From 8ec4e538f5fe0ebf9cb9bb0df3f42f8b4053e71a Mon Sep 17 00:00:00 2001
From: Sofia <sofia@teascade.net>
Date: Mon, 13 Apr 2026 16:56:33 +0300
Subject: [PATCH] Fix a bug, add type kind

---
 src/typechecker.cpp | 13 ++++++++++++-
 src/types.h         | 17 ++++++++++++++---
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/typechecker.cpp b/src/typechecker.cpp
index 84ad77a..bd98d26 100644
--- a/src/typechecker.cpp
+++ b/src/typechecker.cpp
@@ -62,7 +62,12 @@ namespace AST {
     ) {
         auto expr_ty = this->m_fn_expr->typecheck(state, scope, {});
 
-        // TODO make sure function_ty really is a function type
+        if (expr_ty->m_kind != types::TypeKind::Function) {
+            state.errors.push_back(CompileError("Tried calling a non-function", this->m_meta));
+            return std::shared_ptr<types::Type> {
+                new types::FundamentalType{ types::FundamentalTypeKind::Void }
+            };
+        }
 
         auto fn_ty = dynamic_cast<types::FunctionType*>(expr_ty.get());
 
@@ -123,6 +128,12 @@ namespace AST {
         typecheck::Scope inner{ scope };
         inner.return_ty = return_ty;
 
+        for (auto& param : this->m_params) {
+            if (param.first) {
+                inner.symbols[*param.first] = param.second;
+            }
+        }
+
         if (this->m_statements) {
             for (auto& statement : *this->m_statements) {
                 statement->typecheck(state, inner);
diff --git a/src/types.h b/src/types.h
index 8d2adeb..61fdafd 100644
--- a/src/types.h
+++ b/src/types.h
@@ -18,6 +18,12 @@ namespace types {
     int operator_precedence(BinOp& op);
     std::string format_operator(BinOp& op);
 
+    enum class TypeKind {
+        Fundamental,
+        Function,
+        Pointer,
+    };
+
     enum FundamentalTypeKind {
         Int,
         Bool,
@@ -27,6 +33,8 @@ namespace types {
 
     class Type {
     public:
+        TypeKind m_kind;
+        Type(TypeKind kind) : m_kind{ kind } {}
         virtual ~Type() = default;
         virtual std::string formatted() = 0;
         virtual llvm::Type* codegen(codegen::Builder& builder) = 0;
@@ -42,7 +50,7 @@ namespace types {
     private:
         FundamentalTypeKind m_ty;
     public:
-        FundamentalType(FundamentalTypeKind kind) : m_ty{ kind } {}
+        FundamentalType(FundamentalTypeKind kind) : Type(TypeKind::Fundamental), m_ty{ kind } {}
         virtual ~FundamentalType() override = default;
         virtual std::string formatted() override;
         virtual llvm::Type* codegen(codegen::Builder& builder) override;
@@ -60,7 +68,10 @@ namespace types {
         std::vector<std::shared_ptr<Type>> m_param_tys;
         bool m_vararg;
         FunctionType(std::shared_ptr<Type> ret_ty, std::vector<std::shared_ptr<Type>> param_tys, bool vararg)
-            : m_ret_ty{ std::move(ret_ty) }, m_param_tys{ std::move(param_tys) }, m_vararg{ vararg } {
+            : Type(TypeKind::Function)
+            , m_ret_ty{ std::move(ret_ty) }
+            , m_param_tys{ std::move(param_tys) }
+            , m_vararg{ vararg } {
         }
         virtual ~FunctionType() override = default;
         virtual std::string formatted() override;
@@ -76,7 +87,7 @@ namespace types {
         std::shared_ptr<Type> m_inner;
     public:
         PointerType(std::shared_ptr<Type> inner)
-            : m_inner{ std::move(inner) } {
+            : Type(TypeKind::Pointer), m_inner{ std::move(inner) } {
         }
         virtual ~PointerType() override = default;
         virtual std::string formatted() override;