From 85dbce112fddd7a9ff16aea82d8a6e28e1296b27 Mon Sep 17 00:00:00 2001
From: Sofia <sofia@teascade.net>
Date: Mon, 13 Apr 2026 01:08:34 +0300
Subject: [PATCH] Fill typechecking methods

---
 src/typechecker.cpp | 62 ++++++++++++++++++++++++++++++++++-----------
 src/types.h         |  3 +--
 2 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/src/typechecker.cpp b/src/typechecker.cpp
index 3276c41..7262438 100644
--- a/src/typechecker.cpp
+++ b/src/typechecker.cpp
@@ -5,43 +5,75 @@
 
 namespace AST {
     std::shared_ptr<types::Type> IntLiteralExpression::typecheck(
-        typecheck::State& state,
-        typecheck::Scope& scope,
-        std::optional<std::shared_ptr<types::Type>> expected_ty
+        typecheck::State&,
+        typecheck::Scope&,
+        std::optional<std::shared_ptr<types::Type>>
     ) {
-        throw CompileError("TODO", {});
+        return std::shared_ptr<types::Type>{
+            new types::FundamentalType{ types::FundamentalTypeKind::Int }
+        };
     }
 
     std::shared_ptr<types::Type> StringLiteralExpression::typecheck(
-        typecheck::State& state,
-        typecheck::Scope& scope,
-        std::optional<std::shared_ptr<types::Type>> expected_ty
+        typecheck::State&,
+        typecheck::Scope&,
+        std::optional<std::shared_ptr<types::Type>>
     ) {
-        throw CompileError("TODO", {});
+        auto char_ty = std::shared_ptr<types::Type>{
+            new types::FundamentalType{ types::FundamentalTypeKind::Char }
+        };
+        auto ptr_ty = new types::PointerType{ char_ty };
+        return std::shared_ptr<types::Type>{ptr_ty};
     }
 
     std::shared_ptr<types::Type> ValueReferenceExpression::typecheck(
-        typecheck::State& state,
+        typecheck::State&,
         typecheck::Scope& scope,
-        std::optional<std::shared_ptr<types::Type>> expected_ty
+        std::optional<std::shared_ptr<types::Type>>
     ) {
-        throw CompileError("TODO", {});
+        return scope.symbols[this->m_name];
     }
 
     std::shared_ptr<types::Type> BinaryOperationExpression::typecheck(
         typecheck::State& state,
         typecheck::Scope& scope,
-        std::optional<std::shared_ptr<types::Type>> expected_ty
+        std::optional<std::shared_ptr<types::Type>>
     ) {
-        throw CompileError("TODO", {});
+        auto lhs_ty = this->m_lhs->typecheck(state, scope, {});
+        auto rhs_ty = this->m_rhs->typecheck(state, scope, {});
+
+        // TODO actually check binop types properly
+
+        return lhs_ty;
     }
 
     std::shared_ptr<types::Type> FunctionCallExpression::typecheck(
         typecheck::State& state,
         typecheck::Scope& scope,
-        std::optional<std::shared_ptr<types::Type>> expected_ty
+        std::optional<std::shared_ptr<types::Type>>
     ) {
-        throw CompileError("TODO", {});
+        auto expr_ty = this->m_fn_expr->typecheck(state, scope, {});
+
+        // TODO make sure function_ty really is a function type
+
+        auto fn_ty = dynamic_cast<types::FunctionType*>(expr_ty.get());
+
+        if (this->m_args.size() < fn_ty->m_param_tys.size()) {
+            state.errors.push_back(CompileError("too few arguments", this->m_meta));
+        }
+        else if (this->m_args.size() > fn_ty->m_param_tys.size() && !fn_ty->m_vararg) {
+            state.errors.push_back(CompileError("too many arguments", this->m_meta));
+        }
+        else {
+            for (int i = 0; i < static_cast<int>(fn_ty->m_param_tys.size()); i++) {
+                auto expected_param_ty = fn_ty->m_param_tys[i];
+                auto param_ty = this->m_args[i]->typecheck(state, scope, expected_param_ty);
+
+                // TODO make sure types actually match
+            }
+        }
+
+        return fn_ty->m_ret_ty;
     }
 
     void ReturnStatement::typecheck(typecheck::State& state, typecheck::Scope& scope) {
diff --git a/src/types.h b/src/types.h
index 640f057..8d2adeb 100644
--- a/src/types.h
+++ b/src/types.h
@@ -55,11 +55,10 @@ namespace types {
 
 
     class FunctionType : public Type {
-    private:
+    public:
         std::shared_ptr<Type> m_ret_ty;
         std::vector<std::shared_ptr<Type>> m_param_tys;
         bool m_vararg;
-    public:
         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 } {
         }