From d427dbff6109e9eaa423bd11e398450df8e9c53d Mon Sep 17 00:00:00 2001
From: Erik Martin-Dorel <erik.martin-dorel@irit.fr>
Date: Wed, 13 Oct 2021 18:17:00 +0200
Subject: [PATCH] fix(grader): Display negative numbers with mandatory parens;
 Fix #440

* Thanks @letouzey for reporting this issue and suggesting a fix
---
 src/grader/introspection.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/grader/introspection.ml b/src/grader/introspection.ml
index 9d6011065..2bd4c0eaf 100644
--- a/src/grader/introspection.ml
+++ b/src/grader/introspection.ml
@@ -183,7 +183,7 @@ let print_value ppf v ty =
                  state := `Undecided ;
                  for i = ofs to ofs + len - 1 do
                    match String.get s i with
-                   | ' ' | '\n' | '\r' | '\t' ->
+                   | '-' | ' ' | '\n' | '\r' | '\t' ->
                        state := `Decided true ;
                        raise Exit
                    | _ ->  ()