From a680064b0f54bbe86e8b340f6a11adf194abbf70 Mon Sep 17 00:00:00 2001
From: sofia <sofia@teascade.net>
Date: Mon, 28 Jul 2025 14:22:27 +0300
Subject: [PATCH] Improve binary operation inference, still not great

---
 reid/src/mir/typecheck/typeinference.rs | 4 ++--
 reid/src/mir/typecheck/typerefs.rs      | 6 +++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/reid/src/mir/typecheck/typeinference.rs b/reid/src/mir/typecheck/typeinference.rs
index 8adb0c6..795b2bf 100644
--- a/reid/src/mir/typecheck/typeinference.rs
+++ b/reid/src/mir/typecheck/typeinference.rs
@@ -285,8 +285,8 @@ impl Block {
                     let rhs_ref = state.ok(rhs_infer, rhs.1);
 
                     // Try to narrow the lhs with rhs
-                    if let (Some(mut lhs_ref), Some(rhs_ref)) = (lhs_ref, rhs_ref) {
-                        lhs_ref.narrow(&rhs_ref);
+                    if let (Some(mut lhs_ref), Some(mut rhs_ref)) = (lhs_ref, rhs_ref) {
+                        rhs_ref.narrow(&lhs_ref);
                     }
                 }
                 StmtKind::Import(_) => panic!(),
diff --git a/reid/src/mir/typecheck/typerefs.rs b/reid/src/mir/typecheck/typerefs.rs
index bdca213..e4f87e8 100644
--- a/reid/src/mir/typecheck/typerefs.rs
+++ b/reid/src/mir/typecheck/typerefs.rs
@@ -366,7 +366,11 @@ impl<'outer> ScopeTypeRefs<'outer> {
                             *idx.borrow_mut() = *hint1.0.borrow();
                         }
                     }
-                    (TypeRefKind::Direct(_), TypeRefKind::BinOp(..)) => {}
+                    (TypeRefKind::Direct(_), TypeRefKind::BinOp(..)) => {
+                        if *idx == hint1.0 && idx != &hint2.0 {
+                            *idx.borrow_mut() = *hint2.0.borrow();
+                        }
+                    }
                     (TypeRefKind::BinOp(..), TypeRefKind::Direct(..)) => {
                         // TODO may not be good ?
                         // if *idx == hint2.0 && idx != &hint1.0 {