Add PartialEq to BoundKind and Value

Implement PartialEq for BoundKind to allow for structural equality
checks during optimization. This enables the optimizer to terminate
early when a node no longer changes.

Also, implement PartialEq for Value to facilitate comparisons between
different Value variants.

src/ast/types.rs

@@ -59,7 +59,7 @@ pub trait Object: fmt::Debug {
 pub type ValueList = Rc<Vec<Value>>;
 
 /// Internal storage for Records to allow sharing schema (keys) between instances.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct RecordData {
     /// Names for slots.
     pub keys: Rc<Vec<Keyword>>,
@@ -85,6 +85,29 @@ pub enum Value {
     TailCallRequest(Box<(Rc<dyn Object>, Vec<Value>)>), // Internal: For TCO (Boxed to keep Value small)
 }
 
+impl PartialEq for Value {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Value::Void, Value::Void) => true,
+            (Value::Bool(a), Value::Bool(b)) => a == b,
+            (Value::Int(a), Value::Int(b)) => a == b,
+            (Value::Float(a), Value::Float(b)) => a == b,
+            (Value::DateTime(a), Value::DateTime(b)) => a == b,
+            (Value::Text(a), Value::Text(b)) => a == b,
+            (Value::Keyword(a), Value::Keyword(b)) => a == b,
+            (Value::Tuple(a), Value::Tuple(b)) => a == b,
+            (Value::Record(a), Value::Record(b)) => a == b,
+            (Value::Function(a), Value::Function(b)) => Rc::ptr_eq(a, b),
+            (Value::Object(a), Value::Object(b)) => Rc::ptr_eq(a, b),
+            (Value::Cell(a), Value::Cell(b)) => Rc::ptr_eq(a, b),
+            (Value::TailCallRequest(a), Value::TailCallRequest(b)) => {
+                Rc::ptr_eq(&a.0, &b.0) && a.1 == b.1
+            }
+            _ => false,
+        }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Signature {
     pub params: StaticType,