feat: Add lambda collection and specialization

Introduces `LambdaCollector` to gather lambda functions and populate the
function registry. This enables the `Specializer` to work with
user-defined functions.

The `Environment` struct is updated to manage the `function_registry`
and `monomorph_cache`, which are essential for the specialization
process.

The `link` method in `Environment` now incorporates lambda collection
and node specialization before applying TCO optimization. This ensures
that lambdas are properly processed and specialized for potential
performance gains.

The `Specializer`'s `new` constructor has been modified to accept and
initialize the `MonoCache` through an `Rc<RefCell<MonoCache>>`. This
allows the cache to be shared across different specialized functions.

Also includes minor refactoring and type adjustments in `specializer.rs`
for better clarity and consistency.

src/ast/compiler/mod.rs

@@ -6,6 +6,7 @@ pub mod dumper;
 pub mod macros;
 pub mod type_checker;
 pub mod specializer;
+pub mod lambda_collector;
 
 pub use binder::*;
 pub use bound_nodes::*;

src/ast/compiler/specializer.rs

@@ -2,7 +2,7 @@ use std::collections::HashMap;
 use std::rc::Rc;
 use std::cell::RefCell;
 use crate::ast::types::{StaticType, Value, Signature};
-use crate::ast::compiler::bound_nodes::{BoundKind, Address, TypedNode, BoundNode};
+use crate::ast::compiler::bound_nodes::{BoundKind, Address, TypedNode};
 use crate::ast::nodes::Node;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -11,15 +11,17 @@ pub struct MonoCacheKey {
     pub arg_types: Vec<StaticType>,
 }
 
-pub type CompileFunc = Rc<dyn Fn(Rc<BoundNode>, &[StaticType]) -> Result<(Value, StaticType), String>>;
+pub type CompileFunc = Rc<dyn Fn(TypedNode, &[StaticType]) -> Result<(Value, StaticType), String>>;
 pub type RtlLookupFunc = Rc<dyn Fn(&str, &[StaticType]) -> Option<(Value, StaticType)>>;
 
 pub trait FunctionRegistry {
-    fn resolve(&self, addr: Address) -> Option<Rc<BoundNode>>;
+    fn resolve(&self, addr: Address) -> Option<TypedNode>;
 }
 
+pub type MonoCache = HashMap<MonoCacheKey, (Value, StaticType)>;
+
 pub struct Specializer {
-    cache: RefCell<HashMap<MonoCacheKey, (Value, StaticType)>>,
+    pub cache: Rc<RefCell<MonoCache>>,
     registry: Option<Rc<dyn FunctionRegistry>>,
     compiler: Option<CompileFunc>,
     rtl_lookup: Option<RtlLookupFunc>,
@@ -30,9 +32,10 @@ impl Specializer {
         registry: Option<Rc<dyn FunctionRegistry>>, 
         compiler: Option<CompileFunc>,
         rtl_lookup: Option<RtlLookupFunc>,
+        cache: Option<Rc<RefCell<MonoCache>>>,
     ) -> Self {
         Self {
-            cache: RefCell::new(HashMap::new()),
+            cache: cache.unwrap_or_else(|| Rc::new(RefCell::new(HashMap::new()))),
             registry,
             compiler,
             rtl_lookup,
@@ -208,7 +211,7 @@ impl Specializer {
 mod tests {
     use super::*;
     use crate::ast::types::{Identity, NodeIdentity, SourceLocation, StaticType, Value, Signature};
-    use crate::ast::compiler::bound_nodes::{BoundKind, Address, BoundNode, TypedNode};
+    use crate::ast::compiler::bound_nodes::{BoundKind, Address, TypedNode};
     use crate::ast::nodes::Symbol;
     use std::rc::Rc;
 
@@ -226,7 +229,7 @@ mod tests {
 
     // Mock Registry
     struct MockRegistry {
-        functions: HashMap<Address, Rc<BoundNode>>,
+        functions: HashMap<Address, TypedNode>,
     }
     
     impl MockRegistry {
@@ -234,13 +237,13 @@ mod tests {
             Self { functions: HashMap::new() }
         }
         
-        fn register(&mut self, addr: Address, node: BoundNode) {
-            self.functions.insert(addr, Rc::new(node));
+        fn register(&mut self, addr: Address, node: TypedNode) {
+            self.functions.insert(addr, node);
         }
     }
     
     impl FunctionRegistry for MockRegistry {
-        fn resolve(&self, addr: Address) -> Option<Rc<BoundNode>> {
+        fn resolve(&self, addr: Address) -> Option<TypedNode> {
             self.functions.get(&addr).cloned()
         }
     }
@@ -253,24 +256,24 @@ mod tests {
         let name = Symbol::from("test_func");
         
         // Def: (fn [x] x) -- generic identity
-        let func_node = BoundNode {
+        let func_node = TypedNode {
             identity: make_identity(),
             kind: BoundKind::Lambda { 
                 param_count: 1, 
                 upvalues: vec![], 
-                body: Rc::new(BoundNode { identity: make_identity(), kind: BoundKind::Nop, ty: () }) 
+                body: Rc::new(TypedNode { identity: make_identity(), kind: BoundKind::Nop, ty: StaticType::Void }) 
             },
-            ty: ()
+            ty: StaticType::Void
         };
         registry.register(addr, func_node);
 
         // Setup Compiler Mock
-        let compiler: CompileFunc = Rc::new(|_node: Rc<BoundNode>, _args: &[StaticType]| -> Result<(Value, StaticType), String> {
+        let compiler: CompileFunc = Rc::new(|_node: TypedNode, _args: &[StaticType]| -> Result<(Value, StaticType), String> {
             // Return a specialized "compiled" value
             Ok((Value::Int(12345), StaticType::Int))
         });
 
-        let spec = Specializer::new(Some(Rc::new(registry)), Some(compiler), None);
+        let spec = Specializer::new(Some(Rc::new(registry)), Some(compiler), None, None);
         
         // Call(Get(Local(0)), [Arg(Int)])
         let callee = make_typed_node(BoundKind::Get { addr, name: name.clone() }, StaticType::Any);
@@ -300,7 +303,7 @@ mod tests {
 
     #[test]
     fn test_specialize_skips_unknown_types() {
-        let spec = Specializer::new(None, None, None);
+        let spec = Specializer::new(None, None, None, None);
         let name0 = Symbol::from("f");
         let name1 = Symbol::from("x");
         
@@ -330,7 +333,7 @@ mod tests {
     #[test]
     fn test_specialize_uses_cache() {
         // Setup cache with a pre-specialized function for (Int) -> Int
-        let spec = Specializer::new(None, None, None);
+        let spec = Specializer::new(None, None, None, None);
         
         let addr = Address::Local(0);
         let name = Symbol::from("cached_func");
@@ -380,7 +383,7 @@ mod tests {
             }
         });
         
-        let spec = Specializer::new(None, None, Some(rtl_lookup));
+        let spec = Specializer::new(None, None, Some(rtl_lookup), None);
         
         let addr = Address::Global(10);
         let name = Symbol::from("rtl_func");
@@ -411,7 +414,7 @@ mod tests {
 
     #[test]
     fn test_specialize_preserves_tail_call() {
-        let spec = Specializer::new(None, None, None);
+        let spec = Specializer::new(None, None, None, None);
         
         let addr = Address::Local(0);
         let name = Symbol::from("tail_func");