copilot feedback

Author: rayokota

src/jsonata/functions.py

@@ -733,7 +733,7 @@ def safe_replace_first(s: str, pattern: CompiledPattern, replacement: str) -> Op
         r = None
         for i in range(0, 10):
             try:
-                r = pattern.sub(replacement, s, count=1)
+                r = pattern.sub(replacement, s, 1)
                 break
             except Exception as e:
                 msg = str(e)
@@ -2045,6 +2045,7 @@ def is_regex(value: Optional[Any]) -> bool:
             callable(getattr(value, "search", None))
             and callable(getattr(value, "finditer", None))
             and callable(getattr(value, "sub", None))
+            and callable(getattr(value, "split", None))
         )
 
     #