Refactor: Simplify type checking context

The type checker's fallback logic for non-lambda nodes was unnecessarily
complex. This commit simplifies it by directly checking the node within
a new, basic type context.

Additionally, the environment now explicitly wraps non-lambda AST nodes
in a lambda before type checking, ensuring consistent handling. This
aligns the type checking process for all top-level expressions.

src/ast/compiler/type_checker.rs

@@ -141,22 +141,8 @@ impl TypeChecker {
                 }
             }
             _ => {
-                // Fallback: Wrap in implicit lambda
-                let virtual_lambda = BoundNode {
-                    identity: node.identity.clone(),
-                    kind: BoundKind::Lambda {
-                        params: Rc::new(Node {
-                            identity: node.identity.clone(),
-                            kind: BoundKind::Tuple { elements: vec![] },
-                            ty: (),
-                        }),
-                        upvalues: vec![],
-                        body: Rc::new(node.clone()),
-                        positional_count: Some(0),
-                    },
-                    ty: (),
-                };
-                self.check(&virtual_lambda, &[], diag)
+                let mut root_ctx = TypeContext::new(0, vec![], &self.global_types, None);
+                self.check_node(node, &mut root_ctx, diag)
             }
         }
     }

src/ast/environment.rs

@@ -428,7 +428,25 @@ impl Environment {
         LambdaCollector::collect(&bound_ast, &mut self.function_registry.borrow_mut());
 
         let checker = TypeChecker::new(self.global_types.clone());
-        let typed_ast = checker.check(&bound_ast, &[], &mut diagnostics);
+        let wrapped_ast = if let crate::ast::compiler::bound_nodes::BoundKind::Lambda { .. } = bound_ast.kind {
+            bound_ast
+        } else {
+            crate::ast::compiler::bound_nodes::BoundNode {
+                identity: bound_ast.identity.clone(),
+                kind: crate::ast::compiler::bound_nodes::BoundKind::Lambda {
+                    params: std::rc::Rc::new(crate::ast::nodes::Node {
+                        identity: bound_ast.identity.clone(),
+                        kind: crate::ast::compiler::bound_nodes::BoundKind::Tuple { elements: vec![] },
+                        ty: (),
+                    }),
+                    upvalues: vec![],
+                    body: std::rc::Rc::new(bound_ast),
+                    positional_count: Some(0),
+                },
+                ty: (),
+            }
+        };
+        let typed_ast = checker.check(&wrapped_ast, &[], &mut diagnostics);
 
         if diagnostics.has_errors() {
             return Err(diagnostics
@@ -556,7 +574,25 @@ impl Environment {
         LambdaCollector::collect(&bound_ast, &mut self.function_registry.borrow_mut());
 
         let checker = TypeChecker::new(self.global_types.clone());
-        let typed_ast = checker.check(&bound_ast, &[], &mut diagnostics);
+        let wrapped_ast = if let crate::ast::compiler::bound_nodes::BoundKind::Lambda { .. } = bound_ast.kind {
+            bound_ast
+        } else {
+            crate::ast::compiler::bound_nodes::BoundNode {
+                identity: bound_ast.identity.clone(),
+                kind: crate::ast::compiler::bound_nodes::BoundKind::Lambda {
+                    params: std::rc::Rc::new(crate::ast::nodes::Node {
+                        identity: bound_ast.identity.clone(),
+                        kind: crate::ast::compiler::bound_nodes::BoundKind::Tuple { elements: vec![] },
+                        ty: (),
+                    }),
+                    upvalues: vec![],
+                    body: std::rc::Rc::new(bound_ast),
+                    positional_count: Some(0),
+                },
+                ty: (),
+            }
+        };
+        let typed_ast = checker.check(&wrapped_ast, &[], &mut diagnostics);
 
         CompilationResult {
             ast: Some(typed_ast),

src/ast/vm.rs

@@ -447,22 +447,28 @@ impl VM {
                 }
 
                 let lambda_val = self.eval_internal(obs, lambda)?;
-                let lambda_obj = if let Value::Object(obj) = lambda_val {
-                    obj
-                } else {
-                    return Err("Pipe lambda must be a function/closure".to_string());
-                };
 
                 // Create the persistent execution closure for the PipeStream
                 let mut pipe_vm = crate::ast::vm::VM::new(self.globals.clone());
-                let my_closure = lambda_obj.clone();
-                let executor: Box<crate::ast::types::PipeFn> =
+                
+                let executor: Box<crate::ast::types::PipeFn> = match lambda_val {
+                    Value::Object(obj) => {
+                        let my_closure = obj.clone();
                         Box::new(move |args: &[Value]| -> Value {
                             match pipe_vm.run_with_args(my_closure.clone(), args) {
                                 Ok(res) => res,
                                 Err(e) => panic!("Pipeline lambda execution failed: {}", e),
                             }
-                    });
+                        })
+                    }
+                    Value::Function(func) => {
+                        let my_func = func.clone();
+                        Box::new(move |args: &[Value]| -> Value {
+                            (my_func.func)(args)
+                        })
+                    }
+                    _ => return Err("Pipe lambda must be a function/closure".to_string()),
+                };
 
                 // Delegate to the RTL Factory for specialized buffer instantiation
                 let node =