From: Nicolas Luck <nicolas@lucksus.eu>
Date: Thu, 27 Jul 2023 09:50:38 +0000 (+0200)
Subject: Add special case when parsing
X-Git-Tag: remove^2~50
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=0d28404aad4acd5a416a5182fb6363771ccff3da;p=scryer-prolog.git

Add special case when parsing
---

diff --git a/src/machine/parsed_results.rs b/src/machine/parsed_results.rs
index ba33089d..ecb58c1c 100644
--- a/src/machine/parsed_results.rs
+++ b/src/machine/parsed_results.rs
@@ -66,6 +66,18 @@ impl From<Vec<QueryResolutionLine>> for QueryResolution {
             }
         }
 
+        // If there is only one line, and it is an empty match, return true.
+        if query_result_lines.len() == 1 {
+            match query_result_lines[0].clone() {
+                QueryResolutionLine::Match(m) => {
+                    if m.is_empty() {
+                        return QueryResolution::True;
+                    }
+                }
+                _ => {}
+            }
+        }
+
         // If there is at least one line with true and no matches, return true.
         if query_result_lines
             .iter()