From 1ec771a6896d01d817adc5bfe81aa5ba65d24885 Mon Sep 17 00:00:00 2001
From: atuonufure <atuonufure@gmail.com>
Date: Tue, 15 Aug 2023 10:32:00 +0200
Subject: [PATCH] Update matches invocation

---
 fhirpathpy/engine/invocations/strings.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fhirpathpy/engine/invocations/strings.py b/fhirpathpy/engine/invocations/strings.py
index 4cf570a..69d959c 100644
--- a/fhirpathpy/engine/invocations/strings.py
+++ b/fhirpathpy/engine/invocations/strings.py
@@ -133,8 +133,11 @@ def join(ctx, coll, separator=""):
 
 # test function
 def matches(ctx, coll, regex):
+    if not regex or not coll:
+        return []
+
     string = ensure_string_singleton(coll)
-    valid = re.compile(regex)
+    valid = re.compile(regex, re.DOTALL)
     return re.search(valid, string) is not None