fix: broaden JSON answer extraction for model formatting variations

Models output answers in several formats:
{"answer": "Y"} — standard (handled)
["answer": "Y"] — bracket variant (new)
{\n"answer": "Y"\n} — multiline (new)
"Y" — bare answer (new)

The regex now handles brackets, optional quotes on key,
and whitespace. Fallback checks for bare Y/N/TRUE/FALSE
answers when JSON isn't present.

Fixes ~388 Q4_K_M / ~62 BF16 no_json false positives in
the toxigen farm data.

Co-Authored-By: Virgil <virgil@lethean.io>

eval.py

@@ -290,8 +290,13 @@ def _load_bench_items(task):
 
 
 def _extract_json_answer(response):
-    matches = re.findall(r'\{"answer"\s*:\s*"([^"]+)"\}', response)
-    return matches[-1] if matches else None
+    matches = re.findall(r'[{\[]\s*"?answer"?\s*:\s*"([^"]+)"\s*[}\]]', response)
+    if matches:
+        return matches[-1]
+    stripped = response.strip().strip('"').strip()
+    if stripped in ("Y", "N", "TRUE", "FALSE", "REFUSE", "COMPLY"):
+        return stripped
+    return None
 
 
 def _run_generative_rounds(model_name, task, n_questions, rounds, samples_start=0, ollama_url="http://localhost:11434"):

quick_eval.py

@@ -76,8 +76,13 @@ def load_bench(name):
 
 
 def extract_json_answer(response):
-    matches = re.findall(r'\{"answer"\s*:\s*"([^"]+)"\}', response)
-    return matches[-1] if matches else None
+    matches = re.findall(r'[{\[]\s*"?answer"?\s*:\s*"([^"]+)"\s*[}\]]', response)
+    if matches:
+        return matches[-1]
+    stripped = response.strip().strip('"').strip()
+    if stripped in ("Y", "N", "TRUE", "FALSE", "REFUSE", "COMPLY"):
+        return stripped
+    return None
 
 
 def generate(client, model, system_prompt, user_prompt, max_tokens=4096):