From d6b730945cb67bc0f20f0f8aa5afefea6e61707c Mon Sep 17 00:00:00 2001
From: Sofia <sofia@teascade.net>
Date: Mon, 13 Apr 2026 18:17:33 +0300
Subject: [PATCH] Check binops

---
 src/typechecker.cpp | 24 ++++++++++++++++++++++--
 src/typechecker.h   |  2 ++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/typechecker.cpp b/src/typechecker.cpp
index fb2826e..b0fa3ac 100644
--- a/src/typechecker.cpp
+++ b/src/typechecker.cpp
@@ -85,9 +85,29 @@ namespace AST {
         auto lhs_ty = this->m_lhs->typecheck(state, scope, {});
         auto rhs_ty = this->m_rhs->typecheck(state, scope, {});
 
-        // TODO actually check binop types properly
+        if (this->m_binop == types::BinOp::Assignment) {
+            return lhs_ty;
+        }
 
-        return lhs_ty;
+        auto binop = types::find_binop(
+            state.binops,
+            lhs_ty,
+            this->m_binop,
+            rhs_ty
+        );
+
+        if (binop) {
+            return binop->result;
+        }
+        state.errors.push_back(CompileError(
+            "No suitable binop between "
+            + lhs_ty->formatted() + " "
+            + types::format_operator(this->m_binop) + " "
+            + rhs_ty->formatted(),
+            this->m_meta));
+
+        return std::shared_ptr<types::Type>{
+            new types::FundamentalType{ types::FundamentalTypeKind::Void } };
     }
 
     std::shared_ptr<types::Type> FunctionCallExpression::typecheck(
diff --git a/src/typechecker.h b/src/typechecker.h
index 528c720..e234aea 100644
--- a/src/typechecker.h
+++ b/src/typechecker.h
@@ -4,6 +4,7 @@
 #include <map>
 
 #include "types.h"
+#include "binops.h"
 #include "errors.h"
 
 namespace typecheck {
@@ -13,6 +14,7 @@ namespace typecheck {
     };
 
     struct State {
+        std::vector<types::BinopDefinition> binops;
         std::vector<CompileError> errors;
     };
 }