From 58748c2a37be7975556028bbe9a7b214ccfe17e9 Mon Sep 17 00:00:00 2001
From: Francesco Cozzuto <francesco.cozzuto@gmail.com>
Date: Sun, 7 Apr 2024 17:58:24 +0200
Subject: [PATCH] Check errors in eval

---
 eval.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/eval.cpp b/eval.cpp
index 13e87f7..d99a24b 100644
--- a/eval.cpp
+++ b/eval.cpp
@@ -125,5 +125,9 @@ double eval(Expr *e)
 {
     EvalVisitor visitor;
     e->visit(visitor);
-    return visitor.stack[visitor.depth-1];
+    
+    if (visitor.fail)
+        return 0;
+    else
+        return visitor.stack[visitor.depth-1];
 }