Add type aliases for registries

Introduces `GlobalFunctionRegistry` and `GlobalAnalyzedRegistry` type
aliases to clarify the usage of `HashMap`s for storing global functions
and their analyzed versions. This change also refactors the
`LambdaCollector` and `Optimizer` to use these new aliases, improving
code readability and maintainability.

src/ast/compiler/lambda_collector.rs

@@ -1,15 +1,16 @@
 use crate::ast::compiler::bound_nodes::{Address, BoundKind, BoundNode, GlobalIdx};
 use std::collections::HashMap;
+use std::rc::Rc;
 
 /// A pass that collects all global function definitions (lambdas) into a registry.
 /// This allows the Specializer to retrieve the original AST of a function for monomorphization.
 pub struct LambdaCollector<'a, T> {
-    registry: &'a mut HashMap<GlobalIdx, BoundNode<T>>,
+    registry: &'a mut HashMap<GlobalIdx, Rc<BoundNode<T>>>,
 }
 
 impl<'a, T: Clone> LambdaCollector<'a, T> {
     /// Performs a full traversal of the AST and populates the provided registry.
-    pub fn collect(node: &BoundNode<T>, registry: &'a mut HashMap<GlobalIdx, BoundNode<T>>) {
+    pub fn collect(node: &BoundNode<T>, registry: &'a mut HashMap<GlobalIdx, Rc<BoundNode<T>>>) {
         let mut collector = Self { registry };
         collector.visit(node);
     }
@@ -32,7 +33,7 @@ impl<'a, T: Clone> LambdaCollector<'a, T> {
 
                     if let BoundKind::Lambda { .. } = &current.kind {
                         self.registry
-                            .insert(*global_index, (*current).as_ref().clone());
+                            .insert(*global_index, Rc::new((**current).clone()));
                     }
                 }
                 self.visit(value);
@@ -48,7 +49,7 @@ impl<'a, T: Clone> LambdaCollector<'a, T> {
 
                     if let BoundKind::Lambda { .. } = &current.kind {
                         self.registry
-                            .insert(*global_index, (*current).as_ref().clone());
+                            .insert(*global_index, Rc::new((**current).clone()));
                     }
                 }
                 self.visit(value);