From ead4a7c48c4789825f9d529e676e4fc169f3efa8 Mon Sep 17 00:00:00 2001
From: Andrew Lamb <andrew@nerdnetworks.org>
Date: Thu, 8 Aug 2024 12:20:30 -0400
Subject: [PATCH] Add comment about why it is ok to return boolean with
 catchall match

---
 datafusion/functions/src/regex/regexplike.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/datafusion/functions/src/regex/regexplike.rs b/datafusion/functions/src/regex/regexplike.rs
index 455d009db778..20029ba005c4 100644
--- a/datafusion/functions/src/regex/regexplike.rs
+++ b/datafusion/functions/src/regex/regexplike.rs
@@ -76,6 +76,8 @@ impl ScalarUDFImpl for RegexpLikeFunc {
 
         Ok(match &arg_types[0] {
             Null => Null,
+            // Type coercion is done by DataFusion based on signature, so if we
+            // get here, the first argument is always a string
             _ => Boolean,
         })
     }