Function extract_protobuf 

pub fn extract_protobuf(
    source_path: &str,
    input: &str,
) -> Result<ProtoFile, ProtobufExtractionError>

Extracts an owned protobuf contract from a .proto source.

Output collections are sorted and deduplicated. The result contains contract metadata and line coordinates, but never retains the input source or source snippets.

Errors

Returns ProtobufExtractionError when parsing fails, declarations conflict, field numbers are invalid, or a message repeats a field name or number.