From: Mark Thom <mark.thom@unb.ca>
Date: Wed, 15 Nov 2023 19:38:24 +0000 (+0100)
Subject: fix sign/1 (#2157)
X-Git-Tag: v0.9.4~116
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=bcb68fcc3d7226eb12010ba06c1f2a8800966e6a;p=scryer-prolog.git

fix sign/1 (#2157)
---

diff --git a/src/forms.rs b/src/forms.rs
index a42dda7f..3a2b743f 100644
--- a/src/forms.rs
+++ b/src/forms.rs
@@ -744,7 +744,11 @@ impl Number {
             Number::Float(f) => Number::Float(OrderedFloat(f.signum())),
             _ => {
                 if self.is_positive() {
-                    Number::Fixnum(Fixnum::build_with(1))
+		    if self.is_zero() {
+			Number::Fixnum(Fixnum::build_with(0))
+		    } else {
+			Number::Fixnum(Fixnum::build_with(1))
+		    }
                 } else if self.is_negative() {
                     Number::Fixnum(Fixnum::build_with(-1))
                 } else {