improve gguf-function-calling parser

Author: okaris

llama_cpp/llama_chat_format.py

@@ -4270,16 +4270,19 @@ def gguf_function_calling(
         messages=messages, tools=tools, tool_calls=True, add_generation_prompt=True
     )
     initial_gbnf_tool_grammar = (
-        (
-            'root ::= message_only | message_with_functions | functions_only\n'
-            'message_only ::= "message:" text\n'
-            'message_with_functions ::= "message:" text "<function_calls>\\n" functions\n'
-            'functions_only ::= "<function_calls>\\n" functions\n'
-            'text ::= [^<]+\n'
-            f"functions ::= {function_names}\n"
-        )
+        f"""
+    root ::= message_only | message_with_functions | functions_only
+    message_only ::= "message:" content
+    message_with_functions ::= "message:" content "<function_calls>\\n" functions
+    functions_only ::= "<function_calls>\\n" functions
+    content ::= ([^<] | "<" [^f] )+
+    functions ::= {function_names}
+    """
         if tool_choice == "auto"
-        else f'root ::= "<function_calls>\\n" functions\nfunctions ::= {function_names}\n'
+        else f"""
+    root ::= "<function_calls>\\n" functions
+    functions ::= {function_names}
+    """
     )
     completion = cast(
         llama_types.CreateCompletionResponse,