Bug: Unable to load grammar from json.gbnf example #7991
Description
What happened?
I have tried to load the json.gbnf grammar example but haven't been able to do so. The following code is not working.
from llama_cpp.llama import Llama, LlamaGrammar
import httpx
grammar_text = httpx.get("https://raw.githubusercontent.com/ggerganov/llama.cpp/master/grammars/json.gbnf").text
grammar = LlamaGrammar.from_string(grammar_text)
This throws the following error:
ValueError: from_string: error parsing grammar file: parsed_grammar.rules is empty
I'm not sure if the problem resides in the grammar definition file or in the LlamaGrammar class. The problem shows up when I use the .from_file method as well.
Name and Version
Ubuntu 22.04
Python 3.11 (Anaconda)
llama_cpp_python 0.2.78
What operating system are you seeing the problem on?
Linux
Relevant log output
parse: error parsing grammar: expecting ')' at {4}) # escapes
)* "\"" ws
number ::= ("-"? ([0-9] | [1-9] [0-9]{0,15})) ("." [0-9]+)? ([eE] [-+]? [0-9] [1-9]{0,15})? ws
# Optional space: by convention, applied in this grammar after literal chars when allowed
ws ::= | " " | "\n" [ \t]{0,20}
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
Cell In[14], line 4
2 import httpx
3 grammar_text = httpx.get("https://raw.githubusercontent.com/ggerganov/llama.cpp/master/grammars/json.gbnf").text
----> 4 grammar = LlamaGrammar.from_string(grammar_text)
File ~/miniconda3/envs/llama-cpp/lib/python3.11/site-packages/llama_cpp/llama_grammar.py:71, in LlamaGrammar.from_string(cls, grammar, verbose)
69 parsed_grammar = parse(const_char_p(grammar)) # type: parse_state
70 if parsed_grammar.rules.empty():
---> 71 raise ValueError(
72 f"{cls.from_string.__name__}: error parsing grammar file: parsed_grammar.rules is empty"
73 )
74 if verbose:
75 print(f"{cls.from_string.__name__} grammar:", file=sys.stderr)
ValueError: from_string: error parsing grammar file: parsed_grammar.rules is empty