Refactor PmpMacro trait and macro registry: replace dyn dispatch with function pointers, streamline handler struct registration, and enhance documentation

crates/pmp-macro/crates/pmp-macro-misc/src/lib.rs

@@ -7,7 +7,7 @@
 //! | `target`     | [`Target`] bitflags for PHP attribute target sites              |
 //! | `descriptor` | [`MacroDescriptor`] and [`ParamDescriptor`] - static metadata   |
 //! | `context`    | [`MacroContext`], [`AttributedNode`], [`ResolvedAttr`], etc.    |
-//! | `traits`     | [`PmpMacro`] trait, [`MacroRegistration`], [`validate_registry`]|
+//! | `traits`     | [`PmpMacro`] trait, [`MacroRegistration`], [`MacroRegistry`]    |
 
 mod target;
 mod traits;

crates/pmp-macro/crates/pmp-macro-misc/src/traits.rs

@@ -10,24 +10,16 @@ use crate::{
 
 // --------------------------------------------------------------------------------------------- //
 
-/// The core trait every PHP macro attribute handler must implement.
+/// The handler trait implemented by each PHP macro attribute struct.
 ///
-/// The `descriptor` method is generated by `#[derive(PmpMacro)]` and should
-/// not be written by hand. The two handler methods have default no-op
+/// The two handler methods have default no-op
 /// implementations so that analysis-only and transform-only macros only need
 /// to override what they actually do.
 ///
-/// The trait is object-safe (`&self`, no generics) so the registry can store
+/// The trait is object-safe (`&self`, no generics), so the registry can store
 /// `Box<dyn PmpMacro>` without knowing concrete types.
-pub trait PmpMacro: Send + Sync {
-    // --- generated by #[derive(PmpMacro)] --------------------------------------------------- //
-
-    /// Returns the static metadata for this macro.
-    /// Must not be implemented by hand - use `#[derive(PmpMacro)]`.
-    fn descriptor(&self) -> &'static MacroDescriptor;
-
-    // --- user-implemented handler hooks ----------------------------------------------------- //
-
+pub trait PmpMacro: Send + Sync
+{
     /// Analyse the attributed PHP node and emit diagnostics.
     ///
     /// Called during the analysis pass. Returning an empty `Vec` means no
@@ -38,9 +30,7 @@ pub trait PmpMacro: Send + Sync {
         ctx:  &MacroContext,
         attr: &ResolvedAttr,
         node: &AttributedNode,
-    ) -> Vec<Diagnostic> {
-        vec![]
-    }
+    ) -> Vec<Diagnostic> { vec![] }
 
     /// Produce rewrite instructions for the attributed PHP node.
     ///
@@ -52,25 +42,40 @@ pub trait PmpMacro: Send + Sync {
         ctx:  &MacroContext,
         attr: &ResolvedAttr,
         node: &AttributedNode,
-    ) -> Vec<Rewrite> {
-        vec![]
-    }
+    ) -> Vec<Rewrite> { vec![] }
 }
 
 // --------------------------------------------------------------------------------------------- //
 
+/// Type alias for the analyze handler function pointer.
+pub type AnalyzeFn   = fn(&MacroContext, &ResolvedAttr, &AttributedNode) -> Vec<Diagnostic>;
+/// Type alias for the transform handler function pointer.
+pub type TransformFn = fn(&MacroContext, &ResolvedAttr, &AttributedNode) -> Vec<Rewrite>;
+
 /// An entry in the global macro registry, submitted via `inventory::submit!`.
 ///
-/// Wraps a `&'static dyn PmpMacro` so the inventory iterator can hand out
-/// references to every registered handler without allocation.
+/// Stores static metadata alongside fn pointers that delegate to the
+/// handler struct's `PmpMacro` impl, avoiding the need for `dyn` dispatch.
+///
+/// Generated via `#[derive(PmpMacro)]`
 pub struct MacroRegistration {
-    pub handler: &'static dyn PmpMacro,
+    /// Static metadata for this macro — attribute name, targets, params, docs.
+    pub descriptor: &'static MacroDescriptor,
+    /// Delegates to `<Handler as PmpMacro>::analyze`.
+    pub analyze:    AnalyzeFn,
+    /// Delegates to `<Handler as PmpMacro>::transform`.
+    pub transform:  TransformFn,
 }
 
 impl MacroRegistration
 {
-    pub const fn new(handler: &'static dyn PmpMacro) -> Self {
-        Self { handler }
+    pub const fn new(
+        descriptor: &'static MacroDescriptor,
+        analyze:    AnalyzeFn,
+        transform:  TransformFn,
+    ) -> Self
+    {
+        Self { descriptor, analyze, transform }
     }
 }
 
@@ -79,11 +84,10 @@ inventory::collect!(MacroRegistration);
 // --------------------------------------------------------------------------------------------- //
 
 /// Validated, deduplicated view of the global macro registry.
-///
-/// Built once on first access and then cached for the lifetime of the process.
+/// Built once on first access via [`registry()`] and cached for the process lifetime.
 pub struct MacroRegistry {
     /// Handlers keyed by attribute name for O(1) lookup during processing.
-    handlers: HashMap<&'static str, &'static dyn PmpMacro>,
+    handlers: HashMap<&'static str, &'static MacroRegistration>,
 }
 
 static REGISTRY: OnceLock<MacroRegistry> = OnceLock::new();
@@ -104,14 +108,13 @@ impl MacroRegistry
 
     fn build() -> Self
     {
-        let mut handlers: HashMap<&'static str, &'static dyn PmpMacro> = HashMap::new();
+        let mut handlers: HashMap<&'static str, &'static MacroRegistration> = HashMap::new();
 
         for reg in inventory::iter::<MacroRegistration>
         {
-            let name = reg.handler.descriptor().name;
+            let name = reg.descriptor.name;
 
-            if handlers.insert(name, reg.handler).is_some()
-            {
+            if handlers.insert(name, reg).is_some() {
                 panic!(
                     "duplicate PmpMacro registration: attribute name \"{name}\" is \
                      registered more than once - check your macro definitions"
@@ -122,13 +125,13 @@ impl MacroRegistry
         Self { handlers }
     }
 
-    /// Look up a registered macro handler by its PHP attribute name.
-    pub fn get(&self, name: &str) -> Option<&'static dyn PmpMacro> {
+    /// Look up a registered macro by its PHP attribute name.
+    pub fn get(&self, name: &str) -> Option<&'static MacroRegistration> {
         self.handlers.get(name).copied()
     }
 
-    /// Iterate over all registered handlers.
-    pub fn iter(&self) -> impl Iterator<Item = &'static dyn PmpMacro> {
+    /// Iterate over all registered macros.
+    pub fn iter(&self) -> impl Iterator<Item = &'static MacroRegistration> {
         self.handlers.values().copied()
     }