribute> {
+    self.iter().filter(move |attr| {
+      attr.path().get_ident().is_some_and(|ident| ident == name)
+    })
+  }
+}