From 0d3929070949719a67dabc6736513447f312b1f7 Mon Sep 17 00:00:00 2001
From: hasslesstech <hasslesstech@tutanota.com>
Date: Wed, 14 Oct 2026 20:07:28 +0300
Subject: [PATCH] fix infitite search for prior operator when opening brackets

---
 src/syntaxer.cpp | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/syntaxer.cpp b/src/syntaxer.cpp
index 94bf5e7..34dd52a 100644
--- a/src/syntaxer.cpp
+++ b/src/syntaxer.cpp
@@ -2,10 +2,10 @@
 #include "parser.hpp"
 #include "print.h"
 #include "syntaxer.hpp"
+#include <cmath>
 #include <queue>
 #include <stack>
 #include <vector>
-#include <cmath>
 
 namespace Syntax {
 
@@ -606,13 +606,26 @@ static int same_inner_level_ops(const std::vector<Expression::Token>& tv, const
 
 static Expression::Token::Operator get_prior_mop(const std::vector<Expression::Token>& tv, const int location)
 {
-	for (int i = location - 1; i >= 0; i--)
+	for (int i = location - 1, lv = 0; i >= 0; i--)
 	{
-		if (tv[i].t == Expression::Token::OPERATOR
-			&& tv[i].v.o != Expression::Token::OPA
-			&& tv[i].v.o != Expression::Token::CPA)
+		const Expression::Token &t = tv[i];
+
+		if (t.t == Expression::Token::OPERATOR)
 		{
-			return tv[i].v.o;
+			if (t.v.o == Expression::Token::OPA)
+			{
+				lv--;
+
+				if (lv == -2)
+				{
+					// enclosed in another pair of brackets, safe to assume ADD
+					return Expression::Token::ADD;
+				}
+			}
+			else
+			{
+				return t.v.o;
+			}
 		}
 	}