fix: accept whitespace after full-rewrite fence languages

openevolve/utils/code_utils.py

@@ -5,7 +5,6 @@
 import re
 from typing import Dict, List, Optional, Tuple, Union
 
-
 _STANDARD_DIFF_PATTERN = r"<<<<<<< SEARCH\n(.*?)=======\n(.*?)>>>>>>> REPLACE"
 _STANDARD_DIFF_MARKER = re.compile(
     r"^[ \t]*(<<<<<<< SEARCH|=======|>>>>>>> REPLACE)[ \t]*\r?$", re.MULTILINE
@@ -238,7 +237,7 @@ def parse_full_rewrite(llm_response: str, language: str = "python") -> Optional[
     Returns:
         Extracted code or None if not found
     """
-    code_block_pattern = r"```" + re.escape(language) + r"\r?\n(.*?)```"
+    code_block_pattern = r"```" + re.escape(language) + r"[ \t]*\r?\n(.*?)```"
     matches = re.findall(code_block_pattern, llm_response, re.DOTALL)
 
     if matches:

tests/test_code_utils.py

@@ -34,6 +34,18 @@ def test_parse_full_rewrite_literal_language(self):
         response = "```c\nint wrong;\n```\n```c++\nint correct;\n```"
         self.assertEqual(parse_full_rewrite(response, "c++"), "int correct;")
 
+    def test_parse_full_rewrite_horizontal_whitespace_after_language(self):
+        for whitespace in (" ", "\t", " \t"):
+            for newline in ("\n", "\r\n"):
+                with self.subTest(whitespace=repr(whitespace), newline=repr(newline)):
+                    response = (
+                        f"```python{whitespace}{newline}"
+                        f"def run():{newline}    return 42{newline}```"
+                    )
+                    namespace = {}
+                    exec(parse_full_rewrite(response), namespace)
+                    self.assertEqual(namespace["run"](), 42)
+
     def test_parse_full_rewrite_fallbacks(self):
         for response in ("```\nx = 1\n```", "x = 1"):
             with self.subTest(response=response):